[Ffmpeg-devel] problem with ASF encoding?

[Pascal Massimino]

  Hi Michael, all,

On 3/19/07, Michael Niedermayer <michaelni at gmx.at> wrote:
>
> Hi
>
> On Mon, Mar 19, 2007 at 09:13:00AM -0700, Pascal Massimino wrote:
> >  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.
>
> well sadly the new code is correct and the old is not for wma audio at
> least,
> i dont have any M$ generated mp3 in asf files to check ...
> also the old code doesnt work correctly with many other players (like wmp
> on
> mac or embeded players)
> all tips to improve the asf muxer are welcome ...



   an update: i overlooked the fact that -b and -ab are now expressed in
  bits/sec. Hence the bitrate settings were insanely low. Now, using some
  more reasonable values (-b 200000 -ab 64000, say), i get valid mp3-in-wmv
bitstreams.
  Might be just hidding the bug. Or maybe ASF muxing is broken for extremely
  small packets (multi_payload case, maybe??)

Skal


[...]
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>
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