swr: scale data down in noise shaping to avoid cliping

[ffmpeg] / libswresample / dither.c

diff --git a/libswresample/dither.c b/libswresample/dither.c
index 79113f4c23d9bce8179411e2cbbe1c605df58825..d7a5b6b55876ef45e9b215e4c8dc6368fffda716 100644 (file)
--- a/libswresample/dither.c
+++ b/libswresample/dither.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2012 Michael Niedermayer (michaelni@gmx.at)
+ * Copyright (C) 2012-2013 Michael Niedermayer (michaelni@gmx.at)
  *
  * This file is part of libswresample
  *
@@ -21,39 +21,26 @@
 #include "libavutil/avassert.h"
 #include "swresample_internal.h"
 
-void swri_get_dither(SwrContext *s, void *dst, int len, unsigned seed, enum AVSampleFormat out_fmt, enum AVSampleFormat in_fmt) {
-    double scale = 0;
+#include "noise_shaping_data.c"
+
+void swri_get_dither(SwrContext *s, void *dst, int len, unsigned seed, enum AVSampleFormat noise_fmt) {
+    double scale = s->dither.noise_scale;
 #define TMP_EXTRA 2
     double *tmp = av_malloc((len + TMP_EXTRA) * sizeof(double));
     int i;
 
-    out_fmt = av_get_packed_sample_fmt(out_fmt);
-    in_fmt  = av_get_packed_sample_fmt( in_fmt);
-
-    if(in_fmt == AV_SAMPLE_FMT_FLT || in_fmt == AV_SAMPLE_FMT_DBL){
-        if(out_fmt == AV_SAMPLE_FMT_S32) scale = 1.0/(1L<<31);
-        if(out_fmt == AV_SAMPLE_FMT_S16) scale = 1.0/(1L<<15);
-        if(out_fmt == AV_SAMPLE_FMT_U8 ) scale = 1.0/(1L<< 7);
-    }
-    if(in_fmt == AV_SAMPLE_FMT_S32 && out_fmt == AV_SAMPLE_FMT_S16) scale = 1L<<16;
-    if(in_fmt == AV_SAMPLE_FMT_S32 && out_fmt == AV_SAMPLE_FMT_U8 ) scale = 1L<<24;
-    if(in_fmt == AV_SAMPLE_FMT_S16 && out_fmt == AV_SAMPLE_FMT_U8 ) scale = 1L<<8;
-
-    scale *= s->dither_scale;
-
     for(i=0; i<len + TMP_EXTRA; i++){
         double v;
         seed = seed* 1664525 + 1013904223;
 
-        switch(s->dither_method){
+        switch(s->dither.method){
             case SWR_DITHER_RECTANGULAR: v= ((double)seed) / UINT_MAX - 0.5; break;
-            case SWR_DITHER_TRIANGULAR :
-            case SWR_DITHER_TRIANGULAR_HIGHPASS :
+            default:
+                av_assert0(s->dither.method < SWR_DITHER_NB);
                 v = ((double)seed) / UINT_MAX;
                 seed = seed*1664525 + 1013904223;
                 v-= ((double)seed) / UINT_MAX;
                 break;
-            default: av_assert0(0);
         }
         tmp[i] = v;
     }
@@ -61,27 +48,95 @@ void swri_get_dither(SwrContext *s, void *dst, int len, unsigned seed, enum AVSa
     for(i=0; i<len; i++){
         double v;
 
-        switch(s->dither_method){
-            case SWR_DITHER_RECTANGULAR:
-            case SWR_DITHER_TRIANGULAR :
+        switch(s->dither.method){
+            default:
+                av_assert0(s->dither.method < SWR_DITHER_NB);
                 v = tmp[i];
                 break;
             case SWR_DITHER_TRIANGULAR_HIGHPASS :
                 v = (- tmp[i] + 2*tmp[i+1] - tmp[i+2]) / sqrt(6);
                 break;
-            default: av_assert0(0);
         }
 
         v*= scale;
 
-        switch(in_fmt){
-            case AV_SAMPLE_FMT_S16: ((int16_t*)dst)[i] = v; break;
-            case AV_SAMPLE_FMT_S32: ((int32_t*)dst)[i] = v; break;
-            case AV_SAMPLE_FMT_FLT: ((float  *)dst)[i] = v; break;
-            case AV_SAMPLE_FMT_DBL: ((double *)dst)[i] = v; break;
+        switch(noise_fmt){
+            case AV_SAMPLE_FMT_S16P: ((int16_t*)dst)[i] = v; break;
+            case AV_SAMPLE_FMT_S32P: ((int32_t*)dst)[i] = v; break;
+            case AV_SAMPLE_FMT_FLTP: ((float  *)dst)[i] = v; break;
+            case AV_SAMPLE_FMT_DBLP: ((double *)dst)[i] = v; break;
             default: av_assert0(0);
         }
     }
 
     av_free(tmp);
 }
+
+int swri_dither_init(SwrContext *s, enum AVSampleFormat out_fmt, enum AVSampleFormat in_fmt)
+{
+    int i;
+    double scale = 0;
+
+    if (s->dither.method > SWR_DITHER_TRIANGULAR_HIGHPASS && s->dither.method <= SWR_DITHER_NS)
+        return AVERROR(EINVAL);
+
+    out_fmt = av_get_packed_sample_fmt(out_fmt);
+    in_fmt  = av_get_packed_sample_fmt( in_fmt);
+
+    if(in_fmt == AV_SAMPLE_FMT_FLT || in_fmt == AV_SAMPLE_FMT_DBL){
+        if(out_fmt == AV_SAMPLE_FMT_S32) scale = 1.0/(1L<<31);
+        if(out_fmt == AV_SAMPLE_FMT_S16) scale = 1.0/(1L<<15);
+        if(out_fmt == AV_SAMPLE_FMT_U8 ) scale = 1.0/(1L<< 7);
+    }
+    if(in_fmt == AV_SAMPLE_FMT_S32 && out_fmt == AV_SAMPLE_FMT_S16) scale = 1L<<16;
+    if(in_fmt == AV_SAMPLE_FMT_S32 && out_fmt == AV_SAMPLE_FMT_U8 ) scale = 1L<<24;
+    if(in_fmt == AV_SAMPLE_FMT_S16 && out_fmt == AV_SAMPLE_FMT_U8 ) scale = 1L<<8;
+
+    scale *= s->dither.scale;
+
+    s->dither.ns_pos = 0;
+    s->dither.noise_scale=   scale;
+    s->dither.ns_scale   =   scale;
+    s->dither.ns_scale_1 = 1/scale;
+    memset(s->dither.ns_errors, 0, sizeof(s->dither.ns_errors));
+    for (i=0; filters[i].coefs; i++) {
+        const filter_t *f = &filters[i];
+        if (fabs(s->out_sample_rate - f->rate) / f->rate <= .05 && f->name == s->dither.method) {
+            int j;
+            s->dither.ns_taps = f->len;
+            for (j=0; j<f->len; j++)
+                s->dither.ns_coeffs[j] = f->coefs[j];
+            s->dither.ns_scale_1 *= 1 - exp(f->gain_cB * M_LN10 * 0.005) * 2 / (1<<(8*av_get_bytes_per_sample(out_fmt)));
+            break;
+        }
+    }
+    if (!filters[i].coefs && s->dither.method > SWR_DITHER_NS) {
+        av_log(s, AV_LOG_WARNING, "Requested noise shaping dither not available at this sampling rate, using triangular hp dither\n");
+        s->dither.method = SWR_DITHER_TRIANGULAR_HIGHPASS;
+    }
+
+    s->dither.noise = s->preout;
+    if (s->dither.method > SWR_DITHER_NS) {
+        s->dither.noise.bps = 4;
+        s->dither.noise.fmt = AV_SAMPLE_FMT_FLTP;
+        s->dither.noise_scale = 1;
+    }
+
+    return 0;
+}
+
+#define TEMPLATE_DITHER_S16
+#include "dither_template.c"
+#undef TEMPLATE_DITHER_S16
+
+#define TEMPLATE_DITHER_S32
+#include "dither_template.c"
+#undef TEMPLATE_DITHER_S32
+
+#define TEMPLATE_DITHER_FLT
+#include "dither_template.c"
+#undef TEMPLATE_DITHER_FLT
+
+#define TEMPLATE_DITHER_DBL
+#include "dither_template.c"
+#undef TEMPLATE_DITHER_DBL