26 #ifndef AVCODEC_GET_BITS_H 27 #define AVCODEC_GET_BITS_H 52 #ifndef UNCHECKED_BITSTREAM_READER 53 #define UNCHECKED_BITSTREAM_READER !CONFIG_SAFE_BITSTREAM_READER 110 #ifdef LONG_BITSTREAM_READER 111 # define MIN_CACHE_BITS 32 113 # define MIN_CACHE_BITS 25 116 #define OPEN_READER_NOSIZE(name, gb) \ 117 unsigned int name ## _index = (gb)->index; \ 118 unsigned int av_unused name ## _cache 120 #if UNCHECKED_BITSTREAM_READER 121 #define OPEN_READER(name, gb) OPEN_READER_NOSIZE(name, gb) 123 #define BITS_AVAILABLE(name, gb) 1 125 #define OPEN_READER(name, gb) \ 126 OPEN_READER_NOSIZE(name, gb); \ 127 unsigned int name ## _size_plus8 = (gb)->size_in_bits_plus8 129 #define BITS_AVAILABLE(name, gb) name ## _index < name ## _size_plus8 132 #define CLOSE_READER(name, gb) (gb)->index = name ## _index 134 # ifdef LONG_BITSTREAM_READER 136 # define UPDATE_CACHE_LE(name, gb) name ## _cache = \ 137 AV_RL64((gb)->buffer + (name ## _index >> 3)) >> (name ## _index & 7) 139 # define UPDATE_CACHE_BE(name, gb) name ## _cache = \ 140 AV_RB64((gb)->buffer + (name ## _index >> 3)) >> (32 - (name ## _index & 7)) 144 # define UPDATE_CACHE_LE(name, gb) name ## _cache = \ 145 AV_RL32((gb)->buffer + (name ## _index >> 3)) >> (name ## _index & 7) 147 # define UPDATE_CACHE_BE(name, gb) name ## _cache = \ 148 AV_RB32((gb)->buffer + (name ## _index >> 3)) << (name ## _index & 7) 153 #ifdef BITSTREAM_READER_LE 155 # define UPDATE_CACHE(name, gb) UPDATE_CACHE_LE(name, gb) 157 # define SKIP_CACHE(name, gb, num) name ## _cache >>= (num) 161 # define UPDATE_CACHE(name, gb) UPDATE_CACHE_BE(name, gb) 163 # define SKIP_CACHE(name, gb, num) name ## _cache <<= (num) 167 #if UNCHECKED_BITSTREAM_READER 168 # define SKIP_COUNTER(name, gb, num) name ## _index += (num) 170 # define SKIP_COUNTER(name, gb, num) \ 171 name ## _index = FFMIN(name ## _size_plus8, name ## _index + (num)) 174 #define BITS_LEFT(name, gb) ((int)((gb)->size_in_bits - name ## _index)) 176 #define SKIP_BITS(name, gb, num) \ 178 SKIP_CACHE(name, gb, num); \ 179 SKIP_COUNTER(name, gb, num); \ 182 #define LAST_SKIP_BITS(name, gb, num) SKIP_COUNTER(name, gb, num) 184 #define SHOW_UBITS_LE(name, gb, num) zero_extend(name ## _cache, num) 185 #define SHOW_SBITS_LE(name, gb, num) sign_extend(name ## _cache, num) 187 #define SHOW_UBITS_BE(name, gb, num) NEG_USR32(name ## _cache, num) 188 #define SHOW_SBITS_BE(name, gb, num) NEG_SSR32(name ## _cache, num) 190 #ifdef BITSTREAM_READER_LE 191 # define SHOW_UBITS(name, gb, num) SHOW_UBITS_LE(name, gb, num) 192 # define SHOW_SBITS(name, gb, num) SHOW_SBITS_LE(name, gb, num) 194 # define SHOW_UBITS(name, gb, num) SHOW_UBITS_BE(name, gb, num) 195 # define SHOW_SBITS(name, gb, num) SHOW_SBITS_BE(name, gb, num) 198 #define GET_CACHE(name, gb) ((uint32_t) name ## _cache) 207 #if UNCHECKED_BITSTREAM_READER 230 return (
NEG_USR32(sign ^ cache, n) ^ sign) - sign;
244 return (
zero_extend(sign ^ cache, n) ^ sign) - sign;
318 #ifdef BITSTREAM_READER_LE 319 result >>= index & 7;
322 result <<= index & 7;
325 #if !UNCHECKED_BITSTREAM_READER 355 #ifdef BITSTREAM_READER_LE 357 return ret | (
get_bits(s, n - 16) << 16);
359 unsigned ret =
get_bits(s, 16) << (n - 16);
373 #ifdef BITSTREAM_READER_LE 438 buffer_size = (bit_size + 7) >> 3;
460 if (byte_size > INT_MAX / 8 || byte_size < 0)
478 #define GET_VLC(code, name, gb, table, bits, max_depth) \ 481 unsigned int index; \ 483 index = SHOW_UBITS(name, gb, bits); \ 484 code = table[index][0]; \ 485 n = table[index][1]; \ 487 if (max_depth > 1 && n < 0) { \ 488 LAST_SKIP_BITS(name, gb, bits); \ 489 UPDATE_CACHE(name, gb); \ 493 index = SHOW_UBITS(name, gb, nb_bits) + code; \ 494 code = table[index][0]; \ 495 n = table[index][1]; \ 496 if (max_depth > 2 && n < 0) { \ 497 LAST_SKIP_BITS(name, gb, nb_bits); \ 498 UPDATE_CACHE(name, gb); \ 502 index = SHOW_UBITS(name, gb, nb_bits) + code; \ 503 code = table[index][0]; \ 504 n = table[index][1]; \ 507 SKIP_BITS(name, gb, n); \ 510 #define GET_RL_VLC(level, run, name, gb, table, bits, \ 511 max_depth, need_update) \ 514 unsigned int index; \ 516 index = SHOW_UBITS(name, gb, bits); \ 517 level = table[index].level; \ 518 n = table[index].len; \ 520 if (max_depth > 1 && n < 0) { \ 521 SKIP_BITS(name, gb, bits); \ 523 UPDATE_CACHE(name, gb); \ 528 index = SHOW_UBITS(name, gb, nb_bits) + level; \ 529 level = table[index].level; \ 530 n = table[index].len; \ 531 if (max_depth > 2 && n < 0) { \ 532 LAST_SKIP_BITS(name, gb, nb_bits); \ 534 UPDATE_CACHE(name, gb); \ 538 index = SHOW_UBITS(name, gb, nb_bits) + level; \ 539 level = table[index].level; \ 540 n = table[index].len; \ 543 run = table[index].run; \ 544 SKIP_BITS(name, gb, n); \ 557 int bits,
int max_depth)
static int get_xbits_le(GetBitContext *s, int n)
static unsigned int show_bits_long(GetBitContext *s, int n)
Show 0-32 bits.
static unsigned int show_bits1(GetBitContext *s)
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
static unsigned int get_bits(GetBitContext *s, int n)
Read 1-25 bits.
static void skip_bits_long(GetBitContext *s, int n)
static int check_marker(void *logctx, GetBitContext *s, const char *msg)
static av_const unsigned zero_extend(unsigned val, unsigned bits)
static int get_sbits(GetBitContext *s, int n)
static int get_sbits_long(GetBitContext *s, int n)
Read 0-32 bits as a signed integer.
#define av_assert2(cond)
assert() equivalent, that does lie in speed critical code.
static int get_bits_count(const GetBitContext *s)
#define SHOW_UBITS_LE(name, gb, num)
static int get_bits_left(GetBitContext *gb)
static uint64_t get_bits64(GetBitContext *s, int n)
Read 0-64 bits.
#define UPDATE_CACHE(name, gb)
static const struct endianess table[]
simple assert() macros that are a bit more flexible than ISO C assert().
#define CLOSE_READER(name, gb)
static unsigned int show_bits(GetBitContext *s, int n)
Show 1-25 bits.
#define LAST_SKIP_BITS(name, gb, num)
static av_always_inline int get_vlc2(GetBitContext *s, VLC_TYPE(*table)[2], int bits, int max_depth)
Parse a vlc code.
#define GET_VLC(code, name, gb, table, bits, max_depth)
If the vlc code is invalid and max_depth=1, then no bits will be removed.
#define SHOW_UBITS(name, gb, num)
static int decode210(GetBitContext *gb)
#define AV_LOG_INFO
Standard information.
Libavcodec external API header.
static int init_get_bits8(GetBitContext *s, const uint8_t *buffer, int byte_size)
Initialize GetBitContext.
static int get_xbits(GetBitContext *s, int n)
Read MPEG-1 dc-style VLC (sign bit + mantissa with no MSB).
#define OPEN_READER(name, gb)
static unsigned int get_bits1(GetBitContext *s)
static void skip_bits1(GetBitContext *s)
static void skip_bits(GetBitContext *s, int n)
#define UPDATE_CACHE_LE(name, gb)
static int init_get_bits(GetBitContext *s, const uint8_t *buffer, int bit_size)
Initialize GetBitContext.
#define GET_CACHE(name, gb)
static unsigned int get_bits_long(GetBitContext *s, int n)
Read 0-32 bits.
static av_const int sign_extend(int val, unsigned bits)
static unsigned int get_bits_le(GetBitContext *s, int n)
#define SHOW_SBITS(name, gb, num)
#define OPEN_READER_NOSIZE(name, gb)
common internal and external API header
const uint8_t * buffer_end
#define AV_INPUT_BUFFER_PADDING_SIZE
Required number of additionally allocated bytes at the end of the input bitstream for decoding...
static int decode012(GetBitContext *gb)
static const uint8_t * align_get_bits(GetBitContext *s)
static int skip_1stop_8data_bits(GetBitContext *gb)
static av_always_inline int get_bitsz(GetBitContext *s, int n)
Read 0-25 bits.