On Thu, Feb 1, 2024 at 5:45 PM Andrew Randrianasulu <randrianas...@gmail.com> wrote:
> I was looking into https://trac.ffmpeg.org/ticket/1258#comment:12 > (mpeg2 <https://trac.ffmpeg.org/ticket/1258#comment:12(mpeg2> > multichannel audio in HDV) and reading documents linked in > this ticket. > > I still have very vague understanding on where ffmpeg audio (PES?) > headers read by ffmpeg > > somewhere in ffmpeg/libavformat/mpeg.c ? > > According to this picture https://ericdevos.be/kask/2BA/2BA > videoformaten/MPEG-2 description.htm > > Figure 2 -- Structure of an MPEG-2 Audio block of data > > multichannel extension can be carried (partially!) in IEC 11172-3 > layer II frame. You just need to search in very beginning of ancillary > data for Multichannel header. > > Extension stream, touched in more details in "An Implementation of the > MPEG—2 Audio Decoding Specification by Chad Mikkelson" (p. 38) sounds a > bit more mysterious to me: mc-capable encoder from dist10 [1] output > extension stream as separate file only their decoder can read. I > wonder how it must be interleaved in real system mpeg stream? And how > it may work in transport stream (as used in HDV) ? > > [1] - https://github.com/Randrianasulu/iso-dist10 (hopefully read > sox-generated uncompressed multichannel 16 bit AIFF correctly). > I wish to reply, but I'm neither FFmpeg developer any more and also consultation costs money and time. > _______________________________________________ > ffmpeg-user mailing list > ffmpeg-user@ffmpeg.org > https://ffmpeg.org/mailman/listinfo/ffmpeg-user > > To unsubscribe, visit link above, or email > ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe". > _______________________________________________ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".