SIGSEGV when trying to play Windows Media Video 8 (not supported) with build from trunk of 20060829

[Franz]

When I try to play a WMV file with non supported format

example:

video2.exe mms://213.254.239.51/tagesschau/msmedia/2006/0828/TV-20060828-2305-1701.wm.hi.wmv

(well not supported after the last changes in trunk) I get:

... Found video codec: Windows Media Video 8 (not supported) ... Video thread started detected 1 audio stream A: 2.971 V: 3.343 A-V: -0.37 fps: 25.00 ft: 0 ms, cpu: OK Killed by SIGSEGV pid=0x004a ppid=0x0043 tid=0x0007 slot=0x0090 pri=0x0300 mc=0x0001 O:\APPS\WVOWNOG\VIDEO2.EXE VIDEO2 0:00266afe cs:eip=005b:00276afe ss:esp=0053:05875d1c ebp=05875d34

ds=0053 es=0053 fs=150b gs=0000 efl=00012246

eax=00003fe0 ebx=008cad90 ecx=05879e4c edx=008cad90 edi=05875dfc esi=00001000 Process dumping was disabled, use DUMPPROC / PROCDUMP to enable it.

(wvgui101 has no problems with this sort of file/stream)

[vladest]

works here

[Franz]

tried a complete rebuild but still same problem here.

What does 'works here' mean?

(a) doesn't crash

or

(b) the mms://... stream with 'Windows Media Video 8' is displayed ?

[vladest]

both i.e. I've played that german news sucessfully

[Franz]

I don't really know how to debug this, but tried anyway...

The last things I see with vac365-debugger (I don't have 3.08 debugger) is

• line 1968 of play.hpp (the end of the _begin_play() function)

• then a disassembly of libc61.dll thread:5

0x16f6e919 call 160265f4h if I press Over or Into I get the SIGSEV

• the very last thing I see after WVGUI has died is

• disassembly libc061:dll Thread:7

0x1F638DC INT 3

I hope this info is useful for solving the problem.

Franz

[Franz]

Call Stack in Debugger after SIGSEGV

[Franz]

Found the culprit (or at least a workaround):

If I downgrade dsputil_mmx.c to changeset 181 and add

static const uint64_t ff_pb_1 attribute_used attribute ((aligned(8))) = 0x0101010101010101ULL;

static const uint64_t ff_pb_3 attribute_used attribute ((aligned(8))) = 0x0303030303030303ULL;

static const uint64_t ff_pb_7 attribute_used attribute ((aligned(8))) = 0x0707070707070707ULL;

and recompile the SIGSEGV is gone and I can watch the news :-)

Franz

[Franz]

Other probably better solution (workaround) is to remove ( comment out ) lines 2935 to 2952 in the current version of libavcodec\i386\dsputil_mmx.c

The inline-assembler version of ff_vector_fmul_add_add_c() is the reason for the SIGSEGV.

Now it's up to you Vlad ;-)

[vladest]

what CPU you have? On my amd64 all works ok

[vladest]

and did you tried -nosse option?

[Franz]

I have a IBM T23 notebook with a mobile 1,13GHz PIII CPU

and no I did not try -nosse, but I'm quite shure this would work.

[vladest]

patched cpu checking for nosse option to make it wvgui wide run video2.exe -nosse this should works looks like some troubles with sse code need to check if its align or just bug in code

[Franz]

I can confirm that the patch works.

Thanks

[Franz]

seems to me that

DECLARE_ALIGNED_16(float, window[BLOCK_MAX_SIZE * 2]);

DECLARE_ALIGNED_16(FFTSample, output[BLOCK_MAX_SIZE * 2]);

don't work as designed.

Hexadecimal representation of 'window' and 'output' in debugger end with 'C' and not with '0'

[vladest]

you right I've moved those declares out of function and all works now I.e. aligned() doesnt works for stack variables

[vladest]

can you confirm this?

[Franz]

confirmed :-)

Tnx

[vladest]

Workaround works