[FFmpeg-cvslog] r14958 - in trunk/libavcodec: ac3dec_data.c ac3dec_data.h

jbr subversion
Mon Aug 25 02:15:29 CEST 2008


Author: jbr
Date: Mon Aug 25 02:15:29 2008
New Revision: 14958

Log:
right shift the values by 8 in GAQ remap "B" table. data now fits in int8_t.

Modified:
   trunk/libavcodec/ac3dec_data.c
   trunk/libavcodec/ac3dec_data.h

Modified: trunk/libavcodec/ac3dec_data.c
==============================================================================
--- trunk/libavcodec/ac3dec_data.c	(original)
+++ trunk/libavcodec/ac3dec_data.c	Mon Aug 25 02:15:29 2008
@@ -87,18 +87,19 @@ const int16_t ff_eac3_gaq_remap_2_4_a[9]
 /**
  * Table E3.6, Gk=2 & Gk=4, B
  * Large mantissa inverse quantization, negative mantissa remapping offsets
+ * Table values from the spec are right-shifted by 8 to simplify calculations.
  * ff_eac3_gaq_remap_3_4_b[hebap-8][Gk=2,4]
  */
-const int16_t ff_eac3_gaq_remap_2_4_b[9][2] = {
-    {  -5461, -1170},
-    { -11703, -4915},
-    { -14199, -6606},
-    { -15327, -7412},
-    { -15864, -7805},
-    { -16126, -7999},
-    { -16255, -8096},
-    { -16320, -8144},
-    { -16352, -8168}
+const int8_t ff_eac3_gaq_remap_2_4_b[9][2] = {
+    { -22,  -5 },
+    { -46, -20 },
+    { -56, -26 },
+    { -60, -29 },
+    { -62, -31 },
+    { -63, -32 },
+    { -64, -32 },
+    { -64, -32 },
+    { -64, -32 },
 };
 
 static const int16_t vq_hebap1[4][6] = {

Modified: trunk/libavcodec/ac3dec_data.h
==============================================================================
--- trunk/libavcodec/ac3dec_data.h	(original)
+++ trunk/libavcodec/ac3dec_data.h	Mon Aug 25 02:15:29 2008
@@ -29,7 +29,7 @@ extern const uint8_t ff_eac3_hebap_tab[6
 extern const uint8_t ff_eac3_bits_vs_hebap[20];
 extern const int16_t ff_eac3_gaq_remap_1[12];
 extern const int16_t ff_eac3_gaq_remap_2_4_a[9][2];
-extern const int16_t ff_eac3_gaq_remap_2_4_b[9][2];
+extern const int8_t  ff_eac3_gaq_remap_2_4_b[9][2];
 
 extern const int16_t (*ff_eac3_vq_hebap[8])[6];
 extern const uint8_t ff_eac3_frm_expstr[32][6];




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