summaryrefslogtreecommitdiff
path: root/lib/rbcodec/codecs/libffmpegFLAC/golomb.h
diff options
context:
space:
mode:
Diffstat (limited to 'lib/rbcodec/codecs/libffmpegFLAC/golomb.h')
-rw-r--r--lib/rbcodec/codecs/libffmpegFLAC/golomb.h110
1 files changed, 110 insertions, 0 deletions
diff --git a/lib/rbcodec/codecs/libffmpegFLAC/golomb.h b/lib/rbcodec/codecs/libffmpegFLAC/golomb.h
new file mode 100644
index 0000000000..197b78ee1c
--- /dev/null
+++ b/lib/rbcodec/codecs/libffmpegFLAC/golomb.h
@@ -0,0 +1,110 @@
1/*
2 * exp golomb vlc stuff
3 * Copyright (c) 2003 Michael Niedermayer <michaelni@gmx.at>
4 * Copyright (c) 2004 Alex Beregszaszi
5 *
6 * This library is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2 of the License, or (at your option) any later version.
10 *
11 * This library is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
15 *
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with this library; if not, write to the Free Software
18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
19 *
20 */
21
22#include <limits.h>
23#include "codeclib.h"
24
25/**
26 * @file golomb.h
27 * @brief
28 * exp golomb vlc stuff
29 * @author Michael Niedermayer <michaelni@gmx.at> and Alex Beregszaszi
30 */
31
32
33/**
34 * read unsigned golomb rice code (jpegls).
35 */
36static inline int get_ur_golomb_jpegls(GetBitContext *gb, int k, int limit, int esc_len){
37 unsigned int buf;
38 int log;
39
40 OPEN_READER(re, gb);
41 UPDATE_CACHE(re, gb);
42 buf=GET_CACHE(re, gb);
43
44 log= av_log2(buf);
45
46 if(log - k >= 32-MIN_CACHE_BITS+(MIN_CACHE_BITS==32) && 32-log < limit){
47 buf >>= log - k;
48 buf += (30-log)<<k;
49 LAST_SKIP_BITS(re, gb, 32 + k - log);
50 CLOSE_READER(re, gb);
51
52 return buf;
53 }else{
54 int i;
55 for(i=0; SHOW_UBITS(re, gb, 1) == 0; i++){
56 LAST_SKIP_BITS(re, gb, 1);
57 UPDATE_CACHE(re, gb);
58 }
59 SKIP_BITS(re, gb, 1);
60
61 if(i < limit - 1){
62 if(k){
63 buf = SHOW_UBITS(re, gb, k);
64 LAST_SKIP_BITS(re, gb, k);
65 }else{
66 buf=0;
67 }
68
69 CLOSE_READER(re, gb);
70 return buf + (i<<k);
71 }else if(i == limit - 1){
72 buf = SHOW_UBITS(re, gb, esc_len);
73 LAST_SKIP_BITS(re, gb, esc_len);
74 CLOSE_READER(re, gb);
75
76 return buf + 1;
77 }else
78 return -1;
79 }
80}
81
82/**
83 * read signed golomb rice code (flac).
84 */
85static inline int get_sr_golomb_flac(GetBitContext *gb, int k, int limit, int esc_len){
86 int v= get_ur_golomb_jpegls(gb, k, limit, esc_len);
87 return (v>>1) ^ -(v&1);
88}
89
90/**
91 * read unsigned golomb rice code (shorten).
92 */
93#define get_ur_golomb_shorten(gb, k) get_ur_golomb_jpegls(gb, k, INT_MAX, 0)
94/*
95static inline unsigned int get_ur_golomb_shorten(GetBitContext *gb, int k){
96 return get_ur_golomb_jpegls(gb, k, INT_MAX, 0);
97}
98*/
99
100/**
101 * read signed golomb rice code (shorten).
102 */
103static inline int get_sr_golomb_shorten(GetBitContext* gb, int k)
104{
105 int uvar = get_ur_golomb_jpegls(gb, k + 1, INT_MAX, 0);
106 if (uvar & 1)
107 return ~(uvar >> 1);
108 else
109 return uvar >> 1;
110}