[FFmpeg-devel] build failure on osx 10.5.8 ppc

Pavel Koshevoy pkoshevoy at gmail.com
Mon Oct 8 01:44:47 CEST 2012

On 10/7/12 4:06 PM, Michael Niedermayer wrote:
> On Sun, Oct 07, 2012 at 03:11:05PM -0600, Pavel Koshevoy wrote:
> I added a NULL pointer de-reference and it didn't crash, so that
> tells me I am not exercising that code path.
> Any other suggestions, or should we give up on the benchmark?  I
> need to go clean the house and then work on a patch for fontconfig
> :)
> compress a mp3 of your choice to .m4a with ffmpeg and then
> try to decompress it, it should excercise the code
> or take aac/al04_44.mp4 from the fate suite as a random samplle that
> should use the code

I rebuilt ffmpeg as follows:
/nfs/scratch/Developer/ffmpeg-git-src/configure --prefix=/Developer/ppc 
--enable-swscale --enable-avfilter --enable-libmp3lame 
--enable-libvorbis --enable-libopus --enable-libtheora 
--enable-libschroedinger --enable-libopenjpeg --enable-libmodplug 
--enable-libvpx --enable-libspeex --enable-shared --enable-pthreads 
--enable-gpl --enable-version3 --enable-libopencore-amrnb 
--enable-libopencore-amrwb --enable-postproc --enable-libx264 
--enable-libxvid --enable-runtime-cpudetect 
--extra-ldflags='-headerpad_max_install_names -L/opt/local/lib' 
--disable-stripping --enable-debug=3 --disable-optimizations

I loaded ffmpeg_g into gdb in emacs and set a breakpoint in 
float_to_int16_stride_altivec.  I converted an mp3 to an m4a (had to add 
-strict -2 to ffmpeg options, and it was really slow).  I then converted 
the output m4a back to mp3 -- the breakpoint (and the NULL pointer 
de-reference were never hit).  I tried with aac/al04_44.mp4 from fate 
suite and that didn't hit float_to_int16_stride_altivec either.  Looking 
at the code, float_to_int16_stride_altivec is only called from 
float_to_int16_interleave_altivec if number of channels is greater than 2.

I also tried converting the 5.1 ch WMV file to flac again, and that 
didn't enter this function either.  ffprobe says that WMV file has flt 
samples, so it would seem to be a perfect candidate for this test.

BTW, Is there a way to turn off ANSI colors on ffmpegs pretty-printed 
output?  It's really annoying in emacs gdb mode (it doesn't interpret 
the color codes, just spams the buffer with them).


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