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1 04d7f601 Diego Biurrun
/*
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 * copyright (c) 2004 Michael Niedermayer <michaelni@gmx.at>
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 *
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 * This file is part of FFmpeg.
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 *
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 * FFmpeg is free software; you can redistribute it and/or
7 04d7f601 Diego Biurrun
 * modify it under the terms of the GNU Lesser General Public
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 * License as published by the Free Software Foundation; either
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 * version 2.1 of the License, or (at your option) any later version.
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 *
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 * FFmpeg is distributed in the hope that it will be useful,
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 * but WITHOUT ANY WARRANTY; without even the implied warranty of
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 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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 * Lesser General Public License for more details.
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 *
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 * You should have received a copy of the GNU Lesser General Public
17 b78e7197 Diego Biurrun
 * License along with FFmpeg; if not, write to the Free Software
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 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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 */
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/**
22 9106a698 Stefano Sabatini
 * @file libavcodec/get_bits.h
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 * bitstream reader API header.
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 */
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26 9106a698 Stefano Sabatini
#ifndef AVCODEC_GET_BITS_H
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#define AVCODEC_GET_BITS_H
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#include <stdint.h>
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#include <stdlib.h>
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#include <assert.h>
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#include "libavutil/bswap.h"
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#include "libavutil/common.h"
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#include "libavutil/intreadwrite.h"
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#include "libavutil/log.h"
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#include "mathops.h"
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#if defined(ALT_BITSTREAM_READER_LE) && !defined(ALT_BITSTREAM_READER)
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#   define ALT_BITSTREAM_READER
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#endif
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#if !defined(LIBMPEG2_BITSTREAM_READER) && !defined(A32_BITSTREAM_READER) && !defined(ALT_BITSTREAM_READER)
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#   if ARCH_ARM
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#       define A32_BITSTREAM_READER
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#   else
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#       define ALT_BITSTREAM_READER
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//#define LIBMPEG2_BITSTREAM_READER
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//#define A32_BITSTREAM_READER
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#   endif
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#endif
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extern const uint8_t ff_reverse[256];
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#if ARCH_X86
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// avoid +32 for shift optimization (gcc should do that ...)
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static inline  int32_t NEG_SSR32( int32_t a, int8_t s){
57 be449fca Diego Pettenò
    __asm__ ("sarl %1, %0\n\t"
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         : "+r" (a)
59
         : "ic" ((uint8_t)(-s))
60
    );
61
    return a;
62
}
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static inline uint32_t NEG_USR32(uint32_t a, int8_t s){
64 be449fca Diego Pettenò
    __asm__ ("shrl %1, %0\n\t"
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         : "+r" (a)
66
         : "ic" ((uint8_t)(-s))
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    );
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    return a;
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}
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#else
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#    define NEG_SSR32(a,s) ((( int32_t)(a))>>(32-(s)))
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#    define NEG_USR32(a,s) (((uint32_t)(a))>>(32-(s)))
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#endif
74
75
/* bit input */
76
/* buffer, buffer_end and size_in_bits must be present and used by every reader */
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typedef struct GetBitContext {
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    const uint8_t *buffer, *buffer_end;
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#ifdef ALT_BITSTREAM_READER
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    int index;
81
#elif defined LIBMPEG2_BITSTREAM_READER
82
    uint8_t *buffer_ptr;
83
    uint32_t cache;
84
    int bit_count;
85
#elif defined A32_BITSTREAM_READER
86
    uint32_t *buffer_ptr;
87
    uint32_t cache0;
88
    uint32_t cache1;
89
    int bit_count;
90
#endif
91
    int size_in_bits;
92
} GetBitContext;
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94
#define VLC_TYPE int16_t
95
96
typedef struct VLC {
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    int bits;
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    VLC_TYPE (*table)[2]; ///< code, bits
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    int table_size, table_allocated;
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} VLC;
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102
typedef struct RL_VLC_ELEM {
103
    int16_t level;
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    int8_t len;
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    uint8_t run;
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} RL_VLC_ELEM;
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/* Bitstream reader API docs:
109
name
110 7a7c4a7b Stefano Sabatini
    arbitrary name which is used as prefix for the internal variables
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112
gb
113
    getbitcontext
114

115
OPEN_READER(name, gb)
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    loads gb into local variables
117

118
CLOSE_READER(name, gb)
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    stores local vars in gb
120

121
UPDATE_CACHE(name, gb)
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    refills the internal cache from the bitstream
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    after this call at least MIN_CACHE_BITS will be available,
124

125
GET_CACHE(name, gb)
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    will output the contents of the internal cache, next bit is MSB of 32 or 64 bit (FIXME 64bit)
127

128
SHOW_UBITS(name, gb, num)
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    will return the next num bits
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131
SHOW_SBITS(name, gb, num)
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    will return the next num bits and do sign extension
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SKIP_BITS(name, gb, num)
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    will skip over the next num bits
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    note, this is equivalent to SKIP_CACHE; SKIP_COUNTER
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SKIP_CACHE(name, gb, num)
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    will remove the next num bits from the cache (note SKIP_COUNTER MUST be called before UPDATE_CACHE / CLOSE_READER)
140

141
SKIP_COUNTER(name, gb, num)
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    will increment the internal bit counter (see SKIP_CACHE & SKIP_BITS)
143

144
LAST_SKIP_CACHE(name, gb, num)
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    will remove the next num bits from the cache if it is needed for UPDATE_CACHE otherwise it will do nothing
146

147
LAST_SKIP_BITS(name, gb, num)
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    is equivalent to LAST_SKIP_CACHE; SKIP_COUNTER
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150
for examples see get_bits, show_bits, skip_bits, get_vlc
151
*/
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153
#ifdef ALT_BITSTREAM_READER
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#   define MIN_CACHE_BITS 25
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156
#   define OPEN_READER(name, gb)\
157
        int name##_index= (gb)->index;\
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        int name##_cache= 0;\
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160
#   define CLOSE_READER(name, gb)\
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        (gb)->index= name##_index;\
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# ifdef ALT_BITSTREAM_READER_LE
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#   define UPDATE_CACHE(name, gb)\
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        name##_cache= AV_RL32( ((const uint8_t *)(gb)->buffer)+(name##_index>>3) ) >> (name##_index&0x07);\
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#   define SKIP_CACHE(name, gb, num)\
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        name##_cache >>= (num);
169
# else
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#   define UPDATE_CACHE(name, gb)\
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        name##_cache= AV_RB32( ((const uint8_t *)(gb)->buffer)+(name##_index>>3) ) << (name##_index&0x07);\
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#   define SKIP_CACHE(name, gb, num)\
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        name##_cache <<= (num);
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# endif
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// FIXME name?
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#   define SKIP_COUNTER(name, gb, num)\
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        name##_index += (num);\
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181
#   define SKIP_BITS(name, gb, num)\
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        {\
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            SKIP_CACHE(name, gb, num)\
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            SKIP_COUNTER(name, gb, num)\
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        }\
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#   define LAST_SKIP_BITS(name, gb, num) SKIP_COUNTER(name, gb, num)
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#   define LAST_SKIP_CACHE(name, gb, num) ;
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# ifdef ALT_BITSTREAM_READER_LE
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#   define SHOW_UBITS(name, gb, num)\
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        ((name##_cache) & (NEG_USR32(0xffffffff,num)))
193 7da4d4cd Gregory Montoir
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#   define SHOW_SBITS(name, gb, num)\
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        NEG_SSR32((name##_cache)<<(32-(num)), num)
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# else
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#   define SHOW_UBITS(name, gb, num)\
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        NEG_USR32(name##_cache, num)
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#   define SHOW_SBITS(name, gb, num)\
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        NEG_SSR32(name##_cache, num)
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# endif
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#   define GET_CACHE(name, gb)\
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        ((uint32_t)name##_cache)
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static inline int get_bits_count(GetBitContext *s){
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    return s->index;
209
}
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static inline void skip_bits_long(GetBitContext *s, int n){
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    s->index += n;
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}
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#elif defined LIBMPEG2_BITSTREAM_READER
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//libmpeg2 like reader
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#   define MIN_CACHE_BITS 17
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#   define OPEN_READER(name, gb)\
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        int name##_bit_count=(gb)->bit_count;\
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        int name##_cache= (gb)->cache;\
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        uint8_t * name##_buffer_ptr=(gb)->buffer_ptr;\
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225
#   define CLOSE_READER(name, gb)\
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        (gb)->bit_count= name##_bit_count;\
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        (gb)->cache= name##_cache;\
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        (gb)->buffer_ptr= name##_buffer_ptr;\
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230
#   define UPDATE_CACHE(name, gb)\
231
    if(name##_bit_count >= 0){\
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        name##_cache+= AV_RB16(name##_buffer_ptr) << name##_bit_count; \
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        name##_buffer_ptr+=2;\
234
        name##_bit_count-= 16;\
235
    }\
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237
#   define SKIP_CACHE(name, gb, num)\
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        name##_cache <<= (num);\
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#   define SKIP_COUNTER(name, gb, num)\
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        name##_bit_count += (num);\
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#   define SKIP_BITS(name, gb, num)\
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        {\
245
            SKIP_CACHE(name, gb, num)\
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            SKIP_COUNTER(name, gb, num)\
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        }\
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249
#   define LAST_SKIP_BITS(name, gb, num) SKIP_BITS(name, gb, num)
250
#   define LAST_SKIP_CACHE(name, gb, num) SKIP_CACHE(name, gb, num)
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#   define SHOW_UBITS(name, gb, num)\
253
        NEG_USR32(name##_cache, num)
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255
#   define SHOW_SBITS(name, gb, num)\
256
        NEG_SSR32(name##_cache, num)
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258
#   define GET_CACHE(name, gb)\
259
        ((uint32_t)name##_cache)
260
261
static inline int get_bits_count(GetBitContext *s){
262
    return (s->buffer_ptr - s->buffer)*8 - 16 + s->bit_count;
263
}
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265 6e4703ca Michael Niedermayer
static inline void skip_bits_long(GetBitContext *s, int n){
266
    OPEN_READER(re, s)
267
    re_bit_count += n;
268
    re_buffer_ptr += 2*(re_bit_count>>4);
269
    re_bit_count &= 15;
270
    re_cache = ((re_buffer_ptr[-2]<<8) + re_buffer_ptr[-1]) << (16+re_bit_count);
271
    UPDATE_CACHE(re, s)
272
    CLOSE_READER(re, s)
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}
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#elif defined A32_BITSTREAM_READER
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277
#   define MIN_CACHE_BITS 32
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279
#   define OPEN_READER(name, gb)\
280
        int name##_bit_count=(gb)->bit_count;\
281
        uint32_t name##_cache0= (gb)->cache0;\
282
        uint32_t name##_cache1= (gb)->cache1;\
283
        uint32_t * name##_buffer_ptr=(gb)->buffer_ptr;\
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285
#   define CLOSE_READER(name, gb)\
286
        (gb)->bit_count= name##_bit_count;\
287
        (gb)->cache0= name##_cache0;\
288
        (gb)->cache1= name##_cache1;\
289
        (gb)->buffer_ptr= name##_buffer_ptr;\
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291
#   define UPDATE_CACHE(name, gb)\
292
    if(name##_bit_count > 0){\
293
        const uint32_t next= be2me_32( *name##_buffer_ptr );\
294
        name##_cache0 |= NEG_USR32(next,name##_bit_count);\
295
        name##_cache1 |= next<<name##_bit_count;\
296
        name##_buffer_ptr++;\
297
        name##_bit_count-= 32;\
298
    }\
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300 b250f9c6 Aurelien Jacobs
#if ARCH_X86
301 caa336b4 Michael Niedermayer
#   define SKIP_CACHE(name, gb, num)\
302 be449fca Diego Pettenò
        __asm__(\
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            "shldl %2, %1, %0          \n\t"\
304
            "shll %2, %1               \n\t"\
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            : "+r" (name##_cache0), "+r" (name##_cache1)\
306 6ff3b2b8 Aurelien Jacobs
            : "Ic" ((uint8_t)(num))\
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           );
308
#else
309
#   define SKIP_CACHE(name, gb, num)\
310
        name##_cache0 <<= (num);\
311
        name##_cache0 |= NEG_USR32(name##_cache1,num);\
312
        name##_cache1 <<= (num);
313
#endif
314
315
#   define SKIP_COUNTER(name, gb, num)\
316
        name##_bit_count += (num);\
317
318
#   define SKIP_BITS(name, gb, num)\
319
        {\
320
            SKIP_CACHE(name, gb, num)\
321
            SKIP_COUNTER(name, gb, num)\
322
        }\
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324
#   define LAST_SKIP_BITS(name, gb, num) SKIP_BITS(name, gb, num)
325
#   define LAST_SKIP_CACHE(name, gb, num) SKIP_CACHE(name, gb, num)
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327
#   define SHOW_UBITS(name, gb, num)\
328
        NEG_USR32(name##_cache0, num)
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330
#   define SHOW_SBITS(name, gb, num)\
331
        NEG_SSR32(name##_cache0, num)
332
333
#   define GET_CACHE(name, gb)\
334
        (name##_cache0)
335
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static inline int get_bits_count(GetBitContext *s){
337
    return ((uint8_t*)s->buffer_ptr - s->buffer)*8 - 32 + s->bit_count;
338
}
339
340 5a7bd283 Michael Niedermayer
static inline void skip_bits_long(GetBitContext *s, int n){
341
    OPEN_READER(re, s)
342
    re_bit_count += n;
343 3dddf21f Michael Niedermayer
    re_buffer_ptr += re_bit_count>>5;
344 5a7bd283 Michael Niedermayer
    re_bit_count &= 31;
345 1491e21c Michael Niedermayer
    re_cache0 = be2me_32( re_buffer_ptr[-1] ) << re_bit_count;
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    re_cache1 = 0;
347 5a7bd283 Michael Niedermayer
    UPDATE_CACHE(re, s)
348
    CLOSE_READER(re, s)
349
}
350
351 caa336b4 Michael Niedermayer
#endif
352
353
/**
354
 * read mpeg1 dc style vlc (sign bit + mantisse with no MSB).
355 115329f1 Diego Biurrun
 * if MSB not set it is negative
356 caa336b4 Michael Niedermayer
 * @param n length in bits
357 115329f1 Diego Biurrun
 * @author BERO
358 caa336b4 Michael Niedermayer
 */
359
static inline int get_xbits(GetBitContext *s, int n){
360 6b250e47 Michael Niedermayer
    register int sign;
361 caa336b4 Michael Niedermayer
    register int32_t cache;
362
    OPEN_READER(re, s)
363
    UPDATE_CACHE(re, s)
364
    cache = GET_CACHE(re,s);
365 6b250e47 Michael Niedermayer
    sign=(~cache)>>31;
366 caa336b4 Michael Niedermayer
    LAST_SKIP_BITS(re, s, n)
367
    CLOSE_READER(re, s)
368 6b250e47 Michael Niedermayer
    return (NEG_USR32(sign ^ cache, n) ^ sign) - sign;
369 caa336b4 Michael Niedermayer
}
370
371
static inline int get_sbits(GetBitContext *s, int n){
372
    register int tmp;
373
    OPEN_READER(re, s)
374
    UPDATE_CACHE(re, s)
375
    tmp= SHOW_SBITS(re, s, n);
376
    LAST_SKIP_BITS(re, s, n)
377
    CLOSE_READER(re, s)
378
    return tmp;
379
}
380
381
/**
382 0ac47d63 Stefan Gehrer
 * reads 1-17 bits.
383 bb628dae Diego Biurrun
 * Note, the alt bitstream reader can read up to 25 bits, but the libmpeg2 reader can't
384 caa336b4 Michael Niedermayer
 */
385
static inline unsigned int get_bits(GetBitContext *s, int n){
386
    register int tmp;
387
    OPEN_READER(re, s)
388
    UPDATE_CACHE(re, s)
389
    tmp= SHOW_UBITS(re, s, n);
390
    LAST_SKIP_BITS(re, s, n)
391
    CLOSE_READER(re, s)
392
    return tmp;
393
}
394
395
/**
396 0ac47d63 Stefan Gehrer
 * shows 1-17 bits.
397 bb628dae Diego Biurrun
 * Note, the alt bitstream reader can read up to 25 bits, but the libmpeg2 reader can't
398 caa336b4 Michael Niedermayer
 */
399
static inline unsigned int show_bits(GetBitContext *s, int n){
400
    register int tmp;
401
    OPEN_READER(re, s)
402
    UPDATE_CACHE(re, s)
403
    tmp= SHOW_UBITS(re, s, n);
404
//    CLOSE_READER(re, s)
405
    return tmp;
406
}
407
408
static inline void skip_bits(GetBitContext *s, int n){
409
 //Note gcc seems to optimize this to s->index+=n for the ALT_READER :))
410
    OPEN_READER(re, s)
411
    UPDATE_CACHE(re, s)
412
    LAST_SKIP_BITS(re, s, n)
413
    CLOSE_READER(re, s)
414
}
415
416
static inline unsigned int get_bits1(GetBitContext *s){
417
#ifdef ALT_BITSTREAM_READER
418
    int index= s->index;
419
    uint8_t result= s->buffer[ index>>3 ];
420 cea27ac7 Michael Niedermayer
#ifdef ALT_BITSTREAM_READER_LE
421
    result>>= (index&0x07);
422
    result&= 1;
423
#else
424 caa336b4 Michael Niedermayer
    result<<= (index&0x07);
425
    result>>= 8 - 1;
426 cea27ac7 Michael Niedermayer
#endif
427 caa336b4 Michael Niedermayer
    index++;
428
    s->index= index;
429
430
    return result;
431
#else
432
    return get_bits(s, 1);
433
#endif
434
}
435
436
static inline unsigned int show_bits1(GetBitContext *s){
437
    return show_bits(s, 1);
438
}
439
440
static inline void skip_bits1(GetBitContext *s){
441
    skip_bits(s, 1);
442
}
443
444
/**
445 8fbc6aae Aurelien Jacobs
 * reads 0-32 bits.
446
 */
447
static inline unsigned int get_bits_long(GetBitContext *s, int n){
448
    if(n<=17) return get_bits(s, n);
449
    else{
450 d1121caa Reimar Döffinger
#ifdef ALT_BITSTREAM_READER_LE
451
        int ret= get_bits(s, 16);
452
        return ret | (get_bits(s, n-16) << 16);
453
#else
454 8fbc6aae Aurelien Jacobs
        int ret= get_bits(s, 16) << (n-16);
455
        return ret | get_bits(s, n-16);
456 d1121caa Reimar Döffinger
#endif
457 8fbc6aae Aurelien Jacobs
    }
458
}
459
460
/**
461 017c0811 Justin Ruggles
 * reads 0-32 bits as a signed integer.
462
 */
463
static inline int get_sbits_long(GetBitContext *s, int n) {
464
    return sign_extend(get_bits_long(s, n), n);
465
}
466
467
/**
468 8fbc6aae Aurelien Jacobs
 * shows 0-32 bits.
469
 */
470
static inline unsigned int show_bits_long(GetBitContext *s, int n){
471
    if(n<=17) return show_bits(s, n);
472
    else{
473
        GetBitContext gb= *s;
474 edd532db Reimar Döffinger
        return get_bits_long(&gb, n);
475 8fbc6aae Aurelien Jacobs
    }
476
}
477
478
static inline int check_marker(GetBitContext *s, const char *msg)
479
{
480
    int bit= get_bits1(s);
481
    if(!bit)
482
        av_log(NULL, AV_LOG_INFO, "Marker bit missing %s\n", msg);
483
484
    return bit;
485
}
486
487
/**
488 caa336b4 Michael Niedermayer
 * init GetBitContext.
489
 * @param buffer bitstream buffer, must be FF_INPUT_BUFFER_PADDING_SIZE bytes larger then the actual read bits
490
 * because some optimized bitstream readers read 32 or 64 bit at once and could read over the end
491
 * @param bit_size the size of the buffer in bits
492 17f0c3be Reimar Döffinger
 *
493
 * While GetBitContext stores the buffer size, for performance reasons you are
494
 * responsible for checking for the buffer end yourself (take advantage of the padding)!
495 caa336b4 Michael Niedermayer
 */
496
static inline void init_get_bits(GetBitContext *s,
497
                   const uint8_t *buffer, int bit_size)
498
{
499 9061be9f Michael Niedermayer
    int buffer_size= (bit_size+7)>>3;
500 288f1e68 Michel Bardiaux
    if(buffer_size < 0 || bit_size < 0) {
501
        buffer_size = bit_size = 0;
502
        buffer = NULL;
503
    }
504 caa336b4 Michael Niedermayer
505
    s->buffer= buffer;
506
    s->size_in_bits= bit_size;
507
    s->buffer_end= buffer + buffer_size;
508
#ifdef ALT_BITSTREAM_READER
509
    s->index=0;
510
#elif defined LIBMPEG2_BITSTREAM_READER
511 6e4703ca Michael Niedermayer
    s->buffer_ptr = (uint8_t*)((intptr_t)buffer&(~1));
512
    s->bit_count = 16 + 8*((intptr_t)buffer&1);
513
    skip_bits_long(s, 0);
514 a42ec9f4 Michael Niedermayer
#elif defined A32_BITSTREAM_READER
515
    s->buffer_ptr = (uint32_t*)((intptr_t)buffer&(~3));
516
    s->bit_count = 32 + 8*((intptr_t)buffer&3);
517
    skip_bits_long(s, 0);
518 caa336b4 Michael Niedermayer
#endif
519
}
520
521 ae5e7e7f Måns Rullgård
static inline void align_get_bits(GetBitContext *s)
522 5a7bd283 Michael Niedermayer
{
523
    int n= (-get_bits_count(s)) & 7;
524
    if(n) skip_bits(s, n);
525
}
526
527 b613bacc Loren Merritt
#define init_vlc(vlc, nb_bits, nb_codes,\
528
                 bits, bits_wrap, bits_size,\
529
                 codes, codes_wrap, codes_size,\
530
                 flags)\
531
        init_vlc_sparse(vlc, nb_bits, nb_codes,\
532
                 bits, bits_wrap, bits_size,\
533
                 codes, codes_wrap, codes_size,\
534
                 NULL, 0, 0, flags)
535
536
int init_vlc_sparse(VLC *vlc, int nb_bits, int nb_codes,
537 caa336b4 Michael Niedermayer
             const void *bits, int bits_wrap, int bits_size,
538
             const void *codes, int codes_wrap, int codes_size,
539 b613bacc Loren Merritt
             const void *symbols, int symbols_wrap, int symbols_size,
540 cea27ac7 Michael Niedermayer
             int flags);
541 ccc54864 Michael Niedermayer
#define INIT_VLC_USE_STATIC 1 ///< VERY strongly deprecated and forbidden
542 cea27ac7 Michael Niedermayer
#define INIT_VLC_LE         2
543 ccc54864 Michael Niedermayer
#define INIT_VLC_USE_NEW_STATIC 4
544 caa336b4 Michael Niedermayer
void free_vlc(VLC *vlc);
545
546 d05b24ff Michael Niedermayer
#define INIT_VLC_STATIC(vlc, bits, a,b,c,d,e,f,g, static_size)\
547
{\
548
    static VLC_TYPE table[static_size][2];\
549
    (vlc)->table= table;\
550
    (vlc)->table_allocated= static_size;\
551
    init_vlc(vlc, bits, a,b,c,d,e,f,g, INIT_VLC_USE_NEW_STATIC);\
552
}
553
554
555 caa336b4 Michael Niedermayer
/**
556
 *
557
 * if the vlc code is invalid and max_depth=1 than no bits will be removed
558
 * if the vlc code is invalid and max_depth>1 than the number of bits removed
559
 * is undefined
560
 */
561
#define GET_VLC(code, name, gb, table, bits, max_depth)\
562
{\
563
    int n, index, nb_bits;\
564
\
565
    index= SHOW_UBITS(name, gb, bits);\
566
    code = table[index][0];\
567
    n    = table[index][1];\
568
\
569
    if(max_depth > 1 && n < 0){\
570
        LAST_SKIP_BITS(name, gb, bits)\
571
        UPDATE_CACHE(name, gb)\
572
\
573
        nb_bits = -n;\
574
\
575
        index= SHOW_UBITS(name, gb, nb_bits) + code;\
576
        code = table[index][0];\
577
        n    = table[index][1];\
578
        if(max_depth > 2 && n < 0){\
579
            LAST_SKIP_BITS(name, gb, nb_bits)\
580
            UPDATE_CACHE(name, gb)\
581
\
582
            nb_bits = -n;\
583
\
584
            index= SHOW_UBITS(name, gb, nb_bits) + code;\
585
            code = table[index][0];\
586
            n    = table[index][1];\
587
        }\
588
    }\
589
    SKIP_BITS(name, gb, n)\
590
}
591
592 e91f4bf1 Michael Niedermayer
#define GET_RL_VLC(level, run, name, gb, table, bits, max_depth, need_update)\
593 caa336b4 Michael Niedermayer
{\
594
    int n, index, nb_bits;\
595
\
596
    index= SHOW_UBITS(name, gb, bits);\
597
    level = table[index].level;\
598
    n     = table[index].len;\
599
\
600
    if(max_depth > 1 && n < 0){\
601 e91f4bf1 Michael Niedermayer
        SKIP_BITS(name, gb, bits)\
602
        if(need_update){\
603
            UPDATE_CACHE(name, gb)\
604
        }\
605 caa336b4 Michael Niedermayer
\
606
        nb_bits = -n;\
607
\
608
        index= SHOW_UBITS(name, gb, nb_bits) + level;\
609
        level = table[index].level;\
610
        n     = table[index].len;\
611
    }\
612
    run= table[index].run;\
613
    SKIP_BITS(name, gb, n)\
614
}
615
616
617
/**
618
 * parses a vlc code, faster then get_vlc()
619 115329f1 Diego Biurrun
 * @param bits is the number of bits which will be read at once, must be
620 caa336b4 Michael Niedermayer
 *             identical to nb_bits in init_vlc()
621 e42dba48 Diego Biurrun
 * @param max_depth is the number of times bits bits must be read to completely
622 115329f1 Diego Biurrun
 *                  read the longest vlc code
623 caa336b4 Michael Niedermayer
 *                  = (max_vlc_length + bits - 1) / bits
624
 */
625 849f1035 Måns Rullgård
static av_always_inline int get_vlc2(GetBitContext *s, VLC_TYPE (*table)[2],
626 caa336b4 Michael Niedermayer
                                  int bits, int max_depth)
627
{
628
    int code;
629 115329f1 Diego Biurrun
630 caa336b4 Michael Niedermayer
    OPEN_READER(re, s)
631
    UPDATE_CACHE(re, s)
632
633
    GET_VLC(code, re, s, table, bits, max_depth)
634
635
    CLOSE_READER(re, s)
636
    return code;
637
}
638
639
//#define TRACE
640
641
#ifdef TRACE
642
static inline void print_bin(int bits, int n){
643
    int i;
644 115329f1 Diego Biurrun
645 caa336b4 Michael Niedermayer
    for(i=n-1; i>=0; i--){
646 61f040dd Loïc Le Loarer
        av_log(NULL, AV_LOG_DEBUG, "%d", (bits>>i)&1);
647 caa336b4 Michael Niedermayer
    }
648
    for(i=n; i<24; i++)
649 61f040dd Loïc Le Loarer
        av_log(NULL, AV_LOG_DEBUG, " ");
650 caa336b4 Michael Niedermayer
}
651
652 61f040dd Loïc Le Loarer
static inline int get_bits_trace(GetBitContext *s, int n, char *file, const char *func, int line){
653 caa336b4 Michael Niedermayer
    int r= get_bits(s, n);
654 115329f1 Diego Biurrun
655 caa336b4 Michael Niedermayer
    print_bin(r, n);
656 61f040dd Loïc Le Loarer
    av_log(NULL, AV_LOG_DEBUG, "%5d %2d %3d bit @%5d in %s %s:%d\n", r, n, r, get_bits_count(s)-n, file, func, line);
657 caa336b4 Michael Niedermayer
    return r;
658
}
659 61f040dd Loïc Le Loarer
static inline int get_vlc_trace(GetBitContext *s, VLC_TYPE (*table)[2], int bits, int max_depth, char *file, const char *func, int line){
660 caa336b4 Michael Niedermayer
    int show= show_bits(s, 24);
661
    int pos= get_bits_count(s);
662
    int r= get_vlc2(s, table, bits, max_depth);
663
    int len= get_bits_count(s) - pos;
664
    int bits2= show>>(24-len);
665 115329f1 Diego Biurrun
666 caa336b4 Michael Niedermayer
    print_bin(bits2, len);
667 115329f1 Diego Biurrun
668 61f040dd Loïc Le Loarer
    av_log(NULL, AV_LOG_DEBUG, "%5d %2d %3d vlc @%5d in %s %s:%d\n", bits2, len, r, pos, file, func, line);
669 caa336b4 Michael Niedermayer
    return r;
670
}
671 61f040dd Loïc Le Loarer
static inline int get_xbits_trace(GetBitContext *s, int n, char *file, const char *func, int line){
672 caa336b4 Michael Niedermayer
    int show= show_bits(s, n);
673
    int r= get_xbits(s, n);
674 115329f1 Diego Biurrun
675 caa336b4 Michael Niedermayer
    print_bin(show, n);
676 61f040dd Loïc Le Loarer
    av_log(NULL, AV_LOG_DEBUG, "%5d %2d %3d xbt @%5d in %s %s:%d\n", show, n, r, get_bits_count(s)-n, file, func, line);
677 caa336b4 Michael Niedermayer
    return r;
678
}
679
680
#define get_bits(s, n)  get_bits_trace(s, n, __FILE__, __PRETTY_FUNCTION__, __LINE__)
681
#define get_bits1(s)    get_bits_trace(s, 1, __FILE__, __PRETTY_FUNCTION__, __LINE__)
682
#define get_xbits(s, n) get_xbits_trace(s, n, __FILE__, __PRETTY_FUNCTION__, __LINE__)
683
#define get_vlc(s, vlc)            get_vlc_trace(s, (vlc)->table, (vlc)->bits, 3, __FILE__, __PRETTY_FUNCTION__, __LINE__)
684
#define get_vlc2(s, tab, bits, max) get_vlc_trace(s, tab, bits, max, __FILE__, __PRETTY_FUNCTION__, __LINE__)
685
686 a9c9a240 Michel Bardiaux
#define tprintf(p, ...) av_log(p, AV_LOG_DEBUG, __VA_ARGS__)
687 caa336b4 Michael Niedermayer
688
#else //TRACE
689 a9c9a240 Michel Bardiaux
#define tprintf(p, ...) {}
690 caa336b4 Michael Niedermayer
#endif
691
692 7d8b13b4 Michael Niedermayer
static inline int decode012(GetBitContext *gb){
693 a64a006e Michael Niedermayer
    int n;
694
    n = get_bits1(gb);
695
    if (n == 0)
696
        return 0;
697
    else
698
        return get_bits1(gb) + 1;
699
}
700
701 b44665c4 Kostya Shishkov
static inline int decode210(GetBitContext *gb){
702
    if (get_bits1(gb))
703
        return 0;
704
    else
705
        return 2 - get_bits1(gb);
706
}
707
708 9106a698 Stefano Sabatini
#endif /* AVCODEC_GET_BITS_H */