[FFmpeg-devel] [PATCH v2 2/2] swscale/input: clamp rgbf32 values before lrintf
James Almer
jamrial at gmail.com
Sun Nov 14 05:02:00 EET 2021
On 11/13/2021 11:56 PM, mindmark at gmail.com wrote:
> From: Mark Reid <mindmark at gmail.com>
>
> if the float pixel * 65535.0f > 2147483647.0f
> lrintf may overfow and return negative values, depending on implementation.
> nan and +/-inf values may also be implementation defined
>
> clamp the value first so lrintf so, always works.
>
> values <=0.0f, -inf, nan = 0.0f
> values >=1.0f, +inf = 1.0f
>
> the clamping adds some performance overhead, but using a inline function
> seems help the compiler optimize on the compiliers I tested.
>
> old timings
> 213920 UNITS in planar_rgbf32le_to_uv, 1 runs, 0 skips
> 218830 UNITS in planar_rgbf32le_to_uv, 2 runs, 0 skips
> 223285 UNITS in planar_rgbf32le_to_uv, 4 runs, 0 skips
> 215405 UNITS in planar_rgbf32le_to_uv, 8 runs, 0 skips
> 208920 UNITS in planar_rgbf32le_to_uv, 16 runs, 0 skips
> 205115 UNITS in planar_rgbf32le_to_uv, 32 runs, 0 skips
> 212220 UNITS in planar_rgbf32le_to_uv, 64 runs, 0 skips
>
> 216440 UNITS in planar_rgbf32be_to_uv, 1 runs, 0 skips
> 222450 UNITS in planar_rgbf32be_to_uv, 2 runs, 0 skips
> 228780 UNITS in planar_rgbf32be_to_uv, 4 runs, 0 skips
> 226900 UNITS in planar_rgbf32be_to_uv, 8 runs, 0 skips
> 223168 UNITS in planar_rgbf32be_to_uv, 16 runs, 0 skips
> 249340 UNITS in planar_rgbf32be_to_uv, 32 runs, 0 skips
> 233746 UNITS in planar_rgbf32be_to_uv, 64 runs, 0 skips
>
> 173360 UNITS in planar_rgbf32le_to_y, 1 runs, 0 skips
> 179970 UNITS in planar_rgbf32le_to_y, 2 runs, 0 skips
> 182960 UNITS in planar_rgbf32le_to_y, 4 runs, 0 skips
> 177040 UNITS in planar_rgbf32le_to_y, 8 runs, 0 skips
> 170351 UNITS in planar_rgbf32le_to_y, 16 runs, 0 skips
> 167136 UNITS in planar_rgbf32le_to_y, 32 runs, 0 skips
> 165821 UNITS in planar_rgbf32le_to_y, 64 runs, 0 skips
>
> 181040 UNITS in planar_rgbf32be_to_y, 1 runs, 0 skips
> 182920 UNITS in planar_rgbf32be_to_y, 2 runs, 0 skips
> 180935 UNITS in planar_rgbf32be_to_y, 4 runs, 0 skips
> 180897 UNITS in planar_rgbf32be_to_y, 8 runs, 0 skips
> 179640 UNITS in planar_rgbf32be_to_y, 16 runs, 0 skips
> 178912 UNITS in planar_rgbf32be_to_y, 32 runs, 0 skips
> 177983 UNITS in planar_rgbf32be_to_y, 64 runs, 0 skips
>
> new timings
> 228860 UNITS in planar_rgbf32le_to_uv, 1 runs, 0 skips
> 232400 UNITS in planar_rgbf32le_to_uv, 2 runs, 0 skips
> 237270 UNITS in planar_rgbf32le_to_uv, 4 runs, 0 skips
> 229992 UNITS in planar_rgbf32le_to_uv, 8 runs, 0 skips
> 222270 UNITS in planar_rgbf32le_to_uv, 16 runs, 0 skips
> 218896 UNITS in planar_rgbf32le_to_uv, 32 runs, 0 skips
> 216938 UNITS in planar_rgbf32le_to_uv, 64 runs, 0 skips
>
> 232340 UNITS in planar_rgbf32be_to_uv, 1 runs, 0 skips
> 231830 UNITS in planar_rgbf32be_to_uv, 2 runs, 0 skips
> 242235 UNITS in planar_rgbf32be_to_uv, 4 runs, 0 skips
> 235210 UNITS in planar_rgbf32be_to_uv, 8 runs, 0 skips
> 229040 UNITS in planar_rgbf32be_to_uv, 16 runs, 0 skips
> 224996 UNITS in planar_rgbf32be_to_uv, 32 runs, 0 skips
> 223581 UNITS in planar_rgbf32be_to_uv, 64 runs, 0 skips
>
> 179220 UNITS in planar_rgbf32le_to_y, 1 runs, 0 skips
> 174790 UNITS in planar_rgbf32le_to_y, 2 runs, 0 skips
> 182630 UNITS in planar_rgbf32le_to_y, 4 runs, 0 skips
> 183002 UNITS in planar_rgbf32le_to_y, 8 runs, 0 skips
> 181005 UNITS in planar_rgbf32le_to_y, 16 runs, 0 skips
> 179390 UNITS in planar_rgbf32le_to_y, 32 runs, 0 skips
> 192476 UNITS in planar_rgbf32le_to_y, 64 runs, 0 skips
>
> 195620 UNITS in planar_rgbf32be_to_y, 1 runs, 0 skips
> 195860 UNITS in planar_rgbf32be_to_y, 2 runs, 0 skips
> 198700 UNITS in planar_rgbf32be_to_y, 4 runs, 0 skips
> 197252 UNITS in planar_rgbf32be_to_y, 8 runs, 0 skips
> 195702 UNITS in planar_rgbf32be_to_y, 16 runs, 0 skips
> 194853 UNITS in planar_rgbf32be_to_y, 32 runs, 0 skips
> 194459 UNITS in planar_rgbf32be_to_y, 64 runs, 0 skips
> ---
> libswscale/input.c | 21 +++++++++++++--------
> 1 file changed, 13 insertions(+), 8 deletions(-)
>
> diff --git a/libswscale/input.c b/libswscale/input.c
> index 90efdd2ffc..2a13846abe 100644
> --- a/libswscale/input.c
> +++ b/libswscale/input.c
> @@ -966,6 +966,11 @@ static av_always_inline void planar_rgb16_to_uv(uint8_t *_dstU, uint8_t *_dstV,
>
> #define rdpx(src) (is_be ? av_int2float(AV_RB32(src)): av_int2float(AV_RL32(src)))
>
> +static av_always_inline float clampf(float x, float min, float max)
Use av_clipf() instead.
> +{
> + return FFMIN(FFMAX(x, min), max);
> +}
> +
> static av_always_inline void planar_rgbf32_to_a(uint8_t *_dst, const uint8_t *_src[4], int width, int is_be, int32_t *rgb2yuv)
> {
> int i;
> @@ -973,7 +978,7 @@ static av_always_inline void planar_rgbf32_to_a(uint8_t *_dst, const uint8_t *_s
> uint16_t *dst = (uint16_t *)_dst;
>
> for (i = 0; i < width; i++) {
> - dst[i] = av_clip_uint16(lrintf(65535.0f * rdpx(src[3] + i)));
> + dst[i] = lrintf(clampf(65535.0f * rdpx(src[3] + i), 0.0f, 65535.0f));
> }
> }
>
> @@ -987,9 +992,9 @@ static av_always_inline void planar_rgbf32_to_uv(uint8_t *_dstU, uint8_t *_dstV,
> int32_t rv = rgb2yuv[RV_IDX], gv = rgb2yuv[GV_IDX], bv = rgb2yuv[BV_IDX];
>
> for (i = 0; i < width; i++) {
> - int g = av_clip_uint16(lrintf(65535.0f * rdpx(src[0] + i)));
> - int b = av_clip_uint16(lrintf(65535.0f * rdpx(src[1] + i)));
> - int r = av_clip_uint16(lrintf(65535.0f * rdpx(src[2] + i)));
> + int g = lrintf(clampf(65535.0f * rdpx(src[0] + i), 0.0f, 65535.0f));
> + int b = lrintf(clampf(65535.0f * rdpx(src[1] + i), 0.0f, 65535.0f));
> + int r = lrintf(clampf(65535.0f * rdpx(src[2] + i), 0.0f, 65535.0f));
>
> dstU[i] = (ru*r + gu*g + bu*b + (0x10001 << (RGB2YUV_SHIFT - 1))) >> RGB2YUV_SHIFT;
> dstV[i] = (rv*r + gv*g + bv*b + (0x10001 << (RGB2YUV_SHIFT - 1))) >> RGB2YUV_SHIFT;
> @@ -1005,9 +1010,9 @@ static av_always_inline void planar_rgbf32_to_y(uint8_t *_dst, const uint8_t *_s
> int32_t ry = rgb2yuv[RY_IDX], gy = rgb2yuv[GY_IDX], by = rgb2yuv[BY_IDX];
>
> for (i = 0; i < width; i++) {
> - int g = av_clip_uint16(lrintf(65535.0f * rdpx(src[0] + i)));
> - int b = av_clip_uint16(lrintf(65535.0f * rdpx(src[1] + i)));
> - int r = av_clip_uint16(lrintf(65535.0f * rdpx(src[2] + i)));
> + int g = lrintf(clampf(65535.0f * rdpx(src[0] + i), 0.0f, 65535.0f));
> + int b = lrintf(clampf(65535.0f * rdpx(src[1] + i), 0.0f, 65535.0f));
> + int r = lrintf(clampf(65535.0f * rdpx(src[2] + i), 0.0f, 65535.0f));
>
> dst[i] = (ry*r + gy*g + by*b + (0x2001 << (RGB2YUV_SHIFT - 1))) >> RGB2YUV_SHIFT;
> }
> @@ -1021,7 +1026,7 @@ static av_always_inline void grayf32ToY16_c(uint8_t *_dst, const uint8_t *_src,
> uint16_t *dst = (uint16_t *)_dst;
>
> for (i = 0; i < width; ++i){
> - dst[i] = av_clip_uint16(lrintf(65535.0f * rdpx(src + i)));
> + dst[i] = lrintf(clampf(65535.0f * rdpx(src + i), 0.0f, 65535.0f));
> }
> }
>
> --
> 2.31.1.windows.1
>
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