1 files changed, 18 insertions, 16 deletions

diff --git a/libavcodec/get_bits.h b/libavcodec/get_bits.h
index 5a0089add8..f16a5082c5 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
@@ -126,7 +125,7 @@ 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
@@ -227,6 +226,7 @@ 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 +241,7 @@ 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);
@@ -255,6 +256,7 @@ 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 +305,22 @@ 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 +382,7 @@ 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 +392,7 @@ 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 +410,8 @@ 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);
 }