[MPlayer-dev-eng] [RFC] rc2

Matthias Hopf mat at mshopf.de
Thu Apr 12 00:19:45 CEST 2007


On Apr 11, 07 20:25:07 +0200, Matthias Hopf wrote:
> > >- MPEG2 TS: DTS in private stream not detected (+)
> > I didn't update the demuxer recently, either this lack is older
> > than today or ... sample needed

I just uploaded it to upload.mplayerhq.hu/MPlayer/incoming/mpeg2_dts.ts

Now what happens with current SVN mplayer is:

- Without [-ac *] the demuxer assumes ac3 data, and uses a52 for
- Same with [-ac ffdts] and [-ac ffdca]
- With [-ac +ffdts] and [-ac +ffdca] we get sound, quite different, but
  I assume due to channel downmixing in dca. AFAICS dca implements
  *only* stereo downmixing ATM.

What happens with current SVN mencoder is:
(General options: mencoder -vf scale=320:240 -ovc xvid -xvidencopts
fixed_quant=3 -o /var/tmp/tst.avi mpeg2_dts.ts)

- With [-demuxer lavf] mencoder segfaults (both with [-oac copy] and
  [-oac mp3lame -ac +ffdca])
- With default demuxer [-demuxer mpegts -oac copy] mencoder duplicates
  about 1 frame every 10 frames, and the resulting avi has strange and
  partially broken audio, that can only be played with [-ac +ffdts], but
  not with [-ac +ffdca], and not without option.
- With [-demuxer mpegts -oac mp3lame] we get an empty file (no sound, no
- With [-demuxer mpegts -oac mp3lame -ac +ffdts] mencoder duplicates
  about 1 frame every 10 frames, and audio is completely broken
  (probably due to channel numbers)
- With [-demuxer mpegts -oac mp3lame -ac +ffdca] it works pretty well.

So AFAICS we have the following issues:

- DTS isn't detected correctly in this file
- libavformat demuxer segfaults for this file
- ffmpeg dts decoder delivers 5.1 channels, but mp3 encoders only
  allow for 2, and this is neither corrected nor detected
- native demuxer with -oac copy doesn't get PTS values right (or
  something else messes up A/V sync)
- same for native demuxer with ffdts decoder
- ffdca decoder works fine, but might need a little bit more advertising
  (well, I didn't know about it until Reimar pushed me to it)

Maybe DTS detection and libavformat segfaults are blockers, but not the

> > >- lavf TS demuxer fails for some streams (+)
> > >- lavf TS demuxer segfaults for some streams w/ DTS (+)
> > >- DTS decoder doesn't work correctly for mencoder at all (*) (+)
> > 
> > probably learn to use -tsprobe

Just to make sure I tried -lavfdopts probesize=10000000 (the file has a
size of 10MB, so it certainly has less than 10m pakets) - no change.

Hope I didn't forget anything. In any case, just ask.



Matthias Hopf <mhopf at suse.de>      __        __   __
Maxfeldstr. 5 / 90409 Nuernberg   (_   | |  (_   |__          mat at mshopf.de
Phone +49-911-74053-715           __)  |_|  __)  |__  R & D   www.mshopf.de

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