Hi all So after looking at options for how to better deal with ID3v2 I'm leaning towards creating a demuxer for it. I'm writing this before going any further with it to get some feedback
A proper demuxer would change things up especially for mp3, since a lot of files that now probe as "mp3" with an mp3 stream and possibly an mjpeg stream for cover art, would then probe as "id3v2" with the same kinds of streams The way my current unfinished prototype works is inspired by concatdec. It uses a subdemuxer to probe the file, starting after the ID3v2 header. Codecprops are then copied to the id3v2's AVStream for the audio A bit more work is necessary to deal with non-seekable files but it doesn't look insurmountable I may reorder the streams, so the cover art comes first, because it comes first in the file and the audio codec can't be had until after probing, at which point it would be too late to seek back. It could be possible to create two streams in anticipation of there being cover art but this is a bit of a pain Non-seekable support also means holding the cover art in RAM for a while. This probably isn't a big deal, but it can mean allocating up to 256 MiB. More realistically far less for most files. If discard could be set before read_header() it would be possible to skip the cover art entirely. Maybe we can add an option if users are really strapped for RAM, but I doubt they are Oh and finally I'm thinking of outputting the cover art once and only once, regardless of seeks. That way it doesn't have to be kept around in RAM /Tomas _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".
