+ # FFmpegMetadataPP should be run after FFmpegVideoConvertorPP and
+ # FFmpegExtractAudioPP as containers before conversion may not support
+ # metadata (3gp, webm, etc.)
+ # And this post-processor should be placed before other metadata
+ # manipulating post-processors (FFmpegEmbedSubtitle) to prevent loss of
+ # extra metadata. By default ffmpeg preserves metadata applicable for both
+ # source and target containers. From this point the container won't change,
+ # so metadata can be added here.
+ if opts.addmetadata:
+ postprocessors.append({'key': 'FFmpegMetadata'})