1 files changed, 32 insertions, 11 deletions

diff --git a/libavcodec/rangecoder.h b/libavcodec/rangecoder.h
index 2ead446..4d4ca4d 100644
--- a/libavcodec/rangecoder.h
+++ b/libavcodec/rangecoder.h
@@ -2,20 +2,20 @@
  * Range coder
  * 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
  */
 
@@ -28,9 +28,9 @@
 #define AVCODEC_RANGECODER_H
 
 #include <stdint.h>
-#include <assert.h>
 
 #include "libavutil/common.h"
+#include "libavutil/avassert.h"
 
 typedef struct RangeCoder {
     int low;
@@ -42,11 +42,30 @@ typedef struct RangeCoder {
     uint8_t *bytestream_start;
     uint8_t *bytestream;
     uint8_t *bytestream_end;
+    int overread;
+#define MAX_OVERREAD 2
 } RangeCoder;
 
 void ff_init_range_encoder(RangeCoder *c, uint8_t *buf, int buf_size);
 void ff_init_range_decoder(RangeCoder *c, const uint8_t *buf, int buf_size);
-int ff_rac_terminate(RangeCoder *c);
+
+/**
+ * Terminates the range coder
+ * @param version version 0 requires the decoder to know the data size in bytes
+ *                version 1 needs about 1 bit more space but does not need to
+ *                          carry the size from encoder to decoder
+ */
+int ff_rac_terminate(RangeCoder *c, int version);
+
+/**
+ * Check if at the current position there is a valid looking termination
+ * @param version version 0 requires the decoder to know the data size in bytes
+ *                version 1 needs about 1 bit more space but does not need to
+ *                          carry the size from encoder to decoder
+ * @returns negative AVERROR code on error or non negative.
+ */
+int ff_rac_check_termination(RangeCoder *c, int version);
+
 void ff_build_rac_states(RangeCoder *c, int factor, int max_p);
 
 static inline void renorm_encoder(RangeCoder *c)
@@ -86,9 +105,9 @@ static inline void put_rac(RangeCoder *c, uint8_t *const state, int bit)
 {
     int range1 = (c->range * (*state)) >> 8;
 
-    assert(*state);
-    assert(range1 < c->range);
-    assert(range1 > 0);
+    av_assert2(*state);
+    av_assert2(range1 < c->range);
+    av_assert2(range1 > 0);
     if (!bit) {
         c->range -= range1;
         *state    = c->zero_state[*state];
@@ -106,9 +125,11 @@ static inline void refill(RangeCoder *c)
     if (c->range < 0x100) {
         c->range <<= 8;
         c->low   <<= 8;
-        if (c->bytestream < c->bytestream_end)
+        if (c->bytestream < c->bytestream_end) {
             c->low += c->bytestream[0];
-        c->bytestream++;
+            c->bytestream++;
+        } else
+            c->overread ++;
     }
 }