1 files changed, 23 insertions, 14 deletions

diff --git a/libavformat/dtsdec.c b/libavformat/dtsdec.c
index 9010711..0ebf847 100644
--- a/libavformat/dtsdec.c
+++ b/libavformat/dtsdec.c
@@ -2,20 +2,20 @@
  * RAW DTS demuxer
  * Copyright (c) 2008 Benjamin Larsson
  *
- * 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
  */
 
@@ -32,34 +32,43 @@ static int dts_probe(AVProbeData *p)
 {
     const uint8_t *buf, *bufp;
     uint32_t state = -1;
-    int markers[3] = {0};
-    int sum, max;
+    int markers[4] = {0};
+    int sum, max, i;
+    int64_t diff = 0;
 
-    buf = p->buf;
+    buf = p->buf + FFMIN(4096, p->buf_size);
 
     for(; buf < (p->buf+p->buf_size)-2; buf+=2) {
         bufp = buf;
         state = (state << 16) | bytestream_get_be16(&bufp);
 
         /* regular bitstream */
-        if (state == DCA_MARKER_RAW_BE || state == DCA_MARKER_RAW_LE)
+        if (state == DCA_MARKER_RAW_BE)
             markers[0]++;
+        if (state == DCA_MARKER_RAW_LE)
+            markers[1]++;
 
         /* 14 bits big-endian bitstream */
         if (state == DCA_MARKER_14B_BE)
             if ((bytestream_get_be16(&bufp) & 0xFFF0) == 0x07F0)
-                markers[1]++;
+                markers[2]++;
 
         /* 14 bits little-endian bitstream */
         if (state == DCA_MARKER_14B_LE)
             if ((bytestream_get_be16(&bufp) & 0xF0FF) == 0xF007)
-                markers[2]++;
+                markers[3]++;
+
+        if (buf - p->buf >= 4)
+            diff += FFABS(((int16_t)AV_RL16(buf)) - (int16_t)AV_RL16(buf-4));
     }
-    sum = markers[0] + markers[1] + markers[2];
-    max = markers[1] > markers[0];
-    max = markers[2] > markers[max] ? 2 : max;
+    sum = markers[0] + markers[1] + markers[2] + markers[3];
+    max = 0;
+    for (i=1; i<4; i++)
+        if (markers[max] < markers[i])
+            max = i;
     if (markers[max] > 3 && p->buf_size / markers[max] < 32*1024 &&
-        markers[max] * 4 > sum * 3)
+        markers[max] * 4 > sum * 3 &&
+        diff / p->buf_size > 200)
         return AVPROBE_SCORE_EXTENSION + 1;
 
     return 0;