Provided by: gpac_2.0.0+dfsg1-2_amd64 bug

NAME

       gpac - GPAC command-line filter session manager

SYNOPSIS

       gpac [options]FILTER[LINK]FILTER[...]
       gpac is GPAC's command line tool for setting up and running filter chains.

       FILTER: a single filter declaration (e.g., -i file, -o dump, inspect, ...), see gpac -h doc.
       [LINK]: a link instruction (e.g., @, @2, @2#StreamType=Visual, ...), see gpac -h doc.
       [options]: one or more option strings, each starting with a - character.
         -  an  option  using  a single - indicates an option of gpac (see gpac -hx) or of libgpac (see gpac -hx
       core)
         -  an  option  using  --  indicates  a  global  filter  or  meta-filter  (e.g.  FFMPEG)  option,   e.g.
       --block_size=1000 or --profile=Baseline (see gpac -h doc)

       Filter  declaration  order may impact the link resolver which will try linking in declaration order. Most
       of the time for simple graphs, this has no impact. However, for complex graphs with no link declarations,
       this can lead to different results.
       Options do not require any specific order, and may be present anywhere, including between link statements
       or filter declarations.
       Boolean values do not need any value specified. Other types shall be formatted as opt=val, except .I  -i,
       -src, .I -o, -dst and .I -h options.

       The  session  can  be  interrupted  at  any  time  using  ctrl+c, which can also be used to toggle global
       reporting.

       The possible options for gpac are:

       -mem-track
              enable memory tracker

       -mem-track-stack
              enable memory tracker with stack dumping

       -ltf
              load test-unit filters (used for for unit tests only)

       -sloop (int)
              loop execution of session, creating a session at each loop, mainly used for testing. If  no  value
              is given, loops forever

       -runfor (int)
              run for the given amount of milliseconds

       -runforx (int)
              run for the given amount of milliseconds and exit with no cleanup

       -runfors (int)
              run for the given amount of milliseconds and exit with segfault (tests)

       -runforl (int)
              run for the given amount of milliseconds and wait forever at end (tests)

       -stats
              print stats after execution

       -graph
              print graph after execution

       -k
              enable keyboard interaction from command line

       -r (string)
              enable reporting
              * r: runtime reporting
              *  r=FA[,FB]: runtime reporting but only print given filters, e.g. r=mp4mx for ISOBMFF multiplexer
              only
              * r=: only print final report

       -seps (string, default: :=#,!@)
              set the default character sets used to separate various arguments
              - the first char is used to separate argument names
              - the second char, if present, is used to separate names and values
              - the third char, if present, is used to separate fragments for PID sources
              - the fourth char, if present, is used for list separators (sourceIDs, gfreg, ...)
              - the fifth char, if present, is used for boolean negation
              - the sixth char, if present, is used for LINK directives (see filters help (-h doc))

       -i,-src (string)
              specify an input file - see filters help (-h doc)

       -o,-dst (string)
              specify an output file - see filters help (-h doc)

       -ib (string)
              specify an input file to wrap as GF_FileIO object (testing of GF_FileIO)

       -ob (string)
              specify an output file to wrap as GF_FileIO object (testing of GF_FileIO)

       -cl
              force complete mode when no link directive are set - see filters help (-h doc)

       -step
              test step mode in non-blocking session

       -h,-help,-ha,-hx,-hh (string)
              print help. Use -help or -h for basic options, -ha for advanced options, -hx  for  expert  options
              and -hh for all.
              Note: The @ character can be used in place of the * character. String parameter can be:
              * empty: print command line options help
              * doc: print the general filter info
              * alias: print the gpac alias syntax
              * log: print the log system help
              * core: print the supported libgpac core options. Use -ha/-hx/-hh for advanced/expert options
              * cfg: print the GPAC configuration help
              * prompt: print the GPAC prompt help when running in interactive mode (see .I -k )
              * modules: print available modules
              * filters: print name of all available filters
              * filters:*: print name of all available filters, including meta filters
              * codecs: print the supported builtin codecs
              * props: print the supported builtin PID and packet properties
              * props PNAME: print the supported builtin PID and packet properties mentioning PNAME
              * colors: print the builtin color names and their values
              * layouts: print the builtin CICP audio channel layout names and their values
              *  links:  print possible connections between each supported filters (use -hx to view src->dst cap
              bundle detail)
              * links FNAME: print sources and sinks for filter FNAME (either builtin or JS filter)
              * FNAME: print filter FNAME info (multiple FNAME can be given)
                - For meta-filters, use FNAME:INST, e.g. ffavin:avfoundation
                - Use * to print info on all filters (big output!), *:* to print info on all  filters  including
              meta filter instances (really big output!)
                -  By  default  only  basic  filter  options and description are shown. Use -ha to show advanced
              options capabilities, -hx for  expert  options,  -hh  for  all  options  and  filter  capabilities
              including on filters disabled in this build
              * FNAME.OPT: print option OPT in filter FNAME
              *  OPT:  look  in filter names and options for OPT and suggest possible matches if none found. Use
              -hx to look for keyword in all option descriptions

       -p (string)
              use indicated profile for the global GPAC config. If not found, config file is created. If a  file
              path  is indicated, this will load profile from that file. Otherwise, this will create a directory
              of the specified name and store new config there. Reserved name 0 means a new profile, not  stored
              to disk. Appending :reload to the profile name will force recreating a new configuration file

       -alias (string)
              assign a new alias or remove an alias. Can be specified several times. See alias usage (-h alias)

       -aliasdoc (string)
              assign documentation for a given alias (optional). Can be specified several times

       -uncache
              revert all items in GPAC cache directory to their original name and server path

       -js (string)
              specify javascript file to use as controller of filter session

       -wc
              write all core options in the config file unless already set

       -we
              write  all  file  extensions  in the config file unless already set (useful to change some default
              file extensions)

       -wf
              write all filter options in the config file unless already set

       -wfx
              write all filter options and all meta filter arguments in  the  config  file  unless  already  set
              (large config file !)

       -xopt
              unrecognized  options  and  filters  declaration  following this option are ignored - used to pass
              arguments to GUI

              The following libgpac core options allow customizing the filter session:

       -dbg-edges
              log edges status in filter graph before dijkstra resolution  (for  debug).  Edges  are  logged  as
              edge_source(status, weight, src_cap_idx, dst_cap_idx)

       -full-link
              throw error if any PID in the filter graph cannot be linked

       -no-block (Enum, default: no)
              disable blocking mode of filters
              * no: enable blocking mode
              *  fanout:  disable  blocking  on  fan-out,  unblocking the PID as soon as one of its destinations
              requires a packet
              * all: disable blocking

       -no-reg
              disable regulation (no sleep) in session

       -no-reassign
              disable source filter reassignment in PID graph resolution

       -sched (Enum, default: free)
              set scheduler mode
              * free: lock-free queues except for task list (default)
              * lock: mutexes for queues when several threads
              * freex: lock-free queues including for task lists (experimental)
              * flock: mutexes for queues even when no thread (debug mode)
              * direct: no threads and direct dispatch of tasks whenever possible (debug mode)

       -max-chain (int, default: 6)
              set maximum chain length when resolving filter links. Default value covers for [ in ->  ]  dmx  ->
              reframe  -> decode -> encode -> reframe -> mx [ -> out]. Filter chains loaded for adaptation (e.g.
              pixel format change) are loaded after the link resolution. Setting the value to 0 disables dynamic
              link resolution. You will have to specify the entire chain manually

       -max-sleep (int, default: 50)
              set maximum sleep time slot in milliseconds when regulation is enabled

       -threads (int)
              set N extra thread for the session. -1 means use all available cores

       -no-probe
              disable data probing on sources and relies on extension (faster load but more error-prone)

       -no-argchk
              disable tracking of argument usage (all arguments will be considered as used)

       -blacklist (string)
              blacklist the filters listed in the given string (comma-separated list).  If  first  character  is
              '-', this is a whitelist, i.e. only filters listed in the given string will be allowed

       -no-graph-cache
              disable internal caching of filter graph connections. If disabled, the graph will be recomputed at
              each link resolution (lower memory usage but slower)

       -no-reservoir
              disable  memory  recycling for packets and properties. This uses much less memory but stresses the
              system memory allocator much more

Using Aliases

       The gpac command line can become quite complex when many  sources  or  filters  are  used.  In  order  to
       simplify this, an alias system is provided.

       To assign an alias, use the syntax gpac -alias="NAME VALUE".
       * `NAME`: shall be a single string, with no space.
       * `VALUE`: the list of argument this alias replaces. If not set, the alias is destroyed

       When parsing arguments, the alias will be replace by its value.
       Example
       gpac -alias="output aout vout"

       This allows later audio and video playback using gpac -i src.mp4 output

       Aliases can use arguments from the command line. The allowed syntaxes are:
       * `@{a}`: replaced by the value of the argument with index a after the alias
       * `@{a,b}`: replaced by the value of the arguments with index a and b
       * `@{a:b}`: replaced by the value of the arguments between index a and b
       * `@{-a,b}`: replaced by the value of the arguments with index a and b, inserting a list separator (comma
       by default) between them
       *  `@{-a:b}`:  replaced  by  the value of the arguments between index a and b, inserting a list separator
       (comma by default) between them
       * `@{+a,b}`: clones the parent word in the alias for a and b, replacing this pattern in each clone by the
       corresponding argument
       * `@{+a:b}`: clones the parent word in the alias for each argument between index a and b, replacing  this
       pattern in each clone by the corresponding argument

       The specified index can be:
       * forward index: a strictly positive integer, 1 being the first argument after the alias
       *  backward  index: the value 'n' (or 'N') to indicate the last argument on the command line. This can be
       followed by -x to rewind arguments (e.g. @{n-1} is the before last argument)

       Before solving aliases, all option arguments are moved at the beginging of the command line. This implies
       that alias arguments cannot be options.
       Arguments not used by any aliases are kept on the command line, other ones are removed

       Example
       -alias="foo src=@{N} dst=test.mp4"

       The command gpac foo f1 f2 expands to gpac src=f2 dst=test.mp4 f1
       Example
       -alias="list: inspect src=@{+:N}"

       The command gpac list f1 f2 f3 expands to gpac inspect src=f1 src=f2 src=f3
       Example
       -alias="list inspect src=@{+2:N}"

       The command gpac list f1 f2 f3 expands to gpac inspect src=f2 src=f3 f1
       Example
       -alias="plist aout vout flist:srcs=@{-,N}"

       The command gpac plist f1 f2 f3 expands to gpac aout vout flist:srcs="f1,f2,f3"

       Alias documentation can be set using gpac -aliasdoc="NAME VALUE", with NAME the alias name and VALUE  the
       documentation.
       Alias documentation will then appear in gpac help.

Configuration file

       GPAC  uses a configuration file to modify default options of libgpac and filters. This configuration file
       is located in $HOME/.gpac/GPAC.cfg.
       Applications in GPAC can also specify a different configuration file through the .I -p option to indicate
       a profile. This allows different configurations for different usages and simplifies command line typing.
       Example
       gpac -p=foo []

       This will load configuration from $HOME/.gpac/foo/GPAC.cfg, creating it if needed.
       The reserved name 0 is used to disable configuration file writing.
       By default the configuration file only holds a  few  system  specific  options  and  directories.  It  is
       possible  to  serialize  the  entire  set of options to the configuration file, using .I -wc .I -wf. This
       should be avoided as the resulting configuration file size will be quite large, hence larger memory usage
       for the applications.
       The options specified in the configuration file may be overridden by  the  values  in  restrict.cfg  file
       located  in GPAC share system directory (e.g. /usr/share/gpac), if present; this allows enforcing system-
       wide configuration values.
       Note: The methods describe in this section apply to any application in GPAC transferring their  arguments
       to libgpac. This is the case for gpac, MP4Box, MP4Client/Osmo4.

Core options

       The  options from libgpac core can also be assigned though the config file from section core using option
       name without initial dash as key name.
       Example
       [core]threads=2

       Setting this in the config file is equivalent to using -threads=2.
       The options specified at prompt overrides the value of the config file.

Filter options in configuration

       It is possible to alter the default value of a filter option by modifying the configuration file.  Filter
       foo  options  are  stored in section [filter@foo], using option name and value as key-value pair. Options
       specified through the configuration file do not take precedence  over  options  specified  at  prompt  or
       through alias.
       Example
       [filter@rtpin]interleave=yes

       This will force the rtp input filter to always request RTP over RTSP by default.
       To generate a configuration file with all filters options serialized, use .I -wf.

Global filter options

       It  is  possible to specify options global to multiple filters using --OPTNAME=VAL. Global options do not
       override filter options but take precedence over options loaded from configuration file.
       This will set option OPTNAME, when present, to VAL in any loaded filter.
       Example
       --buffer=100 -i file vout aout

       This is equivalent to specifying vout:buffer=100 aout:buffer=100.
       Example
       --buffer=100 -i file vout aout:buffer=10

       This is equivalent to specifying vout:buffer=100 aout:buffer=10.
       Warning: This syntax only applies to regular filter options. It cannot be  used  with  builtin  shortcuts
       (gfreg, enc, ...).
       Meta-filter options can be set in the same way using the syntax --OPT_NAME=VAL.
       Example
       --profile=Baseline -i file.cmp -o dump.264

       This is equivalent to specifying -o dump.264:profile=Baseline.

       For   both   syntax,  it  is  possible  to  specify  the  filter  registry  name  of  the  option,  using
       --FNAME:OPTNAME=VAL or --FNAME@OPTNAME=VAL.
       In this case the option will only be set for filters which are instances of registry FNAME. This is  used
       when several registries use same option names.
       Example
       --flist@timescale=100 -i plist1 -i plist2 -o live.mpd

       This will set the timescale option on the playlists filters but not on the dasher filter.

libgpac core options:

       -noprog
              disable progress messages

       -quiet
              disable all messages, including errors

       -proglf
              use new line at each progress messages

       -strict-error,-se
              exit after the first error is reported

       -store-dir (string)
              set storage directory

       -mod-dirs (string list)
              set additional module directories as a semi-colon ; separated list

       -js-dirs (string list)
              set javascript directories

       -no-js-mods (string list)
              disable javascript module loading

       -ifce (string)
              set default multicast interface through interface IP address (default is 127.0.0.1)

       -lang (string)
              set preferred language

       -cfg,-opt (string)
              get or set configuration file value. The string parameter can be formatted as:
              * `section:key=val`: set the key to a new value
              * `section:key=null`, `section:key`: remove the key
              * `section=null`: remove the section
              * no argument: print the entire configuration file
              * `section`: print the given section
              *  `section:key`: print the given key in section (section can be set to *)- *:key: print the given
              key in all sections

       -no-save
              discard any changes made to the config file upon exit

       -mod-reload
              unload / reload module shared libs when no longer used

       -for-test
              disable all creation/modification dates and GPAC versions in files

       -old-arch
              enable compatibility with pre-filters versions of GPAC

       -ntp-shift (int)
              shift NTP clock by given amount in seconds

       -bs-cache-size (int, default: 512)
              cache size for bitstream read and write from file (0 disable cache, slower IOs)

       -no-check
              disable compliance tests for inputs (ISOBMFF for now). This will likely result in random crashes

       -unhandled-rejection
              dump unhandled promise rejections

       -cache (string)
              cache directory location

       -proxy-on
              enable HTTP proxy

       -proxy-name (string)
              set HTTP proxy address

       -proxy-port (int, default: 80)
              set HTTP proxy port

       -maxrate (int)
              set max HTTP download rate in bits per sec. 0 means unlimited

       -no-cache
              disable HTTP caching

       -offline-cache
              enable offline HTTP caching (no re-validation of existing resource in cache)

       -clean-cache
              indicate if HTTP cache should be clean upon launch/exit

       -cache-size (int, default: 100M)
              specify cache size in bytes

       -head-timeout (int, default: 5000)
              set HTTP head request timeout in milliseconds

       -req-timeout (int, default: 20000)
              set HTTP/RTSP request timeout in milliseconds

       -no-timeout
              ignore HTTP 1.1 timeout in keep-alive

       -broken-cert
              enable accepting broken SSL certificates

       -user-agent,-ua (string)
              set user agent name for HTTP/RTSP

       -user-profileid (string)
              set user profile ID (through X-UserProfileID entity header) in HTTP requests

       -user-profile (string)
              set user profile filename. Content of  file  is  appended  as  body  to  HTTP  HEAD/GET  requests,
              associated Mime is text/xml

       -query-string (string)
              insert query string (without ?) to URL on requests

       -dm-threads
              force using threads for async download requests rather than session scheduler

       -cte-rate-wnd (int, default: 20)
              set window analysis length in milliseconds for chunk-transfer encoding rate estimation

       -no-h2
              disable HTTP2

       -no-h2c
              disable HTTP2 upgrade (i.e. over non-TLS)

       -h2-copy
              enable  intermediate  copy of data in nghttp2 (default is disabled but may report as broken frames
              in wireshark)

       -dbg-edges
              log edges status in filter graph before dijkstra resolution  (for  debug).  Edges  are  logged  as
              edge_source(status, weight, src_cap_idx, dst_cap_idx)

       -full-link
              throw error if any PID in the filter graph cannot be linked

       -no-block (Enum, default: no)
              disable blocking mode of filters
              * no: enable blocking mode
              *  fanout:  disable  blocking  on  fan-out,  unblocking the PID as soon as one of its destinations
              requires a packet
              * all: disable blocking

       -no-reg
              disable regulation (no sleep) in session

       -no-reassign
              disable source filter reassignment in PID graph resolution

       -sched (Enum, default: free)
              set scheduler mode
              * free: lock-free queues except for task list (default)
              * lock: mutexes for queues when several threads
              * freex: lock-free queues including for task lists (experimental)
              * flock: mutexes for queues even when no thread (debug mode)
              * direct: no threads and direct dispatch of tasks whenever possible (debug mode)

       -max-chain (int, default: 6)
              set maximum chain length when resolving filter links. Default value covers for [ in ->  ]  dmx  ->
              reframe  -> decode -> encode -> reframe -> mx [ -> out]. Filter chains loaded for adaptation (e.g.
              pixel format change) are loaded after the link resolution. Setting the value to 0 disables dynamic
              link resolution. You will have to specify the entire chain manually

       -max-sleep (int, default: 50)
              set maximum sleep time slot in milliseconds when regulation is enabled

       -threads (int)
              set N extra thread for the session. -1 means use all available cores

       -no-probe
              disable data probing on sources and relies on extension (faster load but more error-prone)

       -no-argchk
              disable tracking of argument usage (all arguments will be considered as used)

       -blacklist (string)
              blacklist the filters listed in the given string (comma-separated list).  If  first  character  is
              '-', this is a whitelist, i.e. only filters listed in the given string will be allowed

       -no-graph-cache
              disable internal caching of filter graph connections. If disabled, the graph will be recomputed at
              each link resolution (lower memory usage but slower)

       -no-reservoir
              disable  memory  recycling for packets and properties. This uses much less memory but stresses the
              system memory allocator much more

       -switch-vres
              select smallest video resolution larger than scene size, otherwise use current video resolution

       -hwvmem (Enum, default: auto)
              specify (2D rendering only) memory type of main video backbuffer. Depending  on  the  scene  type,
              this may drastically change the playback speed
              * always: always on hardware
              * never: always on system memory
              * auto: selected by GPAC based on content type (graphics or video)

       -pref-yuv4cc (string)
              set preferred YUV 4CC for overlays (used by DirectX only)

       -offscreen-yuv
              indicate if offscreen yuv->rgb is enabled. can be set to false to force disabling

       -overlay-color-key (string)
              color to use for overlay keying, hex format

       -gl-bits-comp (int, default: 8)
              number of bits per color component in OpenGL

       -gl-bits-depth (int, default: 16)
              number of bits for depth buffer in OpenGL

       -gl-doublebuf
              enable OpenGL double buffering

       -sdl-defer
              use defer rendering for SDL

       -no-colorkey
              disable color keying at the video output level

       -glfbo-txid (int)
              set  output  texture  ID  when  using  glfbo  output.  The OpenGL context shall be initialized and
              gf_term_process shall be called with the OpenGL context active

       -video-output (string)
              indicate the name of the video output module to use (see gpac -h modules). The reserved name glfbo
              is used in player mode to draw in the OpenGL texture identified by .I glfbo-txid.  In  this  mode,
              the application is responsible for sending event to the terminal

       -audio-output (string)
              indicate the name of the audio output module to use

       -alsa-devname (string)
              set ALSA dev name

       -force-alsarate (int)
              force ALSA and OSS output sample rate

       -ds-disable-notif
              disable DirectSound audio buffer notifications when supported

       -font-reader (string)
              indicate name of font reader module

       -font-dirs (string)
              indicate comma-separated list of directories to scan for fonts

       -rescan-fonts
              indicate the font directory must be rescanned

       -wait-fonts
              wait for SVG fonts to be loaded before displaying frames

       -webvtt-hours
              force writing hour when serializing WebVTT

       -rmt
              enable  profiling  through  Remotery.  A copy of Remotery visualizer is in gpac/share/vis, usually
              installed in /usr/share/gpac/vis or Program Files/GPAC/vis

       -rmt-port (int, default: 17815)
              set remotery port

       -rmt-reuse
              allow remotery to reuse port

       -rmt-localhost
              make remotery only accepts localhost connection

       -rmt-sleep (int, default: 10)
              set remotery sleep (ms) between server updates

       -rmt-nmsg (int, default: 10)
              set remotery number of messages per update

       -rmt-qsize (int, default: 131072)
              set remotery message queue size in bytes

       -rmt-log
              redirect logs to remotery (experimental, usually not well handled by browser)

       -rmt-ogl
              make remotery sample opengl calls

       -m2ts-vvc-old
              hack for old TS streams using 0x32 for VVC instead of 0x33

       -piff-force-subsamples
              hack for PIFF PSEC files generated by 0.9.0 and 1.0 MP4Box with wrong subsample_count inserted for
              audio

       -vvdec-annexb
              hack for old vvdec+libavcodec supporting only annexB format

libgpac logs options:

       -noprog
              disable progress messages

       -quiet
              disable all messages, including errors

       -log-file,-lf (string)
              set output log file

       -log-clock,-lc
              log time in micro sec since start time of GPAC before each log line except for app tool

       -log-utc,-lu
              log UTC time in ms before each log line except for app tool

       -logs (string)
              set log tools and levels.

              You can independently log different tools involved in a session.
              log_args is formatted as a colon (':') separated list of toolX[:toolZ]@levelX
              levelX can be one of:
              * quiet: skip logs
              * error: logs only error messages
              * warning: logs error+warning messages
              * info: logs error+warning+info messages
              * debug: logs all messages

              toolX can be one of:
              * core: libgpac core
              * mutex: log all mutex calls
              * mem: GPAC memory tracker
              * module: GPAC modules (av out, font engine, 2D rasterizer)
              * filter: filter session debugging
              * sched: filter session scheduler debugging
              * codec: codec messages (used by encoder and decoder filters)
              * coding: bitstream formats (audio, video, scene)
              * container: container formats (ISO File,  MPEG-2  TS,  AVI,  ...)  and  multiplexer/demultiplexer
              filters
              * network: TCP/UDP sockets and TLS
              * http: HTTP traffic
              * cache: HTTP cache subsystem
              * rtp: RTP traffic
              * dash: HTTP streaming logs
              * route: ROUTE (ATSC3) debugging
              * media: messages from generic filters and reframer/rewriter filters
              * parser: textual parsers (svg, xmt, bt, ...)
              * mmio: I/O management (AV devices, file, pipes, OpenGL)
              * audio: audio renderer/mixer/output
              * script: script engine except console log
              * console: script console log
              * scene: scene graph and scene manager
              * compose: composition engine (2D, 3D, etc)
              * ctime: media and SMIL timing info from composition engine
              * interact: interaction messages (UI events and triggered DOM events and VRML route)
              * rti: run-time stats of compositor
              * all: all tools logged - other tools can be specified afterwards.
              The special keyword ncl can be set to disable color logs.
              The special keyword strict can be set to exit at first error.

              Example
              -logs=all@info:dash@debug:ncl

              This moves all log to info level, dash to debug level and disable color logs

       -proglf
              use new line at each progress messages

General

       Filters are configurable processing units consuming and producing data packets. These packets are carried
       between  filters  through  a  data  channel  called  PID.  A PID is in charge of allocating/tracking data
       packets, and passing the packets to the destination filter(s). A filter output PID may  be  connected  to
       zero or more filters. This fan-out is handled internally by GPAC (no such thing as a tee filter in GPAC).
       Note:  When  a  PID  cannot be connected to any filter, a warning is thrown and all packets dispatched on
       this PID will be destroyed. The session may however still run, unless .I -full-link is set.

       Each output PID carries a set of properties describing the data it delivers (e.g. width,  height,  codec,
       ...).  Properties  can  be built-in (see gpac -h props ), or user-defined. Each PID tracks its properties
       changes and triggers filter reconfiguration during packet processing. This allows the filter chain to  be
       reconfigured  at  run  time,  potentially  reloading  part of the chain (e.g. unload a video decoder when
       switching from compressed to uncompressed sources).

       Each filter exposes a set of argument to configure itself, using property types and values  described  as
       strings  formatted  with  separators.  This  help  is  given with default separator sets :=#,@ to specify
       filters, properties and options. Use .I -seps to change them.

Property and filter option format

       * boolean: formatted as yes,true,1 or no,false,0
       * enumeration (for filter arguments only): must  use  the  syntax  given  in  the  argument  description,
       otherwise value 0 (first in enum) is assumed.
       * 1-dimension (numbers, floats, ints...): formatted as value[unit], where unit can be k,K (x 1000) or m,M
       (x 1000000) or g,G (x 1000000000) or sec (x 1000) or min (x 60000). +I means max float/int/uint value, -I
       min float/int/uint value.
       *  fraction:  formatted  as  num/den  or  num-den or num, in which case the denominator is 1 if num is an
       integer, or 1000000 if num is a floating-point value.
       * unsigned 32 bit integer: formatted as number or hexadecimal using the format 0xAABBCCDD.
       * N-dimension (vectors): formatted as DIM1xDIM2[xDIM3[xDIM4]] values, without unit multiplier.
       * string: formatted as:
         * `value`: copies value to string.
         * `file@FILE`: load string from local FILE (opened in binary mode).
         *  `bxml@FILE`:  binarize  XML  from   local   FILE   and   set   property   type   to   data   -   see
       https://wiki.gpac.io/NHML-Format.
       * data: formatted as:
         * `size@address`: constant data block, not internally copied; size gives the size of the block, address
       the data pointer.
         * `0xBYTESTRING`: data block specified in hexadecimal, internally copied.
         * `file@FILE`: load data from local FILE (opened in binary mode).
         * `bxml@FILE`: binarize XML from local FILE - see https://wiki.gpac.io/NHML-Format.
         * `b64@DATA`: load data from base-64 encoded DATA.
       * pointer: pointer address as formatted by %p in C.
       * string lists: formatted as val1,val2[,...]. Each value can also use file@FILE syntax.
       * integer lists: formatted as val1,val2[,...]
       Note: The special characters in property formats (0x,/,-,+I,-I,x) cannot be configured.

Filter declaration [FILTER]

   Generic declaration
       Each filter is declared by its name, with optional filter arguments appended as a list of colon-separated
       name=value pairs. Additional syntax is provided for:
       *  boolean:  value can be omitted, defaulting to true (e.g. :noedit). Using ! before the name negates the
       result (e.g. :!moof_first)
       * enumerations: name can be omitted, e.g. :disp=pbo is equivalent to :pbo.

       When string parameters are used (e.g. URLs), it is recommended to escape the  string  using  the  keyword
       gpac.
       Example
       filter:ARG=http://foo/bar?yes:gpac:opt=VAL

       This will properly extract the URL.
       Example
       filter:ARG=http://foo/bar?yes:opt=VAL

       This will fail to extract it and keep :opt=VAL as part of the URL.
       The  escape  mechanism is not needed for local source, for which file existence is probed during argument
       parsing. It is also not needed for builtin protocol handlers (avin://, video://, audio://, pipe://)
       For tcp:// and udp:// protocols, the escape is not needed if a trailing /  is  appended  after  the  port
       number.
       Example
       -i tcp://127.0.0.1:1234:OPT

       This will fail to extract the URL and options.
       Example
       -i tcp://127.0.0.1:1234/:OPT

       This will extract the URL and options.
       Note:  one  trick  to  avoid  the  escape  sequence  is  to  declare  the  URLs  option  at the end, e.g.
       f1:opt1=foo:url=http://bar, provided you have only one URL parameter to specify on the filter.

       It is possible to disable option parsing (for string options) by duplicating the separator.
       Example
       filter::opt1=UDP://IP:PORT/:someopt=VAL::opt2=VAL2

       This will pass UDP://IP:PORT/:someopt=VAL to opt1 without inspecting it, and VAL2 to opt2.

   Source and Sink filters
       Source and sink filters do not need to be addressed by the filter name, specifying src= or  dst=  instead
       is  enough.  You  can  also  use  the  syntax  -src  URL or -i URL for sources and -dst URL or -o URL for
       destination, this allows prompt completion in shells.
       Example
       "src=file.mp4" or "-src file.mp4" or  "-i file.mp4"

       This will find a filter (for example fin) able to load file.mp4. The same result can be achieved by using
       fin:src=file.mp4.
       Example
       "dst=dump.yuv" or "-dst dump.yuv" or "-o dump.yuv"

       This will dump the video content in dump.yuv. The same result can be achieved by using fout:dst=dump.yuv.

       Specific source or sink filters may also be specified using filterName:src=URL or filterName:dst=URL.

       The src= and dst= syntaxes can also be used in alias for dynamic argument cloning (see gpac -hx alias).

   Forcing specific filters
       There is a special option called gfreg which allows specifying preferred filters  to  use  when  handling
       URLs.
       Example
       src=file.mp4:gfreg=ffdmx,ffdec

       This will use ffdmx to read file.mp4 and ffdec to decode it.
       This can be used to test a specific filter when alternate filter chains are possible.

   Specifying encoders and decoders
       By  default  filters  chain will be resolved without any decoding/encoding if the destination accepts the
       desired format. Otherwise, decoders/encoders will be dynamically loaded to perform the conversion, unless
       dynamic resolution is disabled. There is a special shortcut filter name  for  encoders  enc  allowing  to
       match a filter providing the desired encoding. The parameters for enc are:
       *  c=NAME:  identifies  the  desired  codec.  NAME can be the GPAC codec name or the encoder instance for
       ffmpeg/others
       * b=UINT, rate=UINT, bitrate=UINT: indicates the bitrate in bits per second
       * g=UINT, gop=UINT: indicates the GOP size in frames
       * pfmt=NAME: indicates the target pixel format name (see properties  (-h  props)  )  of  the  source,  if
       supported by codec
       * all_intra=BOOL: indicates all frames should be intra frames, if supported by codec

       Other  options  will  be  passed to the filter if it accepts generic argument parsing (as is the case for
       ffmpeg).
       The shortcut syntax c=TYPE (e.g. c=aac:opts) is also supported.

       Example
       gpac -i dump.yuv:size=320x240:fps=25 enc:c=avc:b=150000:g=50:cgop=true:fast=true -o raw.264

       This creates a 25 fps AVC at 175kbps with a gop duration of 2 seconds, using closed gop and fast encoding
       settings for ffmpeg.

       The inverse operation (forcing a decode to happen) is possible using the reframer filter.
       Example
       gpac -i file.mp4 reframer:raw=av -o null

       This will force decoding media from file.mp4 and trash  (send  to  null)  the  result  (doing  a  decoder
       benchmark for example).

   Escaping option separators
       When  a  filter  uses  an  option defined as a string using the same separator character as gpac, you can
       either modify the set of separators, or escape the separator by duplicating it. The options  enclosed  by
       duplicated  separator  are  not  parsed.  This  is  mostly used for meta filters, such as ffmpeg, to pass
       options to sub-filters such as libx264 (cf x264opts parameter).
       Example
       f:a=foo:b=bar

       This will set option a to foo and option b to bar on the filter.
       Example
       f::a=foo:b=bar

       This will set option a to foo:b=bar on the filter.
       Example
       f:a=foo::b=bar:c::d=fun

       This will set option a to foo, b to bar:c and the option d to fun on the filter.

Filter linking [LINK]

       Each filter exposes one or more sets of capabilities, called capability bundle, which are  property  type
       and values that must be matched or excluded by connecting PIDs.
       To check the possible sources and destination for a filter FNAME, use gpac -h links FNAME

       The  filter  graph  resolver uses this information together with the PID properties to link the different
       filters.

       Link directives, when provided, specify which source a filter can accept connections from.
       They do not specify which destination a filter can connect to.

   Default filter linking
       When no link instructions are given (see below), the default linking strategy  used  is  either  implicit
       mode (default in gpac) or complete mode (if .I -cl is set).
       Each PID is checked for possible connection to all defined filters, in their declaration order.
       For each filter DST accepting a connection from the PID, directly or with intermediate filters:
       - if DST filter has link directives, use them to allow or reject PID connection.
       - otherwise, if complete mode is enabled, allow connection.
       - otherwise (implicit mode):
        - if DST is not a sink and is the first matching filter with no link directive, allow connection.
        -  otherwise,  if  DST is not a sink and is not the first matching filter with no link directive, reject
       connection.
        - otherwise (DST is a sink) and no previous connections to a non-sink filter, allow connection.

       Example
       gpac -i file.mp4 c=avc -o output

       With this setup in implicit mode:
       - if the file has a video PID, it will connect to enc but not to output.  The  output  PID  of  enc  will
       connect to output.
       -  if the file has other PIDs than video, they will connect to output, since this enc filter accepts only
       video.

       Example
       gpac -cl -i file.mp4 c=avc -o output

       With this setup in complete mode:
       - if the file has a video PID, it will connect both to enc and to output, and the output PID of enc  will
       connect to output.
       - if the file has other PIDs than video, they will connect to output.

       Furthermore  in  implicit  mode,  filter  connections  are restricted to filters defined between the last
       source and the sink(s).
       Example
       gpac -i video1 reframer:saps=1 -i video2 ffsws:osize=128x72 -o output

       This will connect:
       - video1 to reframer then reframer to output but will prevent reframer to ffsws connection.
       - video2 to ffsws then ffsws to output but will prevent video2 to reframer connection.

       Example
       gpac -i video1 -i video2 reframer:saps=1 ffsws:osize=128x72 -o output

       This will connect video1 AND video2 to reframer->ffsws->output

       The implicit mode allows specifying linear processing chains (no PID fan-out except for final  output(s))
       without link directives, simplifying command lines for common cases.
       Warning: Argument order really matters in implicit mode!

       Example
       gpac -i file.mp4 c=avc c=aac -o output

       If  the  file  has  a video PID, it will connect to c=avc but not to output. The output PID of c=avc will
       connect to output.
       If the file has an audio PID, it will connect to c=aac but not to output. The output PID  of  c=aac  will
       connect to output.
       If the file has other PIDs than audio or video, they will connect to output.

       Example
       gpac -i file.mp4 ffswf=osize:128x72 c=avc resample=osr=48k c=aac -o output

       This will force:
       -   SRC(video)->ffsws->enc(video)->output  and  prevent  SRC(video)->output,  SRC(video)->enc(video)  and
       ffsws->output connections which would happen in complete mode.
       - SRC(audio)->resample->enc(audio)->output and  prevent  SRC(audio)->output,  SRC(audio)->enc(audio)  and
       resample->output connections which would happen in complete mode.

   Quick links
       Link  between  filters  may be manually specified. The syntax is an @ character optionally followed by an
       integer (0 if omitted).
       This indicates that the following filter specified at prompt should be linked only to a  previous  listed
       filter.
       The  optional  integer  is a 0-based index to the previous filter declarations, 0 indicating the previous
       filter declaration, 1 the one before the previous declaration, ...).
       If @@ is used instead of @, the optional integer gives the filter index starting from  the  first  filter
       (index 0) specified in command line.
       Several link directives can be given for a filter.
       Example
       fA fB @1 fC

       This indicates that fC only accepts inputs from fA.
       Example
       fA fB fC @1 @0 fD

       This indicates that fD only accepts inputs from fB and fC.
       Example
       fA fB fC ... @@1 fZ

       This indicates that fZ only accepts inputs from fB.

   Complex links
       The @ link directive is just a quick shortcut to set the following filter arguments:
       * FID=name: assigns an identifier to the filter
       * SID=name1[,name2...]: sets a list of filter identifiers, or sourceIDs, restricting the list of possible
       inputs for a filter.

       Example
       fA fB @1 fC

       This is equivalent to fA:FID=1 fB fC:SID=1.
       Example
       fA:FID=1 fB fC:SID=1

       This indicates that fC only accepts input from fA, but fB might accept inputs from fA.
       Example
       fA:FID=1 fB:FID=2 fC:SID=1 fD:SID=1,2

       This indicates that fD only accepts input from fA and fB and fC only from fA
       Note: A filter with sourceID set cannot get input from filters with no IDs.

       A sourceID name can be further extended using fragment identifier (# by default):
       * name#PIDNAME: accepts only PID(s) with name PIDNAME
       * name#TYPE: accepts only PIDs of matching media type. TYPE can be audio, video, scene, text, font, meta
       * name#TYPEN: accepts only N (1-based index) PID of matching type from source (e.g. video2 to only accept
       second video PID)
       * name#TAG=VAL: accepts the PID if its parent filter has no tag or a tag matching VAL
       * name#P4CC=VAL: accepts only PIDs with builtin property of type P4CC and value VAL.
       * name#PName=VAL: same as above, using the builtin name corresponding to the property.
       * name#AnyName=VAL: same as above, using the name of a non built-in property.
       * name#Name=OtherPropName: compares the value with the value of another property of the PID. The matching
       will fail if the value to compare to is not present or different from the value to check. The property to
       compare with shall be a built-in property.
       If  the  property  is  not  defined  on the PID, the property is matched. Otherwise, its value is checked
       against the given value.

       The following modifiers for comparisons are allowed (for any fragment format using =):
       * name#P4CC=!VAL: accepts only PIDs with property NOT matching VAL.
       * name#P4CC-VAL: accepts only PIDs with property strictly less than  VAL  (only  for  1-dimension  number
       properties).
       *  name#P4CC+VAL:  accepts only PIDs with property strictly greater than VAL (only for 1-dimension number
       properties).

       A sourceID name can also use wildcard or be empty to match a property regardless of the source filter.
       Example
       fA fB:SID=*#ServiceID=2
       fA fB:SID=#ServiceID=2

       This indicates to match connection between fA and fB only for PIDs with a ServiceID property of 2.
       These extensions also work with the LINK @ shortcut.
       Example
       fA fB @1#video fC

       This indicates that fC only accepts inputs from fA, and of type video.
       Example
       gpac -i img.heif @#ItemID=200 vout

       This indicates to connect to vout only PIDs with ItemID property equal to 200.
       Example
       gpac -i vid.mp4 @#PID=1 vout

       This indicates to connect to vout only PIDs with ID property equal to 1.
       Example
       gpac -i vid.mp4 @#Width=640 vout

       This indicates to connect to vout only PIDs with Width property equal to 640.
       Example
       gpac -i vid.mp4 @#Width-640 vout

       This indicates to connect to vout only PIDs with Width property less than 640
       Example
       gpac -i vid.mp4 @#ID=ItemID#ItemNumber=1 vout

       This will connect to vout only PID with an ID property equal to  ItemID  property  (keep  items,  discard
       tracks) and an Item number of 1 (first item).

       Multiple fragment can be specified to check for multiple PID properties.
       Example
       gpac -i vid.mp4 @#Width=640#Height+380 vout

       This indicates to connect to vout only PIDs with Width property equal to 640 and Height greater than 380.

       Warning:  If  a  PID  directly connects to one or more explicitly loaded filters, no further dynamic link
       resolution will be done to connect it to other filters with no sourceID set. Link  directives  should  be
       carefully setup.
       Example
       fA @ reframer fB

       If  fB  accepts  inputs provided by fA but reframer does not, this will link fA PID to fB filter since fB
       has no sourceID.
       Since the PID is connected, the filter engine will not try to solve a link between fA and reframer.

       An exception is made for local files: by default, a local file destination will force  a  remultiplex  of
       input PIDs from a local file.
       Example
       gpac -i file.mp4 -o dump.mp4

       This will prevent direct connection of PID of type file to dst file.mp4, remultiplexing the file.

       The special option nomux is used to allow direct connections (ignored for non-sink filters).
       Example
       gpac -i file.mp4 -o dump.mp4:nomux

       This will result in a direct file copy.

       This only applies to local files destination. For pipes, sockets or other file outputs (HTTP, ROUTE):
       - direct copy is enabled by default
       - nomux=0 can be used to force remultiplex

   Sub-session tagging
       Filters may be assigned to a sub-session using :FS=N, with N a positive integer.
       Filters belonging to different sub-sessions may only link to each-other:
       - if explicitly allowed through sourceID directives (@ or SID)
       - or if they have the same sub-session identifier

       This  is  mostly  used  for implicit mode in gpac: each first source filter specified after a sink filter
       will trigger a new sub-session.
       Example
       gpac -i in1.mp4 -i in2.mp4 -o out1.mp4 -o out2.mp4

       This will result in both inputs multiplexed in both outputs.
       Example
       gpac -i in1.mp4 -o out1.mp4 -i in2.mp4 -o out2.mp4

       This will result in in1 mixed to out1 and in2 mixed to out2,  these  last  two  filters  belonging  to  a
       different sub-session.

Arguments inheriting

       Unless  explicitly  disabled  (see  .I  -max-chain),  the filter engine will resolve implicit or explicit
       (LINK) connections between filters and will allocate any filter chain required to connect the filters. In
       doing so, it loads new filters with arguments inherited from both the source and the destination.
       Example
       gpac -i file.mp4:OPT -o file.aac -o file.264

       This will pass the :OPT to all filters loaded between the source and the two destinations.
       Example
       gpac -i file.mp4 -o file.aac:OPT -o file.264

       This will pass the :OPT to all filters loaded between the source and the file.aac destination.
       Note: the destination arguments inherited are the arguments placed AFTER the dst= option.
       Example
       gpac -i file.mp4 fout:OPTFOO:dst=file.aac:OPTBAR

       This will pass the :OPTBAR to all filters loaded between file.mp4 source and  file.aac  destination,  but
       not OPTFOO.
       Arguments  inheriting  can be stopped by using the keyword gfloc: arguments after the keyword will not be
       inherited.
       Example
       gpac -i file.mp4 -o file.aac:OPTFOO:gfloc:OPTBAR -o file.264

       This will pass :OPTFOO to all filters loaded between file.mp4 source and file.aac  destination,  but  not
       OPTBAR
       Arguments  are by default tracked to check if they were used by the filter chain, and a warning is thrown
       if this is not the case.
       It may be useful to specify arguments which may not be consumed depending on the  graph  resolution;  the
       specific keyword gfopt indicates that arguments after the keyword will not be tracked.
       Example
       gpac -i file.mp4 -o file.aac:OPTFOO:gfopt:OPTBAR -o file.264

       This will warn if OPTFOO is not consumed, but will not track OPTBAR.

       A  filter may be assigned a name (for inspection purposes, not inherited) using :N=name option. This name
       is not used in link resolution and may be changed at runtime by the filter instance.

       A filter may be assigned a tag (any string) using :TAG=name option. This tag does not need to be  unique,
       and  can  be  used  to  exclude  filter in link resolution. Tags are not inherited, therefore dynamically
       loaded filters never have a tag.

URL templating

       Destination URLs can be dynamically constructed using templates. Pattern $KEYWORD$  is  replaced  in  the
       template  with  the  resolved  value  and  $KEYWORD%%0Nd$  is  replaced in the template with the resolved
       integer, padded with up to N zeros if needed.
       KEYWORD is case sensitive, and may be present multiple times in the string. Supported KEYWORD:
       * num: replaced by file number if defined, 0 otherwise
       * PID: ID of the source PID
       * URL: URL of source file
       * File: path on disk for source file; if not found, use URL if set, or PID name otherwise
       * Type: name of stream type of PID (video, audio ...)
       * p4cc=ABCD: uses PID property with 4CC value ABCD
       * pname=VAL: uses PID property with name VAL
       * OTHER: locates property 4CC for the given name, or property name if no 4CC matches.

       $$ is an escape for $

       Templating can be useful when encoding several qualities in one pass.
       Example
       gpac    -i    dump.yuv:size=640x360    vcrop:wnd=0x0x320x180    c=avc:b=1M     @2     c=avc:b=750k     -o
       dump_$CropOrigin$x$Width$x$Height$.264:clone

       This will create a cropped version of the source, encoded in AVC at 1M, and a full version of the content
       in AVC at 750k. Outputs will be dump_0x0x320x180.264 for the cropped version and dump_0x0x640x360.264 for
       the non-cropped one.

Cloning filters

       When  a  filter  accepts  a  single  connection  and has a connected input, it is no longer available for
       dynamic resolution. There may be cases where this behavior is undesired. Take a HEIF file  with  N  items
       and do:
       Example
       gpac -i img.heif -o dump_$ItemID$.jpg

       In this case, only one item (likely the first declared in the file) will connect to the destination.
       Other items will not be connected since the destination only accepts one input PID.
       There is a special option clone allowing filters to be cloned with the same arguments. The cloned filters
       have the same ID as the original one.
       Example
       gpac -i img.heif -o dump_$ItemID$.jpg:clone

       In  this  case, the destination will be cloned for each item, and all will be exported to different JPEGs
       thanks to URL templating.
       Example
       gpac -i vid.mpd c=avc:FID=1:clone -o transcode.mpd:SID=1

       In this case, the encoder will be cloned for each video PIDs in the source, and the destination will only
       use PIDs coming from the encoders.

       When implicit linking is enabled, all filters are  by  default  clonable.  This  allows  duplicating  the
       processing for each PIDs of the same type.
       Example
       gpac -i dual_audio resample:osr=48k c=aac -o dst

       The resampler filter will be cloned for each audio PID, and the encoder will be cloned for each resampler
       output.
       You can explicitly deactivate the cloning instructions:
       Example
       gpac -i dual_audio resample:osr=48k:clone=0 c=aac -o dst

       The first audio will connect to the resample filter, the second to the enc filter and the resample output
       will connect to a clone of the enc filter.

Templating filter chains

       There can be cases where the number of desired outputs depends on the source content, for example dumping
       a  multiplex  of  N services into N files. When the destination involves multiplexing the input PIDs, the
       :clone option is not enough since the multiplexer will always accept the input PIDs.
       To handle this, it is possible to use a PID property name in the sourceID of a filter with the value * or
       an empty value. In this case, whenever a new PID with a new value for the property is found,  the  filter
       with such sourceID will be dynamically cloned.
       Warning:  This  feature  should  only be called with a single property set to * (or empty) per source ID,
       results are undefined otherwise.
       Example
       gpac -i source.ts -o file_$ServiceID$.mp4:SID=*#ServiceID=*
       gpac -i source.ts -o file_$ServiceID$.mp4:SID=#ServiceID=

       In this case, each new ServiceID value found when connecting PIDs to the destination will  create  a  new
       destination file.

       Cloning in implicit linking mode applies to output as well:
       Example
       gpac -i dual_audio -o dst_$PID$.aac

       Each audio track will be dumped to aac (potentially reencoding if needed).

Assigning PID properties

       It is possible to define properties on output PIDs that will be declared by a filter. This allows tagging
       parts  of the graph with different properties than other parts (for example ServiceID). The syntax is the
       same as filter option, and uses the fragment separator to identify properties, e.g. #Name=Value.
       This sets output PIDs property (4cc, built-in name or any name) to the given value. Value can be  omitted
       for boolean (defaults to true, e.g. :#Alpha).
       Non built-in properties are parsed as follows:
       - file@FOO will be declared as string with a value set to the content of FOO.
       - bxml@FOO will be declared as data with a value set to the binarized content of FOO.
       - FOO will be declared as string with a value set to FOO.
       - TYPE@FOO will be parsed according to TYPE. If the type is not recognized, the entire value is copied as
       string. See gpac -h props for defined types.

       User-assigned PID properties on filter fA will be inherited by all filters dynamically loaded to solve fA
       -> fB connection.
       If  fB  also has user-assigned PID properties, these only apply starting from fB in the chain and are not
       inherited by filters between fA and fB.

       Warning: Properties are not filtered and override the properties of the filter's output PIDs, be  careful
       not to break the session by overriding core properties such as width/height/samplerate/... !
       Example
       gpac -i v1.mp4:#ServiceID=4 -i v2.mp4:#ServiceID=2 -o dump.ts

       This  will  multiplex  the streams in dump.ts, using ServiceID 4 for PIDs from v1.mp4 and ServiceID 2 for
       PIDs from v2.mp4.

       PID properties may  be  conditionally  assigned  by  checking  other  PID  properties.  The  syntax  uses
       parenthesis (not configurable) after the property assignment sign:
       #Prop=(CP=CV)VAL
       This will assign PID property Prop to VAL for PIDs with property CP equal to CV.
       #Prop=(CP=CV)VAL,(CP2=CV2)VAL2
       This  will  assign  PID  property Prop to VAL for PIDs with property CP equal to CV, and to VAL2 for PIDs
       with property CP2 equal to CV2.
       #Prop=(CP=CV)(CP2=CV2)VAL
       This will assign PID property Prop to VAL for PIDs with property CP equal to CV and property CP2 equal to
       CV2.
       #Prop=(CP=CV)VAL,()DEFAULT
       This will assign PID property Prop to VAL for PIDs with property CP equal to CV, or to DEFAULT for  other
       PIDs.
       The condition syntax is the same as source ID fragment syntax.
       Note: When set, the default value (empty condition) always matches the PID, therefore it should be placed
       last in the list of conditions.
       Example
       gpac -i source.mp4:#MyProp=(audio)"Super Audio",(video)"Super Video"

       This will assign property MyProp to Super Audio for audio PIDs and to Super Video for video PIDs.
       Example
       gpac -i source.mp4:#MyProp=(audio1)"Super Audio"

       This will assign property MyProp to Super Audio for first audio PID declared.
       Example
       gpac -i source.mp4:#MyProp=(Width+1280)HD

       This will assign property MyProp to HD for PIDs with property Width greater than 1280.

Using option files

       It  is  possible  to  use  a file to define options of a filter, by specifying the target file name as an
       option without value, i.e. :myopts.txt.
       Warning: Only local files are allowed.
       An option file is a simple text file containing one or more options or PID  properties  on  one  or  more
       lines.
       A line beginning with "//" is a comment and is ignored.
       Options in an option file may point to other option files, with a maximum redirection level of 5.
       An option file declaration (filter:myopts.txt) follows the same inheritance rules as regular options.
       Example
       gpac -i source.mp4:myopts.txt:foo=bar -o dst

       Any  filter  loaded  between  source.mp4  and  dst  will inherit both myopts.txt and foo options and will
       resolve options and PID properties given in myopts.txt.

Specific filter options

       Some specific keywords are replaced when processing filter options.
       Warning: These keywords do not apply to PID properties. Multiple keywords cannot be defined for a  single
       option.
       Defined keywords:
       * $GSHARE: replaced by system path to GPAC shared directory (e.g. /usr/share/gpac)
       *  $GJS:  replaced  by  the first path from global share directory and paths set through .I -js-dirs that
       contains the file name following the macro, e.g. $GJS/source.js
       * $GLANG: replaced by the global config language option .I -lang
       * $GUA: replaced by the global config user agent option .I -user-agent
       * $GINC(init_val[,inc]): replaced by init_val and increment init_val by inc (positive or negative number,
       1 if not specified) each time a new filter using this string is created.

       The $GINC construct can be used to dynamically assign numbers in filter chains:
       Example
       gpac -i source.ts tssplit @#ServiceID= -o dump_$GINC(10,2).ts

       This will dump first service in dump_10.ts, second service in dump_12.ts, etc...

       As seen previously, the following options may be set on any filter, but are  not  visible  in  individual
       filter help:
       * FID: filter identifier
       * SID: filter source(s)
       * N: filter name
       * FS: sub-session identifier
       * TAG: filter tag
       * clone: filter cloning flag
       * nomux: enable/disable direct file copy
       * gfreg: preferred filter registry names for link solving
       * gfloc: following options are local to filter declaration (not inherited)
       * gfopt: following options are not tracked
       * gpac: argument separator for URLs

External filters

       GPAC  comes  with  a  set  of  built-in  filters in libgpac. It may also load external filters in dynamic
       libraries, located in default module folder or folders listed in .I -mod-dirs option. The files shall  be
       named  gf_*  and  shall export a single function RegisterFilter returning a filter register - see libgpac
       documentation for more details.

GPAC Built-in properties

       Built-in property types

       sint
              signed 32 bit integer

       uint
              unsigned 32 bit integer

       lsint
              signed 64 bit integer

       luint
              unsigned 32 bit integer

       bool
              boolean

       frac
              32/32 bit fraction

       lfrac
              64/64 bit fraction

       flt
              32 bit float number

       dbl
              64 bit float number

       v2di
              2D 32-bit integer vector

       v2d
              2D 64-bit float vector

       v3di
              3D 32-bit integer vector

       v4di
              4D 32-bit integer vector

       str
              UTF-8 string

       mem
              data buffer

       cstr
              const UTF-8 string

       cmem
              const data buffer

       ptr
              32 or 64 bit pointer

       strl
              UTF-8 string list

       uintl
              unsigned 32 bit integer list

       sintl
              signed 32 bit integer list

       v2il
              2D 32-bit integer vector list

       4cc
              Four character code

       4ccl
              four-character codes list

       pfmt
              raw pixel format

       afmt
              raw audio format

       cprm
              color primaries, string or int value from ISO/IEC 23091-2

       ctfc
              color transfer characteristics, string or int value from ISO/IEC 23091-2

       cmxc
              color matrix coefficients, string or int value from ISO/IEC 23091-2

              Built-in properties for PIDs and packets listed as Name (4CC type FLAGS): description
              FLAGS can be D (droppable - see GSF multiplexer filter help), P (packet property)

       ID (PIDI,uint, )
              Stream ID

       ESID (ESID,uint,D )
              MPEG-4 ESID of PID

       ItemID (ITID,uint, )
              ID of image item in HEIF, same value as ID

       ItemNumber (ITIX,uint, )
              Number (1-based) of image item in HEIF, in order of declaration in file

       TrackNumber (PIDX,uint, )
              Number (1-based) of track in order of declaration in file

       ServiceID (PSID,uint,D )
              ID of parent service

       ClockID (CKID,uint,D )
              ID of clock reference PID

       DependencyID (DPID,uint, )
              ID of layer depended on

       SubLayer (DPSL,bool, )
              PID is a sublayer of the stream depended on rather than an enhancement layer

       PlaybackMode (PBKM,uint,D )
              Playback mode supported:
              * 0: no time control
              * 1: play/pause/seek,speed=1
              * 2: play/pause/seek,speed>=0
              * 3: play/pause/seek, reverse playback

       Scalable (SCAL,bool, )
              Scalable stream

       TileBase (SABT,bool, )
              Tile base stream

       TileID (PTID,uint, )
              ID of the tile for hvt1/hvt2 PIDs

       Language (LANG,cstr, )
              Language code: ISO639 2/3 character code or RFC 4646

       ServiceName (SNAM,str,D )
              Name of parent service

       ServiceProvider (SPRO,str,D )
              Provider of parent service

       StreamType (PMST,uint, )
              Media stream type

       StreamSubtype (PSST,4cc,D )
              Media subtype 4CC (auxiliary, pic sequence, etc ..), matches ISOM handler type

       ISOMSubtype (PIST,4cc,D )
              ISOM media subtype 4CC (avc1 avc2...)

       OrigStreamType (POST,uint, )
              Original stream type before encryption

       CodecID (POTI,uint, )
              Codec ID (MPEG-4 OTI or ISOBMFF 4CC)

       InitialObjectDescriptor (PIOD,bool, )
              PID is declared in the IOD for MPEG-4

       Unframed (PFRM,bool, )
              The media data is not framed, i.e. each packet is not a complete AU/frame or is  not  in  internal
              format (e.g. annexB for avc/hevc, adts for aac)

       UnframedAU (PFRF,bool, )
              The  unframed  media  still  has  correct AU boundaries: one packet is one full AU, but the packet
              format might not be the internal one (e.g. annexB for avc/hevc, adts for aac)

       LATM (LATM,bool, )
              Media is unframed AAC in LATM format

       Duration (PDUR,lfrac, )
              Media duration

       NumFrames (NFRM,uint,D )
              Number of frames in the stream

       FrameOffset (FRMO,uint,D )
              Index of first frame in the stream (used for reporting)

       ConstantFrameSize (CFRS,uint, )
              Size of the frames for constant frame size streams

       TimeshiftDepth (PTSD,frac,D )
              Depth of the timeshift buffer

       TimeshiftTime (PTST,dbl,D )
              Time in the timeshift buffer in seconds - changes are signaled through PID info (no reconfigure)

       TimeshiftState (PTSS,uint,D )
              State of timeshift buffer: 0 is OK, 1 is underflow, 2 is overflow - changes are  signaled  through
              PID info (no reconfigure)

       Timescale (TIMS,uint, )
              Media timescale (a timestamp delta of N is N/timescale seconds)

       ProfileLevel (PRPL,uint,D )
              MPEG-4 profile and level

       DecoderConfig (DCFG,mem, )
              Decoder configuration data

       DecoderConfigEnhancement (ECFG,mem, )
              Decoder  configuration  data  of the enhancement layer(s). Also used by 3GPP/Apple text streams to
              give the full sample description table used in SDP.

       DecoderConfigIndex (ICFG,uint, )
              1-based index of decoder config for ISO base media files

       SampleRate (AUSR,uint, )
              Audio sample rate

       SamplesPerFrame (FRMS,uint, )
              Number of audio sample in one coded frame

       NumChannels (CHNB,uint, )
              Number of audio channels

       BPS (ABPS,uint, )
              Number of bits per sample in compressed source

       ChannelLayout (CHLO,luint, )
              Channel Layout mask

       AudioFormat (AFMT,afmt, )
              Audio sample format

       AudioPlaybackSpeed (ASPD,dbl,D )
              Audio playback speed, only used for audio output reconfiguration

       Delay (MDLY,lsint, )
              Delay of presentation compared to composition timestamps, in media timescale. Positive value imply
              holding (delaying) the stream. Negative value imply skipping the beginning of stream

       CTSShift (MDTS,uint, )
              CTS offset to apply in case of negative ctts

       SkipPriming (ASKP,bool, )
              Audio priming shall not to be removed when initializing decoding

       Width (WIDT,uint, )
              Visual Width (video / text / graphics)

       Height (HEIG,uint, )
              Visual Height (video / text / graphics)

       PixelFormat (PFMT,pfmt, )
              Pixel format

       PixelFormatWrapped (PFMW,pfmt, )
              Underlying pixel format of video stream if pixel format is external GL texture

       Stride (VSTY,uint, )
              Image or Y/alpha plane stride

       StrideUV (VSTC,uint, )
              UV plane or U/V planes stride

       BitDepthLuma (YBPS,uint, )
              Bit depth for luma components

       BitDepthChroma (CBPS,uint, )
              Bit depth for chroma components

       FPS (VFPF,frac, )
              Video framerate

       Interlaced (VILC,bool, )
              Video is interlaced

       SAR (PSAR,frac, )
              Sample (i.e. pixel) aspect ratio

       PAR (VPAR,frac,D )
              Picture aspect ratio

       MaxWidth (MWID,uint, )
              Maximum width (video / text / graphics) of all enhancement layers

       MaxHeight (MHEI,uint, )
              Maximum height (video / text / graphics) of all enhancement layers

       ZOrder (VZIX,sint, )
              Z-order of the video, from 0 (first) to max int (last)

       TransX (VTRX,sint, )
              Horizontal translation of the video

       TransY (VTRY,sint, )
              Vertical translation of the video

       Hidden (HIDE,bool, )
              PID is hidden in visual/audio rendering

       CropOrigin (VCXY,v2di, )
              Position in source window, X,Y indicates coord in source

       OriginalSize (VOWH,v2di, )
              Original resolution of video

       SRD (SRD ,v4di, )
              Position and size of the video in the referential given by SRDRef

       SRDRef (SRDR,v2di, )
              Width and Height of the SRD referential

       SRDMap (SRDM,uintl, )
              Mapping of input videos in reconstructed video, expressed as {Ox,Oy,Ow,Oh,Dx,Dy,Dw,Dh} per  input,
              with:
              * Ox,Oy,Ow,Oh: position and size of the input video (usually matching its SRD property), expressed
              in the output referential given by SRDRef
              *  Dx,Dy,Dw,Dh: Position and Size of the input video in the reconstructed output, expressed in the
              output referential given by SRDRef

       Alpha (VALP,bool, )
              Video in this PID is an alpha map

       Mirror (VMIR,uint, )
              Mirror mode (0: no mirror, 1: along Y-axis, 2: along X-axis)

       Rotate (VROT,uint, )
              Video rotation as value*90 degree anti-clockwise

       ClapW (CLPW,frac, )
              Width of clean aperture in luma pixels

       ClapH (CLPH,frac, )
              Height of clean aperture in luma pixels

       ClapX (CLPX,frac, )
              Horizontal offset of clean aperture center in luma pixels, 0 at image center

       ClapY (CLPY,frac, )
              Vertical offset of clean aperture center in luma pixels, 0 at image center

       NumViews (PNBV,uint, )
              Number of views packed in a frame (top-to-bottom only)

       Bitrate (RATE,uint, )
              Bitrate in bps

       Maxrate (MRAT,uint, )
              Max bitrate in bps

       TargetRate (TBRT,uint, )
              Target bitrate in bps, used to setup encoders

       DBSize (DBSZ,uint, )
              Decode buffer size in bytes

       MediaDataSize (MDSZ,luint,D )
              Size in bytes of media data

       DataRef (DREF,bool,D )
              Data referencing is possible (each compressed frame is a continuous set of bytes in  source,  with
              no transformation)

       URL (FURL,str,D )
              URL of source

       RemoteURL (RURL,str,D )
              Remote URL of source - used for MPEG-4 systems

       RedirectURL (RELO,str,D )
              Redirection URL of source

       SourcePath (FSRC,str,D )
              Path of source file on file system

       MIMEType (MIME,str,D )
              MIME type of source

       Extension (FEXT,str,D )
              File extension of source

       Cached (CACH,bool,D )
              File is completely cached

       DownloadRate (DLBW,uint,D )
              Download  rate  of  resource  in  bits  per  second  -  changes  are signaled through PID info (no
              reconfigure)

       DownloadSize (DLSZ,luint,D )
              Size of resource in bytes

       DownBytes (DLBD,luint,D )
              Number of bytes downloaded - changes are signaled through PID info (no reconfigure)

       ByteRange (FBRA,lfrac,D )
              Byte range of resource

       DisableProgressive (NPRG,uint, )
              Some blocks in file need patching (replace  or  insertion)  upon  closing,  potentially  disabling
              progressive upload

       IsoAltBrands (ABRD,4ccl,D )
              ISOBMFF brands associated with PID/file

       IsoBrand (MBRD,4cc,D )
              ISOBMFF major brand associated with PID/file

       MovieTime (MHTS,lfrac,D )
              ISOBMFF movie header duration and timescale

       HasSync (PSYN,bool,D )
              PID has sync points

       ServiceWidth (DWDT,uint,D )
              Display width of service

       ServiceHeight (DHGT,uint,D )
              Display height of service

       CarouselRate (CARA,uint,D )
              Repeat rate in ms for systems carousel data

       UTC (UTCD,luint,D )
              UTC date and time of PID

       UTCTimestamp (UTCT,luint,D )
              Timestamp corresponding to UTC date and time

       AudioVolume (AVOL,uint,D )
              Volume of audio

       AudioPan (APAN,uint,D )
              Balance/Pan of audio

       AudioPriority (APRI,uint,D )
              Audio thread priority

       ProtectionScheme (SCHT,4cc, )
              Protection scheme type (4CC) used

       SchemeVersion (SCHV,uint, )
              Protection scheme version used

       SchemeURI (SCHU,str, )
              Protection scheme URI

       KMS_URI (KMSU,str, )
              URI for key management system

       SelectiveEncryption (ISSE,bool, )
              ISMA/OMA selective encryption is used

       IVLength (ISIV,uint, )
              ISMA IV size

       KILength (ISKI,uint, )
              ISMA KeyIndication size

       CryptType (OMCT,uint, )
              OMA encryption type

       ContentID (OMID,str, )
              OMA Content ID

       TextualHeaders (OMTH,str, )
              OMA textual headers

       PlaintextLen (OMPT,luint, )
              OMA size of plaintext data

       CryptInfo (ECRI,str,D )
              URL (local file only) of crypt info file for this PID, use clear to force passthrough

       DecryptInfo (EDRI,str,D )
              URL (local file only) of crypt info file for this PID - see decrypter help

       SenderNTP (NTPS,luint,DP)
              NTP time at sender side or grabber side

       ReceiverNTP (NTPR,luint,DP)
              Receiver NTP time (usually associated with the sender NTP property)

       Encrypted (EPCK,bool, )
              Packets for the stream are by default encrypted (however the encryption state is carried in packet
              crypt flags) - changes are signaled through PID info change (no reconfigure)

       OMAPreview (ODPR,luint, )
              OMA Preview range

       CENC_PSSH (PSSH,mem, )
              PSSH  blob  for  CENC,  formatted  as (u32)NbSystems [ (bin128)SystemID(u32)version(u32)KID_count[
              (bin128)keyID ] (u32)priv_size(char*priv_size)priv_data]

       CENC_SAI (SAIS,mem, P)
              CENC    SAI    for     the     packet,     formatted     as     (char(IV_Size))IV(u16)NbSubSamples
              [(u16)ClearBytes(u32)CryptedBytes]

       KeyInfo (CBIV,mem, )
              Multi key info formatted as:
               is_mkey(u8);
              nb_keys(u16);
              [
                   IV_size(u8);
                   KID(bin128);
                   if (!IV_size) {;
                        const_IV_size(u8);
                        constIV(const_IV_size);
              }
              ]

       CENCPattern (CPTR,frac, )
              CENC crypt pattern, CENC pattern, skip as frac.num crypt as frac.den

       CENCStore (CSTR,4cc, )
              Storage location 4CC of SAI data

       CENCstsdMode (CSTM,uint, )
              Mode for CENC sample description when using clear samples:
              * 0: single sample description is used
              *  1:  a  clear  clone  of  the  sample  description  is  created, inserted before the CENC sample
              description
              * 2: a clear clone  of  the  sample  description  is  created,  inserted  after  the  CENC  sample
              description

       AMRModeSet (AMST,uint, )
              ModeSet for AMR and AMR-WideBand

       SubSampleInfo (SUBS,mem, )
              Binary     blob     describing     N    subsamples    of    the    sample,    formatted    as    N
              [(u32)flags(u32)size(u32)codec_param(u8)priority(u8) discardable]. Subsamples  for  a  given  flag
              MUST appear in order, however flags can be interleaved

       NALUMaxSize (NALS,uint, )
              Max size of NAL units in stream - changes are signaled through PID info change (no reconfigure)

       FileNumber (FNUM,uint, P)
              Index of file when dumping to files

       FileName (FNAM,str, P)
              Name of output file when dumping / dashing. Must be set on first packet belonging to new file

       IDXName (INAM,str, P)
              Name of index file when dashing MPEG-2 TS. Must be set on first packet belonging to new file

       FileSuffix (FSUF,str, P)
              File suffix name, replacement for $FS$ in tile templates

       EODS (EODS,bool, P)
              End of DASH segment

       CueStart (PCUS,bool, P)
              Set  on  packets  marking  the  beginning  of a DASH/HLS segment for cue-driven segmentation - see
              dasher help

       MaxFrameSize (MFRS,uint,D )
              Max size of frame in stream - changes are signaled through PID info change (no reconfigure)

       AvgFrameSize (AFRS,uint,D )
              Average size of frame in stream (ISOBMFF only, static property)

       MaxTSDelta (MTSD,uint,D )
              Maximum DTS delta between frames (ISOBMFF only, static property)

       MaxCTSOffset (MCTO,uint,D )
              Maximum absolute CTS offset (ISOBMFF only, static property)

       ConstantDuration (SCTD,uint,D )
              Constant duration of samples, 0 means variable duration (ISOBMFF only, static property)

       TrackTemplate (ITKT,mem,D )
              ISOBMFF serialized track box for this PID, without any sample info (empty stbl and empty dref)

       TrexTemplate (ITXT,mem,D )
              ISOBMFF serialized trex box for this PID

       STSDTemplate (ISTD,mem,D )
              ISOBMFF serialized sample description box (stsd entry) for this PID

       MovieUserData (IMUD,mem,D )
              ISOBMFF serialized moov UDTA and other moov-level boxes (list) for this PID

       HandlerName (IHDL,str,D )
              ISOBMFF track handler name

       TrackFlags (ITKF,uint,D )
              ISOBMFF track header flags

       TrackMatrix (ITKM,sintl,D )
              ISOBMFF track header matrix

       AltGroup (IALG,uint,D )
              ISOBMFF alt group ID

       ForceNCTTS (IFNC,bool,D )
              ISOBMFF force negative CTS offsets

       Disable (ITKD,bool,D )
              ISOBMFF disable flag

       Period (PEID,str,D )
              ID of DASH period

       PStart (PEST,lfrac,D )
              DASH Period start - cf dasher help

       PDur (PEDU,lfrac,D )
              DASH Period duration - cf dasher help

       Representation (DRID,str,D )
              ID of DASH representation

       ASID (DAID,uint,D )
              ID of parent DASH AS

       MuxSrc (MSRC,str,D )
              Name of mux source(s), set by dasher to direct its outputs

       DashMode (DMOD,uint,D )
              DASH mode to be used by multiplexer if any, set by dasher. 0 is no DASH, 1 is regular DASH,  2  is
              VoD

       DashDur (DDUR,frac,D )
              DASH target segment duration in seconds

       Role (ROLE,strl,D )
              List  of  roles  for  this PID, where each role string can be a DASH role, a URN:role-value or any
              other string (this will throw a warning and use a custom URI for the role)

       PDesc (PDES,strl,D )
              List of descriptors for the DASH period containing this PID

       ASDesc (ACDS,strl,D )
              List of conditional descriptors for the DASH AdaptationSet containing this PID. If a PID with  the
              same property type but different value is found, the PIDs will be in different AdaptationSets

       ASCDesc (AADS,strl,D )
              List of common descriptors for the DASH AdaptationSet containing this PID

       RDesc (RDES,strl,D )
              List of descriptors for the DASH Representation containing this PID

       BUrl (BURL,strl,D )
              List of base URLs for this PID

       Template (DTPL,str, )
              Template to use for DASH generation for this PID

       StartNumber (DRSN,uint, )
              Start number to use for this PID - cf dasher help

       xlink (XLNK,str,D )
              Remote period URL for DASH - cf dasher help

       ClampDur (DCMD,lfrac,D )
              Max media duration to process from PID in DASH mode

       HLSPL (HLVP,str,D )
              Name of the HLS variant playlist for this media

       HLSGroup (HLGI,str,D )
              Name of HLS Group of a stream

       HLSMExt (HLMX,strl,D )
              List of extensions to add to the master playlist for this PID

       HLSVExt (HLVX,strl,D )
              List of extensions to add to the variant playlist for this PID

       DCue (DCUE,str,D )
              Name of a cue list file for this PID - see dasher help

       DSegs (DCNS,uint,D )
              Number of DASH segments defined by the DASH cue info

       Codec (CODS,str,D )
              codec  parameter  string to force. If starting with '.', appended to ISOBMFF code point; otherwise
              replace the codec string

       SingleScale (DSTS,bool,D )
              Movie header should use the media timescale of the first track added

       RequireReorder (PUDP,bool,D )
              PID packets come from source with losses and reordering happening (UDP)

       Primary (PITM,bool,D )
              Primary item in ISOBMFF

       DFMode (DFWD,uint,D )
              DASH forward mode is used for this PID. If 2, the manifest is also carried in packet propery

       DFManifest (DMPD,str,D )
              Value of manifest in forward mode

       DFVariant (DHLV,strl,D )
              Value of variant playlist in forward mode

       DFVariantName (DHLN,strl,D )
              Value of variant playlist name in forward mode

       DFPStart (DPST,luint,D )
              Value of active period start time in forward mode

       HLSKey (HLSK,str, )
              URI, KEYFORMAT and KEYFORMATVERSIONS for HLS full segment encryption creation, Key URI otherwise (
              decoding and sample-AES)

       HLSIV (HLSI,mem, )
              Init Vector for HLS decode

       ColorPrimaries (CPRM,cprm,D )
              Color primaries

       ColorTransfer (CTRC,ctfc,D )
              Color transfer characteristics

       ColorMatrix (CMXC,cmxc,D )
              Color matrix coefficient

       FullRange (CFRA,bool,D )
              Color full range flag

       Chroma (CFMT,uint,D )
              Chroma format (see ISO/IEC 23001-8 / 23091-2)

       ChromaLoc (CLOC,uint,D )
              Chroma location (see ISO/IEC 23001-8 / 23091-2)

       ContentLightLevel (CLLI,mem,D )
              Content light level, payload of clli box (see ISO/IEC 14496-12),  can  be  set  as  a  list  of  2
              integers in fragment declaration (e.g. "=max_cll,max_pic_avg_ll")

       MasterDisplayColour (MDCV,mem,D )
              Master display colour info, payload of mdcv box (see ISO/IEC 14496-12), can be set as a list of 10
              integers in fragment declaration (e.g. "=dpx0,dpy0,dpx1,dpy1,dpx2,dpy2,wpx,wpy,max,min")

       SrcMagic (PSMG,luint,D )
              Magic number to store in the track, only used by importers

       MuxIndex (TIDX,luint,D )
              Target track index in destination file, stored by lowest value first (not set by demultiplexers)

       NoTSLoop (NTSL,bool, )
              Timestamps on this PID are adjusted in case of loops (used by TS multiplexer output)

       MHAProfiles (MHCP,uintl,D )
              List of compatible profiles for this MPEG-H Audio object

       FragStart (PFRB,uint,DP)
              Packet is a fragment start (value 1) or a segment start (value 2)

       FragRange (PFRR,lfrac,DP)
              Start and end position in bytes of fragment if packet is a fragment or segment start

       SIDXRange (PFSR,lfrac,DP)
              Start and end position in bytes of sidx if packet is a fragment or segment start

       MoofTemplate (MFTP,mem,DP)
              Serialized  moof  box  corresponding  to  the  start of a movie fragment or segment (with styp and
              optionally sidx)

       InitSeg (PCKI,bool, P)
              Set to true if packet is a complete DASH init segment file

       RawGrab (PGRB,bool,D )
              PID is a raw media grabber (webcam, microphone, etc...)

       KeepAfterEOS (PKAE,bool,D )
              PID must be kept alive after EOS (LASeR and BIFS)

       CoverArt (PCOV,mem,D )
              PID cover art image data. If associated data is NULL, the data is carried in the PID

       BufferLength (PBPL,uint,D )
              Playout buffer in ms

       MaxBuffer (PBMX,uint,D )
              Maximum buffer occupancy in ms

       ReBuffer (PBRE,uint,D )
              Rebuffer threshold in ms, 0 disable rebuffering

       ViewIdx (VIDX,uint,D )
              View index for multiview (1 being left)

       FragURL (OFRA,str,D )
              Fragment URL (without '#') of original URL (used by some filters to  set  the  property  on  media
              PIDs)

       ROUTEIP (RSIP,str,D )
              ROUTE session IP address

       ROUTEPort (RSPN,uint,D )
              ROUTE session port number

       ROUTEName (RSFN,str,D )
              Name (location) of raw file to advertise in ROUTE session

       ROUTECarousel (RSCR,frac,D )
              Carousel period in seconds of raw file in ROUTE session

       ROUTEUpload (RSST,frac,D )
              Upload time in seconds of raw file in ROUTE session

       Stereo (PSTT,uint,D )
              Stereo type of video

       Projection (PPJT,uint,D )
              Projection type of video

       InitalPose (PPOS,v3di,D )
              Initial pose for 360 video, in degrees expressed as 16.16 bits (x is yaw, y is pitch, z is roll)

       CMPad (PCMP,uint,D )
              Number of pixels to pad from edge of each face in cube map

       EQRClamp (PEQC,v4di,D )
              Clamping of frame for EQR as 0.32 fixed point (x is top, y is bottom, z is left and w is right)

       SceneNode (PSND,bool, )
              PID is a scene node decoder (AFX BitWrapper in BIFS)

       OrigCryptoScheme (POCS,uint, )
              Original crypto scheme on a decrypted PID

       TSBSegs (PTSN,uint,D )
              Time shift in number of segments for HAS streams, only set by dashin and dasher filters

       IsManifest (PHSM,bool,D )
              PID is a HAS manifest

       SkipBegin (PCKS,uint, P)
              Amount of media to skip from beginning of packet in PID timescale

       SkipPres (PCKD,bool, P)
              Packet  and  any  following  with  CTS  greater  than  this packet shall not be presented (used by
              reframer to create edit lists)

       HLSRef (HPLR,luint,DP)
              HLS playlist reference, gives a unique ID identifying media mux, and indicated in packets carrying
              child playlists

       LLHLS (HLSL,uint,D )
              HLS low latency mode

       LLHLSFragNum (HLSN,uint, P)
              LLHLS fragment number

       DownloadSession (GHTT,ptr,D )
              Pointer to download session

       HasTemi (PTEM,bool,D )
              TEMI present flag

       XPSMask (PXPM,uint,DP)
              Parameter set mask

       RangeEnd (PCER,bool, P)
              Signal packet is the last in the desired play range

Pixel formats

       yuv420 (ext *.yuv)
              Planar YUV 420 8 bit

       yvu420 (ext *.yvu)
              Planar YVU 420 8 bit

       yuv420_10 (ext *.yuvl)
              Planar YUV 420 10 bit

       yuv422 (ext *.yuv2)
              Planar YUV 422 8 bit

       yuv422_10 (ext *.yp2l)
              Planar YUV 422 10 bit

       yuv444 (ext *.yuv4)
              Planar YUV 444 8 bit

       yuv444_10 (ext *.yp4l)
              Planar YUV 444 10 bit

       uyvy (ext *.uyvy)
              Packed UYVY 422 8 bit

       vyuy (ext *.vyuy)
              Packed VYUV 422 8 bit

       yuyv (ext *.yuyv)
              Packed YUYV 422 8 bit

       yvyu (ext *.yvyu)
              Packed YVYU 422 8 bit

       uyvl (ext *.uyvl)
              Packed UYVY 422 10->16 bit

       vyul (ext *.vyul)
              Packed VYUV 422 10->16 bit

       yuyl (ext *.yuyl)
              Packed YUYV 422 10->16 bit

       yvyl (ext *.yvyl)
              Packed YVYU 422 10->16 bit

       nv12 (ext *.nv12)
              Semi-planar YUV 420 8 bit, Y plane and UV packed plane

       nv21 (ext *.nv21)
              Semi-planar YUV 420 8 bit, Y plane and VU packed plane

       nv1l (ext *.nv1l)
              Semi-planar YUV 420 10 bit, Y plane and UV plane

       nv2l (ext *.nv2l)
              Semi-planar YUV 420 8 bit, Y plane and VU plane

       yuva (ext *.yuva)
              Planar YUV+alpha 420 8 bit

       yuvd (ext *.yuvd)
              Planar YUV+depth  420 8 bit

       yuv444a (ext *.yp4a)
              Planar YUV+alpha 444 8 bit

       yuv444p (ext *.yv4p)
              Packed YUV 444 8 bit

       yuv444ap (ext *.y4ap)
              Packed YUV+alpha 444 8 bit

       yuv444p_10 (ext *.y4lp)
              Packed YUV 444 10 bit

       grey (ext *.grey)
              Greyscale 8 bit

       algr (ext *.algr)
              Alpha+Grey 8 bit

       gral (ext *.gral)
              Grey+Alpha 8 bit

       rgb4 (ext *.rgb4)
              RGB 444, 12 bits (16 stored) / pixel

       rgb5 (ext *.rgb5)
              RGB 555, 15 bits (16 stored) / pixel

       rgb6 (ext *.rgb6)
              RGB 555, 16 bits / pixel

       rgba (ext *.rgba)
              RGBA 32 bits (8 bits / component)

       argb (ext *.argb)
              ARGB 32 bits (8 bits / component)

       bgra (ext *.bgra)
              BGRA 32 bits (8 bits / component)

       abgr (ext *.abgr)
              ABGR 32 bits (8 bits / component)

       rgb (ext *.rgb)
              RGB 24 bits (8 bits / component)

       bgr (ext *.bgr)
              BGR 24 bits (8 bits / component)

       xrgb (ext *.xrgb)
              xRGB 32 bits (8 bits / component)

       rgbx (ext *.rgbx)
              RGBx 32 bits (8 bits / component)

       xbgr (ext *.xbgr)
              xBGR 32 bits (8 bits / component)

       bgrx (ext *.bgrx)
              BGRx 32 bits (8 bits / component)

       rgbd (ext *.rgbd)
              RGB+depth 32 bits (8 bits / component)

       rgbds (ext *.rgbds)
              RGB+depth+bit shape (8 bits / RGB component, 7 bit depth (low bits) + 1 bit shape)

       rgbs (ext *.rgbs)
              RGB 24 bits stereo (side-by-side) - to be removed

       rgbas (ext *.rgbas)
              RGBA 32 bits stereo (side-by-side) - to be removed

       extgl (ext *.extgl)
              External OpenGL texture of unknown format, to be used with samplerExternalOES

Audio formats

       u8 (ext *.pc8)
              8 bit PCM

       s16 (ext *.pcm)
              16 bit PCM Little Endian

       s16b (ext *.pcmb)
              16 bit PCM Big Endian

       s24 (ext *.s24)
              24 bit PCM

       s32 (ext *.s32)
              32 bit PCM Little Endian

       flt (ext *.flt)
              32-bit floating point PCM

       dbl (ext *.dbl)
              64-bit floating point PCM

       u8p (ext *.pc8p)
              8 bit PCM planar

       s16p (ext *.pcmp)
              16 bit PCM Little Endian planar

       s24p (ext *.s24p)
              24 bit PCM planar

       s32p (ext *.s32p)
              32 bit PCM Little Endian planar

       fltp (ext *.fltp)
              32-bit floating point PCM planar

       dblp (ext *.dblp)
              64-bit floating point PCM planar

Stream types

       Visual
              Video or Image stream

       Audio
              Audio stream

       SceneDescription
              Scene stream

       Text
              Text or subtitle stream

       Metadata
              Metadata stream

       File
              Raw file stream

       Encrypted
              Encrypted media stream

       ObjectDescriptor
              MPEG-4 ObjectDescriptor stream

       ClockReference
              MPEG-4 Clock Reference stream

       MPEG7
              MPEG-7 description stream

       IPMP
              MPEG-4 IPMP/DRM stream

       OCI
              MPEG-4 ObjectContentInformation stream

       MPEGJ
              MPEG-4 JAVA stream

       Interaction
              MPEG-4 Interaction Sensor stream

       Font
              MPEG-4 Font stream

Codecs

       bifs
              MPEG-4 BIFS v1 Scene Description

       bifs2
              MPEG-4 BIFS v2 Scene Description

       bifsX
              MPEG-4 BIFS Extended Scene Description

       od
              MPEG-4 ObjectDescriptor v1

       od2
              MPEG-4 ObjectDescriptor v2

       interact
              MPEG-4 Interaction Stream

       afx
              MPEG-4 AFX Stream

       font
              MPEG-4 Font Stream

       syntex
              MPEG-4 Synthetized Texture

       m4txt
              MPEG-4 Streaming Text

       laser
              MPEG-4 LASeR

       saf
              MPEG-4 Simple Aggregation Format

       cmp|m4ve|m4v
              MPEG-4 Visual part 2

       264|avc|h264
              MPEG-4 AVC|H264 Video

       avcps
              MPEG-4 AVC|H264 Video Parameter Sets

       svc|avc|264|h264
              MPEG-4 AVC|H264 Scalable Video Coding

       mvc
              MPEG-4 AVC|H264 Multiview Video Coding

       hvc|hevc|h265
              HEVC Video

       lhvc|shvc|mhvc
              HEVC Video Layered Extensions

       m2vs
              MPEG-2 Visual Simple

       m2v
              MPEG-2 Visual Main

       m2v|m2vsnr
              MPEG-2 Visual SNR

       m2v|m2vspat
              MPEG-2 Visual Spatial

       m2v|m2vh
              MPEG-2 Visual High

       m2v|m2v4
              MPEG-2 Visual 422

       m1v
              MPEG-1 Video

       jpg|jpeg
              JPEG Image

       png
              PNG Image

       jp2|j2k
              JPEG2000 Image

       aac
              MPEG-4 AAC Audio

       aac|aac2m
              MPEG-2 AAC Audio Main

       aac|aac2l
              MPEG-2 AAC Audio Low Complexity

       aac|aac2s
              MPEG-2 AAC Audio Scalable Sampling Rate

       mp3|m1a
              MPEG-1 Audio

       mp2
              MPEG-2 Audio

       mp1
              MPEG-1 Audio Layer 1

       h263
              H263 Video

       h263
              H263 Video

       hvt1
              HEVC tiles Video

       evc|evrc
              EVRC Voice

       smv
              SMV Voice

       qcp|qcelp
              QCELP Voice

       amr
              AMR Audio

       amr|amrwb
              AMR WideBand Audio

       qcp|evrcpv
              EVRC (PacketVideo MUX) Audio

       vc1
              SMPTE VC-1 Video

       dirac
              Dirac Video

       ac3
              AC3 Audio

       eac3
              Enhanced AC3 Audio

       mlp
              Dolby TrueHD

       dra
              DRA Audio

       g719
              G719 Audio

       dstca
              DTS Coherent Acoustics Audio

       dtsh
              DTS-HD High Resolution Audio

       dstm
              DTS-HD Master Audio

       dtsl
              DTS Express low bit rate Audio

       opus
              Opus Audio

       eti
              DVB Event Information

       svgr
              SVG over RTP

       svgzr
              SVG+gz over RTP

       dims
              3GPP DIMS Scene

       vtt
              WebVTT Text

       txt
              Simple Text Stream

       mtxt
              Metadata Text Stream

       mxml
              Metadata XML Stream

       subs
              Subtitle text Stream

       subx
              Subtitle XML Stream

       tx3g
              Subtitle/text 3GPP/Apple Stream

       theo|theora
              Theora Video

       vorb|vorbis
              Vorbis Audio

       opus
              Opus Audio

       flac
              Flac Audio

       spx|speex
              Speex Audio

       vobsub
              VobSub Subtitle

       vobsub
              VobSub Subtitle

       adpcm
              AD-PCM

       csvd
              IBM CSVD

       alaw
              ALAW

       mulaw
              MULAW

       okiadpcm
              OKI ADPCM

       dviadpcm
              DVI ADPCM

       digistd
              DIGISTD

       yamadpcm
              YAMAHA ADPCM

       truespeech
              DSP TrueSpeech

       g610
              GSM 610

       imulaw
              IBM MULAW

       ialaw
              IBM ALAW

       iadpcl
              IBM ADPCL

       swf
              Adobe Flash

       raw
              Raw media

       av1|ivf|obu|av1b
              AOM AV1 Video

       vp8|ivf
              VP8 Video

       vp9|ivf
              VP9 Video

       vp10|ivf
              VP10 Video

       mhas
              MPEG-H Audio

       mhas
              MPEG-H AudioMux

       prores|apch
              ProRes Video 422 HQ

       prores|apco
              ProRes Video 422 Proxy

       prores|apcn
              ProRes Video 422 STD

       prores|apcs
              ProRes Video 422 LT

       prores|ap4x
              ProRes Video 4444 XQ

       prores|ap4h
              ProRes Video 4444

       ffmpeg
              FFMPEG unmapped codec

       tmcd
              QT TimeCode

       vvc|266|h266
              VVC Video

       vvs1
              VVC Subpicture Video

       usac|xheaac
              xHEAAC / USAC Audio

       v210
              v210 YUV 422 10 bits

       ffv1
              FFMPEG Video Codec 1

Stream types

       mono (int 1)
              Layout 0x0000000000000004

       stereo (int 2)
              Layout 0x0000000000000003

       3/0.0 (int 3)
              Layout 0x0000000000000007

       3/1.0 (int 4)
              Layout 0x0000000000000407

       3/2.0 (int 5)
              Layout 0x0000000000000307

       3/2.1 (int 6)
              Layout 0x000000000000030f

       5/2.1 (int 7)
              Layout 0x000000000000030f

       1+1 (int 8)
              Layout 0x0000000000000003

       2/1.0 (int 9)
              Layout 0x0000000000000403

       2/2.0 (int 10)
              Layout 0x0000000000000033

       3/3.1 (int 11)
              Layout 0x000000000000043f

       3/4.1 (int 12)
              Layout 0x000000000000033f

       11/11.2 (int 13)
              Layout 0x000000003ffe67cf

       5/2.1 (int 14)
              Layout 0x000000000006030f

       5/5.2 (int 15)
              Layout 0x000000000606630f

       5/4.1 (int 16)
              Layout 0x000000000036003f

       6/5.1 (int 17)
              Layout 0x00000000023e003f

       6/7.1 (int 18)
              Layout 0x00000600023e003f

       5/6.1 (int 19)
              Layout 0x000000000036630f

       7/6.1 (int 20)
              Layout 0x000000600036630f

EXAMPLES

       Basic and advanced examples are available at https://wiki.gpac.io/Filters

MORE

       Authors: GPAC developers, see git repo history (-log)
       For bug reports, feature requests, more information and source code, visit https://github.com/gpac/gpac
       build: 1.1.0-DEV-rev1777-gb91a8dad3-master
       Copyright: (c) 2000-2022 Telecom Paris distributed under LGPL v2.1+ - http://gpac.io

SEE ALSO

       gpac-filters(1), MP4Client(1), MP4Box(1)

gpac                                                  2019                                               gpac(1)