From: Thorsten Jordan To: FFmpeg development discussions and patches Reply-To: FFmpeg development discussions and patches Subject: [FFmpeg-devel] Bugreport: mpegts-demuxer gives wrong pts/dts with avchd files Date: Thu, 14 Feb 2008 10:32:40 +0100 Sender: ffmpeg-devel-bounces@mplayerhq.hu User-Agent: Mozilla-Thunderbird 2.0.0.4 (X11/20070828) Hello, i just stumbled over misbehvaiour of the mpegts-demuxer of ffmpeg. I have some avchd files here (.mts) which are just transport stream files with 4 extra bytes before each packet. Video format is h.264 with PAFF coding. Plays nice with some sync issues, caused by wrong timestamps. The problem is that normally h.264 in TS has one timestamp per access unit or per frame/field. "normally" means DVB sources. Some TV stations code the same timestamp for both fields of a frame, others code + 1/2 frame duration. But for avchd only every second field, the top field of each frame, has a timestamp. The material has AUDs per field, the timestamps are right before the AUDs, all ok. However the mpegts demuxer delivers wrong values here, non-monotonous DTS! In contrast it works ok with DVB/Paff material where each field has pts. As example some field sizes and pts/dts values how its stored and how the demuxer reports it field length pts 186221 54171 40974 -- 5353 46971 11050 -- 24266 50571 17645 -- 26668 64971 34917 -- and what libavformat reports field length pts dts 186221 54171 43371 40974 46971 46971 5353 50571 50571 11050 54171 54171 24266 50571 50571 17645 54171 54171 26668 64971 54171 34917 57771 57771 frame duration is 3600 (PAL) it seems DTS is increased for every field by 3600, and sometimes reset to values coded in the stream. Obviously it is non monotonous. Is there any interest in this? example file? Who maintains the mpegts demuxer? -- Greetings, Thorsten _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@mplayerhq.hu https://lists.mplayerhq.hu/mailman/listinfo/ffmpeg-devel