1 files changed, 77 insertions, 35 deletions

diff --git a/libavcodec/get_bits.h b/libavcodec/get_bits.h
index 5a0089add8..7824e5ab0f 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;
@@ -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