[FFmpeg-cvslog] SIMD opus pvq_search implementation
Ivan Kalvachev
git at videolan.org
Fri Aug 18 19:18:57 EEST 2017
ffmpeg | branch: master | Ivan Kalvachev <ikalvachev at gmail.com> | Thu Jun 8 22:24:33 2017 +0300| [7205513f8f4b32c403c733d7d2ce2f440837397d] | committer: Rostislav Pehlivanov
SIMD opus pvq_search implementation
Explanation on the workings and methods used by the
Pyramid Vector Quantization Search function
could be found in the following Work-In-Progress mail threads:
http://ffmpeg.org/pipermail/ffmpeg-devel/2017-June/212146.html
http://ffmpeg.org/pipermail/ffmpeg-devel/2017-June/212816.html
http://ffmpeg.org/pipermail/ffmpeg-devel/2017-July/213030.html
http://ffmpeg.org/pipermail/ffmpeg-devel/2017-July/213436.html
Signed-off-by: Ivan Kalvachev <ikalvachev at gmail.com>
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=7205513f8f4b32c403c733d7d2ce2f440837397d
---
libavcodec/opus_pvq.c | 3 +
libavcodec/opus_pvq.h | 5 +-
libavcodec/x86/Makefile | 3 +
libavcodec/x86/opus_dsp_init.c | 45 +++++
libavcodec/x86/opus_pvq_search.asm | 395 +++++++++++++++++++++++++++++++++++++
5 files changed, 449 insertions(+), 2 deletions(-)
diff --git a/libavcodec/opus_pvq.c b/libavcodec/opus_pvq.c
index 2ac66a0ede..2fb276099b 100644
--- a/libavcodec/opus_pvq.c
+++ b/libavcodec/opus_pvq.c
@@ -947,6 +947,9 @@ int av_cold ff_celt_pvq_init(CeltPVQ **pvq)
s->encode_band = pvq_encode_band;
s->band_cost = pvq_band_cost;
+ if (ARCH_X86)
+ ff_opus_dsp_init_x86(s);
+
*pvq = s;
return 0;
diff --git a/libavcodec/opus_pvq.h b/libavcodec/opus_pvq.h
index 6691494838..9246337360 100644
--- a/libavcodec/opus_pvq.h
+++ b/libavcodec/opus_pvq.h
@@ -33,8 +33,8 @@
float *lowband_scratch, int fill)
struct CeltPVQ {
- DECLARE_ALIGNED(32, int, qcoeff )[176];
- DECLARE_ALIGNED(32, float, hadamard_tmp)[176];
+ DECLARE_ALIGNED(32, int, qcoeff )[256];
+ DECLARE_ALIGNED(32, float, hadamard_tmp)[256];
float (*pvq_search)(float *X, int *y, int K, int N);
@@ -45,6 +45,7 @@ struct CeltPVQ {
};
int ff_celt_pvq_init (struct CeltPVQ **pvq);
+void ff_opus_dsp_init_x86(struct CeltPVQ *s);
void ff_celt_pvq_uninit(struct CeltPVQ **pvq);
#endif /* AVCODEC_OPUS_PVQ_H */
diff --git a/libavcodec/x86/Makefile b/libavcodec/x86/Makefile
index 0dbc46504e..e36644c72a 100644
--- a/libavcodec/x86/Makefile
+++ b/libavcodec/x86/Makefile
@@ -52,6 +52,8 @@ OBJS-$(CONFIG_APNG_DECODER) += x86/pngdsp_init.o
OBJS-$(CONFIG_CAVS_DECODER) += x86/cavsdsp.o
OBJS-$(CONFIG_DCA_DECODER) += x86/dcadsp_init.o x86/synth_filter_init.o
OBJS-$(CONFIG_DNXHD_ENCODER) += x86/dnxhdenc_init.o
+OBJS-$(CONFIG_OPUS_DECODER) += x86/opus_dsp_init.o
+OBJS-$(CONFIG_OPUS_ENCODER) += x86/opus_dsp_init.o
OBJS-$(CONFIG_HEVC_DECODER) += x86/hevcdsp_init.o
OBJS-$(CONFIG_JPEG2000_DECODER) += x86/jpeg2000dsp_init.o
OBJS-$(CONFIG_MLP_DECODER) += x86/mlpdsp_init.o
@@ -123,6 +125,7 @@ X86ASM-OBJS-$(CONFIG_MDCT15) += x86/mdct15.o
X86ASM-OBJS-$(CONFIG_ME_CMP) += x86/me_cmp.o
X86ASM-OBJS-$(CONFIG_MPEGAUDIODSP) += x86/imdct36.o
X86ASM-OBJS-$(CONFIG_MPEGVIDEOENC) += x86/mpegvideoencdsp.o
+X86ASM-OBJS-$(CONFIG_OPUS_ENCODER) += x86/opus_pvq_search.o
X86ASM-OBJS-$(CONFIG_PIXBLOCKDSP) += x86/pixblockdsp.o
X86ASM-OBJS-$(CONFIG_QPELDSP) += x86/qpeldsp.o \
x86/fpel.o \
diff --git a/libavcodec/x86/opus_dsp_init.c b/libavcodec/x86/opus_dsp_init.c
new file mode 100644
index 0000000000..c51f786ee8
--- /dev/null
+++ b/libavcodec/x86/opus_dsp_init.c
@@ -0,0 +1,45 @@
+/*
+ * Opus encoder assembly optimizations
+ * Copyright (C) 2017 Ivan Kalvachev <ikalvachev 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 "config.h"
+
+#include "libavutil/x86/cpu.h"
+#include "libavcodec/opus_pvq.h"
+
+extern float ff_pvq_search_sse2(float *X, int *y, int K, int N);
+extern float ff_pvq_search_sse4(float *X, int *y, int K, int N);
+extern float ff_pvq_search_avx (float *X, int *y, int K, int N);
+
+av_cold void ff_opus_dsp_init_x86(CeltPVQ *s)
+{
+ int cpu_flags = av_get_cpu_flags();
+
+#if CONFIG_OPUS_ENCODER
+ if (EXTERNAL_SSE2(cpu_flags))
+ s->pvq_search = ff_pvq_search_sse2;
+
+ if (EXTERNAL_SSE4(cpu_flags))
+ s->pvq_search = ff_pvq_search_sse4;
+
+ if (EXTERNAL_AVX(cpu_flags))
+ s->pvq_search = ff_pvq_search_avx;
+#endif
+}
diff --git a/libavcodec/x86/opus_pvq_search.asm b/libavcodec/x86/opus_pvq_search.asm
new file mode 100644
index 0000000000..f0d9950e34
--- /dev/null
+++ b/libavcodec/x86/opus_pvq_search.asm
@@ -0,0 +1,395 @@
+;******************************************************************************
+;* SIMD optimized Opus encoder DSP function
+;*
+;* Copyright (C) 2017 Ivan Kalvachev <ikalvachev 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 "config.asm"
+%include "libavutil/x86/x86util.asm"
+
+%ifdef __NASM_VER__
+%use "smartalign"
+ALIGNMODE p6
+%endif
+
+; Use float op that give half precision but execute for around 3 cycles.
+; On Skylake & Ryzen the division is much faster (around 11c/3),
+; that makes the full precision code about 2% slower.
+; Opus also does use rsqrt approximation in their intrinsics code.
+%define USE_APPROXIMATION 1
+
+; Presearch tries to quantize by using the property Sum( abs(x[i]*K)/Sx ) = K.
+; If we use truncation for the division result then the integer Sum would be <= K.
+; By using nearest rounding we get closer approximation, but
+; we could also get more than K pulses and we have to remove the extra ones.
+; This method is the main improvement of the ffmpeg C function over the Opus original.
+%define PRESEARCH_ROUNDING 1
+
+SECTION_RODATA 64
+
+const_float_abs_mask: times 8 dd 0x7fffffff
+const_align_abs_edge: times 8 dd 0
+
+const_float_0_5: times 8 dd 0.5
+const_float_1: times 8 dd 1.0
+const_float_sign_mask: times 8 dd 0x80000000
+
+const_int32_offsets:
+ %rep 8
+ dd $-const_int32_offsets
+ %endrep
+SECTION .text
+
+;
+; Setup High Register to be used
+; for holding memory constants
+;
+; %1 - the register to be used, assmues it is >= mm8
+; %2 - name of the constant.
+;
+; Subsequent opcodes are going to use the constant in the form
+; "addps m0, mm_const_name" and it would be turned into:
+; "addps m0, [const_name]" on 32 bit arch or
+; "addps m0, m8" on 64 bit arch
+%macro SET_HI_REG_MM_CONSTANT 3 ; movop, reg, const_name
+%if num_mmregs > 8
+ %define mm_%3 %2
+ %{1} %2, [%3] ; movaps m8, [const_name]
+%else
+ %define mm_%3 [%3]
+%endif
+%endmacro
+
+;
+; Set Position Independent Code
+; Base address of a constant
+; %1 - the register to be used, if PIC is set
+; %2 - name of the constant.
+;
+; Subsequent opcode are going to use the base address in the form
+; "movaps m0, [pic_base_constant_name+r4]" and it would be turned into
+; "movaps m0, [r5 + r4]" if PIC is enabled
+; "movaps m0, [constant_name + r4]" if texrel are used
+%macro SET_PIC_BASE 3; reg, const_label
+%ifdef PIC
+ %{1} %2, [%3] ; lea r5, [rip+const]
+ %define pic_base_%3 %2
+%else
+ %define pic_base_%3 %3
+%endif
+%endmacro
+
+%macro PULSES_SEARCH 1
+; m6 Syy_norm
+; m7 Sxy_norm
+ addps m6, mm_const_float_0_5 ; Syy_norm += 1.0/2
+ pxor m1, m1 ; max_idx
+ xorps m3, m3 ; p_max
+ xor r4d, r4d
+align 16
+%%distortion_search:
+ movd xm2, dword r4d ; movd zero extends
+%ifidn %1,add
+ movaps m4, [tmpY + r4] ; y[i]
+ movaps m5, [tmpX + r4] ; X[i]
+
+ %if USE_APPROXIMATION == 1
+ xorps m0, m0
+ cmpps m0, m0, m5, 4 ; m0 = (X[i] != 0.0)
+ %endif
+
+ addps m4, m6 ; m4 = Syy_new = y[i] + Syy_norm
+ addps m5, m7 ; m5 = Sxy_new = X[i] + Sxy_norm
+
+ %if USE_APPROXIMATION == 1
+ andps m5, m0 ; if(X[i] == 0) Sxy_new = 0; Prevent aproximation error from setting pulses in array padding.
+ %endif
+
+%else
+ movaps m5, [tmpY + r4] ; m5 = y[i]
+
+ xorps m0, m0 ; m0 = 0;
+ cmpps m0, m0, m5, 1 ; m0 = (0<y)
+
+ subps m4, m6, m5 ; m4 = Syy_new = Syy_norm - y[i]
+ subps m5, m7, [tmpX + r4] ; m5 = Sxy_new = Sxy_norm - X[i]
+ andps m5, m0 ; (0<y)?m5:0
+%endif
+
+%if USE_APPROXIMATION == 1
+ rsqrtps m4, m4
+ mulps m5, m4 ; m5 = p = Sxy_new*approx(1/sqrt(Syy) )
+%else
+ mulps m5, m5
+ divps m5, m4 ; m5 = p = Sxy_new*Sxy_new/Syy
+%endif
+ VPBROADCASTD m2, xm2 ; m2=i (all lanes get same values, we add the offset-per-lane, later)
+
+ cmpps m0, m3, m5, 1 ; m0 = (m3 < m5) ; (p_max < p) ; (p > p_max)
+ maxps m3, m5 ; m3=max(p_max,p)
+ ; maxps here is faster than blendvps, despite blend having lower latency.
+
+ pand m2, m0 ; This version seems faster than sse41 pblendvb
+ pmaxsw m1, m2 ; SSE2 signed word, so it would work for N < 32768/4
+
+ add r4d, mmsize
+ cmp r4d, Nd
+ jb %%distortion_search
+
+ por m1, mm_const_int32_offsets ; max_idx offsets per individual lane (skipped in the inner loop)
+ movdqa m4, m1 ; needed for the aligned y[max_idx]+=1; processing
+
+%if mmsize >= 32
+; Merge parallel maximums round 8 (4 vs 4)
+
+ vextractf128 xm5, ym3, 1 ; xmm5 = ymm3[1x128] = ymm3[255..128b]
+ cmpps xm0, xm3, xm5, 1 ; m0 = (m3 < m5) = ( p[0x128] < p[1x128] )
+
+ vextracti128 xm2, ym1, 1 ; xmm2 = ymm1[1x128] = ymm1[255..128b]
+ BLENDVPS xm3, xm5, xm0 ; max_idx = m0 ? max_idx[1x128] : max_idx[0x128]
+ PBLENDVB xm1, xm2, xm0 ; p = m0 ? p[1x128] : p[0x128]
+%endif
+
+; Merge parallel maximums round 4 (2 vs 2)
+ ; m3=p[3210]
+ movhlps xm5, xm3 ; m5=p[xx32]
+ cmpps xm0, xm3, xm5, 1 ; m0 = (m3 < m5) = ( p[1,0] < p[3,2] )
+
+ pshufd xm2, xm1, q3232
+ BLENDVPS xm3, xm5, xm0 ; max_idx = m0 ? max_idx[3,2] : max_idx[1,0]
+ PBLENDVB xm1, xm2, xm0 ; p = m0 ? p[3,2] : p[1,0]
+
+; Merge parallel maximums final round (1 vs 1)
+ shufps xm0, xm3, xm3, q1111 ; m0 = m3[1] = p[1]
+ cmpss xm0, xm3, 5 ; m0 = !(m0 >= m3) = !( p[1] >= p[0] )
+
+ pshufd xm2, xm1, q1111
+ PBLENDVB xm1, xm2, xm0
+
+ movd dword r4d, xm1 ; zero extends to the rest of r4q
+
+ VBROADCASTSS m3, [tmpX + r4]
+ %{1}ps m7, m3 ; Sxy += X[max_idx]
+
+ VBROADCASTSS m5, [tmpY + r4]
+ %{1}ps m6, m5 ; Syy += Y[max_idx]
+
+ ; We have to update a single element in Y[i]
+ ; However writing 4 bytes and then doing 16 byte load in the inner loop
+ ; could cause a stall due to breaking write forwarding.
+ VPBROADCASTD m1, xm1
+ pcmpeqd m1, m1, m4 ; exactly 1 element matches max_idx and this finds it
+
+ and r4d, ~(mmsize-1) ; align address down, so the value pointed by max_idx is inside a mmsize load
+ movaps m5, [tmpY + r4] ; m5 = Y[y3...ym...y0]
+ andps m1, mm_const_float_1 ; m1 = [ 0...1.0...0]
+ %{1}ps m5, m1 ; m5 = Y[y3...ym...y0] +/- [0...1.0...0]
+ movaps [tmpY + r4], m5 ; Y[max_idx] +-= 1.0;
+%endmacro
+
+;
+; We need one more register for
+; PIC relative addressing. Use this
+; to count it in cglobal
+;
+%ifdef PIC
+ %define num_pic_regs 1
+%else
+ %define num_pic_regs 0
+%endif
+
+;
+; Pyramid Vector Quantization Search implementation
+;
+; float * inX - Unaligned (SIMD) access, it will be overread,
+; but extra data is masked away.
+; int32 * outY - Should be aligned and padded buffer.
+; It is used as temp buffer.
+; uint32 K - Number of pulses to have after quantizations.
+; uint32 N - Number of vector elements. Must be 0 < N < 256
+;
+%macro PVQ_FAST_SEARCH 0
+cglobal pvq_search, 4, 5+num_pic_regs, 11, 256*4, inX, outY, K, N
+%define tmpX rsp
+%define tmpY outYq
+
+ movaps m0, [const_float_abs_mask]
+ shl Nd, 2 ; N *= sizeof(float); also 32 bit operation zeroes the high 32 bits in 64 bit mode.
+ mov r4d, Nd
+
+ neg r4d
+ and r4d, mmsize-1
+
+ SET_PIC_BASE lea, r5, const_align_abs_edge ; rip+const
+ movups m2, [pic_base_const_align_abs_edge + r4 - mmsize]
+
+ add Nd, r4d ; N = align(N, mmsize)
+
+ lea r4d, [Nd - mmsize] ; N is rounded up (aligned up) to mmsize, so r4 can't become negative here, unless N=0.
+ movups m1, [inXq + r4]
+ andps m1, m2
+ movaps [tmpX + r4], m1 ; Sx = abs( X[N-1] )
+
+align 16
+%%loop_abs_sum:
+ sub r4d, mmsize
+ jc %%end_loop_abs_sum
+
+ movups m2, [inXq + r4]
+ andps m2, m0
+
+ movaps [tmpX + r4], m2 ; tmpX[i]=abs(X[i])
+ addps m1, m2 ; Sx += abs(X[i])
+ jmp %%loop_abs_sum
+
+align 16
+%%end_loop_abs_sum:
+
+ HSUMPS m1, m2 ; m1 = Sx
+
+ xorps m0, m0
+ comiss xm0, xm1 ;
+ jz %%zero_input ; if (Sx==0) goto zero_input
+
+ cvtsi2ss xm0, dword Kd ; m0 = K
+%if USE_APPROXIMATION == 1
+ rcpss xm1, xm1 ; m1 = approx(1/Sx)
+ mulss xm0, xm1 ; m0 = K*(1/Sx)
+%else
+ divss xm0, xm1 ; b = K/Sx
+ ; b = K/max_x
+%endif
+
+ VBROADCASTSS m0, xm0
+
+ lea r4d, [Nd - mmsize]
+ pxor m5, m5 ; Sy ( Sum of abs( y[i]) )
+ xorps m6, m6 ; Syy ( Sum of y[i]*y[i] )
+ xorps m7, m7 ; Sxy ( Sum of X[i]*y[i] )
+align 16
+%%loop_guess:
+ movaps m1, [tmpX + r4] ; m1 = X[i]
+ mulps m2, m0, m1 ; m2 = res*X[i]
+ %if PRESEARCH_ROUNDING == 0
+ cvttps2dq m2, m2 ; yt = (int)truncf( res*X[i] )
+ %else
+ cvtps2dq m2, m2 ; yt = (int)lrintf( res*X[i] )
+ %endif
+ paddd m5, m2 ; Sy += yt
+ cvtdq2ps m2, m2 ; yt = (float)yt
+ mulps m1, m2 ; m1 = X[i]*yt
+ movaps [tmpY + r4], m2 ; y[i] = m2
+ addps m7, m1 ; Sxy += m1;
+ mulps m2, m2 ; m2 = yt*yt
+ addps m6, m2 ; Syy += m2
+
+ sub r4d, mmsize
+ jnc %%loop_guess
+
+ HSUMPS m6, m1 ; Syy_norm
+ HADDD m5, m4 ; pulses
+
+ movd dword r4d, xm5 ; zero extends to the rest of r4q
+
+ sub Kd, r4d ; K -= pulses , also 32 bit operation zeroes high 32 bit in 64 bit mode.
+ jz %%finish ; K - pulses == 0
+
+ SET_HI_REG_MM_CONSTANT movaps, m8, const_float_0_5
+ SET_HI_REG_MM_CONSTANT movaps, m9, const_float_1
+ SET_HI_REG_MM_CONSTANT movdqa, m10, const_int32_offsets
+ ; Use Syy/2 in distortion parameter calculations.
+ ; Saves pre and post-caclulation to correct Y[] values.
+ ; Same precision, since float mantisa is normalized.
+ ; The SQRT approximation does differ.
+ HSUMPS m7, m0 ; Sxy_norm
+ mulps m6, mm_const_float_0_5
+
+ jc %%remove_pulses_loop ; K - pulses < 0
+
+align 16 ; K - pulses > 0
+%%add_pulses_loop:
+
+ PULSES_SEARCH add ; m6 Syy_norm ; m7 Sxy_norm
+
+ sub Kd, 1
+ jnz %%add_pulses_loop
+
+ addps m6, m6 ; Syy*=2
+
+ jmp %%finish
+
+align 16
+%%remove_pulses_loop:
+
+ PULSES_SEARCH sub ; m6 Syy_norm ; m7 Sxy_norm
+
+ add Kd, 1
+ jnz %%remove_pulses_loop
+
+ addps m6, m6 ; Syy*=2
+
+align 16
+%%finish:
+ lea r4d, [Nd - mmsize]
+ movaps m2, [const_float_sign_mask]
+
+align 16
+%%restore_sign_loop:
+ movaps m0, [tmpY + r4] ; m0 = Y[i]
+ movups m1, [inXq + r4] ; m1 = X[i]
+ andps m1, m2 ; m1 = sign(X[i])
+ orps m0, m1 ; m0 = Y[i]*sign
+ cvtps2dq m3, m0 ; m3 = (int)m0
+ movaps [outYq + r4], m3
+
+ sub r4d, mmsize
+ jnc %%restore_sign_loop
+%%return:
+
+%if ARCH_X86_64 == 0 ; sbrdsp
+ movss r0m, xm6 ; return (float)Syy_norm
+ fld dword r0m
+%else
+ movaps m0, m6 ; return (float)Syy_norm
+%endif
+
+ RET
+
+align 16
+%%zero_input:
+ lea r4d, [Nd - mmsize]
+ xorps m0, m0
+%%zero_loop:
+ movaps [outYq + r4], m0
+ sub r4d, mmsize
+ jnc %%zero_loop
+
+ movaps m6, [const_float_1]
+ jmp %%return
+%endmacro
+
+
+INIT_XMM sse2
+PVQ_FAST_SEARCH
+
+INIT_XMM sse4
+PVQ_FAST_SEARCH
+
+INIT_XMM avx
+PVQ_FAST_SEARCH
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