I was looking into 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). _______________________________________________ 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".