NAME

Media::Convert::Asset::ProfileFactory - Create an output profile from an input video.

SYNOPSIS

    use Media::Convert::Asset;
    use Media::Convert::Pipe;
    use Media::Convert::Asset::ProfileFactory;

    package Media::Convert::Asset::Profile::myprofile;
    use Moose;
    extends Media::Convert::Asset::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 = Media::Convert::Asset->new(url => "foo.mp4");
    my $profile = Media::Convert::Asset::ProfileFactory->create("myprofile", $input);
    my $output = Media::Convert::Asset->new(url => "foo." . $profile->exten, reference => $profile);
    Media::Convert::Pipe->new(inputs => [$input], output => $output)->run();

    # Or using an ad-hoc profile:
    $profile = Media::Convert::Asset::ProfileFactory->create("extraprofile", $input,
    	{
		extraprofile => {
			parent => "webm",
			settings => { audio_codec => "vorbis", quality => 10 },
		}
	});
    # After this, using the profile happens exactly the same way.

DESCRIPTION

Media::Convert::Asset::Profile::Base is a subclass of Media::Convert::Asset, 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 Media::Convert::Asset::ProfileFactory's create method is a simple helper to:

• ensure that the relevant Media::Convert::Asset::Profile::profile module has been loaded (the module for the parent attribute of the ad-hoc profile, if one is chosen)

• create a Media::Convert::Asset subclass of the right type, with reference set to the passed input Media::Convert::Asset object.

• if an ad-hoc profile was selected, ensure that the relevant attributes of the resulting object are set to the values in the settings key of the ad-hoc profile's settings

CREATING NEW PROFILES

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

Alternatively, one can create new profiles in the ad-hoc manner. This is easier, since it only requires an extra parameter be passed to the create function; 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 Media::Convert::Asset::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.

Note that future versions of this class may switch to subclassing from the AV1 profile rather than the VP9 profile, although this will not happen before AV1 encoding can be done at reasonable speeds by Media::Convert.

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 4.

SEE ALSO

Media::Convert::Asset, Media::Convert::Profile::mp4, Media::Convert::Profile::mpeg2, Media::Convert::Profile::copy