From c3d63262fe61a8e219c4b69c61af6e0c9d49be2d Mon Sep 17 00:00:00 2001
From: Justin Ruggles <justin.ruggles@gmail.com>
Date: Fri, 5 Aug 2011 16:28:39 -0400
Subject: ac3enc: allow new coupling coordinates to be sent independently for
 each channel.

---
 libavcodec/ac3enc_template.c | 50 +++++++++++++++++---------------------------
 1 file changed, 19 insertions(+), 31 deletions(-)

(limited to 'libavcodec/ac3enc_template.c')

diff --git a/libavcodec/ac3enc_template.c b/libavcodec/ac3enc_template.c
index dd1e48d1f8..4b0c768e63 100644
--- a/libavcodec/ac3enc_template.c
+++ b/libavcodec/ac3enc_template.c
@@ -206,9 +206,10 @@ static void apply_channel_coupling(AC3EncodeContext *s)
     for (blk = 0; blk < s->num_blocks; blk++) {
         AC3Block *block  = &s->blocks[blk];
         AC3Block *block0 = blk ? &s->blocks[blk-1] : NULL;
-        int new_coords = 0;
         CoefSumType coord_diff[AC3_MAX_CHANNELS] = {0,};
 
+        memset(block->new_cpl_coords, 0, sizeof(block->new_cpl_coords));
+
         if (block->cpl_in_use) {
             /* calculate coupling coordinates for all blocks and calculate the
                average difference between coordinates in successive blocks */
@@ -233,28 +234,18 @@ static void apply_channel_coupling(AC3EncodeContext *s)
              * using coupling has changed from the previous block, or the
              * coordinate difference from the last block for any channel is
              * greater than a threshold value. */
-            if (blk == 0) {
-                new_coords = 1;
-            } else if (!block0->cpl_in_use) {
-                new_coords = 1;
+            if (blk == 0 || !block0->cpl_in_use) {
+                for (ch = 1; ch <= s->fbw_channels; ch++)
+                    block->new_cpl_coords[ch] = 1;
             } else {
                 for (ch = 1; ch <= s->fbw_channels; ch++) {
-                    if (block->channel_in_cpl[ch] && !block0->channel_in_cpl[ch]) {
-                        new_coords = 1;
-                        break;
-                    }
-                }
-                if (!new_coords) {
-                    for (ch = 1; ch <= s->fbw_channels; ch++) {
-                        if (block->channel_in_cpl[ch] && coord_diff[ch] > 0.04) {
-                            new_coords = 1;
-                            break;
-                        }
+                    if ((block->channel_in_cpl[ch] && !block0->channel_in_cpl[ch]) ||
+                        (block->channel_in_cpl[ch] && coord_diff[ch] > 0.03)) {
+                        block->new_cpl_coords[ch] = 1;
                     }
                 }
             }
         }
-        block->new_cpl_coords = new_coords;
     }
 
     /* calculate final coupling coordinates, taking into account reusing of
@@ -262,8 +253,7 @@ static void apply_channel_coupling(AC3EncodeContext *s)
     for (bnd = 0; bnd < s->num_cpl_bands; bnd++) {
         blk = 0;
         while (blk < s->num_blocks) {
-            int blk1;
-            CoefSumType energy_cpl;
+            int av_uninit(blk1);
             AC3Block *block  = &s->blocks[blk];
 
             if (!block->cpl_in_use) {
@@ -271,23 +261,18 @@ static void apply_channel_coupling(AC3EncodeContext *s)
                 continue;
             }
 
-            energy_cpl = energy[blk][CPL_CH][bnd];
-            blk1 = blk+1;
-            while (!s->blocks[blk1].new_cpl_coords && blk1 < s->num_blocks) {
-                if (s->blocks[blk1].cpl_in_use)
-                    energy_cpl += energy[blk1][CPL_CH][bnd];
-                blk1++;
-            }
-
             for (ch = 1; ch <= s->fbw_channels; ch++) {
-                CoefType energy_ch;
+                CoefSumType energy_ch, energy_cpl;
                 if (!block->channel_in_cpl[ch])
                     continue;
+                energy_cpl = energy[blk][CPL_CH][bnd];
                 energy_ch = energy[blk][ch][bnd];
                 blk1 = blk+1;
-                while (!s->blocks[blk1].new_cpl_coords && blk1 < s->num_blocks) {
-                    if (s->blocks[blk1].cpl_in_use)
+                while (!s->blocks[blk1].new_cpl_coords[ch] && blk1 < s->num_blocks) {
+                    if (s->blocks[blk1].cpl_in_use) {
+                        energy_cpl += energy[blk1][CPL_CH][bnd];
                         energy_ch += energy[blk1][ch][bnd];
+                    }
                     blk1++;
                 }
                 cpl_coords[blk][ch][bnd] = calc_cpl_coord(energy_ch, energy_cpl);
@@ -299,7 +284,7 @@ static void apply_channel_coupling(AC3EncodeContext *s)
     /* calculate exponents/mantissas for coupling coordinates */
     for (blk = 0; blk < s->num_blocks; blk++) {
         AC3Block *block = &s->blocks[blk];
-        if (!block->cpl_in_use || !block->new_cpl_coords)
+        if (!block->cpl_in_use)
             continue;
 
         clip_coefficients(&s->dsp, cpl_coords[blk][1], s->fbw_channels * 16);
@@ -313,6 +298,9 @@ static void apply_channel_coupling(AC3EncodeContext *s)
         for (ch = 1; ch <= s->fbw_channels; ch++) {
             int bnd, min_exp, max_exp, master_exp;
 
+            if (!block->new_cpl_coords[ch])
+                continue;
+
             /* determine master exponent */
             min_exp = max_exp = block->cpl_coord_exp[ch][0];
             for (bnd = 1; bnd < s->num_cpl_bands; bnd++) {
-- 
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