[FFmpeg-cvslog] swscale/aarch64: dotprod implementation of rgba32_to_Y
Krzysztof Pyrkosz
git at videolan.org
Tue Mar 4 10:27:06 EET 2025
ffmpeg | branch: master | Krzysztof Pyrkosz <ffmpeg at szaka.eu> | Mon Mar 3 22:00:23 2025 +0100| [d765e5f043d981294303fe210d643c5156efeeb3] | committer: Martin Storsjö
swscale/aarch64: dotprod implementation of rgba32_to_Y
The idea is to split the 16 bit coefficients into lower and upper half,
invoke udot for the lower half, shift by 8, and follow by udot for the
upper half.
Benchmark on A78:
bgra_to_y_128_c: 682.0 ( 1.00x)
bgra_to_y_128_neon: 181.2 ( 3.76x)
bgra_to_y_128_dotprod: 117.8 ( 5.79x)
bgra_to_y_1080_c: 5742.5 ( 1.00x)
bgra_to_y_1080_neon: 1472.5 ( 3.90x)
bgra_to_y_1080_dotprod: 906.5 ( 6.33x)
bgra_to_y_1920_c: 10194.0 ( 1.00x)
bgra_to_y_1920_neon: 2589.8 ( 3.94x)
bgra_to_y_1920_dotprod: 1573.8 ( 6.48x)
Signed-off-by: Martin Storsjö <martin at martin.st>
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=d765e5f043d981294303fe210d643c5156efeeb3
---
libswscale/aarch64/input.S | 88 ++++++++++++++++++++++++++++++++++++++++++++
libswscale/aarch64/swscale.c | 17 +++++++++
2 files changed, 105 insertions(+)
diff --git a/libswscale/aarch64/input.S b/libswscale/aarch64/input.S
index 5cb18711fb..c1c0adffc8 100644
--- a/libswscale/aarch64/input.S
+++ b/libswscale/aarch64/input.S
@@ -313,3 +313,91 @@ rgbToUV_neon bgr24, rgb24, element=3
rgbToUV_neon bgra32, rgba32, element=4
rgbToUV_neon abgr32, argb32, element=4, alpha_first=1
+
+#if HAVE_DOTPROD
+ENABLE_DOTPROD
+
+function ff_bgra32ToY_neon_dotprod, export=1
+ cmp w4, #0 // check width > 0
+ ldp w12, w11, [x5] // w12: ry, w11: gy
+ ldr w10, [x5, #8] // w10: by
+ b.gt 4f
+ ret
+endfunc
+
+function ff_rgba32ToY_neon_dotprod, export=1
+ cmp w4, #0 // check width > 0
+ ldp w10, w11, [x5] // w10: ry, w11: gy
+ ldr w12, [x5, #8] // w12: by
+ b.le 3f
+4:
+ mov w9, #256 // w9 = 1 << (RGB2YUV_SHIFT - 7)
+ movk w9, #8, lsl #16 // w9 += 32 << (RGB2YUV_SHIFT - 1)
+ dup v6.4s, w9 // w9: const_offset
+
+ cmp w4, #16
+ mov w7, w10
+ bfi w7, w11, 8, 8 // the bfi instructions are used to assemble
+ bfi w7, w12, 16, 8 // 4 byte r,g,b,0 mask to be then used by udot.
+ dup v0.4s, w7 // v0 holds the lower byte of each coefficient
+
+ lsr w6, w10, #8
+ lsr w7, w11, #8
+ lsr w8, w12, #8
+
+ bfi w6, w7, 8, 8
+ bfi w6, w8, 16, 8
+ dup v1.4s, w6 // v1 holds the upper byte of each coefficient
+ b.lt 2f
+1:
+ ld1 { v16.16b, v17.16b, v18.16b, v19.16b }, [x1], #64
+ sub w4, w4, #16 // width -= 16
+
+ mov v2.16b, v6.16b
+ mov v3.16b, v6.16b
+ mov v4.16b, v6.16b
+ mov v5.16b, v6.16b
+ cmp w4, #16 // width >= 16 ?
+
+ udot v2.4s, v16.16b, v0.16b
+ udot v3.4s, v17.16b, v0.16b
+ udot v4.4s, v18.16b, v0.16b
+ udot v5.4s, v19.16b, v0.16b
+
+ ushr v2.4s, v2.4s, #8
+ ushr v3.4s, v3.4s, #8
+ ushr v4.4s, v4.4s, #8
+ ushr v5.4s, v5.4s, #8
+
+ udot v2.4s, v16.16b, v1.16b
+ udot v3.4s, v17.16b, v1.16b
+ udot v4.4s, v18.16b, v1.16b
+ udot v5.4s, v19.16b, v1.16b
+
+ sqshrn v16.4h, v2.4s, #1
+ sqshrn2 v16.8h, v3.4s, #1
+ sqshrn v17.4h, v4.4s, #1
+ sqshrn2 v17.8h, v5.4s, #1
+
+ stp q16, q17, [x0], #32 // store to dst
+ b.ge 1b
+ cbz x4, 3f
+2:
+ ldrb w13, [x1] // w13: r
+ ldrb w14, [x1, #1] // w14: g
+ ldrb w15, [x1, #2] // w15: b
+
+ smaddl x13, w13, w10, x9 // x13 = ry * r + const_offset
+ smaddl x13, w14, w11, x13 // x13 += gy * g
+ smaddl x13, w15, w12, x13 // x13 += by * b
+ asr w13, w13, #9 // x13 >>= 9
+ sub w4, w4, #1 // width--
+ add x1, x1, #4
+ strh w13, [x0], #2 // store to dst
+ cbnz w4, 2b
+3:
+ ret
+endfunc
+
+DISABLE_DOTPROD
+#endif
diff --git a/libswscale/aarch64/swscale.c b/libswscale/aarch64/swscale.c
index 92c49dcf3a..18746b1b19 100644
--- a/libswscale/aarch64/swscale.c
+++ b/libswscale/aarch64/swscale.c
@@ -210,6 +210,9 @@ void ff_##name##ToUV_neon(uint8_t *, uint8_t *, const uint8_t *, \
void ff_##name##ToUV_half_neon(uint8_t *, uint8_t *, const uint8_t *, \
const uint8_t *, const uint8_t *, int w, \
uint32_t *coeffs, void *)
+#define NEON_INPUT_DOTPROD(name) \
+void ff_##name##ToY_neon_dotprod(uint8_t *dst, const uint8_t *src, const uint8_t *, \
+ const uint8_t *, int w, uint32_t *coeffs, void *);
NEON_INPUT(abgr32);
NEON_INPUT(argb32);
@@ -217,6 +220,8 @@ NEON_INPUT(bgr24);
NEON_INPUT(bgra32);
NEON_INPUT(rgb24);
NEON_INPUT(rgba32);
+NEON_INPUT_DOTPROD(bgra32);
+NEON_INPUT_DOTPROD(rgba32);
void ff_lumRangeFromJpeg8_neon(int16_t *dst, int width,
uint32_t coeff, int64_t offset);
@@ -295,6 +300,12 @@ av_cold void ff_sws_init_swscale_aarch64(SwsInternal *c)
c->chrToYV12 = ff_bgr24ToUV_neon;
break;
case AV_PIX_FMT_BGRA:
+#if HAVE_DOTPROD
+ if (have_dotprod(cpu_flags)) {
+ c->lumToYV12 = ff_bgra32ToY_neon_dotprod;
+ }
+ else
+#endif
c->lumToYV12 = ff_bgra32ToY_neon;
if (c->chrSrcHSubSample)
c->chrToYV12 = ff_bgra32ToUV_half_neon;
@@ -309,6 +320,12 @@ av_cold void ff_sws_init_swscale_aarch64(SwsInternal *c)
c->chrToYV12 = ff_rgb24ToUV_neon;
break;
case AV_PIX_FMT_RGBA:
+#if HAVE_DOTPROD
+ if (have_dotprod(cpu_flags)) {
+ c->lumToYV12 = ff_rgba32ToY_neon_dotprod;
+ }
+ else
+#endif
c->lumToYV12 = ff_rgba32ToY_neon;
if (c->chrSrcHSubSample)
c->chrToYV12 = ff_rgba32ToUV_half_neon;
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