[FFmpeg-devel] PTS for H.264 in MPEG-TS: should be delayed?
nicolas.george at normalesup.org
Tue Aug 21 17:33:29 CEST 2012
I am trying to analyze the files in this:
When reading the MPEG-TS files pointed by it, lavf gives a lot of warnings:
[mpegts @ 0x1b743c0] Invalid timestamps stream=1, pts=903000, dts=906000, size=709
If I dump things straight from the file, I get:
st=1 dts=900000 pts=900000 (P?)
st=1 dts=903000 pts=906000 (I?)
st=1 dts=906000 pts=903000 (B?)
st=1 dts=909000 pts=912000 (I?)
st=1 dts=912000 pts=909000 (B?)
st=1 dts=915000 pts=918000 (I?)
st=1 dts=918000 pts=915000 (B?)
st=1 dts=921000 pts=924000 (I?)
st=1 dts=924000 pts=921000 (B?)
(I added the frame type by hand, by matching with the decoded frames and
Obviously, the PTS are wrong, since for B-frames there is PTS < DTS.
If I were to add one frame delay to all PTS values, then everything becomes
valid and logic. Are these files invalid, or is the MPEG-TS demuxer
forgetting to add the delay to the PTS value?
Note: when the decoder is inited, it has delay=4 and ticks_per_frame=2.
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Size: 198 bytes
Desc: Digital signature
More information about the ffmpeg-devel