[FFmpeg-devel] [PATCH v3 2/3] swscale/x86/output: add AVX2 version of yuv2nv12cX
Nelson Gomez
negomez at linux.microsoft.com
Sun Apr 26 05:37:02 EEST 2020
From: Nelson Gomez <nelson.gomez at microsoft.com>
256 bits is just wide enough to fit all the operands needed to vectorize
the software implementation, but AVX2 is needed to for a couple of
instructions like cross-lane permutation.
Output is bit-for-bit identical to C.
Signed-off-by: Nelson Gomez <nelson.gomez at microsoft.com>
---
libswscale/x86/output.asm | 126 +++++++++++++++++++++++++++++++++++++-
libswscale/x86/swscale.c | 28 +++++++++
2 files changed, 153 insertions(+), 1 deletion(-)
diff --git a/libswscale/x86/output.asm b/libswscale/x86/output.asm
index db3e9934f8..7f82665e1b 100644
--- a/libswscale/x86/output.asm
+++ b/libswscale/x86/output.asm
@@ -2,6 +2,7 @@
;* x86-optimized vertical line scaling functions
;* Copyright (c) 2011 Ronald S. Bultje <rsbultje at gmail.com>
;* Kieran Kunhya <kieran at kunhya.com>
+;* (c) 2020 Nelson Gomez <nelson.gomez at microsoft.com>
;*
;* This file is part of FFmpeg.
;*
@@ -22,7 +23,7 @@
%include "libavutil/x86/x86util.asm"
-SECTION_RODATA
+SECTION_RODATA 32
minshort: times 8 dw 0x8000
yuv2yuvX_16_start: times 4 dd 0x4000 - 0x40000000
@@ -34,9 +35,20 @@ pd_4: times 4 dd 4
pd_4min0x40000:times 4 dd 4 - (0x40000)
pw_16: times 8 dw 16
pw_32: times 8 dw 32
+pd_255: times 8 dd 255
pw_512: times 8 dw 512
pw_1024: times 8 dw 1024
+yuv2nv12_shuffle_mask: times 2 db 0, 4, 8, 12, \
+ -1, -1, -1, -1, \
+ -1, -1, -1, -1, \
+ -1, -1, -1, -1
+yuv2nv21_shuffle_mask: times 2 db 4, 0, 12, 8, \
+ -1, -1, -1, -1, \
+ -1, -1, -1, -1, \
+ -1, -1, -1, -1
+yuv2nv12_permute_mask: dd 0, 4, 1, 2, 3, 5, 6, 7
+
SECTION .text
;-----------------------------------------------------------------------------
@@ -423,3 +435,115 @@ yuv2plane1_fn 9, 5, 3
yuv2plane1_fn 10, 5, 3
yuv2plane1_fn 16, 5, 3
%endif
+
+%undef movsx
+
+;-----------------------------------------------------------------------------
+; AVX2 yuv2nv12cX implementation
+;
+; void ff_yuv2nv12cX_avx2(enum AVPixelFormat format, const uint8_t *dither,
+; const int16_t *filter, int filterSize,
+; const int16_t **u, const int16_t **v,
+; uint8_t *dst, int dstWidth)
+;
+; void ff_yuv2nv21cX_avx2(enum AVPixelFormat format, const uint8_t *dither,
+; const int16_t *filter, int filterSize,
+; const int16_t **u, const int16_t **v,
+; uint8_t *dst, int dstWidth)
+;-----------------------------------------------------------------------------
+
+%if ARCH_X86_64
+%macro yuv2nv12cX_fn 1
+cglobal %1cX, 8, 11, 13, tmp1, dither, filter, filterSize, u, v, dst, dstWidth
+
+ mov tmp1q, qword [ditherq]
+ movq xm0, tmp1q
+ ror tmp1q, 24
+ movq xm1, tmp1q
+
+ pmovzxbd m0, xm0
+ pslld m0, m0, 12 ; ditherLo
+ pmovzxbd m1, xm1
+ pslld m1, m1, 12 ; ditherHi
+
+ pxor m9, m9 ; uint8_min dwords
+ mova m10, [pd_255] ; uint8_max dwords
+ mova m11, [%1_shuffle_mask] ; shuffle_mask
+ mova m12, [yuv2nv12_permute_mask] ; permute mask
+
+ DEFINE_ARGS tmp1, tmp2, filter, filterSize, u, v, dst, dstWidth
+
+ xor r8q, r8q
+
+nv12_outer_%1:
+ mova m2, m0 ; resultLo
+ mova m3, m1 ; resultHi
+ xor r9q, r9q
+
+nv12_inner_%1:
+ movsx r10d, word [filterq + (2 * r9q)]
+ movd xm4, r10d
+ vpbroadcastd m4, xm4 ; filter
+
+ mov tmp1q, [uq + (gprsize * r9q)]
+ mova xm7, oword [tmp1q + 2 * r8q]
+
+ mov tmp2q, [vq + (gprsize * r9q)]
+ mova xm8, oword [tmp2q + 2 * r8q]
+
+ punpcklwd xm5, xm7, xm8
+ pmovsxwd m5, xm5 ; multiplicandsLo
+ punpckhwd xm6, xm7, xm8
+ pmovsxwd m6, xm6 ; multiplicandsHi
+
+ pmulld m7, m5, m4 ; mulResultLo
+ pmulld m8, m6, m4 ; mulResultHi
+ paddd m2, m2, m7 ; resultLo += mulResultLo
+ paddd m3, m3, m8 ; resultHi += mulResultHi
+
+ inc r9d
+ cmp r9d, filterSized
+ jl nv12_inner_%1
+ ; end of inner loop
+
+ psrad m2, m2, 19
+ psrad m3, m3, 19
+
+ ; Vectorized av_clip_uint8
+ pmaxsd m2, m2, m9
+ pmaxsd m3, m3, m9
+ pminsd m2, m2, m10
+ pminsd m3, m3, m10
+
+ ; At this point we have clamped uint8s arranged in this order:
+ ; m2: u1 0 0 0 v1 0 0 0 [...]
+ ; m3: u5 0 0 0 v5 0 0 0 [...]
+ ;
+ ; First, we shuffle the bytes to make the bytes semi-contiguous.
+ ; AVX-2 doesn't have cross-lane shuffling, so we'll end up with:
+ ; m2: u1 v1 u2 v2 0 0 0 0 0 0 0 0 u3 v3 u4 v4
+ ; m3: u5 v5 u6 v6 0 0 0 0 0 0 0 0 u7 v7 u8 v8
+ pshufb m2, m2, m11
+ pshufb m3, m3, m11
+
+ ; To fix the cross-lane shuffling issue, we'll then use cross-lane
+ ; permutation to combine the two segments
+ vpermd m2, m12, m2
+ vpermd m3, m12, m3
+
+ ; Now we have the final results in the lower 8 bytes of each register
+ movq [dstq], xm2
+ movq [dstq + 8], xm3
+
+ add r8d, 8
+ add dstq, 16
+
+ cmp r8d, dstWidthd
+ jl nv12_outer_%1
+ RET
+%endmacro
+
+INIT_YMM avx2
+yuv2nv12cX_fn yuv2nv12
+yuv2nv12cX_fn yuv2nv21
+%endif ; ARCH_X86_64
diff --git a/libswscale/x86/swscale.c b/libswscale/x86/swscale.c
index 61110839ee..3160fedf04 100644
--- a/libswscale/x86/swscale.c
+++ b/libswscale/x86/swscale.c
@@ -380,6 +380,17 @@ INPUT_FUNCS(sse2);
INPUT_FUNCS(ssse3);
INPUT_FUNCS(avx);
+#if ARCH_X86_64
+#define YUV2NV_DECL(fmt, opt) \
+void ff_yuv2 ## fmt ## cX_ ## opt(enum AVPixelFormat format, const uint8_t *dither, \
+ const int16_t *filter, int filterSize, \
+ const int16_t **u, const int16_t **v, \
+ uint8_t *dst, int dstWidth)
+
+YUV2NV_DECL(nv12, avx2);
+YUV2NV_DECL(nv21, avx2);
+#endif
+
av_cold void ff_sws_init_swscale_x86(SwsContext *c)
{
int cpu_flags = av_get_cpu_flags();
@@ -580,4 +591,21 @@ switch(c->dstBpc){ \
break;
}
}
+
+#if ARCH_X86_64
+ if (EXTERNAL_AVX2_FAST(cpu_flags)) {
+ switch (c->dstFormat) {
+ case AV_PIX_FMT_NV12:
+ case AV_PIX_FMT_NV24:
+ c->yuv2nv12cX = ff_yuv2nv12cX_avx2;
+ break;
+ case AV_PIX_FMT_NV21:
+ case AV_PIX_FMT_NV42:
+ c->yuv2nv12cX = ff_yuv2nv21cX_avx2;
+ break;
+ default:
+ break;
+ }
+ }
+#endif
}
--
2.25.1
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