On Fri, Feb 7, 2025 at 5:18 PM Marth64 <mart...@proxyid.net> wrote: > (libavcodec’s definition of AV_CODEC_ID_EIA_608 is a fallacy, it is > actually A/53 Part 4 coding that is passed around with this codec ID, > which can contain multiple sub-streams including EIA-608 and CEA-708)
I probably wouldn't call it a "fallacy". I would say it's highly inconsistent. In some cases it contains 608 with both pairs, in some cases with only one pair, in some cases it contains both 608 and 708. Whether it works properly in all those cases varies wildly depending on which muxer and demuxers are involved (there are lots of cases where the 708 gets stripped out unnecessarily, or the format only assumes 608 will ever be present and thus improperly handles the 708 data). It is a huge mess. I suspect to get things into more reasonable shape would require a set of test vectors that exercise all the different combinations of muxer/demuxer/encoder/decoders that support captions. Devin -- Devin Heitmueller, Senior Software Engineer LTN Global Communications o: +1 (301) 363-1001 w: https://ltnglobal.com e: devin.heitmuel...@ltnglobal.com _______________________________________________ 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".
