[FFmpeg-devel] [Spam] Re: [Spam] Re: ffmpeg's alignment troubles

Gonzalo Garramuño ggarra
Thu Jan 3 08:54:35 CET 2008

Uoti Urpala wrote:
> On Thu, 2008-01-03 at 04:21 -0300, Gonzalo Garramu?o wrote:
>> It is, but only as technology preview.  It works better, but still no cigar:
>> $ main_gcc4.exe
>> align5 not aligned 00404038
> That's a function-static variable. Does FFmpeg need aligned variables
> like that anywhere? At least a grep for "static DECLARE_ALIGNED" only
> shows matches starting at the first column (almost certainly not inside
> a function).
> I'm not sure why being inside a function would make a difference though.
> On Linux it does seem to work correctly in that case too.

It doesn't.  Problem shows for normal static variables.  ffmpeg uses 
them here:

libavcodec/i386/dsputil_mmx.c:static DECLARE_ALIGNED_8(const unsigned 
char, vector128[8]) =
libavcodec/i386/vp3dsp_sse2.c:static DECLARE_ALIGNED_16(const unsigned 
short, SSE2_dequant_const[]) =
libavcodec/i386/vp3dsp_sse2.c:static DECLARE_ALIGNED_16(const unsigned 
int, eight_data[]) =
libavcodec/i386/vp3dsp_sse2.c:static DECLARE_ALIGNED_16(const unsigned 
short, SSE2_idct_data[7 * 8]) =
libavcodec/atrac3.c:static DECLARE_ALIGNED_16(float,mdct_window[512]);
libavcodec/mpegaudiodec.c:static DECLARE_ALIGNED_16(MPA_INT, window[512]);
libavcodec/mpc.c:static DECLARE_ALIGNED_16(MPA_INT, mpa_window[512]);
libavcodec/qdm2.c:static DECLARE_ALIGNED_16(MPA_INT, mpa_window[512]);
libpostproc/postprocess.c:static DECLARE_ALIGNED(8, uint64_t 
attribute_used, w05)= 0x0005000500050005LL;

Gonzalo Garramu?o
ggarra at advancedsl.com.ar

AMD4400 - ASUS48N-E
Xubuntu Gutsy

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