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| author | Mans Rullgard <mans@mansr.com> | 2012-06-22 21:40:28 +0100 |
|---|---|---|
| committer | Mans Rullgard <mans@mansr.com> | 2012-06-30 00:12:05 +0100 |
| commit | f2fd167835b6f039a593e46ab3a84e1b9a453660 (patch) | |
| tree | b1fab7a091df57227003fa639768e3d5dae3f231 /libavcodec | |
| parent | 3b1ab197be185b61247ef2472f15eeac3e765252 (diff) | |
| download | ffmpeg-f2fd167835b6f039a593e46ab3a84e1b9a453660.tar.gz | |
x86: vc1: fix and enable optimised loop filter
The problem is that the ssse3 psign instruction does the wrong
thing here. Commit ea60dfe incorrectly removed a macro emulating
this instruction for pre-ssse3 code. However, the emulation is
incorrect, and the code relies on the behaviour of the macro.
Specifically, the psign sets destination elements to zero where
the corresponding source element is zero, whereas the emulation
only negates destination elements where the source is negative.
Furthermore, the PSIGNW_MMX macro in x86util.asm is totally bogus,
which is why the original VC-1 code had an additional right shift
when using it. Since the psign instruction cannot be used here,
skip all the macro hell and use the working instruction sequence
directly.
None of this was noticed due a stray return statement in
ff_vc1dsp_init_mmx() which meant that only the mmx version of the
loop filter was ever used (before being removed in ea60dfe).
Signed-off-by: Mans Rullgard <mans@mansr.com>
Diffstat (limited to 'libavcodec')
| -rw-r--r-- | libavcodec/x86/vc1dsp_mmx.c | 2 | ||||
| -rw-r--r-- | libavcodec/x86/vc1dsp_yasm.asm | 5 |
2 files changed, 4 insertions, 3 deletions
diff --git a/libavcodec/x86/vc1dsp_mmx.c b/libavcodec/x86/vc1dsp_mmx.c index 4e996f1ce6..717f74f287 100644 --- a/libavcodec/x86/vc1dsp_mmx.c +++ b/libavcodec/x86/vc1dsp_mmx.c @@ -797,7 +797,7 @@ void ff_vc1dsp_init_mmx(VC1DSPContext *dsp) if (mm_flags & AV_CPU_FLAG_MMX) { dsp->put_no_rnd_vc1_chroma_pixels_tab[0]= ff_put_vc1_chroma_mc8_mmx_nornd; } - return; + if (mm_flags & AV_CPU_FLAG_MMX2) { ASSIGN_LF(mmx2); dsp->avg_no_rnd_vc1_chroma_pixels_tab[0]= ff_avg_vc1_chroma_mc8_mmx2_nornd; diff --git a/libavcodec/x86/vc1dsp_yasm.asm b/libavcodec/x86/vc1dsp_yasm.asm index 2c5cf22a0a..ced2b5ba88 100644 --- a/libavcodec/x86/vc1dsp_yasm.asm +++ b/libavcodec/x86/vc1dsp_yasm.asm @@ -119,7 +119,9 @@ section .text pand m2, m6 pand m3, m2 ; d final - PSIGNW m3, m7 + psraw m7, 15 + pxor m3, m7 + psubw m3, m7 psubw m0, m3 paddw m1, m3 packuswb m0, m0 @@ -284,7 +286,6 @@ cglobal vc1_h_loop_filter8_sse2, 3,6,8 RET %define PABSW PABSW_SSSE3 -%define PSIGNW PSIGNW_SSSE3 INIT_MMX ; void ff_vc1_v_loop_filter4_ssse3(uint8_t *src, int stride, int pq) |