[Ffmpeg-devel] problem with ASF encoding?

[Pascal Massimino]

  Hi everybody (long time! :))

  seems like asf-enc.c is currently generating WMVs unplayable with
  Windows Media Player (version 10.00.00.4036 here).

  for instance, with fresh svn from this morning, and using
  ftp://mplayerhq.hu/MPlayer/samples/FLV/zelda.flv as input (just a random
pick):

ffmpeg -i zelda.flv -acodec mp3 -vcodec msmpeg4 -f asf -vtag MP43 -b 512 -ab
64 -y zelda.wmv

Input #0, flv, from 'zelda.flv':
  Duration: 00:00:29.6, start: 0.000000, bitrate: N/A
  Stream #0.0: Video: flv, yuv420p, 160x120, 12.00 fps(r)
  Stream #0.1: Audio: adpcm_swf, 22050 Hz, mono
Output #0, asf, to 'zelda.wmv':
  Stream #0.0: Video: msmpeg4, yuv420p, 160x120, q=2-31, 200 kb/s, 12.00fps(c)
  Stream #0.1: Audio: mp3, 22050 Hz, mono, 64 kb/s
Stream mapping:
  Stream #0.0 -> #0.0
  Stream #0.1 -> #0.1
Press [q] to stop encoding
[msmpeg4 @ 0x85afb34]warning, clipping 1 dct coefficients to -127..127
[msmpeg4 @ 0x85afb34]warning, clipping 1 dct coefficients to -127..127
[msmpeg4 @ 0x85afb34]warning, clipping 1 dct coefficients to -127..127
[msmpeg4 @ 0x85afb34]warning, clipping 1 dct coefficients to -127..127
[msmpeg4 @ 0x85afb34]warning, clipping 1 dct coefficients to -127..127
[msmpeg4 @ 0x85afb34]warning, clipping 1 dct coefficients to -127..127s/s
frame=  358 fps=  0 q=2.0 Lsize=       1kB time=29.7 bitrate=   0.2kbits/s
video:541kB audio:232kB global headers:0kB muxing overhead -99.928603%

  WMP says "Windows Media Player cannot play the file because it is
corrupted."
  MPC cannot play it either ("Cannot render file"). Note that mplayer decode
this .wmv right.

   Now, it seems related to audio track, since changing to -acodec
pcm_s16le, for instance,
   generates correctly playable bitstreams.

   Rolling back the svn revisions a little, I've tracked the problem a
little to the /*ERROR correction*/ part, asf-enc.c:397
   If i remove all of the /*ERROR correction*/ part, set extra_size2 to 0
instead of 8, and put back put_guid(pb, &video_conceal_none)
   instead of &audio_conceal_spred, i get files playable with WMP and MPC.
These were changed around rev 7960.

   Don't know if it's the correct spot to dig further, though.

Skal