Add a NEON rgb24tobgr24 using ld3/st3 to swap R and B channels in packed 24bpp RGB buffers. Handles all input sizes with a 16-pixel NEON fast path, 8-pixel NEON cleanup, and scalar tail.
checkasm --bench on Apple M3 Max (1920*3 = 5760 bytes): rgb24tobgr24_c: 872.3 ( 1.00x) rgb24tobgr24_neon: 62.4 (13.98x) Signed-off-by: David Christle <[email protected]> --- libswscale/aarch64/rgb2rgb.c | 3 +++ libswscale/aarch64/rgb2rgb_neon.S | 43 +++++++++++++++++++++++++++++++ tests/checkasm/sw_rgb.c | 31 ++++++++++++++++++++++ 3 files changed, 77 insertions(+) diff --git a/libswscale/aarch64/rgb2rgb.c b/libswscale/aarch64/rgb2rgb.c index f474228298..5873439db5 100644 --- a/libswscale/aarch64/rgb2rgb.c +++ b/libswscale/aarch64/rgb2rgb.c @@ -51,6 +51,8 @@ static void rgb24toyv12(const uint8_t *src, uint8_t *ydst, uint8_t *udst, } } +void ff_rgb24tobgr24_neon(const uint8_t *src, uint8_t *dst, int src_size); + void ff_interleave_bytes_neon(const uint8_t *src1, const uint8_t *src2, uint8_t *dest, int width, int height, int src1Stride, int src2Stride, int dstStride); @@ -85,6 +87,7 @@ av_cold void rgb2rgb_init_aarch64(void) if (have_neon(cpu_flags)) { ff_rgb24toyv12 = rgb24toyv12; + rgb24tobgr24 = ff_rgb24tobgr24_neon; interleaveBytes = ff_interleave_bytes_neon; deinterleaveBytes = ff_deinterleave_bytes_neon; shuffle_bytes_0321 = ff_shuffle_bytes_0321_neon; diff --git a/libswscale/aarch64/rgb2rgb_neon.S b/libswscale/aarch64/rgb2rgb_neon.S index f6d625f11f..25e6c73f42 100644 --- a/libswscale/aarch64/rgb2rgb_neon.S +++ b/libswscale/aarch64/rgb2rgb_neon.S @@ -241,6 +241,49 @@ function ff_rgb24toyv12_neon, export=1 ret endfunc +// void ff_rgb24tobgr24_neon(const uint8_t *src, uint8_t *dst, int src_size); +function ff_rgb24tobgr24_neon, export=1 + // x0 = src, x1 = dst, w2 = src_size (bytes) + + // Fast path: 48 bytes (16 pixels) per iteration + subs w2, w2, #48 + b.lt 2f +1: + ld3 {v0.16b, v1.16b, v2.16b}, [x0], #48 + mov v3.16b, v0.16b + mov v0.16b, v2.16b + mov v2.16b, v3.16b + st3 {v0.16b, v1.16b, v2.16b}, [x1], #48 + subs w2, w2, #48 + b.ge 1b +2: + add w2, w2, #48 + // Medium path: 24 bytes (8 pixels) + cmp w2, #24 + b.lt 3f + ld3 {v0.8b, v1.8b, v2.8b}, [x0], #24 + mov v3.8b, v0.8b + mov v0.8b, v2.8b + mov v2.8b, v3.8b + sub w2, w2, #24 + st3 {v0.8b, v1.8b, v2.8b}, [x1], #24 +3: + // Scalar tail: 3 bytes (1 pixel) at a time + cmp w2, #3 + b.lt 4f +5: + ldrb w3, [x0], #1 + ldrb w4, [x0], #1 + ldrb w5, [x0], #1 + subs w2, w2, #3 + strb w5, [x1], #1 + strb w4, [x1], #1 + strb w3, [x1], #1 + b.gt 5b +4: + ret +endfunc + // void ff_interleave_bytes_neon(const uint8_t *src1, const uint8_t *src2, // uint8_t *dest, int width, int height, // int src1Stride, int src2Stride, int dstStride); diff --git a/tests/checkasm/sw_rgb.c b/tests/checkasm/sw_rgb.c index 6edfc93b0b..baeb34b465 100644 --- a/tests/checkasm/sw_rgb.c +++ b/tests/checkasm/sw_rgb.c @@ -834,6 +834,37 @@ void checkasm_check_sw_rgb(void) check_shuffle_bytes(shuffle_bytes_2130, "shuffle_bytes_2130"); report("shuffle_bytes_2130"); + { + /* rgb24tobgr24 operates on 3-byte pixels, so test widths must be + * multiples of 3 to avoid reading past the source buffer. */ + static const int rgb24_width[] = {3, 12, 24, 36, 48, 126, 1920 * 3}; + int i; +#define RGB24_BENCH_WIDTH (1920 * 3) + LOCAL_ALIGNED_32(uint8_t, src0, [RGB24_BENCH_WIDTH]); + LOCAL_ALIGNED_32(uint8_t, src1, [RGB24_BENCH_WIDTH]); + LOCAL_ALIGNED_32(uint8_t, dst0, [RGB24_BENCH_WIDTH]); + LOCAL_ALIGNED_32(uint8_t, dst1, [RGB24_BENCH_WIDTH]); + + declare_func(void, const uint8_t *src, uint8_t *dst, int src_size); + + memset(dst0, 0, RGB24_BENCH_WIDTH); + memset(dst1, 0, RGB24_BENCH_WIDTH); + randomize_buffers(src0, RGB24_BENCH_WIDTH); + memcpy(src1, src0, RGB24_BENCH_WIDTH); + + if (check_func(rgb24tobgr24, "rgb24tobgr24")) { + for (i = 0; i < FF_ARRAY_ELEMS(rgb24_width); i++) { + call_ref(src0, dst0, rgb24_width[i]); + call_new(src1, dst1, rgb24_width[i]); + if (memcmp(dst0, dst1, rgb24_width[i])) + fail(); + } + bench_new(src0, dst0, RGB24_BENCH_WIDTH); + } +#undef RGB24_BENCH_WIDTH + } + report("rgb24tobgr24"); + check_uyvy_to_422p(); report("uyvytoyuv422"); -- 2.52.0 _______________________________________________ ffmpeg-devel mailing list -- [email protected] To unsubscribe send an email to [email protected]
