[FFmpeg-devel] [PATCH 2/2] libswscale: Adds ff_hscale8to15_4_avx2 and ff_hscale8to15_X4_avx2 for all filter sizes.

Alan Kelly alankelly at google.com
Fri Jul 16 16:48:18 EEST 2021


These functions replace all ff_hscale8to15_*_ssse3 when avx2 is available.
---
EXTERNAL_AVX2_FAST is now used instead of EXTERNAL_AVX2_FAST_GATHER as
discussed in the email thread for part 1 of this patch.

Benchmark results on Skylake and Haswell:

                                Skylake	Haswell
hscale_8_to_15_width4_ssse3	761.2	760
hscale_8_to_15_width4_avx2	468.7	957
hscale_8_to_15_width8_ssse3	1170.7	1032
hscale_8_to_15_width8_avx2	865.7	1979
hscale_8_to_15_width12_ssse3	2172.2	2472
hscale_8_to_15_width12_avx2	1245.7	2901
hscale_8_to_15_width16_ssse3	2244.2	2400
hscale_8_to_15_width16_avx2	1647.2	3681

 libswscale/swscale_internal.h |   2 +
 libswscale/utils.c            |  37 +++++++++++
 libswscale/x86/Makefile       |   1 +
 libswscale/x86/scale_avx2.asm | 112 ++++++++++++++++++++++++++++++++++
 libswscale/x86/swscale.c      |  19 ++++++
 tests/checkasm/sw_scale.c     |  20 ++++--
 6 files changed, 186 insertions(+), 5 deletions(-)
 create mode 100644 libswscale/x86/scale_avx2.asm

diff --git a/libswscale/swscale_internal.h b/libswscale/swscale_internal.h
index 673407636a..fba3dabe5b 100644
--- a/libswscale/swscale_internal.h
+++ b/libswscale/swscale_internal.h
@@ -1064,4 +1064,6 @@ void ff_init_vscale_pfn(SwsContext *c, yuv2planar1_fn yuv2plane1, yuv2planarX_fn
 //number of extra lines to process
 #define MAX_LINES_AHEAD 4
 
+//shuffle filter and filterPos for hyScale and hcScale filters in avx2
+void ff_shuffle_filter_coefficients(SwsContext *c, int* filterPos, int filterSize, int16_t *filter, int dstW);
 #endif /* SWSCALE_SWSCALE_INTERNAL_H */
diff --git a/libswscale/utils.c b/libswscale/utils.c
index 176fc6fd63..0577fd5490 100644
--- a/libswscale/utils.c
+++ b/libswscale/utils.c
@@ -268,6 +268,41 @@ static const FormatEntry format_entries[] = {
     [AV_PIX_FMT_X2RGB10LE]   = { 1, 1 },
 };
 
+void ff_shuffle_filter_coefficients(SwsContext *c, int *filterPos, int filterSize, int16_t *filter, int dstW){
+#if ARCH_X86_64
+    int i, j, k, l;
+    int cpu_flags = av_get_cpu_flags();
+    if (EXTERNAL_AVX2_FAST(cpu_flags)){
+        if ((c->srcBpc == 8) && (c->dstBpc <= 14)){
+            if (dstW % 16 == 0){
+                if (filter != NULL){
+                    for (i = 0; i < dstW; i += 8){
+                        FFSWAP(int, filterPos[i + 2], filterPos[i+4]);
+                        FFSWAP(int, filterPos[i + 3], filterPos[i+5]);
+                    }
+                    if (filterSize > 4){
+                        int16_t *tmp2 = av_malloc(dstW * filterSize * 2);
+                        memcpy(tmp2, filter, dstW * filterSize * 2);
+                        for (i = 0; i < dstW; i += 16){//pixel
+                            for (k = 0; k < filterSize / 4; ++k){//fcoeff
+                                for (j = 0; j < 16; ++j){//inner pixel
+                                    for (l = 0; l < 4; ++l){//coeff
+                                        int from = i * filterSize + j * filterSize + k * 4 + l;
+                                        int to = (i) * filterSize + j * 4 + l + k * 64;
+                                        filter[to] = tmp2[from];
+                                    }
+                                }
+                            }
+                        }
+                        av_free(tmp2);
+                    }
+                }
+            }
+        }
+    }
+#endif
+}
+
 int sws_isSupportedInput(enum AVPixelFormat pix_fmt)
 {
     return (unsigned)pix_fmt < FF_ARRAY_ELEMS(format_entries) ?
@@ -1699,6 +1734,7 @@ av_cold int sws_init_context(SwsContext *c, SwsFilter *srcFilter,
                            get_local_pos(c, 0, 0, 0),
                            get_local_pos(c, 0, 0, 0))) < 0)
                 goto fail;
+            ff_shuffle_filter_coefficients(c, c->hLumFilterPos, c->hLumFilterSize, c->hLumFilter, dstW);
             if ((ret = initFilter(&c->hChrFilter, &c->hChrFilterPos,
                            &c->hChrFilterSize, c->chrXInc,
                            c->chrSrcW, c->chrDstW, filterAlign, 1 << 14,
@@ -1708,6 +1744,7 @@ av_cold int sws_init_context(SwsContext *c, SwsFilter *srcFilter,
                            get_local_pos(c, c->chrSrcHSubSample, c->src_h_chr_pos, 0),
                            get_local_pos(c, c->chrDstHSubSample, c->dst_h_chr_pos, 0))) < 0)
                 goto fail;
+            ff_shuffle_filter_coefficients(c, c->hChrFilterPos, c->hChrFilterSize, c->hChrFilter, c->chrDstW);
         }
     } // initialize horizontal stuff
 
diff --git a/libswscale/x86/Makefile b/libswscale/x86/Makefile
index bfe383364e..68391494be 100644
--- a/libswscale/x86/Makefile
+++ b/libswscale/x86/Makefile
@@ -11,6 +11,7 @@ OBJS-$(CONFIG_XMM_CLOBBER_TEST) += x86/w64xmmtest.o
 X86ASM-OBJS                     += x86/input.o                          \
                                    x86/output.o                         \
                                    x86/scale.o                          \
+                                   x86/scale_avx2.o                          \
                                    x86/rgb_2_rgb.o                      \
                                    x86/yuv_2_rgb.o                      \
                                    x86/yuv2yuvX.o                       \
diff --git a/libswscale/x86/scale_avx2.asm b/libswscale/x86/scale_avx2.asm
new file mode 100644
index 0000000000..d90fd2d791
--- /dev/null
+++ b/libswscale/x86/scale_avx2.asm
@@ -0,0 +1,112 @@
+;******************************************************************************
+;* x86-optimized horizontal line scaling functions
+;* Copyright 2020 Google LLC
+;* Copyright (c) 2011 Ronald S. Bultje <rsbultje at gmail.com>
+;*
+;* This file is part of FFmpeg.
+;*
+;* FFmpeg is free software; you can redistribute it and/or
+;* modify it under the terms of the GNU Lesser General Public
+;* License as published by the Free Software Foundation; either
+;* version 2.1 of the License, or (at your option) any later version.
+;*
+;* FFmpeg is distributed in the hope that it will be useful,
+;* but WITHOUT ANY WARRANTY; without even the implied warranty of
+;* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+;* Lesser General Public License for more details.
+;*
+;* You should have received a copy of the GNU Lesser General Public
+;* License along with FFmpeg; if not, write to the Free Software
+;* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+;******************************************************************************
+
+%include "libavutil/x86/x86util.asm"
+
+SECTION_RODATA
+
+swizzle: dd 0, 4, 1, 5, 2, 6, 3, 7
+four: times 8 dd 4
+
+SECTION .text
+
+;-----------------------------------------------------------------------------
+; horizontal line scaling
+;
+; void hscale8to15_<filterSize>_<opt>
+;                   (SwsContext *c, int16_t *dst,
+;                    int dstW, const uint8_t *src,
+;                    const int16_t *filter,
+;                    const int32_t *filterPos, int filterSize);
+;
+; Scale one horizontal line. Input is 8-bit width Filter is 14 bits. Output is
+; 15 bits (in int16_t). Each output pixel is generated from $filterSize input
+; pixels, the position of the first pixel is given in filterPos[nOutputPixel].
+;-----------------------------------------------------------------------------
+
+%macro SCALE_FUNC 1
+cglobal hscale8to15_%1, 7, 9, 15, pos0, dst, w, srcmem, filter, fltpos, fltsize, count, inner
+  pxor m0, m0
+  movu m15, [swizzle]
+  mov countq, $0
+%ifidn %1, X4
+  movu m14, [four]
+  movsxd fltsizeq, fltsized
+  shr fltsizeq, 2
+%endif
+.loop:
+  movu m1, [fltposq]
+  movu m2, [fltposq+32]
+%ifidn %1, X4
+  pxor m9, m9
+  pxor m10, m10
+  pxor m11, m11
+  pxor m12, m12
+  mov innerq, $0
+.innerloop:
+%endif
+  vpcmpeqd  m13, m13
+  vpgatherdd m3,[srcmemq + m1], m13
+  vpcmpeqd  m13, m13
+  vpgatherdd m4,[srcmemq + m2], m13
+  vpunpcklbw m5, m3, m0
+  vpunpckhbw m6, m3, m0
+  vpunpcklbw m7, m4, m0
+  vpunpckhbw m8, m4, m0
+  vpmaddwd m5, m5, [filterq]
+  vpmaddwd m6, m6, [filterq + 32]
+  vpmaddwd m7, m7, [filterq + 64]
+  vpmaddwd m8, m8, [filterq + 96]
+  add filterq, $80
+%ifidn %1, X4
+  paddd m9, m5
+  paddd m10, m6
+  paddd m11, m7
+  paddd m12, m8
+  paddd m1, m14
+  paddd m2, m14
+  add innerq, $1
+  cmp innerq, fltsizeq
+  jl .innerloop
+  vphaddd m5, m9, m10
+  vphaddd m6, m11, m12
+%else
+  vphaddd m5, m5, m6
+  vphaddd m6, m7, m8
+%endif
+  vpsrad  m5, 7
+  vpsrad  m6, 7
+  vpackssdw m5, m5, m6
+  vpermd m5, m15, m5
+  vmovdqu [dstq + countq * 2], m5
+  add fltposq, $40
+  add countq, $10
+  cmp countq, wq
+  jl .loop
+REP_RET
+%endmacro
+
+%if ARCH_X86_64
+INIT_YMM avx2
+SCALE_FUNC 4
+SCALE_FUNC X4
+%endif
diff --git a/libswscale/x86/swscale.c b/libswscale/x86/swscale.c
index 0848a31461..164b06d6ba 100644
--- a/libswscale/x86/swscale.c
+++ b/libswscale/x86/swscale.c
@@ -276,6 +276,9 @@ SCALE_FUNCS_SSE(sse2);
 SCALE_FUNCS_SSE(ssse3);
 SCALE_FUNCS_SSE(sse4);
 
+SCALE_FUNC(4, 8, 15, avx2);
+SCALE_FUNC(X4, 8, 15, avx2);
+
 #define VSCALEX_FUNC(size, opt) \
 void ff_yuv2planeX_ ## size ## _ ## opt(const int16_t *filter, int filterSize, \
                                         const int16_t **src, uint8_t *dest, int dstW, \
@@ -568,6 +571,22 @@ switch(c->dstBpc){ \
     }
 
 #if ARCH_X86_64
+#define ASSIGN_AVX2_SCALE_FUNC(hscalefn, filtersize) \
+    switch (filtersize) { \
+    case 4:  hscalefn = ff_hscale8to15_4_avx2; break; \
+    default:  hscalefn = ff_hscale8to15_X4_avx2; break; \
+             break; \
+    }
+
+    if (EXTERNAL_AVX2_FAST(cpu_flags)){
+      if ((c->srcBpc == 8) && (c->dstBpc <= 14)){
+        if(c->chrDstW % 16 == 0)
+          ASSIGN_AVX2_SCALE_FUNC(c->hcScale, c->hChrFilterSize);
+        if(c->dstW % 16 == 0)
+          ASSIGN_AVX2_SCALE_FUNC(c->hyScale, c->hLumFilterSize);
+      }
+    }
+
     if (EXTERNAL_AVX2_FAST(cpu_flags)) {
         switch (c->dstFormat) {
         case AV_PIX_FMT_NV12:
diff --git a/tests/checkasm/sw_scale.c b/tests/checkasm/sw_scale.c
index 40c5eb3aa8..103b1aa5da 100644
--- a/tests/checkasm/sw_scale.c
+++ b/tests/checkasm/sw_scale.c
@@ -135,13 +135,13 @@ static void check_yuv2yuvX(void)
 }
 
 #undef SRC_PIXELS
-#define SRC_PIXELS 128
+#define SRC_PIXELS 512
 
 static void check_hscale(void)
 {
 #define MAX_FILTER_WIDTH 40
-#define FILTER_SIZES 5
-    static const int filter_sizes[FILTER_SIZES] = { 4, 8, 16, 32, 40 };
+#define FILTER_SIZES 6
+    static const int filter_sizes[FILTER_SIZES] = { 4, 8, 12, 16, 32, 40 };
 
 #define HSCALE_PAIRS 2
     static const int hscale_pairs[HSCALE_PAIRS][2] = {
@@ -160,6 +160,8 @@ static void check_hscale(void)
     // padded
     LOCAL_ALIGNED_32(int16_t, filter, [SRC_PIXELS * MAX_FILTER_WIDTH + MAX_FILTER_WIDTH]);
     LOCAL_ALIGNED_32(int32_t, filterPos, [SRC_PIXELS]);
+    LOCAL_ALIGNED_32(int16_t, filterAvx2, [SRC_PIXELS * MAX_FILTER_WIDTH + MAX_FILTER_WIDTH]);
+    LOCAL_ALIGNED_32(int32_t, filterPosAvx, [SRC_PIXELS]);
 
     // The dst parameter here is either int16_t or int32_t but we use void* to
     // just cover both cases.
@@ -167,6 +169,8 @@ static void check_hscale(void)
                       const uint8_t *src, const int16_t *filter,
                       const int32_t *filterPos, int filterSize);
 
+    int cpu_flags = av_get_cpu_flags();
+
     ctx = sws_alloc_context();
     if (sws_init_context(ctx, NULL, NULL) < 0)
         fail();
@@ -180,9 +184,11 @@ static void check_hscale(void)
             ctx->srcBpc = hscale_pairs[hpi][0];
             ctx->dstBpc = hscale_pairs[hpi][1];
             ctx->hLumFilterSize = ctx->hChrFilterSize = width;
+            ctx->dstW = ctx->chrDstW = SRC_PIXELS;
 
             for (i = 0; i < SRC_PIXELS; i++) {
                 filterPos[i] = i;
+                filterPosAvx[i] = i;
 
                 // These filter cofficients are chosen to try break two corner
                 // cases, namely:
@@ -211,16 +217,20 @@ static void check_hscale(void)
                 filter[SRC_PIXELS * width + i] = rnd();
             }
             ff_sws_init_scale(ctx);
+            memcpy(filterAvx2, filter, sizeof(uint16_t) * (SRC_PIXELS * MAX_FILTER_WIDTH + MAX_FILTER_WIDTH));
+            if (cpu_flags & AV_CPU_FLAG_AVX2){
+                ff_shuffle_filter_coefficients(ctx, filterPosAvx, width, filterAvx2, SRC_PIXELS);
+            }
 
             if (check_func(ctx->hcScale, "hscale_%d_to_%d_width%d", ctx->srcBpc, ctx->dstBpc + 1, width)) {
                 memset(dst0, 0, SRC_PIXELS * sizeof(dst0[0]));
                 memset(dst1, 0, SRC_PIXELS * sizeof(dst1[0]));
 
                 call_ref(NULL, dst0, SRC_PIXELS, src, filter, filterPos, width);
-                call_new(NULL, dst1, SRC_PIXELS, src, filter, filterPos, width);
+                call_new(NULL, dst1, SRC_PIXELS, src, filterAvx2, filterPosAvx, width);
                 if (memcmp(dst0, dst1, SRC_PIXELS * sizeof(dst0[0])))
                     fail();
-                bench_new(NULL, dst0, SRC_PIXELS, src, filter, filterPos, width);
+                bench_new(NULL, dst0, SRC_PIXELS, src, filter, filterPosAvx, width);
             }
         }
     }
-- 
2.32.0.402.g57bb445576-goog



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