[vlc-devel] commit: contrib: turn off Thumb ISA for libavcodec and libmad ( Rémi Denis-Courmont )

Rémi Denis-Courmont remi at remlab.net
Wed Sep 2 20:13:20 CEST 2009

Le mardi 1 septembre 2009 23:40:23 Måns Rullgård, vous avez écrit :
> > I just started decoding MPEG4 Part 2 (in MKV with AAC) or Part 10
> > (in AVI with MP3). Disabling video decoding worked around it. VLC
> > did not use FFMPEG for MKV, AVI, AAC nor MP3. It fails immediately,
> > as far as I can tell.
> Compiler flags as below?

Yes. I just retried with the entire stack (VLC+contribs)
-mtune=cortex-a8 -mcpu=cortex-a8 -march=arvm7-a -mfpu=neon
-O3 -fno-tree-vectorize

and I get the exact same result.

> Can you get a core dump?
> Where does it crash?

Program received signal SIGSEGV, Segmentation fault.
[Switching to Thread 0x4159d490 (LWP 2571)]
0x4285bfcc in ff_simple_idct_put_neon ()
   from /opt/VideoLAN/lib/vlc/codec/libavcodec_plugin.so
0x4285bfcc <ff_simple_idct_put_neon+24>:        vld1.64 {d0-d1}, [r3, :128]
(gdb) bt
#0  0x4285bfcc in ff_simple_idct_put_neon ()
   from /opt/VideoLAN/lib/vlc/codec/libavcodec_plugin.so
#1  0x00000000 in ?? ()

(I guess VLC contribs strips ffmpeg debug symbols).

> Can you decode the file with a standalone FFmpeg build?


Rémi Denis-Courmont

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