mpeg12: do not fail on zero dimensions in the sequence header.

[ffmpeg] / libavcodec / lzw.c

diff --git a/libavcodec/lzw.c b/libavcodec/lzw.c
index 833c9d0ab376b936988523e27645a29cf5c81110..2c99014c2a9fe574fda5811b01f9d07cb111a497 100644 (file)
--- a/libavcodec/lzw.c
+++ b/libavcodec/lzw.c
@@ -1,34 +1,35 @@
 /*
  * LZW decoder
- * Copyright (c) 2003 Fabrice Bellard.
- * Copyright (c) 2006 Konstantin Shishkov.
+ * Copyright (c) 2003 Fabrice Bellard
+ * Copyright (c) 2006 Konstantin Shishkov
  *
- * This file is part of FFmpeg.
+ * This file is part of Libav.
  *
- * FFmpeg is free software; you can redistribute it and/or
+ * Libav 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.
  *
- * FFmpeg is distributed in the hope that it will be useful,
+ * Libav 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 FFmpeg; if not, write to the Free Software
+ * License along with Libav; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
 /**
- * @file lzw.c
+ * @file
  * @brief LZW decoding routines
  * @author Fabrice Bellard
- * Modified for use in TIFF by Konstantin Shishkov
+ * @author modified for use in TIFF by Konstantin Shishkov
  */
 
 #include "avcodec.h"
 #include "lzw.h"
+#include "libavutil/mem.h"
 
 #define LZW_MAXBITS                 12
 #define LZW_SIZTABLE                (1<<LZW_MAXBITS)
@@ -101,27 +102,32 @@ void ff_lzw_decode_tail(LZWState *p)
     struct LZWState *s = (struct LZWState *)p;
 
     if(s->mode == FF_LZW_GIF) {
-        while(s->pbuf < s->ebuf && s->bs>0){
-            s->pbuf += s->bs;
-            s->bs = *s->pbuf++;
+        while (s->bs > 0) {
+            if (s->bs >= s->ebuf - s->pbuf) {
+                s->pbuf = s->ebuf;
+                break;
+            } else {
+                s->pbuf += s->bs;
+                s->bs = *s->pbuf++;
+            }
         }
     }else
         s->pbuf= s->ebuf;
 }
 
-void ff_lzw_decode_open(LZWState **p)
+av_cold void ff_lzw_decode_open(LZWState **p)
 {
     *p = av_mallocz(sizeof(struct LZWState));
 }
 
-void ff_lzw_decode_close(LZWState **p)
+av_cold void ff_lzw_decode_close(LZWState **p)
 {
     av_freep(p);
 }
 
 /**
  * Initialize LZW decoder
- * @param s LZW context
+ * @param p LZW context
  * @param csize initial code size in bits
  * @param buf input data
  * @param buf_size input data size
@@ -131,7 +137,7 @@ int ff_lzw_decode_init(LZWState *p, int csize, const uint8_t *buf, int buf_size,
 {
     struct LZWState *s = (struct LZWState *)p;
 
-    if(csize < 1 || csize > LZW_MAXBITS)
+    if(csize < 1 || csize >= LZW_MAXBITS)
         return -1;
     /* read buffer */
     s->pbuf = buf;
@@ -161,7 +167,7 @@ int ff_lzw_decode_init(LZWState *p, int csize, const uint8_t *buf, int buf_size,
  * NOTE: the algorithm here is inspired from the LZW GIF decoder
  *  written by Steven A. Bennett in 1987.
  *
- * @param s LZW context
+ * @param p LZW context
  * @param buf output buffer
  * @param len number of bytes to decode
  * @return number of bytes decoded