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-rw-r--r--libavcodec/get_bits.h97
1 files changed, 63 insertions, 34 deletions
diff --git a/libavcodec/get_bits.h b/libavcodec/get_bits.h
index 5a0089add8..5da90b6b42 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)
@@ -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;
@@ -303,20 +332,22 @@ 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 +409,7 @@ 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 +419,7 @@ 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 +437,8 @@ 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);
}
generated by cgit v1.2.3 (git 2.39.1) at 2024-07-10 06:22:02 +0000