[Ffmpeg-devel] WMV3 segfault

[Michel Bardiaux]

ffmpeg_g -i PLU_050227_060009_q2.wmv -b 600 -acodec mp2 -ab 32 -cgop 
-sgop -g 12 -bt 60 -sc_threshold 1000000000 -y ip.mpg
ffmpeg version 0.4.9-pre1, build 4756, Copyright (c) 2000-2004 Fabrice 
Bellard
   configuration:  --disable-strip --enable-static --disable-shared 
--disable-opts
   built on Jun  6 2005 12:10:14, gcc: 2.95.4 20011002 (Debian prerelease)
[wmv3 @ 0x82bdf2c]Profile 1:
frmrtq_postproc=6, bitrtq_postproc=8
LoopFilter=1, MultiRes=0, FastUVMV=0, Extended MV=0
Rangered=0, VSTransform=1, Overlap=1, SyncMarker=0
DQuant=1, Quantizer mode=0, Max B frames=0

Seems that stream 1 comes from film source: 1000.00 (1000/1) -> 25.00 (25/1)
Input #0, asf, from 'PLU_050227_060009_q2.wmv':
   Duration: 23:59:40.5, start: 5.000000, bitrate: 594 kb/s
   Stream #0.0: Audio: wmav2, 48000 Hz, stereo, 64 kb/s
   Stream #0.1: Video: wmv3, yuv420p, 384x288, 1000.00 fps
Output #0, mpeg, to 'ip.mpg':
   Stream #0.0: Video: mpeg1video, yuv420p, 384x288, 25.00 fps, q=2-31, 
600 kb/s
   Stream #0.1: Audio: mp2, 48000 Hz, stereo, 32 kb/s
Stream mapping:
   Stream #0.1 -> #0.0
   Stream #0.0 -> #0.1
[wmv3 @ 0x82bdf2c]Profile 1:
frmrtq_postproc=6, bitrtq_postproc=8
LoopFilter=1, MultiRes=0, FastUVMV=0, Extended MV=0
Rangered=0, VSTransform=1, Overlap=1, SyncMarker=0
DQuant=1, Quantizer mode=0, Max B frames=0
Press [q] to stop encoding
[wmv3 @ 0x82bdf2c]concealing 432 DC, 432 AC, 432 MV errors
Segmentation fault (core dumped)

gdb backtrace:

#0  0x082028af in vc9_decode_p_mb (v=0x848aff0, block=0x84bde90) at 
vc9.c:2069
#1  0x08203a06 in standard_decode_mbs (v=0x848aff0) at vc9.c:2294
#2  0x082040ef in vc9_decode_frame (avctx=0x8329598, data=0xbfffea38, 
data_size=0xbfffeaf8, buf=0x832d650 "c?", buf_size=7361) at vc9.c:2597
#3  0x080b4a65 in avcodec_decode_video (avctx=0x8329598, 
picture=0xbfffea38, got_picture_ptr=0xbfffeaf8, buf=0x832d650 "c?", 
buf_size=7361) at utils.c:623
#4  0x0805712f in output_packet (ist=0x8342440, ist_index=1, 
ost_table=0x8375550, nb_ostreams=2, pkt=0xbfffeb9c) at ffmpeg.c:1254
#5  0x08059a42 in av_encode (output_files=0x82c5280, nb_output_files=1, 
input_files=0x82c5180, nb_input_files=1, stream_maps=0x82c52e0, 
nb_stream_maps=0)
     at ffmpeg.c:2083
#6  0x0805ead0 in main (argc=19, argv=0xbffff0a4) at ffmpeg.c:4480

(Note that if configured without disable-opts, the backtrace is nonsense 
because of the inlining of get_vlc2).

Reason for crash is that v->cbpcy_vlc is NULL.

I have no clue how to fix this since I am wholly unfamiliar with that 
codec. I dont even understand why decoding a wmv3 ends up in the vc9 codec!

TIA for any fix...
-- 
Michel Bardiaux
Peaktime Belgium S.A.  Bd. du Souverain, 191  B-1160 Bruxelles
Tel : +32 2 790.29.41