aacsbr: move some simdable loops to function pointers

This prepares for assembly optimisations by moving the most
time-consuming loops to functions called through pointers
in a new context.
Signed-off-by: Mans Rullgard <mans@mansr.com>

libavcodec/Makefile

@@ -52,7 +52,8 @@ OBJS-$(CONFIG_VDPAU)                   += vdpau.o
 OBJS-$(CONFIG_A64MULTI_ENCODER)        += a64multienc.o elbg.o
 OBJS-$(CONFIG_A64MULTI5_ENCODER)       += a64multienc.o elbg.o
 OBJS-$(CONFIG_AAC_DECODER)             += aacdec.o aactab.o aacsbr.o aacps.o \
-                                          aacadtsdec.o mpeg4audio.o kbdwin.o
+                                          aacadtsdec.o mpeg4audio.o kbdwin.o \
+                                          sbrdsp.o
 OBJS-$(CONFIG_AAC_ENCODER)             += aacenc.o aaccoder.o    \
                                           aacpsy.o aactab.o      \
                                           psymodel.o iirfilter.o \

libavcodec/aacsbrdata.h

@@ -352,7 +352,7 @@ static DECLARE_ALIGNED(16, float, sbr_qmf_window_us)[640] = {
      0.8537385600,
 };
 
-static const float sbr_noise_table[512][2] = {
+const float ff_sbr_noise_table[512][2] = {
 {-0.99948153278296, -0.59483417516607}, { 0.97113454393991, -0.67528515225647},
 { 0.14130051758487, -0.95090983575689}, {-0.47005496701697, -0.37340549728647},
 { 0.80705063769351,  0.29653668284408}, {-0.38981478896926,  0.89572605717087},

libavcodec/sbr.h

@@ -32,6 +32,7 @@
 #include <stdint.h>
 #include "fft.h"
 #include "aacps.h"
+#include "sbrdsp.h"
 
 /**
  * Spectral Band Replication header - spectrum parameters that invoke a reset if they differ from the previous header.
@@ -180,6 +181,7 @@ typedef struct {
     DECLARE_ALIGNED(16, float, qmf_filter_scratch)[5][64];
     FFTContext         mdct_ana;
     FFTContext         mdct;
+    SBRDSPContext      dsp;
 } SpectralBandReplication;
 
 #endif /* AVCODEC_SBR_H */

libavcodec/sbrdsp.c

+/*
+ * AAC Spectral Band Replication decoding functions
+ * Copyright (c) 2008-2009 Robert Swain ( rob opendot cl )
+ * Copyright (c) 2009-2010 Alex Converse <alex.converse@gmail.com>
+ *
+ * This file is part of Libav.
+ *
+ * Libav 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.
+ *
+ * Libav 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 Libav; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include "libavutil/attributes.h"
+#include "sbrdsp.h"
+
+static void sbr_sum64x5_c(float *z)
+{
+    int k;
+    for (k = 0; k < 64; k++) {
+        float f = z[k] + z[k + 64] + z[k + 128] + z[k + 192] + z[k + 256];
+        z[k] = f;
+    }
+}
+
+static float sbr_sum_square_c(float (*x)[2], int n)
+{
+    float sum = 0.0f;
+    int i;
+
+    for (i = 0; i < n; i++)
+        sum += x[i][0] * x[i][0] + x[i][1] * x[i][1];
+
+    return sum;
+}
+
+static void sbr_neg_odd_64_c(float *x)
+{
+    int i;
+    for (i = 1; i < 64; i += 2)
+        x[i] = -x[i];
+}
+
+static void sbr_qmf_pre_shuffle_c(float *z)
+{
+    int k;
+    z[64] = z[0];
+    z[65] = z[1];
+    for (k = 1; k < 32; k++) {
+        z[64+2*k  ] = -z[64 - k];
+        z[64+2*k+1] =  z[ k + 1];
+    }
+}
+
+static void sbr_qmf_post_shuffle_c(float W[32][2], const float *z)
+{
+    int k;
+    for (k = 0; k < 32; k++) {
+        W[k][0] = -z[63-k];
+        W[k][1] = z[k];
+    }
+}
+
+static void sbr_qmf_deint_neg_c(float *v, const float *src)
+{
+    int i;
+    for (i = 0; i < 32; i++) {
+        v[     i] =  src[63 - 2*i    ];
+        v[63 - i] = -src[63 - 2*i - 1];
+    }
+}
+
+static void sbr_qmf_deint_bfly_c(float *v, const float *src0, const float *src1)
+{
+    int i;
+    for (i = 0; i < 64; i++) {
+        v[      i] = src0[i] - src1[63 - i];
+        v[127 - i] = src0[i] + src1[63 - i];
+    }
+}
+
+static av_always_inline void autocorrelate(const float x[40][2],
+                                           float phi[3][2][2], int lag)
+{
+    int i;
+    float real_sum = 0.0f;
+    float imag_sum = 0.0f;
+    if (lag) {
+        for (i = 1; i < 38; i++) {
+            real_sum += x[i][0] * x[i+lag][0] + x[i][1] * x[i+lag][1];
+            imag_sum += x[i][0] * x[i+lag][1] - x[i][1] * x[i+lag][0];
+        }
+        phi[2-lag][1][0] = real_sum + x[ 0][0] * x[lag][0] + x[ 0][1] * x[lag][1];
+        phi[2-lag][1][1] = imag_sum + x[ 0][0] * x[lag][1] - x[ 0][1] * x[lag][0];
+        if (lag == 1) {
+            phi[0][0][0] = real_sum + x[38][0] * x[39][0] + x[38][1] * x[39][1];
+            phi[0][0][1] = imag_sum + x[38][0] * x[39][1] - x[38][1] * x[39][0];
+        }
+    } else {
+        for (i = 1; i < 38; i++) {
+            real_sum += x[i][0] * x[i][0] + x[i][1] * x[i][1];
+        }
+        phi[2][1][0] = real_sum + x[ 0][0] * x[ 0][0] + x[ 0][1] * x[ 0][1];
+        phi[1][0][0] = real_sum + x[38][0] * x[38][0] + x[38][1] * x[38][1];
+    }
+}
+
+static void sbr_autocorrelate_c(const float x[40][2], float phi[3][2][2])
+{
+    autocorrelate(x, phi, 0);
+    autocorrelate(x, phi, 1);
+    autocorrelate(x, phi, 2);
+}
+
+static void sbr_hf_gen_c(float (*X_high)[2], const float (*X_low)[2],
+                         const float alpha0[2], const float alpha1[2],
+                         float bw, int start, int end)
+{
+    float alpha[4];
+    int i;
+
+    alpha[0] = alpha1[0] * bw * bw;
+    alpha[1] = alpha1[1] * bw * bw;
+    alpha[2] = alpha0[0] * bw;
+    alpha[3] = alpha0[1] * bw;
+
+    for (i = start; i < end; i++) {
+        X_high[i][0] =
+            X_low[i - 2][0] * alpha[0] -
+            X_low[i - 2][1] * alpha[1] +
+            X_low[i - 1][0] * alpha[2] -
+            X_low[i - 1][1] * alpha[3] +
+            X_low[i][0];
+        X_high[i][1] =
+            X_low[i - 2][1] * alpha[0] +
+            X_low[i - 2][0] * alpha[1] +
+            X_low[i - 1][1] * alpha[2] +
+            X_low[i - 1][0] * alpha[3] +
+            X_low[i][1];
+    }
+}
+
+static void sbr_hf_g_filt_c(float (*Y)[2], const float (*X_high)[40][2],
+                            const float *g_filt, int m_max, int ixh)
+{
+    int m;
+
+    for (m = 0; m < m_max; m++) {
+        Y[m][0] = X_high[m][ixh][0] * g_filt[m];
+        Y[m][1] = X_high[m][ixh][1] * g_filt[m];
+    }
+}
+
+static av_always_inline void sbr_hf_apply_noise(float (*Y)[2],
+                                                const float *s_m,
+                                                const float *q_filt,
+                                                int noise,
+                                                float phi_sign0,
+                                                float phi_sign1,
+                                                int m_max)
+{
+    int m;
+
+    for (m = 0; m < m_max; m++) {
+        float y0 = Y[m][0];
+        float y1 = Y[m][1];
+        noise = (noise + 1) & 0x1ff;
+        if (s_m[m]) {
+            y0 += s_m[m] * phi_sign0;
+            y1 += s_m[m] * phi_sign1;
+        } else {
+            y0 += q_filt[m] * ff_sbr_noise_table[noise][0];
+            y1 += q_filt[m] * ff_sbr_noise_table[noise][1];
+        }
+        Y[m][0] = y0;
+        Y[m][1] = y1;
+        phi_sign1 = -phi_sign1;
+    }
+}
+
+static void sbr_hf_apply_noise_0(float (*Y)[2], const float *s_m,
+                                 const float *q_filt, int noise,
+                                 int kx, int m_max)
+{
+    sbr_hf_apply_noise(Y, s_m, q_filt, noise, 1.0, 0.0, m_max);
+}
+
+static void sbr_hf_apply_noise_1(float (*Y)[2], const float *s_m,
+                                 const float *q_filt, int noise,
+                                 int kx, int m_max)
+{
+    float phi_sign = 1 - 2 * (kx & 1);
+    sbr_hf_apply_noise(Y, s_m, q_filt, noise, 0.0, phi_sign, m_max);
+}
+
+static void sbr_hf_apply_noise_2(float (*Y)[2], const float *s_m,
+                                 const float *q_filt, int noise,
+                                 int kx, int m_max)
+{
+    sbr_hf_apply_noise(Y, s_m, q_filt, noise, -1.0, 0.0, m_max);
+}
+
+static void sbr_hf_apply_noise_3(float (*Y)[2], const float *s_m,
+                                 const float *q_filt, int noise,
+                                 int kx, int m_max)
+{
+    float phi_sign = 1 - 2 * (kx & 1);
+    sbr_hf_apply_noise(Y, s_m, q_filt, noise, 0.0, -phi_sign, m_max);
+}
+
+av_cold void ff_sbrdsp_init(SBRDSPContext *s)
+{
+    s->sum64x5 = sbr_sum64x5_c;
+    s->sum_square = sbr_sum_square_c;
+    s->neg_odd_64 = sbr_neg_odd_64_c;
+    s->qmf_pre_shuffle = sbr_qmf_pre_shuffle_c;
+    s->qmf_post_shuffle = sbr_qmf_post_shuffle_c;
+    s->qmf_deint_neg = sbr_qmf_deint_neg_c;
+    s->qmf_deint_bfly = sbr_qmf_deint_bfly_c;
+    s->autocorrelate = sbr_autocorrelate_c;
+    s->hf_gen = sbr_hf_gen_c;
+    s->hf_g_filt = sbr_hf_g_filt_c;
+
+    s->hf_apply_noise[0] = sbr_hf_apply_noise_0;
+    s->hf_apply_noise[1] = sbr_hf_apply_noise_1;
+    s->hf_apply_noise[2] = sbr_hf_apply_noise_2;
+    s->hf_apply_noise[3] = sbr_hf_apply_noise_3;
+}

libavcodec/sbrdsp.h

+/*
+ * Copyright (c) 2012 Mans Rullgard
+ *
+ * This file is part of Libav.
+ *
+ * Libav 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.
+ *
+ * Libav 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 Libav; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#ifndef LIBAVCODEC_SBRDSP_H
+#define LIBAVCODEC_SBRDSP_H
+
+typedef struct SBRDSPContext {
+    void (*sum64x5)(float *z);
+    float (*sum_square)(float (*x)[2], int n);
+    void (*neg_odd_64)(float *x);
+    void (*qmf_pre_shuffle)(float *z);
+    void (*qmf_post_shuffle)(float W[32][2], const float *z);
+    void (*qmf_deint_neg)(float *v, const float *src);
+    void (*qmf_deint_bfly)(float *v, const float *src0, const float *src1);
+    void (*autocorrelate)(const float x[40][2], float phi[3][2][2]);
+    void (*hf_gen)(float (*X_high)[2], const float (*X_low)[2],
+                   const float alpha0[2], const float alpha1[2],
+                   float bw, int start, int end);
+    void (*hf_g_filt)(float (*Y)[2], const float (*X_high)[40][2],
+                      const float *g_filt, int m_max, int ixh);
+    void (*hf_apply_noise[4])(float (*Y)[2], const float *s_m,
+                              const float *q_filt, int noise,
+                              int kx, int m_max);
+} SBRDSPContext;
+
+extern const float ff_sbr_noise_table[][2];
+
+void ff_sbrdsp_init(SBRDSPContext *s);
+
+#endif