[FFmpeg-cvslog] r10119 - in trunk/libavcodec: golomb.c golomb.h

[marco]

Author: marco
Date: Wed Aug 15 14:59:27 2007
New Revision: 10119

Log:
Make the Golomb decoder work for Dirac

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

Modified: trunk/libavcodec/golomb.c
==============================================================================
--- trunk/libavcodec/golomb.c	(original)
+++ trunk/libavcodec/golomb.c	Wed Aug 15 14:59:27 2007
@@ -153,3 +153,21 @@ const int8_t ff_interleaved_se_golomb_vl
   0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,
   0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,
 };
+
+const uint8_t ff_interleaved_dirac_golomb_vlc_code[256]={
+0, 1, 0, 0, 2, 3, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0,
+4, 5, 2, 2, 6, 7, 3, 3, 1, 1, 1, 1, 1, 1, 1, 1,
+0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+8, 9, 4, 4, 10,11,5, 5, 2, 2, 2, 2, 2, 2, 2, 2,
+12,13,6, 6, 14,15,7, 7, 3, 3, 3, 3, 3, 3, 3, 3,
+1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
+1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
+0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,};

Modified: trunk/libavcodec/golomb.h
==============================================================================
--- trunk/libavcodec/golomb.h	(original)
+++ trunk/libavcodec/golomb.h	Wed Aug 15 14:59:27 2007
@@ -43,6 +43,7 @@ extern const uint8_t ff_ue_golomb_len[25
 extern const uint8_t ff_interleaved_golomb_vlc_len[256];
 extern const uint8_t ff_interleaved_ue_golomb_vlc_code[256];
 extern const  int8_t ff_interleaved_se_golomb_vlc_code[256];
+extern const uint8_t ff_interleaved_dirac_golomb_vlc_code[256];
 
 
  /**
@@ -75,7 +76,6 @@ static inline int get_ue_golomb(GetBitCo
 
 static inline int svq3_get_ue_golomb(GetBitContext *gb){
     uint32_t buf;
-    int log;
 
     OPEN_READER(re, gb);
     UPDATE_CACHE(re, gb);
@@ -88,21 +88,24 @@ static inline int svq3_get_ue_golomb(Get
 
         return ff_interleaved_ue_golomb_vlc_code[buf];
     }else{
-        LAST_SKIP_BITS(re, gb, 8);
-        UPDATE_CACHE(re, gb);
-        buf |= 1 | (GET_CACHE(re, gb) >> 8);
+        int ret = 1;
 
-        if((buf & 0xAAAAAAAA) == 0)
-            return INVALID_VLC;
+        while (1) {
+            buf >>= 32 - 8;
+            LAST_SKIP_BITS(re, gb, FFMIN(ff_interleaved_golomb_vlc_len[buf], 8));
 
-        for(log=31; (buf & 0x80000000) == 0; log--){
-            buf = (buf << 2) - ((buf << log) >> (log - 1)) + (buf >> 30);
+            if (ff_interleaved_golomb_vlc_len[buf] != 9){
+                ret <<= (ff_interleaved_golomb_vlc_len[buf] - 1) >> 1;
+                ret |= ff_interleaved_dirac_golomb_vlc_code[buf];
+                break;
+            }
+            ret = (ret << 4) | ff_interleaved_dirac_golomb_vlc_code[buf];
+            UPDATE_CACHE(re, gb);
+            buf = GET_CACHE(re, gb);
         }
 
-        LAST_SKIP_BITS(re, gb, 63 - 2*log - 8);
         CLOSE_READER(re, gb);
-
-        return ((buf << log) >> log) - 1;
+        return ret - 1;
     }
 }
 
@@ -192,6 +195,24 @@ static inline int svq3_get_se_golomb(Get
     }
 }
 
+static inline int dirac_get_se_golomb(GetBitContext *gb){
+    uint32_t buf;
+    uint32_t ret;
+
+    ret = svq3_get_ue_golomb(gb);
+
+    if (ret) {
+        OPEN_READER(re, gb);
+        UPDATE_CACHE(re, gb);
+        buf = SHOW_SBITS(re, gb, 1);
+        LAST_SKIP_BITS(re, gb, 1);
+        ret = (ret ^ buf) - buf;
+        CLOSE_READER(re, gb);
+    }
+
+    return ret;
+}
+
 /**
  * read unsigned golomb rice code (ffv1).
  */