[FFmpeg-cvslog] r13696 - in trunk/libavcodec: ac3_parser.c ac3dec.c

[jbr]

Author: jbr
Date: Sun Jun  8 00:30:09 2008
New Revision: 13696

Log:
move mix level tables from parser to decoder. have parser read bitstream value instead of using an index to a table in the decoder.


Modified:
   trunk/libavcodec/ac3_parser.c
   trunk/libavcodec/ac3dec.c

Modified: trunk/libavcodec/ac3_parser.c
==============================================================================
--- trunk/libavcodec/ac3_parser.c	(original)
+++ trunk/libavcodec/ac3_parser.c	Sun Jun  8 00:30:09 2008
@@ -33,18 +33,6 @@ static const uint8_t eac3_blocks[4] = {
     1, 2, 3, 6
 };
 
-/**
- * Table for center mix levels
- * reference: Section 5.4.2.4 cmixlev
- */
-static const uint8_t center_levels[4] = { 4, 5, 6, 5 };
-
-/**
- * Table for surround mix levels
- * reference: Section 5.4.2.5 surmixlev
- */
-static const uint8_t surround_levels[4] = { 4, 6, 7, 6 };
-
 
 int ff_ac3_parse_header(GetBitContext *gbc, AC3HeaderInfo *hdr)
 {
@@ -64,8 +52,8 @@ int ff_ac3_parse_header(GetBitContext *g
     hdr->num_blocks = 6;
 
     /* set default mix levels */
-    hdr->center_mix_level   = 3;  // -4.5dB
-    hdr->surround_mix_level = 4;  // -6.0dB
+    hdr->center_mix_level   = 1;  // -4.5dB
+    hdr->surround_mix_level = 1;  // -6.0dB
 
     if(hdr->bitstream_id <= 10) {
         /* Normal AC-3 */
@@ -87,9 +75,9 @@ int ff_ac3_parse_header(GetBitContext *g
             skip_bits(gbc, 2); // skip dsurmod
         } else {
             if((hdr->channel_mode & 1) && hdr->channel_mode != AC3_CHMODE_MONO)
-                hdr->center_mix_level = center_levels[get_bits(gbc, 2)];
+                hdr->center_mix_level = get_bits(gbc, 2);
             if(hdr->channel_mode & 4)
-                hdr->surround_mix_level = surround_levels[get_bits(gbc, 2)];
+                hdr->surround_mix_level = get_bits(gbc, 2);
         }
         hdr->lfe_on = get_bits1(gbc);
 

Modified: trunk/libavcodec/ac3dec.c
==============================================================================
--- trunk/libavcodec/ac3dec.c	(original)
+++ trunk/libavcodec/ac3dec.c	Sun Jun  8 00:30:09 2008
@@ -95,6 +95,18 @@ static const float gain_levels[9] = {
 };
 
 /**
+ * Table for center mix levels
+ * reference: Section 5.4.2.4 cmixlev
+ */
+static const uint8_t center_levels[4] = { 4, 5, 6, 5 };
+
+/**
+ * Table for surround mix levels
+ * reference: Section 5.4.2.5 surmixlev
+ */
+static const uint8_t surround_levels[4] = { 4, 6, 7, 6 };
+
+/**
  * Table for default stereo downmixing coefficients
  * reference: Section 7.8.2 Downmixing Into Two Channels
  */
@@ -383,8 +395,8 @@ static int ac3_parse_header(AC3DecodeCon
 static void set_downmix_coeffs(AC3DecodeContext *s)
 {
     int i;
-    float cmix = gain_levels[s->center_mix_level];
-    float smix = gain_levels[s->surround_mix_level];
+    float cmix = gain_levels[center_levels[s->center_mix_level]];
+    float smix = gain_levels[surround_levels[s->surround_mix_level]];
 
     for(i=0; i<s->fbw_channels; i++) {
         s->downmix_coeffs[i][0] = gain_levels[ac3_default_coeffs[s->channel_mode][i][0]];