Sean McGovern: > Andreas: > > On Tue, Mar 12, 2024 at 8:53 PM Andreas Rheinhardt > <andreas.rheinha...@outlook.com> wrote: >> >> It is accessed via AV_RN64() in ff_simple_idct_put_int32_10bit(). >> Should fix the UBSan failures in the mpeg4-simple-studio-profile >> test here: >> https://fate.ffmpeg.org/report.cgi?time=20240312011016&slot=ppc-linux-gcc-13.2-ubsan-altivec-qemu >> >> Signed-off-by: Andreas Rheinhardt <andreas.rheinha...@outlook.com> >> --- >> libavcodec/mpeg4videodec.h | 3 ++- >> 1 file changed, 2 insertions(+), 1 deletion(-) >> >> diff --git a/libavcodec/mpeg4videodec.h b/libavcodec/mpeg4videodec.h >> index c0e6ec6592..4a26d18987 100644 >> --- a/libavcodec/mpeg4videodec.h >> +++ b/libavcodec/mpeg4videodec.h >> @@ -29,6 +29,7 @@ >> #include "mpegvideo.h" >> #include "mpeg4videodsp.h" >> >> +#include "libavutil/mem_internal.h" >> >> typedef struct Mpeg4DecContext { >> MpegEncContext m; >> @@ -83,7 +84,7 @@ typedef struct Mpeg4DecContext { >> >> Mpeg4VideoDSPContext mdsp; >> >> - int32_t block32[12][64]; >> + DECLARE_ALIGNED(8, int32_t, block32)[12][64]; >> // 0 = DCT, 1 = DPCM top to bottom scan, -1 = DPCM bottom to top scan >> int dpcm_direction; >> int16_t dpcm_macroblock[3][256]; >> -- >> 2.40.1 >> >> _______________________________________________ >> ffmpeg-devel mailing list >> ffmpeg-devel@ffmpeg.org >> https://ffmpeg.org/mailman/listinfo/ffmpeg-devel >> >> To unsubscribe, visit link above, or email >> ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe". > > Confirming that this fixes fate-mpeg4-simple-studio-profile on PowerPC > QEMU with GCC UBsan as noted. > > It was not failing on POWER7 (ppc64) or POWER9 (ppc64le). >
Not surprising: The Mpeg4VideoDSPContext immediately before block32 contains (function) pointers and therefore has alignment 8 on 64bit machines, so that block32 happens to be properly aligned already. - Andreas _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".
