Hi, 2011/7/10 Måns Rullgård <[email protected]>: > "Ronald S. Bultje" <[email protected]> writes: > >> From: Anton Mitrofanov <[email protected]> >> >> ptrdiff_t can be 4 bytes, which leads to the next element being 4-byte >> aligned and thus at a different offset than intended. Forcing 8-byte >> alignment forces equal offset of dither16/32 on x86-32 and x86-64. >> >> Signed-off-by: Ronald S. Bultje <[email protected]> >> --- >> libswscale/swscale_internal.h | 4 ++-- >> 1 files changed, 2 insertions(+), 2 deletions(-) >> >> diff --git a/libswscale/swscale_internal.h b/libswscale/swscale_internal.h >> index b602541..a6d4a2f 100644 >> --- a/libswscale/swscale_internal.h >> +++ b/libswscale/swscale_internal.h >> @@ -347,8 +347,8 @@ typedef struct SwsContext { >> int32_t alpMmxFilter[4*MAX_FILTER_SIZE]; >> DECLARE_ALIGNED(8, ptrdiff_t, uv_off_px); ///< offset (in pixels) >> between u and v planes >> DECLARE_ALIGNED(8, ptrdiff_t, uv_off_byte); ///< offset (in bytes) >> between u and v planes >> - uint16_t dither16[8]; >> - uint32_t dither32[8]; >> + DECLARE_ALIGNED(8, uint16_t, dither16)[8]; >> + DECLARE_ALIGNED(8, uint32_t, dither32)[8]; >> >> const uint8_t *chrDither8, *lumDither8; >> >> -- > > Since the asm is inline, why not pass the offset using an operand with > "i" constraint instead of this? > > If those fields really need 8-byte alignment for some other reason, the > commit message should state that instead or in addition.
I plan to do that, but as said before, it's a major undertaking. I can't fix the world all at once. World hunger will continue for considerably longer beyond today, and so will swscale being broken. I'll fix it, really, but small pieces at a time. Ronald _______________________________________________ libav-devel mailing list [email protected] https://lists.libav.org/mailman/listinfo/libav-devel
