diff options
Diffstat (limited to 'libavcodec/get_bits.h')
| -rw-r--r-- | libavcodec/get_bits.h | 114 |
1 files changed, 78 insertions, 36 deletions
diff --git a/libavcodec/get_bits.h b/libavcodec/get_bits.h index 5a0089add8..82421cba32 100644 --- a/libavcodec/get_bits.h +++ b/libavcodec/get_bits.h @@ -1,20 +1,20 @@ /* * copyright (c) 2004 Michael Niedermayer <michaelni@gmx.at> * - * This file is part of Libav. + * This file is part of FFmpeg. * - * Libav is free software; you can redistribute it and/or + * 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 2.1 of the License, or (at your option) any later version. * - * Libav 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 Libav; 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 */ @@ -31,6 +31,7 @@ #include "libavutil/common.h" #include "libavutil/intreadwrite.h" #include "libavutil/log.h" +#include "libavutil/avassert.h" #include "mathops.h" /* @@ -54,9 +55,7 @@ typedef struct GetBitContext { const uint8_t *buffer, *buffer_end; int index; int size_in_bits; -#if !UNCHECKED_BITSTREAM_READER int size_in_bits_plus8; -#endif } GetBitContext; #define VLC_TYPE int16_t @@ -65,6 +64,7 @@ typedef struct VLC { int bits; VLC_TYPE (*table)[2]; ///< code, bits int table_size, table_allocated; + void * volatile init_state; } VLC; typedef struct RL_VLC_ELEM { @@ -126,7 +126,7 @@ typedef struct RL_VLC_ELEM { #if UNCHECKED_BITSTREAM_READER #define OPEN_READER(name, gb) \ unsigned int name ## _index = (gb)->index; \ - unsigned int av_unused name ## _cache = 0 + unsigned int av_unused name ## _cache #define HAVE_BITS_REMAINING(name, gb) 1 #else @@ -140,27 +140,34 @@ typedef struct RL_VLC_ELEM { #define CLOSE_READER(name, gb) (gb)->index = name ## _index +# ifdef LONG_BITSTREAM_READER + +# define UPDATE_CACHE_LE(name, gb) name ## _cache = \ + AV_RL64((gb)->buffer + (name ## _index >> 3)) >> (name ## _index & 7) + +# define UPDATE_CACHE_BE(name, gb) name ## _cache = \ + AV_RB64((gb)->buffer + (name ## _index >> 3)) >> (32 - (name ## _index & 7)) + +#else + +# define UPDATE_CACHE_LE(name, gb) name ## _cache = \ + AV_RL32((gb)->buffer + (name ## _index >> 3)) >> (name ## _index & 7) + +# define UPDATE_CACHE_BE(name, gb) name ## _cache = \ + AV_RB32((gb)->buffer + (name ## _index >> 3)) << (name ## _index & 7) + +#endif + + #ifdef BITSTREAM_READER_LE -# ifdef LONG_BITSTREAM_READER -# define UPDATE_CACHE(name, gb) name ## _cache = \ - AV_RL64((gb)->buffer + (name ## _index >> 3)) >> (name ## _index & 7) -# else -# define UPDATE_CACHE(name, gb) name ## _cache = \ - AV_RL32((gb)->buffer + (name ## _index >> 3)) >> (name ## _index & 7) -# endif +# define UPDATE_CACHE(name, gb) UPDATE_CACHE_LE(name, gb) # define SKIP_CACHE(name, gb, num) name ## _cache >>= (num) #else -# ifdef LONG_BITSTREAM_READER -# define UPDATE_CACHE(name, gb) name ## _cache = \ - AV_RB64((gb)->buffer + (name ## _index >> 3)) >> (32 - (name ## _index & 7)) -# else -# define UPDATE_CACHE(name, gb) name ## _cache = \ - AV_RB32((gb)->buffer + (name ## _index >> 3)) << (name ## _index & 7) -# endif +# define UPDATE_CACHE(name, gb) UPDATE_CACHE_BE(name, gb) # define SKIP_CACHE(name, gb, num) name ## _cache <<= (num) @@ -181,12 +188,18 @@ typedef struct RL_VLC_ELEM { #define LAST_SKIP_BITS(name, gb, num) SKIP_COUNTER(name, gb, num) +#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) + #ifdef BITSTREAM_READER_LE -# define SHOW_UBITS(name, gb, num) zero_extend(name ## _cache, num) -# define SHOW_SBITS(name, gb, num) sign_extend(name ## _cache, num) +# define SHOW_UBITS(name, gb, num) SHOW_UBITS_LE(name, gb, num) +# define SHOW_SBITS(name, gb, num) SHOW_SBITS_LE(name, gb, num) #else -# define SHOW_UBITS(name, gb, num) NEG_USR32(name ## _cache, num) -# define SHOW_SBITS(name, gb, num) NEG_SSR32(name ## _cache, num) +# define SHOW_UBITS(name, gb, num) SHOW_UBITS_BE(name, gb, num) +# define SHOW_SBITS(name, gb, num) SHOW_SBITS_BE(name, gb, num) #endif #define GET_CACHE(name, gb) ((uint32_t) name ## _cache) @@ -206,7 +219,7 @@ static inline void skip_bits_long(GetBitContext *s, int n) } /** - * read mpeg1 dc style vlc (sign bit + mantisse with no MSB). + * read mpeg1 dc style vlc (sign bit + mantissa with no MSB). * if MSB not set it is negative * @param n length in bits */ @@ -215,6 +228,7 @@ static inline int get_xbits(GetBitContext *s, int n) register int sign; register int32_t cache; OPEN_READER(re, s); + av_assert2(n>0 && n<=25); UPDATE_CACHE(re, s); cache = GET_CACHE(re, s); sign = ~cache >> 31; @@ -227,6 +241,7 @@ static inline int get_sbits(GetBitContext *s, int n) { register int tmp; OPEN_READER(re, s); + av_assert2(n>0 && n<=25); UPDATE_CACHE(re, s); tmp = SHOW_SBITS(re, s, n); LAST_SKIP_BITS(re, s, n); @@ -241,6 +256,7 @@ static inline unsigned int get_bits(GetBitContext *s, int n) { register int tmp; OPEN_READER(re, s); + av_assert2(n>0 && n<=25); UPDATE_CACHE(re, s); tmp = SHOW_UBITS(re, s, n); LAST_SKIP_BITS(re, s, n); @@ -248,6 +264,18 @@ static inline unsigned int get_bits(GetBitContext *s, int n) return tmp; } +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; +} + /** * Show 1-25 bits. */ @@ -255,6 +283,7 @@ static inline unsigned int show_bits(GetBitContext *s, int n) { register int tmp; OPEN_READER(re, s); + av_assert2(n>0 && n<=25); UPDATE_CACHE(re, s); tmp = SHOW_UBITS(re, s, n); return tmp; @@ -263,7 +292,6 @@ static inline unsigned int show_bits(GetBitContext *s, int n) static inline void skip_bits(GetBitContext *s, int n) { OPEN_READER(re, s); - UPDATE_CACHE(re, s); LAST_SKIP_BITS(re, s, n); CLOSE_READER(re, s); } @@ -303,20 +331,22 @@ static inline void skip_bits1(GetBitContext *s) */ static inline unsigned int get_bits_long(GetBitContext *s, int n) { - if (n <= MIN_CACHE_BITS) { + if (!n) { + return 0; + } else if (n <= MIN_CACHE_BITS) { return get_bits(s, n); } else { #ifdef BITSTREAM_READER_LE - int ret = get_bits(s, 16); + unsigned ret = get_bits(s, 16); return ret | (get_bits(s, n - 16) << 16); #else - int ret = get_bits(s, 16) << (n - 16); + unsigned ret = get_bits(s, 16) << (n - 16); return ret | get_bits(s, n - 16); #endif } } -/* +/** * Read 0-64 bits. */ static inline uint64_t get_bits64(GetBitContext *s, int n) @@ -378,7 +408,7 @@ static inline int init_get_bits(GetBitContext *s, const uint8_t *buffer, int buffer_size; int ret = 0; - if (bit_size > INT_MAX - 7 || bit_size < 0 || !buffer) { + if (bit_size >= INT_MAX - 7 || bit_size < 0 || !buffer) { buffer_size = bit_size = 0; buffer = NULL; ret = AVERROR_INVALIDDATA; @@ -388,9 +418,7 @@ static inline int init_get_bits(GetBitContext *s, const uint8_t *buffer, s->buffer = buffer; s->size_in_bits = bit_size; -#if !UNCHECKED_BITSTREAM_READER s->size_in_bits_plus8 = bit_size + 8; -#endif s->buffer_end = buffer + buffer_size; s->index = 0; @@ -408,8 +436,8 @@ static inline int init_get_bits(GetBitContext *s, const uint8_t *buffer, static inline int init_get_bits8(GetBitContext *s, const uint8_t *buffer, int byte_size) { - if (byte_size > INT_MAX / 8) - return AVERROR_INVALIDDATA; + if (byte_size > INT_MAX / 8 || byte_size < 0) + byte_size = -1; return init_get_bits(s, buffer, byte_size * 8); } @@ -557,6 +585,20 @@ static inline int get_bits_left(GetBitContext *gb) return gb->size_in_bits - get_bits_count(gb); } +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; +} + //#define TRACE #ifdef TRACE |