I apologize if this is a repeat of something discussed elsewhere in this forum but I haven't been able to find solution through Google.
I'm having trouble transcoding from H264 sources in VLC version in the 0.9.* and 1.0 brances. It seems that the source is not decoded correctly, which means that every clip starts in gray and videos is played in shadowy quality for the the first 10 seconds of every clip. After the tenth second the quality is perfectly acceptable. This obviously leads me to believe that the first keyframe in the file is not detected correctly by the decoder.
Oddly, however, transcoding with VLC 0.8.6i (and earlier) works perfectly well!
The original (using H264, prepared and cropped to 25 seconds with MPEG Streamclip):
http://www.refresh.dk/vlcbug/original.mp4
These version are converted with different versions of VLC:
Transcoded using 0.8.6i (perfect): http://www.refresh.dk/vlcbug/vlc-0.8.6i.h264
Transcoded using 0.9.8a (buggy): http://www.refresh.dk/vlcbug/vlc-0.9.8a.h264
Transcoded using 1.0.0 from git (buggy): http://www.refresh.dk/vlcbug/vlc-1.0.0-git20090122.h264
- All conversions for sample files are done with this command on Debian:
Code: Select all
vlc -I dummy -V dummy original.mp4 :sout="#transcode{vcodec=xvid,vb=1000,width=640,height=360,acodec=null}:standard{access=file,mux=raw,dst=out.h264}" vlc://quit- The same behaviour occurs with recent nighlies of ffmpeg and libx264; although I couldn't perfect a test with 0.8.6i since it doesn't compile with x264 after Sep 14th 2009)
- The exact same behaviour is reproducable using the transcoding wizard on Mac OS X with the respective versions: 0.8.6i looks good, 0.9* and 1.0* doesn't.
- In this case I've used H264 as output format, but the same behavious occurs with other output codecs -- leading me to believe the problem lies with the decoder.
- Encoding non-H264 sources to H264 is not a problem.
Does anyone know what I'm doing wrong? Or if VLC is the evil-doer?