[FFmpeg-soc] [soc]: r3729 - in eac3: ac3dec.c eac3dec.c ffmpeg.patch

[jbr]

Author: jbr
Date: Mon Sep  8 04:36:32 2008
New Revision: 3729

Log:
apply noise-blended scaling of SPX coeffs

Modified:
   eac3/ac3dec.c
   eac3/eac3dec.c
   eac3/ffmpeg.patch

Modified: eac3/ac3dec.c
==============================================================================
--- eac3/ac3dec.c	(original)
+++ eac3/ac3dec.c	Mon Sep  8 04:36:32 2008
@@ -197,6 +197,7 @@ static av_cold int ac3_decode_init(AVCod
     ff_kbd_window_init(s->window, 5.0, 256);
     dsputil_init(&s->dsp, avctx);
     av_lfg_init(&s->dith_state, 0);
+    av_znrng_init(&s->spx_noise_state, 0xDEADBEEF);
 
     /* set bias values for float to int16 conversion */
     if(s->dsp.float_to_int16_interleave == ff_float_to_int16_interleave_c) {

Modified: eac3/eac3dec.c
==============================================================================
--- eac3/eac3dec.c	(original)
+++ eac3/eac3dec.c	Mon Sep  8 04:36:32 2008
@@ -117,6 +117,16 @@ void ff_eac3_apply_spectral_extension(AC
 
         /* Apply coefficient and noise scaling based on previously calculated
            RMS energy and blending factors for each band. */
+        bin = s->spx_start_freq;
+        for (bnd = 0; bnd < s->num_spx_bands; bnd++) {
+            int64_t nscale = (s->spx_noise_blend [ch][bnd] * rms_energy[bnd]) >> 23;
+            int64_t sscale =  s->spx_signal_blend[ch][bnd];
+            for (i = 0; i < s->spx_band_sizes[bnd]; i++) {
+                int64_t noise  = nscale * (av_znrng_get(&s->spx_noise_state) >> 5);
+                int64_t signal = sscale * s->fixed_coeffs[ch][bin];
+                s->fixed_coeffs[ch][bin++] = (noise + signal) >> 23;
+            }
+        }
 
         /* Scale coefficients using spectral extension coordinates */
     }

Modified: eac3/ffmpeg.patch
==============================================================================
--- eac3/ffmpeg.patch	(original)
+++ eac3/ffmpeg.patch	Mon Sep  8 04:36:32 2008
@@ -2,7 +2,15 @@ Index: libavcodec/ac3dec.h
 ===================================================================
 --- libavcodec/ac3dec.h	(revision 15141)
 +++ libavcodec/ac3dec.h	(working copy)
-@@ -42,7 +42,13 @@
+@@ -28,6 +28,7 @@
+ #define AVCODEC_AC3DEC_H
+ 
+ #include "libavutil/lfg.h"
++#include "libavutil/znrng.h"
+ #include "ac3.h"
+ #include "bitstream.h"
+ #include "dsputil.h"
+@@ -42,7 +43,13 @@
  #define AC3_MAX_COEFS   256
  #define AC3_BLOCK_SIZE  256
  #define MAX_BLOCKS        6
@@ -16,7 +24,7 @@ Index: libavcodec/ac3dec.h
  typedef struct {
      AVCodecContext *avctx;                  ///< parent context
      GetBitContext gbc;                      ///< bitstream reader
-@@ -79,15 +85,34 @@
+@@ -79,15 +86,35 @@
      int cpl_strategy_exists[MAX_BLOCKS];    ///< coupling strategy exists               (cplstre)
      int channel_in_cpl[AC3_MAX_CHANNELS];   ///< channel in coupling                    (chincpl)
      int phase_flags_in_use;                 ///< phase flags in use                     (phsflginu)
@@ -49,12 +57,13 @@ Index: libavcodec/ac3dec.h
 +    int spx_noise_blend[AC3_MAX_CHANNELS][SPX_MAX_BANDS];   ///< spx noise blending factor  (nblendfact)
 +    int spx_signal_blend[AC3_MAX_CHANNELS][SPX_MAX_BANDS];  ///< spx signal blending factor (sblendfact)
 +    int spx_coords[AC3_MAX_CHANNELS][SPX_MAX_BANDS];    ///< spectral extension coordinates (spxco)
++    AVRandomState spx_noise_state;          ///< random context for noise generation
 +///@}
 +
  ///@defgroup aht adaptive hybrid transform
      int channel_uses_aht[AC3_MAX_CHANNELS];                         ///< channel AHT in use (chahtinu)
      int pre_mantissa[AC3_MAX_CHANNELS][AC3_MAX_COEFS][MAX_BLOCKS];  ///< pre-IDCT mantissas
-@@ -179,4 +204,6 @@
+@@ -179,4 +206,6 @@
   */
  void ff_eac3_decode_transform_coeffs_aht_ch(AC3DecodeContext *s, int ch);