NAME

       SReview::Video::ProfileFactory - Create an output profile from an input video.

SYNOPSIS

           use SReview::Video;
           use SReview::Videopipe;
           use SReview::Video::ProfileFactory;

           package SReview::Video::Profile::myprofile;
           use Moose;
           extends SReview::Video::Profile::webm;

           has '+audio_samplerate' => (
               builder => '_probe_my_audiorate',
           );

           has '+audio_codec' => (
               default => 'vorbis',
           );

           sub _probe_exten {
               return 'my.webm',
           }

           sub _probe_my_audiorate {
               my $self = shift;
               return $self->reference->audio_samplerate / 2;
           }

           no Moose;

           package main;

           my $input = SReview::Video->new(url => "foo.mp4");
           my $profile = SReview::Video::ProfileFactory->create("myprofile", $input);
           my $output = SReview::Video->new(url => "foo." . $profile->exten, reference => $profile);
           SReview::Videopipe->new(inputs => [$input], output => $output)->run();

DESCRIPTION

       "SReview::Video::Profile::Base" is a subclass of SReview::Video, but with a number of the probing methods
       overridden so that they return values that are not in line with the reference of the given video.

       The "SReview::Video::ProfileFactory"'s "create" method is a simple helper to:

       •   ensure that the relevant "SReview::Video::Profile::profile" module has been loaded

       •   create  an  "SReview::Video"  subclass  of  the  right  type,  with reference set to the passed input
           "SReview::Video" object.

CREATING NEW PROFILES

       It is possible to create a new profile by extending an existing one. The "myprofile" profile in the above
       example shows how to do so. Any property that is known by SReview::Video can be overridden in the  manner
       given.

       To  create  a  new  profile,  one  can  use the "extra_profiles" configuration setting; however, profiles
       created in this manner can only hardcode values, and cannot vary any parameters based on the input  file.
       To  create  a  profile  that  can  do so, when the new profile just changes a minor detail of an existing
       profile, extend that profile and change the detail which you want to change. To create a new profile from
       scratch, extend the "Base" profile (see below).

PRE-EXISTING PROFILES

       The following profiles are defined by "SReview::Video::ProfileFactory":

   Base
       This profile serves as a base class for the other profiles. It should not be used directly.

       It adds the extension, and defaults the pixel format to yuv420p.

   vp9
       Produces a video in WebM/VP9  format,  using  the  quality/bitrate  settings  recommended  by  Google  on
       <https://developers.google.com/media/vp9/>,  and  with  OPUS  audio.  Produces  files with the "vp9.webm"
       extension.

       Audio settings are hardcoded to 48KHz sampling rate, 128k bits per second.

   vp8
       Produces a video in WebM/VP8 format. Since no similar recommendations for VP8 exist as  do  for  VP9,  no
       explicit  quality or bitrate settings are configured in this profile. The libvpx video codec is selected,
       and the libvorbis one for audio.

       The audio bitrate is explicitly left to ffmpeg defaults; the extension is set to "vp8.webm"

   webm
       This profile subclasses from the "vp9" profile, and only changes the extension to plain "webm" instead of
       "vp9.webm".

       Additionally, if a future version of WebM is ever defined, then  when  SReview  gains  support  for  that
       version of WebM, this class will become a subclass of that class instead.

   vp8_lq
       This  profile  subclasses  from  the "vp8" profile. The extension is set to "lq.webm". In addition to the
       changes made by the "vp8" profile, this profile also rescales the video to a fraction  of  the  original;
       that is, the height and width of the video are both divided by 8.

SEE ALSO

       SReview::Video

perl v5.32.1                                       2021-09-09                SReview::Video::ProfileFactory(3pm)