[XviD-devel] Public release of the xvid vbr lib.

[Edouard Gomez]

Additional note for transcode testers (xvidcvs) :

The 2 pass mode options have changed.

During the  first pass,  the module uses  a constant  quant=2 whatever
bitrate you  pass to transcode in  command line. As a  quant=2 means a
very big encoded stream, i decided  to discard the first pass data. So
don't be afraid  if the resulting avi has just sound  and if its video
stream it totally broken.

During the 2nd pass, you can tell to the vbr code how big you want the
video  stream to be  with teh  video bitrate  option (-w).   The video
stream length  must be given  in Mo.  The  vbr code takes care  of AVI
overhead  so the  video size  you give  him will  be  respected. Don't
forget that there's  also the sound track, the  vbr code controls only
the  video  length part  not  the audio.  So  compute  the video  size
according to the audio bitrate used and movie length.

eg :

1st pass :
transcode -i somefile.vob -o dummy.avi -y xvidcvs -Q 0 -R 1

2nd pass (with a 100M byte target size for *video part*) :
transcode -i somefile.vob -o dummy.avi -y xvidcvs -Q 0 -R 2 -w 100

Other modes have not changed (fixed quant and cbr)

Final Note :

You have to use a BFrame  build of XviD or comment the #define BFRAMES
in the xvidcvs module. Don't  forget to configure the transcode source
after applying the patch... else it will not compile.

Final Final note :

The module looks  for a xvid.cfg file in the  working directory. So if
you  want to specify  the flags,  create this  file into  the encoding
directory. There's a file sample in the posted vbr lib.

-- 
Edouard Gomez                             <vbr lib - still no bugs ?!>