Hi all,
I'm using libavcodec and libavformat for h264 encoding and it seems that
I might have stumbled upon a bug in libavformat. I was hoping to get
your opinion about this.
It is illustrated by the gdb session below. the segmentation fault is
cause by the fact that "enc->extradata == 0x0" while
"enc->extradata_size = 35". It could potentially be fixed by adding an
extra check "&& (enc->extradata != NULL)" but I suspect that the bug
actually occurs at the place where extradata_size is set to 35 while
extradata receives a null-pointer. I could (and might) go looking for
this place, but I was hoping that someone here could give me some
"pointers" :).
Just in case, I apologize if I'm being stupid ;).
cheers,
Mart van de Sanden
--- Start gdb + some stdout log ---
[libx264 @ 0x9cee7940] frame I:1 Avg QP:28.48 size: 30386
[libx264 @ 0x9cee7940] frame P:67 Avg QP:40.20 size: 7642
[libx264 @ 0x9cee7940] mb I I16..4: 85.9% 0.0% 14.1%
[libx264 @ 0x9cee7940] mb P I16..4: 5.9% 0.0% 0.9% P16..4: 2.8%
0.3% 0.0% 0.0% 0.0% skip:89.9%
[libx264 @ 0x9cee7940] final ratefactor: 33.55
[libx264 @ 0x9cee7940] coded y,uvDC,uvAC intra: 33.2% 42.8% 29.7% inter:
1.1% 1.4% 0.4%
[libx264 @ 0x9cee7940] i16 v,h,dc,p: 41% 26% 20% 14%
[libx264 @ 0x9cee7940] i4 v,h,dc,ddl,ddr,vr,hd,vl,hu: 24% 32% 26% 2%
3% 2% 4% 2% 5%
[libx264 @ 0x9cee7940] i8c dc,h,v,p: 59% 21% 13% 6%
[libx264 @ 0x9cee7940] Weighted P-Frames: Y:6.0% UV:3.0%
[libx264 @ 0x9cee7940] kb/s:957.12
Program received signal SIGSEGV, Segmentation fault.
0x029f9ce8 in flv_write_packet (s=0x7f7f3da0, pkt=0xbffff038) at
libavformat/flvenc.c:401
401 if (enc->extradata_size > 0 && *(uint8_t*)enc->extradata
!= 1) {
(gdb) bt
#0 0x029f9ce8 in flv_write_packet (s=0x7f7f3da0, pkt=0xbffff038) at
libavformat/flvenc.c:401
#1 0x02a7e71f in av_write_trailer (s=0x7f7f3da0) at
libavformat/utils.c:3188
... (Deleted a few lines)
#18 0x08050ce7 in main (argc=1, argv=0xbffff404) at
/home/mart/Projects/yb/test_framework2.cc:34
(gdb) select 0
(gdb) print enc->extradata_size
$1 = 35
(gdb) print enc->extradata
$2 = (uint8_t *) 0x0
(gdb)
--- End log ---
--
Mart van de Sanden | yellowBird
yellowBird - See the world like never before
Brugstraat 32 / 9711 HZ Groningen / The Netherlands
M. (Mart) van de Sanden / Software Specialist
T +31 50 8222 822
F +31 50 8501 351
E [email protected]
W http://www.yb.nl
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