optimize imdct_half:

[ffmpeg] / libavcodec / golomb.h

diff --git a/libavcodec/golomb.h b/libavcodec/golomb.h
index ef74f15c6602bf629306508fd67163794fbf7f9a..db4586521cda490f368382521603fae4a7ddf513 100644 (file)
--- a/libavcodec/golomb.h
+++ b/libavcodec/golomb.h
@@ -3,20 +3,21 @@
  * Copyright (c) 2003 Michael Niedermayer <michaelni@gmx.at>
  * Copyright (c) 2004 Alex Beregszaszi
  *
- * This library is free software; you can redistribute it and/or
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
- * version 2 of the License, or (at your option) any later version.
+ * version 2.1 of the License, or (at your option) any later version.
  *
- * This library is distributed in the hope that it will be useful,
+ * FFmpeg is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Lesser General Public License for more details.
  *
  * You should have received a copy of the GNU Lesser General Public
- * License along with this library; if not, write to the Free Software
+ * License along with FFmpeg; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
- *
  */
 
 /**
@@ -26,6 +27,12 @@
  * @author Michael Niedermayer <michaelni@gmx.at> and Alex Beregszaszi
  */
 
+#ifndef FFMPEG_GOLOMB_H
+#define FFMPEG_GOLOMB_H
+
+#include <stdint.h>
+#include "bitstream.h"
+
 #define INVALID_VLC           0x80000000
 
 extern const uint8_t ff_golomb_vlc_len[512];
@@ -36,6 +43,7 @@ extern const uint8_t ff_ue_golomb_len[256];
 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];
 
 
  /**
@@ -68,7 +76,6 @@ static inline int get_ue_golomb(GetBitContext *gb){
 
 static inline int svq3_get_ue_golomb(GetBitContext *gb){
     uint32_t buf;
-    int log;
 
     OPEN_READER(re, gb);
     UPDATE_CACHE(re, gb);
@@ -81,21 +88,24 @@ static inline int svq3_get_ue_golomb(GetBitContext *gb){
 
         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;
     }
 }
 
@@ -185,6 +195,24 @@ static inline int svq3_get_se_golomb(GetBitContext *gb){
     }
 }
 
+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).
  */
@@ -435,10 +463,18 @@ static inline void set_ur_golomb_jpegls(PutBitContext *pb, int i, int k, int lim
 
     e= (i>>k) + 1;
     if(e<limit){
+        while(e > 31) {
+            put_bits(pb, 31, 0);
+            e -= 31;
+        }
         put_bits(pb, e, 1);
         if(k)
-            put_bits(pb, k, i&((1<<k)-1));
+            put_sbits(pb, k, i);
     }else{
+        while(limit > 31) {
+            put_bits(pb, 31, 0);
+            limit -= 31;
+        }
         put_bits(pb, limit  , 1);
         put_bits(pb, esc_len, i - 1);
     }
@@ -467,3 +503,5 @@ static inline void set_sr_golomb_flac(PutBitContext *pb, int i, int k, int limit
 
     set_ur_golomb_jpegls(pb, v, k, limit, esc_len);
 }
+
+#endif /* FFMPEG_GOLOMB_H */