2006-09-10 17:02:42 +03:00
|
|
|
/*
|
2017-07-07 16:56:10 +02:00
|
|
|
* Copyright (c) 2004 Michael Niedermayer <michaelni@gmx.at>
|
2006-09-10 17:02:42 +03:00
|
|
|
*
|
2006-10-07 18:30:46 +03:00
|
|
|
* This file is part of FFmpeg.
|
|
|
|
*
|
|
|
|
* FFmpeg is free software; you can redistribute it and/or
|
2006-09-10 17:02:42 +03:00
|
|
|
* modify it under the terms of the GNU Lesser General Public
|
|
|
|
* License as published by the Free Software Foundation; either
|
2006-10-07 18:30:46 +03:00
|
|
|
* version 2.1 of the License, or (at your option) any later version.
|
2006-09-10 17:02:42 +03:00
|
|
|
*
|
2006-10-07 18:30:46 +03:00
|
|
|
* FFmpeg is distributed in the hope that it will be useful,
|
2006-09-10 17:02:42 +03:00
|
|
|
* 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
|
2006-10-07 18:30:46 +03:00
|
|
|
* License along with FFmpeg; if not, write to the Free Software
|
2006-09-10 17:02:42 +03:00
|
|
|
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
|
|
|
|
*/
|
|
|
|
|
2004-12-29 19:50:25 +02:00
|
|
|
/**
|
2010-04-20 17:45:34 +03:00
|
|
|
* @file
|
2009-04-13 19:20:26 +03:00
|
|
|
* bitstream reader API header.
|
2004-12-29 19:50:25 +02:00
|
|
|
*/
|
|
|
|
|
2009-04-13 19:20:26 +03:00
|
|
|
#ifndef AVCODEC_GET_BITS_H
|
|
|
|
#define AVCODEC_GET_BITS_H
|
2004-12-29 19:50:25 +02:00
|
|
|
|
2007-06-17 01:59:13 +03:00
|
|
|
#include <stdint.h>
|
2013-01-20 18:10:24 +03:00
|
|
|
|
2008-05-09 14:56:36 +03:00
|
|
|
#include "libavutil/common.h"
|
|
|
|
#include "libavutil/intreadwrite.h"
|
2012-04-07 17:04:09 +03:00
|
|
|
#include "libavutil/avassert.h"
|
2021-05-21 18:22:03 +02:00
|
|
|
|
|
|
|
#include "defs.h"
|
2009-03-03 04:00:47 +02:00
|
|
|
#include "mathops.h"
|
2016-05-14 11:45:01 +02:00
|
|
|
#include "vlc.h"
|
2006-08-28 21:44:49 +03:00
|
|
|
|
2011-12-17 00:42:04 +03:00
|
|
|
/*
|
|
|
|
* Safe bitstream reading:
|
|
|
|
* optionally, the get_bits API can check to ensure that we
|
|
|
|
* don't read past input buffer boundaries. This is protected
|
|
|
|
* with CONFIG_SAFE_BITSTREAM_READER at the global level, and
|
|
|
|
* then below that with UNCHECKED_BITSTREAM_READER at the per-
|
|
|
|
* decoder level. This means that decoders that check internally
|
|
|
|
* can "#define UNCHECKED_BITSTREAM_READER 1" to disable
|
|
|
|
* overread checks.
|
|
|
|
* Boundary checking causes a minor performance penalty so for
|
|
|
|
* applications that won't want/need this, it can be disabled
|
|
|
|
* globally using "#define CONFIG_SAFE_BITSTREAM_READER 0".
|
|
|
|
*/
|
|
|
|
#ifndef UNCHECKED_BITSTREAM_READER
|
|
|
|
#define UNCHECKED_BITSTREAM_READER !CONFIG_SAFE_BITSTREAM_READER
|
|
|
|
#endif
|
|
|
|
|
2018-08-30 22:36:55 +02:00
|
|
|
#ifndef CACHED_BITSTREAM_READER
|
|
|
|
#define CACHED_BITSTREAM_READER 0
|
|
|
|
#endif
|
|
|
|
|
|
|
|
#if CACHED_BITSTREAM_READER
|
2021-01-28 16:59:14 +02:00
|
|
|
|
|
|
|
// we always want the LE implementation, to provide get_bits_le()
|
|
|
|
#define BITSTREAM_LE
|
|
|
|
|
|
|
|
#ifndef BITSTREAM_READER_LE
|
|
|
|
# define BITSTREAM_BE
|
|
|
|
# define BITSTREAM_DEFAULT_BE
|
2017-07-07 16:56:10 +02:00
|
|
|
#endif
|
2021-01-28 16:59:14 +02:00
|
|
|
|
|
|
|
#include "bitstream.h"
|
|
|
|
|
|
|
|
#undef BITSTREAM_LE
|
|
|
|
#undef BITSTREAM_BE
|
|
|
|
#undef BITSTREAM_DEFAULT_BE
|
|
|
|
|
|
|
|
typedef BitstreamContext GetBitContext;
|
|
|
|
|
|
|
|
#define get_bits_count bits_tell
|
|
|
|
#define get_bits_left bits_left
|
|
|
|
#define skip_bits_long bits_skip
|
|
|
|
#define skip_bits bits_skip
|
|
|
|
#define get_bits bits_read_nz
|
|
|
|
#define get_bitsz bits_read
|
|
|
|
#define get_bits_long bits_read
|
|
|
|
#define get_bits1 bits_read_bit
|
|
|
|
#define get_bits64 bits_read_64
|
|
|
|
#define get_xbits bits_read_xbits
|
2023-01-15 11:21:36 +02:00
|
|
|
#define get_sbits bits_read_signed_nz
|
2021-01-28 16:59:14 +02:00
|
|
|
#define get_sbits_long bits_read_signed
|
|
|
|
#define show_bits bits_peek
|
|
|
|
#define show_bits_long bits_peek
|
|
|
|
#define init_get_bits bits_init
|
|
|
|
#define init_get_bits8 bits_init8
|
|
|
|
#define align_get_bits bits_align
|
|
|
|
#define get_vlc2 bits_read_vlc
|
2023-08-27 21:18:46 +02:00
|
|
|
#define get_vlc_multi bits_read_vlc_multi
|
2021-01-28 16:59:14 +02:00
|
|
|
|
|
|
|
#define init_get_bits8_le(s, buffer, byte_size) bits_init8_le((BitstreamContextLE*)s, buffer, byte_size)
|
|
|
|
#define get_bits_le(s, n) bits_read_le((BitstreamContextLE*)s, n)
|
|
|
|
|
|
|
|
#define show_bits1(s) bits_peek(s, 1)
|
|
|
|
#define skip_bits1(s) bits_skip(s, 1)
|
|
|
|
|
|
|
|
#define skip_1stop_8data_bits bits_skip_1stop_8data
|
|
|
|
|
|
|
|
#else // CACHED_BITSTREAM_READER
|
|
|
|
|
|
|
|
typedef struct GetBitContext {
|
|
|
|
const uint8_t *buffer, *buffer_end;
|
2004-12-29 19:50:25 +02:00
|
|
|
int index;
|
|
|
|
int size_in_bits;
|
2011-12-17 00:42:04 +03:00
|
|
|
int size_in_bits_plus8;
|
2004-12-29 19:50:25 +02:00
|
|
|
} GetBitContext;
|
|
|
|
|
2017-07-07 16:56:10 +02:00
|
|
|
static inline unsigned int get_bits(GetBitContext *s, int n);
|
|
|
|
static inline void skip_bits(GetBitContext *s, int n);
|
|
|
|
static inline unsigned int show_bits(GetBitContext *s, int n);
|
|
|
|
|
2004-12-29 19:50:25 +02:00
|
|
|
/* Bitstream reader API docs:
|
2013-01-20 18:10:24 +03:00
|
|
|
* name
|
|
|
|
* arbitrary name which is used as prefix for the internal variables
|
|
|
|
*
|
|
|
|
* gb
|
|
|
|
* getbitcontext
|
|
|
|
*
|
|
|
|
* OPEN_READER(name, gb)
|
|
|
|
* load gb into local variables
|
|
|
|
*
|
|
|
|
* CLOSE_READER(name, gb)
|
|
|
|
* store local vars in gb
|
|
|
|
*
|
|
|
|
* UPDATE_CACHE(name, gb)
|
|
|
|
* Refill the internal cache from the bitstream.
|
|
|
|
* After this call at least MIN_CACHE_BITS will be available.
|
|
|
|
*
|
|
|
|
* GET_CACHE(name, gb)
|
|
|
|
* Will output the contents of the internal cache,
|
2016-04-27 19:45:23 +02:00
|
|
|
* next bit is MSB of 32 or 64 bits (FIXME 64 bits).
|
2013-01-20 18:10:24 +03:00
|
|
|
*
|
|
|
|
* SHOW_UBITS(name, gb, num)
|
|
|
|
* Will return the next num bits.
|
|
|
|
*
|
|
|
|
* SHOW_SBITS(name, gb, num)
|
|
|
|
* Will return the next num bits and do sign extension.
|
|
|
|
*
|
|
|
|
* SKIP_BITS(name, gb, num)
|
|
|
|
* Will skip over the next num bits.
|
|
|
|
* Note, this is equivalent to SKIP_CACHE; SKIP_COUNTER.
|
|
|
|
*
|
|
|
|
* SKIP_CACHE(name, gb, num)
|
|
|
|
* Will remove the next num bits from the cache (note SKIP_COUNTER
|
|
|
|
* MUST be called before UPDATE_CACHE / CLOSE_READER).
|
|
|
|
*
|
|
|
|
* SKIP_COUNTER(name, gb, num)
|
|
|
|
* Will increment the internal bit counter (see SKIP_CACHE & SKIP_BITS).
|
|
|
|
*
|
|
|
|
* LAST_SKIP_BITS(name, gb, num)
|
|
|
|
* Like SKIP_BITS, to be used if next call is UPDATE_CACHE or CLOSE_READER.
|
|
|
|
*
|
2014-08-11 16:15:19 +03:00
|
|
|
* BITS_LEFT(name, gb)
|
|
|
|
* Return the number of bits left
|
|
|
|
*
|
2013-01-20 18:10:24 +03:00
|
|
|
* For examples see get_bits, show_bits, skip_bits, get_vlc.
|
|
|
|
*/
|
2004-12-29 19:50:25 +02:00
|
|
|
|
2021-01-28 16:59:14 +02:00
|
|
|
#if defined LONG_BITSTREAM_READER
|
2011-12-18 03:46:36 +03:00
|
|
|
# define MIN_CACHE_BITS 32
|
|
|
|
#else
|
2004-12-29 19:50:25 +02:00
|
|
|
# define MIN_CACHE_BITS 25
|
2011-12-18 03:46:36 +03:00
|
|
|
#endif
|
2004-12-29 19:50:25 +02:00
|
|
|
|
2014-08-22 15:37:39 +03:00
|
|
|
#define OPEN_READER_NOSIZE(name, gb) \
|
2013-01-20 18:10:24 +03:00
|
|
|
unsigned int name ## _index = (gb)->index; \
|
2013-01-22 15:49:45 +03:00
|
|
|
unsigned int av_unused name ## _cache
|
2004-12-29 19:50:25 +02:00
|
|
|
|
2014-08-22 15:37:39 +03:00
|
|
|
#if UNCHECKED_BITSTREAM_READER
|
|
|
|
#define OPEN_READER(name, gb) OPEN_READER_NOSIZE(name, gb)
|
|
|
|
|
2014-08-22 13:36:12 +03:00
|
|
|
#define BITS_AVAILABLE(name, gb) 1
|
2012-02-22 23:09:33 +03:00
|
|
|
#else
|
|
|
|
#define OPEN_READER(name, gb) \
|
2014-08-22 15:37:39 +03:00
|
|
|
OPEN_READER_NOSIZE(name, gb); \
|
|
|
|
unsigned int name ## _size_plus8 = (gb)->size_in_bits_plus8
|
2012-02-22 23:09:33 +03:00
|
|
|
|
2014-08-22 13:36:12 +03:00
|
|
|
#define BITS_AVAILABLE(name, gb) name ## _index < name ## _size_plus8
|
2012-02-22 23:09:33 +03:00
|
|
|
#endif
|
|
|
|
|
2013-01-20 18:10:24 +03:00
|
|
|
#define CLOSE_READER(name, gb) (gb)->index = name ## _index
|
2011-12-17 04:05:35 +03:00
|
|
|
|
2022-06-22 03:52:53 +02:00
|
|
|
#define UPDATE_CACHE_BE_EXT(name, gb, bits, dst_bits) name ## _cache = \
|
|
|
|
AV_RB ## bits((gb)->buffer + (name ## _index >> 3)) << (name ## _index & 7) >> (bits - dst_bits)
|
|
|
|
|
|
|
|
#define UPDATE_CACHE_LE_EXT(name, gb, bits, dst_bits) name ## _cache = \
|
|
|
|
(uint ## dst_bits ## _t)(AV_RL ## bits((gb)->buffer + (name ## _index >> 3)) >> (name ## _index & 7))
|
|
|
|
|
|
|
|
/* Using these two macros ensures that 32 bits are available. */
|
|
|
|
# define UPDATE_CACHE_LE_32(name, gb) UPDATE_CACHE_LE_EXT(name, (gb), 64, 32)
|
|
|
|
|
|
|
|
# define UPDATE_CACHE_BE_32(name, gb) UPDATE_CACHE_BE_EXT(name, (gb), 64, 32)
|
|
|
|
|
2013-07-04 22:54:43 +03:00
|
|
|
# ifdef LONG_BITSTREAM_READER
|
|
|
|
|
2022-06-22 03:52:53 +02:00
|
|
|
# define UPDATE_CACHE_LE(name, gb) UPDATE_CACHE_LE_32(name, (gb))
|
2013-07-04 22:54:43 +03:00
|
|
|
|
2022-06-22 03:52:53 +02:00
|
|
|
# define UPDATE_CACHE_BE(name, gb) UPDATE_CACHE_BE_32(name, (gb))
|
2013-07-04 22:54:43 +03:00
|
|
|
|
|
|
|
#else
|
|
|
|
|
2022-06-22 03:52:53 +02:00
|
|
|
# define UPDATE_CACHE_LE(name, gb) UPDATE_CACHE_LE_EXT(name, (gb), 32, 32)
|
2013-07-04 22:54:43 +03:00
|
|
|
|
2022-06-22 03:52:53 +02:00
|
|
|
# define UPDATE_CACHE_BE(name, gb) UPDATE_CACHE_BE_EXT(name, (gb), 32, 32)
|
2013-07-04 22:54:43 +03:00
|
|
|
|
|
|
|
#endif
|
|
|
|
|
|
|
|
|
2011-12-22 18:33:31 +03:00
|
|
|
#ifdef BITSTREAM_READER_LE
|
2004-12-29 19:50:25 +02:00
|
|
|
|
2013-07-04 22:54:43 +03:00
|
|
|
# define UPDATE_CACHE(name, gb) UPDATE_CACHE_LE(name, gb)
|
2022-06-22 03:52:53 +02:00
|
|
|
# define UPDATE_CACHE_32(name, gb) UPDATE_CACHE_LE_32(name, (gb))
|
2005-05-11 04:46:13 +03:00
|
|
|
|
2013-01-20 18:10:24 +03:00
|
|
|
# define SKIP_CACHE(name, gb, num) name ## _cache >>= (num)
|
2011-12-17 04:05:35 +03:00
|
|
|
|
|
|
|
#else
|
|
|
|
|
2013-07-04 22:54:43 +03:00
|
|
|
# define UPDATE_CACHE(name, gb) UPDATE_CACHE_BE(name, gb)
|
2022-06-22 03:52:53 +02:00
|
|
|
# define UPDATE_CACHE_32(name, gb) UPDATE_CACHE_BE_32(name, (gb))
|
2004-12-29 19:50:25 +02:00
|
|
|
|
2013-01-20 18:10:24 +03:00
|
|
|
# define SKIP_CACHE(name, gb, num) name ## _cache <<= (num)
|
2004-12-29 19:50:25 +02:00
|
|
|
|
2011-12-17 04:05:35 +03:00
|
|
|
#endif
|
2004-12-29 19:50:25 +02:00
|
|
|
|
2011-12-17 00:42:04 +03:00
|
|
|
#if UNCHECKED_BITSTREAM_READER
|
2013-01-20 18:10:24 +03:00
|
|
|
# define SKIP_COUNTER(name, gb, num) name ## _index += (num)
|
2011-12-17 00:42:04 +03:00
|
|
|
#else
|
|
|
|
# define SKIP_COUNTER(name, gb, num) \
|
2013-01-20 18:10:24 +03:00
|
|
|
name ## _index = FFMIN(name ## _size_plus8, name ## _index + (num))
|
2011-12-17 00:42:04 +03:00
|
|
|
#endif
|
2004-12-29 19:50:25 +02:00
|
|
|
|
2014-08-11 16:15:19 +03:00
|
|
|
#define BITS_LEFT(name, gb) ((int)((gb)->size_in_bits - name ## _index))
|
|
|
|
|
2013-01-20 18:10:24 +03:00
|
|
|
#define SKIP_BITS(name, gb, num) \
|
|
|
|
do { \
|
2011-01-23 03:56:27 +02:00
|
|
|
SKIP_CACHE(name, gb, num); \
|
|
|
|
SKIP_COUNTER(name, gb, num); \
|
|
|
|
} while (0)
|
2004-12-29 19:50:25 +02:00
|
|
|
|
2011-12-17 04:05:35 +03:00
|
|
|
#define LAST_SKIP_BITS(name, gb, num) SKIP_COUNTER(name, gb, num)
|
2004-12-29 19:50:25 +02:00
|
|
|
|
2013-07-04 22:54:43 +03:00
|
|
|
#define SHOW_UBITS_LE(name, gb, num) zero_extend(name ## _cache, num)
|
|
|
|
#define SHOW_SBITS_LE(name, gb, num) sign_extend(name ## _cache, num)
|
|
|
|
|
|
|
|
#define SHOW_UBITS_BE(name, gb, num) NEG_USR32(name ## _cache, num)
|
|
|
|
#define SHOW_SBITS_BE(name, gb, num) NEG_SSR32(name ## _cache, num)
|
|
|
|
|
2011-12-22 18:33:31 +03:00
|
|
|
#ifdef BITSTREAM_READER_LE
|
2013-07-04 22:54:43 +03:00
|
|
|
# define SHOW_UBITS(name, gb, num) SHOW_UBITS_LE(name, gb, num)
|
|
|
|
# define SHOW_SBITS(name, gb, num) SHOW_SBITS_LE(name, gb, num)
|
2011-12-17 04:05:35 +03:00
|
|
|
#else
|
2013-07-04 22:54:43 +03:00
|
|
|
# define SHOW_UBITS(name, gb, num) SHOW_UBITS_BE(name, gb, num)
|
|
|
|
# define SHOW_SBITS(name, gb, num) SHOW_SBITS_BE(name, gb, num)
|
2011-12-17 04:05:35 +03:00
|
|
|
#endif
|
2004-12-29 19:50:25 +02:00
|
|
|
|
2013-01-20 18:10:24 +03:00
|
|
|
#define GET_CACHE(name, gb) ((uint32_t) name ## _cache)
|
2004-12-29 19:50:25 +02:00
|
|
|
|
2017-07-07 16:56:10 +02:00
|
|
|
|
2011-12-17 04:05:35 +03:00
|
|
|
static inline int get_bits_count(const GetBitContext *s)
|
|
|
|
{
|
2004-12-29 19:50:25 +02:00
|
|
|
return s->index;
|
2017-07-07 16:56:10 +02:00
|
|
|
}
|
|
|
|
|
2018-03-23 19:58:33 +02:00
|
|
|
/**
|
|
|
|
* Skips the specified number of bits.
|
|
|
|
* @param n the number of bits to skip,
|
|
|
|
* For the UNCHECKED_BITSTREAM_READER this must not cause the distance
|
|
|
|
* from the start to overflow int32_t. Staying within the bitstream + padding
|
|
|
|
* is sufficient, too.
|
|
|
|
*/
|
2013-01-20 18:10:24 +03:00
|
|
|
static inline void skip_bits_long(GetBitContext *s, int n)
|
|
|
|
{
|
2011-12-17 00:42:04 +03:00
|
|
|
#if UNCHECKED_BITSTREAM_READER
|
2006-08-26 14:50:23 +03:00
|
|
|
s->index += n;
|
2011-12-17 00:42:04 +03:00
|
|
|
#else
|
|
|
|
s->index += av_clip(n, -s->index, s->size_in_bits_plus8 - s->index);
|
|
|
|
#endif
|
2017-07-07 16:56:10 +02:00
|
|
|
}
|
|
|
|
|
2004-12-29 19:50:25 +02:00
|
|
|
/**
|
2016-06-21 21:55:20 +02:00
|
|
|
* Read MPEG-1 dc-style VLC (sign bit + mantissa with no MSB).
|
2005-12-17 20:14:38 +02:00
|
|
|
* if MSB not set it is negative
|
2004-12-29 19:50:25 +02:00
|
|
|
* @param n length in bits
|
|
|
|
*/
|
2011-12-17 04:05:35 +03:00
|
|
|
static inline int get_xbits(GetBitContext *s, int n)
|
|
|
|
{
|
2006-03-31 23:40:22 +03:00
|
|
|
register int sign;
|
2004-12-29 19:50:25 +02:00
|
|
|
register int32_t cache;
|
2011-01-23 03:24:46 +02:00
|
|
|
OPEN_READER(re, s);
|
2013-06-30 01:31:51 +03:00
|
|
|
av_assert2(n>0 && n<=25);
|
2011-01-23 03:24:46 +02:00
|
|
|
UPDATE_CACHE(re, s);
|
2011-01-23 03:56:27 +02:00
|
|
|
cache = GET_CACHE(re, s);
|
2013-01-20 18:10:24 +03:00
|
|
|
sign = ~cache >> 31;
|
2011-01-23 03:24:46 +02:00
|
|
|
LAST_SKIP_BITS(re, s, n);
|
|
|
|
CLOSE_READER(re, s);
|
2006-03-31 23:40:22 +03:00
|
|
|
return (NEG_USR32(sign ^ cache, n) ^ sign) - sign;
|
2017-01-08 13:07:09 +02:00
|
|
|
}
|
|
|
|
|
|
|
|
static inline int get_xbits_le(GetBitContext *s, int n)
|
|
|
|
{
|
|
|
|
register int sign;
|
|
|
|
register int32_t cache;
|
|
|
|
OPEN_READER(re, s);
|
|
|
|
av_assert2(n>0 && n<=25);
|
|
|
|
UPDATE_CACHE_LE(re, s);
|
|
|
|
cache = GET_CACHE(re, s);
|
|
|
|
sign = sign_extend(~cache, n) >> 31;
|
|
|
|
LAST_SKIP_BITS(re, s, n);
|
|
|
|
CLOSE_READER(re, s);
|
|
|
|
return (zero_extend(sign ^ cache, n) ^ sign) - sign;
|
2004-12-29 19:50:25 +02:00
|
|
|
}
|
|
|
|
|
2011-12-17 04:05:35 +03:00
|
|
|
static inline int get_sbits(GetBitContext *s, int n)
|
|
|
|
{
|
2004-12-29 19:50:25 +02:00
|
|
|
register int tmp;
|
2011-01-23 03:24:46 +02:00
|
|
|
OPEN_READER(re, s);
|
2012-04-07 17:04:09 +03:00
|
|
|
av_assert2(n>0 && n<=25);
|
2011-01-23 03:24:46 +02:00
|
|
|
UPDATE_CACHE(re, s);
|
2011-01-23 03:56:27 +02:00
|
|
|
tmp = SHOW_SBITS(re, s, n);
|
2011-01-23 03:24:46 +02:00
|
|
|
LAST_SKIP_BITS(re, s, n);
|
|
|
|
CLOSE_READER(re, s);
|
2004-12-29 19:50:25 +02:00
|
|
|
return tmp;
|
|
|
|
}
|
|
|
|
|
|
|
|
/**
|
2011-01-23 03:18:13 +02:00
|
|
|
* Read 1-25 bits.
|
2004-12-29 19:50:25 +02:00
|
|
|
*/
|
2011-12-17 04:05:35 +03:00
|
|
|
static inline unsigned int get_bits(GetBitContext *s, int n)
|
|
|
|
{
|
2019-02-17 01:48:13 +02:00
|
|
|
register unsigned int tmp;
|
2011-01-23 03:24:46 +02:00
|
|
|
OPEN_READER(re, s);
|
2012-04-07 17:04:09 +03:00
|
|
|
av_assert2(n>0 && n<=25);
|
2011-01-23 03:24:46 +02:00
|
|
|
UPDATE_CACHE(re, s);
|
2011-01-23 03:56:27 +02:00
|
|
|
tmp = SHOW_UBITS(re, s, n);
|
2011-01-23 03:24:46 +02:00
|
|
|
LAST_SKIP_BITS(re, s, n);
|
|
|
|
CLOSE_READER(re, s);
|
2019-02-17 01:21:09 +02:00
|
|
|
av_assert2(tmp < UINT64_C(1) << n);
|
2004-12-29 19:50:25 +02:00
|
|
|
return tmp;
|
|
|
|
}
|
|
|
|
|
2016-01-03 01:28:42 +02:00
|
|
|
/**
|
|
|
|
* Read 0-25 bits.
|
|
|
|
*/
|
|
|
|
static av_always_inline int get_bitsz(GetBitContext *s, int n)
|
|
|
|
{
|
|
|
|
return n ? get_bits(s, n) : 0;
|
|
|
|
}
|
|
|
|
|
2013-07-04 22:54:43 +03:00
|
|
|
static inline unsigned int get_bits_le(GetBitContext *s, int n)
|
|
|
|
{
|
|
|
|
register int tmp;
|
|
|
|
OPEN_READER(re, s);
|
|
|
|
av_assert2(n>0 && n<=25);
|
|
|
|
UPDATE_CACHE_LE(re, s);
|
|
|
|
tmp = SHOW_UBITS_LE(re, s, n);
|
|
|
|
LAST_SKIP_BITS(re, s, n);
|
|
|
|
CLOSE_READER(re, s);
|
|
|
|
return tmp;
|
|
|
|
}
|
|
|
|
|
2004-12-29 19:50:25 +02:00
|
|
|
/**
|
2011-12-07 15:03:53 +03:00
|
|
|
* Show 1-25 bits.
|
2004-12-29 19:50:25 +02:00
|
|
|
*/
|
2011-12-17 04:05:35 +03:00
|
|
|
static inline unsigned int show_bits(GetBitContext *s, int n)
|
|
|
|
{
|
2019-02-17 01:48:13 +02:00
|
|
|
register unsigned int tmp;
|
2014-08-22 15:37:39 +03:00
|
|
|
OPEN_READER_NOSIZE(re, s);
|
2012-04-07 17:04:09 +03:00
|
|
|
av_assert2(n>0 && n<=25);
|
2011-01-23 03:24:46 +02:00
|
|
|
UPDATE_CACHE(re, s);
|
2011-01-23 03:56:27 +02:00
|
|
|
tmp = SHOW_UBITS(re, s, n);
|
2004-12-29 19:50:25 +02:00
|
|
|
return tmp;
|
|
|
|
}
|
|
|
|
|
2011-12-17 04:05:35 +03:00
|
|
|
static inline void skip_bits(GetBitContext *s, int n)
|
|
|
|
{
|
2011-01-23 03:24:46 +02:00
|
|
|
OPEN_READER(re, s);
|
|
|
|
LAST_SKIP_BITS(re, s, n);
|
|
|
|
CLOSE_READER(re, s);
|
2004-12-29 19:50:25 +02:00
|
|
|
}
|
|
|
|
|
2011-12-17 04:05:35 +03:00
|
|
|
static inline unsigned int get_bits1(GetBitContext *s)
|
|
|
|
{
|
2011-01-23 03:56:27 +02:00
|
|
|
unsigned int index = s->index;
|
2013-01-20 18:10:24 +03:00
|
|
|
uint8_t result = s->buffer[index >> 3];
|
2011-12-22 18:33:31 +03:00
|
|
|
#ifdef BITSTREAM_READER_LE
|
2011-01-23 03:56:27 +02:00
|
|
|
result >>= index & 7;
|
2013-01-20 18:10:24 +03:00
|
|
|
result &= 1;
|
2005-05-11 04:46:13 +03:00
|
|
|
#else
|
2011-01-23 03:56:27 +02:00
|
|
|
result <<= index & 7;
|
|
|
|
result >>= 8 - 1;
|
2005-05-11 04:46:13 +03:00
|
|
|
#endif
|
2011-12-17 00:42:04 +03:00
|
|
|
#if !UNCHECKED_BITSTREAM_READER
|
|
|
|
if (s->index < s->size_in_bits_plus8)
|
|
|
|
#endif
|
|
|
|
index++;
|
2011-01-23 03:56:27 +02:00
|
|
|
s->index = index;
|
2004-12-29 19:50:25 +02:00
|
|
|
|
|
|
|
return result;
|
|
|
|
}
|
|
|
|
|
2011-12-17 04:05:35 +03:00
|
|
|
static inline unsigned int show_bits1(GetBitContext *s)
|
|
|
|
{
|
2004-12-29 19:50:25 +02:00
|
|
|
return show_bits(s, 1);
|
|
|
|
}
|
|
|
|
|
2011-12-17 04:05:35 +03:00
|
|
|
static inline void skip_bits1(GetBitContext *s)
|
|
|
|
{
|
2004-12-29 19:50:25 +02:00
|
|
|
skip_bits(s, 1);
|
|
|
|
}
|
|
|
|
|
2006-08-28 21:44:49 +03:00
|
|
|
/**
|
2011-12-07 15:03:53 +03:00
|
|
|
* Read 0-32 bits.
|
2006-08-28 21:44:49 +03:00
|
|
|
*/
|
2011-12-17 04:05:35 +03:00
|
|
|
static inline unsigned int get_bits_long(GetBitContext *s, int n)
|
|
|
|
{
|
2016-12-18 11:06:29 +02:00
|
|
|
av_assert2(n>=0 && n<=32);
|
2012-10-06 23:25:04 +03:00
|
|
|
if (!n) {
|
|
|
|
return 0;
|
2022-06-22 03:52:53 +02:00
|
|
|
} else if ((!HAVE_FAST_64BIT || av_builtin_constant_p(n <= MIN_CACHE_BITS))
|
|
|
|
&& n <= MIN_CACHE_BITS) {
|
2011-12-17 04:05:35 +03:00
|
|
|
return get_bits(s, n);
|
2013-01-20 18:10:24 +03:00
|
|
|
} else {
|
2022-06-22 03:52:53 +02:00
|
|
|
#if HAVE_FAST_64BIT
|
|
|
|
unsigned tmp;
|
|
|
|
OPEN_READER(re, s);
|
|
|
|
UPDATE_CACHE_32(re, s);
|
|
|
|
tmp = SHOW_UBITS(re, s, n);
|
|
|
|
LAST_SKIP_BITS(re, s, n);
|
|
|
|
CLOSE_READER(re, s);
|
|
|
|
return tmp;
|
|
|
|
#else
|
2011-12-22 18:33:31 +03:00
|
|
|
#ifdef BITSTREAM_READER_LE
|
2012-09-30 03:37:40 +03:00
|
|
|
unsigned ret = get_bits(s, 16);
|
2013-01-20 18:10:24 +03:00
|
|
|
return ret | (get_bits(s, n - 16) << 16);
|
2006-09-26 01:47:55 +03:00
|
|
|
#else
|
2013-01-22 15:49:45 +03:00
|
|
|
unsigned ret = get_bits(s, 16) << (n - 16);
|
2013-01-20 18:10:24 +03:00
|
|
|
return ret | get_bits(s, n - 16);
|
2022-06-22 03:52:53 +02:00
|
|
|
#endif
|
2006-09-26 01:47:55 +03:00
|
|
|
#endif
|
2006-08-28 21:44:49 +03:00
|
|
|
}
|
|
|
|
}
|
|
|
|
|
2012-09-30 03:39:55 +03:00
|
|
|
/**
|
|
|
|
* Read 0-64 bits.
|
|
|
|
*/
|
2012-12-08 16:39:11 +03:00
|
|
|
static inline uint64_t get_bits64(GetBitContext *s, int n)
|
2012-09-30 03:39:55 +03:00
|
|
|
{
|
2012-09-30 03:39:55 +03:00
|
|
|
if (n <= 32) {
|
2012-09-30 03:39:55 +03:00
|
|
|
return get_bits_long(s, n);
|
2012-09-30 03:39:55 +03:00
|
|
|
} else {
|
2012-09-30 03:39:55 +03:00
|
|
|
#ifdef BITSTREAM_READER_LE
|
|
|
|
uint64_t ret = get_bits_long(s, 32);
|
2013-01-20 18:10:24 +03:00
|
|
|
return ret | (uint64_t) get_bits_long(s, n - 32) << 32;
|
2012-09-30 03:39:55 +03:00
|
|
|
#else
|
2013-01-20 18:10:24 +03:00
|
|
|
uint64_t ret = (uint64_t) get_bits_long(s, n - 32) << 32;
|
2012-09-30 03:39:55 +03:00
|
|
|
return ret | get_bits_long(s, 32);
|
2012-09-30 03:39:55 +03:00
|
|
|
#endif
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
2009-03-03 04:00:47 +02:00
|
|
|
/**
|
2011-12-07 15:03:53 +03:00
|
|
|
* Read 0-32 bits as a signed integer.
|
2009-03-03 04:00:47 +02:00
|
|
|
*/
|
2011-12-17 04:05:35 +03:00
|
|
|
static inline int get_sbits_long(GetBitContext *s, int n)
|
|
|
|
{
|
2016-12-04 00:44:56 +02:00
|
|
|
// sign_extend(x, 0) is undefined
|
|
|
|
if (!n)
|
|
|
|
return 0;
|
|
|
|
|
2009-03-03 04:00:47 +02:00
|
|
|
return sign_extend(get_bits_long(s, n), n);
|
|
|
|
}
|
|
|
|
|
2022-10-11 19:24:35 +02:00
|
|
|
/**
|
|
|
|
* Read 0-64 bits as a signed integer.
|
|
|
|
*/
|
|
|
|
static inline int64_t get_sbits64(GetBitContext *s, int n)
|
|
|
|
{
|
|
|
|
// sign_extend(x, 0) is undefined
|
|
|
|
if (!n)
|
|
|
|
return 0;
|
|
|
|
|
|
|
|
return sign_extend64(get_bits64(s, n), n);
|
|
|
|
}
|
|
|
|
|
2006-08-28 21:44:49 +03:00
|
|
|
/**
|
2011-12-07 15:03:53 +03:00
|
|
|
* Show 0-32 bits.
|
2006-08-28 21:44:49 +03:00
|
|
|
*/
|
2011-12-17 04:05:35 +03:00
|
|
|
static inline unsigned int show_bits_long(GetBitContext *s, int n)
|
|
|
|
{
|
2013-01-20 18:10:24 +03:00
|
|
|
if (n <= MIN_CACHE_BITS) {
|
2011-12-17 04:05:35 +03:00
|
|
|
return show_bits(s, n);
|
2013-01-20 18:10:24 +03:00
|
|
|
} else {
|
2011-01-23 03:56:27 +02:00
|
|
|
GetBitContext gb = *s;
|
2009-03-02 21:42:31 +02:00
|
|
|
return get_bits_long(&gb, n);
|
2006-08-28 21:44:49 +03:00
|
|
|
}
|
|
|
|
}
|
|
|
|
|
2021-01-28 16:59:14 +02:00
|
|
|
|
|
|
|
/**
|
|
|
|
* Initialize GetBitContext.
|
|
|
|
* @param buffer bitstream buffer, must be AV_INPUT_BUFFER_PADDING_SIZE bytes
|
|
|
|
* larger than the actual read bits because some optimized bitstream
|
|
|
|
* readers read 32 or 64 bit at once and could read over the end
|
|
|
|
* @param bit_size the size of the buffer in bits
|
|
|
|
* @return 0 on success, AVERROR_INVALIDDATA if the buffer_size would overflow.
|
|
|
|
*/
|
|
|
|
static inline int init_get_bits(GetBitContext *s, const uint8_t *buffer,
|
|
|
|
int bit_size)
|
2004-12-29 19:50:25 +02:00
|
|
|
{
|
2013-01-13 21:52:45 +03:00
|
|
|
int buffer_size;
|
|
|
|
int ret = 0;
|
|
|
|
|
2018-03-24 02:38:53 +02:00
|
|
|
if (bit_size >= INT_MAX - FFMAX(7, AV_INPUT_BUFFER_PADDING_SIZE*8) || bit_size < 0 || !buffer) {
|
2014-07-16 06:56:28 +03:00
|
|
|
bit_size = 0;
|
2013-01-20 18:10:24 +03:00
|
|
|
buffer = NULL;
|
|
|
|
ret = AVERROR_INVALIDDATA;
|
2005-09-22 02:18:52 +03:00
|
|
|
}
|
2004-12-29 19:50:25 +02:00
|
|
|
|
2013-01-13 21:52:45 +03:00
|
|
|
buffer_size = (bit_size + 7) >> 3;
|
|
|
|
|
2013-01-20 18:10:24 +03:00
|
|
|
s->buffer = buffer;
|
|
|
|
s->size_in_bits = bit_size;
|
2011-12-17 00:42:04 +03:00
|
|
|
s->size_in_bits_plus8 = bit_size + 8;
|
2013-01-20 18:10:24 +03:00
|
|
|
s->buffer_end = buffer + buffer_size;
|
|
|
|
s->index = 0;
|
|
|
|
|
2013-01-13 21:52:45 +03:00
|
|
|
return ret;
|
2004-12-29 19:50:25 +02:00
|
|
|
}
|
|
|
|
|
2013-01-14 01:37:11 +03:00
|
|
|
/**
|
|
|
|
* Initialize GetBitContext.
|
2015-06-29 23:48:34 +02:00
|
|
|
* @param buffer bitstream buffer, must be AV_INPUT_BUFFER_PADDING_SIZE bytes
|
2013-01-14 01:37:11 +03:00
|
|
|
* larger than the actual read bits because some optimized bitstream
|
|
|
|
* readers read 32 or 64 bit at once and could read over the end
|
|
|
|
* @param byte_size the size of the buffer in bytes
|
|
|
|
* @return 0 on success, AVERROR_INVALIDDATA if the buffer_size would overflow.
|
|
|
|
*/
|
|
|
|
static inline int init_get_bits8(GetBitContext *s, const uint8_t *buffer,
|
|
|
|
int byte_size)
|
|
|
|
{
|
2013-01-14 18:22:41 +03:00
|
|
|
if (byte_size > INT_MAX / 8 || byte_size < 0)
|
2013-01-14 18:23:39 +03:00
|
|
|
byte_size = -1;
|
2013-01-14 01:37:11 +03:00
|
|
|
return init_get_bits(s, buffer, byte_size * 8);
|
2004-12-29 19:50:25 +02:00
|
|
|
}
|
|
|
|
|
2019-03-26 12:10:54 +02:00
|
|
|
static inline int init_get_bits8_le(GetBitContext *s, const uint8_t *buffer,
|
|
|
|
int byte_size)
|
|
|
|
{
|
|
|
|
if (byte_size > INT_MAX / 8 || byte_size < 0)
|
|
|
|
byte_size = -1;
|
2021-01-28 16:59:14 +02:00
|
|
|
return init_get_bits(s, buffer, byte_size * 8);
|
2019-03-26 12:10:54 +02:00
|
|
|
}
|
|
|
|
|
2013-02-11 03:46:07 +03:00
|
|
|
static inline const uint8_t *align_get_bits(GetBitContext *s)
|
2006-08-26 13:26:14 +03:00
|
|
|
{
|
2011-01-23 03:56:27 +02:00
|
|
|
int n = -get_bits_count(s) & 7;
|
2013-01-20 18:10:24 +03:00
|
|
|
if (n)
|
|
|
|
skip_bits(s, n);
|
2013-02-11 03:46:07 +03:00
|
|
|
return s->buffer + (s->index >> 3);
|
2006-08-26 13:26:14 +03:00
|
|
|
}
|
|
|
|
|
2004-12-29 19:50:25 +02:00
|
|
|
/**
|
2010-02-17 23:20:43 +02:00
|
|
|
* If the vlc code is invalid and max_depth=1, then no bits will be removed.
|
|
|
|
* If the vlc code is invalid and max_depth>1, then the number of bits removed
|
|
|
|
* is undefined.
|
2004-12-29 19:50:25 +02:00
|
|
|
*/
|
2011-12-17 04:05:35 +03:00
|
|
|
#define GET_VLC(code, name, gb, table, bits, max_depth) \
|
|
|
|
do { \
|
2011-01-23 03:56:27 +02:00
|
|
|
int n, nb_bits; \
|
|
|
|
unsigned int index; \
|
|
|
|
\
|
|
|
|
index = SHOW_UBITS(name, gb, bits); \
|
2022-06-13 23:02:57 +02:00
|
|
|
code = table[index].sym; \
|
|
|
|
n = table[index].len; \
|
2011-01-23 03:56:27 +02:00
|
|
|
\
|
|
|
|
if (max_depth > 1 && n < 0) { \
|
|
|
|
LAST_SKIP_BITS(name, gb, bits); \
|
|
|
|
UPDATE_CACHE(name, gb); \
|
|
|
|
\
|
|
|
|
nb_bits = -n; \
|
|
|
|
\
|
|
|
|
index = SHOW_UBITS(name, gb, nb_bits) + code; \
|
2022-06-13 23:02:57 +02:00
|
|
|
code = table[index].sym; \
|
|
|
|
n = table[index].len; \
|
2011-01-23 03:56:27 +02:00
|
|
|
if (max_depth > 2 && n < 0) { \
|
|
|
|
LAST_SKIP_BITS(name, gb, nb_bits); \
|
|
|
|
UPDATE_CACHE(name, gb); \
|
|
|
|
\
|
|
|
|
nb_bits = -n; \
|
|
|
|
\
|
|
|
|
index = SHOW_UBITS(name, gb, nb_bits) + code; \
|
2022-06-13 23:02:57 +02:00
|
|
|
code = table[index].sym; \
|
|
|
|
n = table[index].len; \
|
2011-01-23 03:56:27 +02:00
|
|
|
} \
|
|
|
|
} \
|
|
|
|
SKIP_BITS(name, gb, n); \
|
|
|
|
} while (0)
|
|
|
|
|
2016-06-26 14:19:48 +02:00
|
|
|
#define GET_RL_VLC(level, run, name, gb, table, bits, \
|
2013-01-20 18:10:24 +03:00
|
|
|
max_depth, need_update) \
|
|
|
|
do { \
|
|
|
|
int n, nb_bits; \
|
|
|
|
unsigned int index; \
|
|
|
|
\
|
|
|
|
index = SHOW_UBITS(name, gb, bits); \
|
|
|
|
level = table[index].level; \
|
|
|
|
n = table[index].len; \
|
|
|
|
\
|
|
|
|
if (max_depth > 1 && n < 0) { \
|
|
|
|
SKIP_BITS(name, gb, bits); \
|
|
|
|
if (need_update) { \
|
|
|
|
UPDATE_CACHE(name, gb); \
|
|
|
|
} \
|
|
|
|
\
|
|
|
|
nb_bits = -n; \
|
|
|
|
\
|
|
|
|
index = SHOW_UBITS(name, gb, nb_bits) + level; \
|
|
|
|
level = table[index].level; \
|
|
|
|
n = table[index].len; \
|
2015-12-13 20:01:50 +02:00
|
|
|
if (max_depth > 2 && n < 0) { \
|
|
|
|
LAST_SKIP_BITS(name, gb, nb_bits); \
|
|
|
|
if (need_update) { \
|
|
|
|
UPDATE_CACHE(name, gb); \
|
|
|
|
} \
|
|
|
|
nb_bits = -n; \
|
|
|
|
\
|
|
|
|
index = SHOW_UBITS(name, gb, nb_bits) + level; \
|
|
|
|
level = table[index].level; \
|
|
|
|
n = table[index].len; \
|
|
|
|
} \
|
2013-01-20 18:10:24 +03:00
|
|
|
} \
|
|
|
|
run = table[index].run; \
|
|
|
|
SKIP_BITS(name, gb, n); \
|
2011-01-23 03:56:27 +02:00
|
|
|
} while (0)
|
2004-12-29 19:50:25 +02:00
|
|
|
|
|
|
|
/**
|
2011-12-17 04:07:32 +03:00
|
|
|
* Parse a vlc code.
|
2005-12-17 20:14:38 +02:00
|
|
|
* @param bits is the number of bits which will be read at once, must be
|
2023-09-08 15:18:12 +02:00
|
|
|
* identical to nb_bits in vlc_init()
|
2007-04-07 17:09:20 +03:00
|
|
|
* @param max_depth is the number of times bits bits must be read to completely
|
2005-12-17 20:14:38 +02:00
|
|
|
* read the longest vlc code
|
2004-12-29 19:50:25 +02:00
|
|
|
* = (max_vlc_length + bits - 1) / bits
|
2018-01-28 03:29:01 +02:00
|
|
|
* @returns the code parsed or -1 if no vlc matches
|
2004-12-29 19:50:25 +02:00
|
|
|
*/
|
2022-06-13 23:02:57 +02:00
|
|
|
static av_always_inline int get_vlc2(GetBitContext *s, const VLCElem *table,
|
2011-12-17 04:05:35 +03:00
|
|
|
int bits, int max_depth)
|
2004-12-29 19:50:25 +02:00
|
|
|
{
|
|
|
|
int code;
|
2005-12-17 20:14:38 +02:00
|
|
|
|
2011-01-23 03:24:46 +02:00
|
|
|
OPEN_READER(re, s);
|
|
|
|
UPDATE_CACHE(re, s);
|
2004-12-29 19:50:25 +02:00
|
|
|
|
2011-01-23 03:24:46 +02:00
|
|
|
GET_VLC(code, re, s, table, bits, max_depth);
|
2004-12-29 19:50:25 +02:00
|
|
|
|
2011-01-23 03:24:46 +02:00
|
|
|
CLOSE_READER(re, s);
|
2013-01-20 18:10:24 +03:00
|
|
|
|
2004-12-29 19:50:25 +02:00
|
|
|
return code;
|
|
|
|
}
|
|
|
|
|
2023-08-27 21:18:46 +02:00
|
|
|
static inline int get_vlc_multi(GetBitContext *s, uint8_t *dst,
|
|
|
|
const VLC_MULTI_ELEM *const Jtable,
|
|
|
|
const VLCElem *const table,
|
2024-03-30 04:25:24 +02:00
|
|
|
const int bits, const int max_depth,
|
|
|
|
const int symbols_size)
|
2023-08-27 21:18:46 +02:00
|
|
|
{
|
|
|
|
dst[0] = get_vlc2(s, table, bits, max_depth);
|
|
|
|
return 1;
|
|
|
|
}
|
|
|
|
|
2011-12-17 04:05:35 +03:00
|
|
|
static inline int decode012(GetBitContext *gb)
|
|
|
|
{
|
2011-01-23 16:01:43 +02:00
|
|
|
int n;
|
|
|
|
n = get_bits1(gb);
|
|
|
|
if (n == 0)
|
|
|
|
return 0;
|
|
|
|
else
|
|
|
|
return get_bits1(gb) + 1;
|
|
|
|
}
|
|
|
|
|
2011-12-17 04:05:35 +03:00
|
|
|
static inline int decode210(GetBitContext *gb)
|
|
|
|
{
|
2011-01-23 16:01:43 +02:00
|
|
|
if (get_bits1(gb))
|
|
|
|
return 0;
|
|
|
|
else
|
|
|
|
return 2 - get_bits1(gb);
|
|
|
|
}
|
|
|
|
|
|
|
|
static inline int get_bits_left(GetBitContext *gb)
|
|
|
|
{
|
|
|
|
return gb->size_in_bits - get_bits_count(gb);
|
|
|
|
}
|
|
|
|
|
2013-10-30 20:22:03 +03:00
|
|
|
static inline int skip_1stop_8data_bits(GetBitContext *gb)
|
|
|
|
{
|
|
|
|
if (get_bits_left(gb) <= 0)
|
|
|
|
return AVERROR_INVALIDDATA;
|
|
|
|
|
|
|
|
while (get_bits1(gb)) {
|
|
|
|
skip_bits(gb, 8);
|
|
|
|
if (get_bits_left(gb) <= 0)
|
|
|
|
return AVERROR_INVALIDDATA;
|
|
|
|
}
|
|
|
|
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
2021-01-28 16:59:14 +02:00
|
|
|
#endif // CACHED_BITSTREAM_READER
|
|
|
|
|
2009-04-13 19:20:26 +03:00
|
|
|
#endif /* AVCODEC_GET_BITS_H */
|