[FFmpeg-devel] [PATCH] swscale/output: Altivec-optimize float yuv2plane1
Lauri Kasanen
cand at gmx.com
Sat Dec 15 18:32:31 EET 2018
This function wouldn't benefit from VSX instructions, and input
and output share alignment, so I put it under altivec.
./ffmpeg_g -f rawvideo -pix_fmt rgb24 -s hd1080 -i /dev/zero -pix_fmt grayf32le \
-f null -vframes 100 -v error -nostats -
3743 UNITS in planar1, 65495 runs, 41 skips
-cpuflags 0
23511 UNITS in planar1, 65530 runs, 6 skips
grayf32be
4647 UNITS in planar1, 65449 runs, 87 skips
-cpuflags 0
28608 UNITS in planar1, 65530 runs, 6 skips
The native speedup is 6.28133, and the bswapping one 6.15623.
Fate passes, each format tested with an image to video conversion.
Signed-off-by: Lauri Kasanen <cand at gmx.com>
---
Tested on POWER8 LE. Testing on earlier ppc and/or BE appreciated.
libswscale/ppc/swscale_altivec.c | 139 ++++++++++++++++++++++++++++++++++++++-
1 file changed, 137 insertions(+), 2 deletions(-)
diff --git a/libswscale/ppc/swscale_altivec.c b/libswscale/ppc/swscale_altivec.c
index 1d2b2fa..2ef5257 100644
--- a/libswscale/ppc/swscale_altivec.c
+++ b/libswscale/ppc/swscale_altivec.c
@@ -31,7 +31,8 @@
#include "yuv2rgb_altivec.h"
#include "libavutil/ppc/util_altivec.h"
-#if HAVE_ALTIVEC && HAVE_BIGENDIAN
+#if HAVE_ALTIVEC
+#if HAVE_BIGENDIAN
#define vzero vec_splat_s32(0)
#define GET_LS(a,b,c,s) {\
@@ -102,7 +103,135 @@
#include "swscale_ppc_template.c"
#undef FUNC
-#endif /* HAVE_ALTIVEC && HAVE_BIGENDIAN */
+#endif /* HAVE_BIGENDIAN */
+
+#define output_pixel(pos, val, bias, signedness) \
+ if (big_endian) { \
+ AV_WB16(pos, bias + av_clip_ ## signedness ## 16(val >> shift)); \
+ } else { \
+ AV_WL16(pos, bias + av_clip_ ## signedness ## 16(val >> shift)); \
+ }
+
+static void
+yuv2plane1_float_u(const int32_t *src, float *dest, int dstW, int start)
+{
+ static const int big_endian = HAVE_BIGENDIAN;
+ static const int shift = 3;
+ static const float float_mult = 1.0f / 65535.0f;
+ int i, val;
+ uint16_t val_uint;
+
+ for (i = start; i < dstW; ++i){
+ val = src[i] + (1 << (shift - 1));
+ output_pixel(&val_uint, val, 0, uint);
+ dest[i] = float_mult * (float)val_uint;
+ }
+}
+
+static void
+yuv2plane1_float_bswap_u(const int32_t *src, uint32_t *dest, int dstW, int start)
+{
+ static const int big_endian = HAVE_BIGENDIAN;
+ static const int shift = 3;
+ static const float float_mult = 1.0f / 65535.0f;
+ int i, val;
+ uint16_t val_uint;
+
+ for (i = start; i < dstW; ++i){
+ val = src[i] + (1 << (shift - 1));
+ output_pixel(&val_uint, val, 0, uint);
+ dest[i] = av_bswap32(av_float2int(float_mult * (float)val_uint));
+ }
+}
+
+static void yuv2plane1_float_altivec(const int32_t *src, float *dest, int dstW)
+{
+ const int dst_u = -(uintptr_t)dest & 3;
+ const int shift = 3;
+ const int add = (1 << (shift - 1));
+ const int clip = (1 << 16) - 1;
+ const float fmult = 1.0f / 65535.0f;
+ const vector uint32_t vadd = (vector uint32_t) {add, add, add, add};
+ const vector uint32_t vshift = (vector uint32_t) vec_splat_u32(shift);
+ const vector uint32_t vlargest = (vector uint32_t) {clip, clip, clip, clip};
+ const vector float vmul = (vector float) {fmult, fmult, fmult, fmult};
+ const vector float vzero = (vector float) {0, 0, 0, 0};
+ vector uint32_t v;
+ vector float vd;
+ int i;
+
+ yuv2plane1_float_u(src, dest, dst_u, 0);
+
+ for (i = dst_u; i < dstW - 3; i += 4) {
+ v = vec_ld(0, (const uint32_t *) &src[i]);
+ v = vec_add(v, vadd);
+ v = vec_sr(v, vshift);
+ v = vec_min(v, vlargest);
+
+ vd = vec_ctf(v, 0);
+ vd = vec_madd(vd, vmul, vzero);
+
+ vec_st(vd, 0, &dest[i]);
+ }
+
+ yuv2plane1_float_u(src, dest, dstW, i);
+}
+
+static void yuv2plane1_float_bswap_altivec(const int32_t *src, uint32_t *dest, int dstW)
+{
+ const int dst_u = -(uintptr_t)dest & 3;
+ const int shift = 3;
+ const int add = (1 << (shift - 1));
+ const int clip = (1 << 16) - 1;
+ const float fmult = 1.0f / 65535.0f;
+ const vector uint32_t vadd = (vector uint32_t) {add, add, add, add};
+ const vector uint32_t vshift = (vector uint32_t) vec_splat_u32(shift);
+ const vector uint32_t vlargest = (vector uint32_t) {clip, clip, clip, clip};
+ const vector float vmul = (vector float) {fmult, fmult, fmult, fmult};
+ const vector float vzero = (vector float) {0, 0, 0, 0};
+ const vector uint32_t vswapbig = (vector uint32_t) {16, 16, 16, 16};
+ const vector uint16_t vswapsmall = vec_splat_u16(8);
+ vector uint32_t v;
+ vector float vd;
+ int i;
+
+ yuv2plane1_float_bswap_u(src, dest, dst_u, 0);
+
+ for (i = dst_u; i < dstW - 3; i += 4) {
+ v = vec_ld(0, (const uint32_t *) &src[i]);
+ v = vec_add(v, vadd);
+ v = vec_sr(v, vshift);
+ v = vec_min(v, vlargest);
+
+ vd = vec_ctf(v, 0);
+ vd = vec_madd(vd, vmul, vzero);
+
+ vd = (vector float) vec_rl((vector uint32_t) vd, vswapbig);
+ vd = (vector float) vec_rl((vector uint16_t) vd, vswapsmall);
+
+ vec_st(vd, 0, (float *) &dest[i]);
+ }
+
+ yuv2plane1_float_bswap_u(src, dest, dstW, i);
+}
+
+#define yuv2plane1_float(template, dest_type, BE_LE) \
+static void yuv2plane1_float ## BE_LE ## _altivec(const int16_t *src, uint8_t *dest, \
+ int dstW, \
+ const uint8_t *dither, int offset) \
+{ \
+ template((const int32_t *)src, (dest_type *)dest, dstW); \
+}
+
+#if HAVE_BIGENDIAN
+yuv2plane1_float(yuv2plane1_float_altivec, float, BE)
+yuv2plane1_float(yuv2plane1_float_bswap_altivec, uint32_t, LE)
+#else
+yuv2plane1_float(yuv2plane1_float_altivec, float, LE)
+yuv2plane1_float(yuv2plane1_float_bswap_altivec, uint32_t, BE)
+#endif
+
+#endif /* HAVE_ALTIVEC */
av_cold void ff_sws_init_swscale_ppc(SwsContext *c)
{
@@ -124,6 +253,12 @@ av_cold void ff_sws_init_swscale_ppc(SwsContext *c)
}
#endif
+ if (dstFormat == AV_PIX_FMT_GRAYF32BE) {
+ c->yuv2plane1 = yuv2plane1_floatBE_altivec;
+ } else if (dstFormat == AV_PIX_FMT_GRAYF32LE) {
+ c->yuv2plane1 = yuv2plane1_floatLE_altivec;
+ }
+
/* The following list of supported dstFormat values should
* match what's found in the body of ff_yuv2packedX_altivec() */
if (!(c->flags & (SWS_BITEXACT | SWS_FULL_CHR_H_INT)) && !c->needAlpha) {
--
2.6.2
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