[FFmpeg-devel] [PATCH v4] avformat/mp3dec: Fixes misdetection of zYLx.wav

[lance.lmwang at gmail.com]

From: Limin Wang <lance.lmwang at gmail.com>

Signed-off-by: Limin Wang <lance.lmwang at gmail.com>
---
By Hendrik comments, I have proposal a more general fix for 
more common case. 
Now It's only tested with fate and all samples in:
http://samples.ffmpeg.org/A-codecs/MP3-pro
http://samples.ffmpeg.org/A-codecs/MP3

 libavformat/mp3dec.c | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/libavformat/mp3dec.c b/libavformat/mp3dec.c
index 258f191..551aa56 100644
--- a/libavformat/mp3dec.c
+++ b/libavformat/mp3dec.c
@@ -73,7 +73,8 @@ static int mp3_read_probe(const AVProbeData *p)
     int frames, ret;
     int framesizes, max_framesizes;
     uint32_t header;
-    const uint8_t *buf, *buf0, *buf2, *end;
+    uint32_t next_sync;
+    const uint8_t *buf, *buf0, *buf2, *buf3, *end;
 
     buf0 = p->buf;
     end = p->buf + p->buf_size - sizeof(uint32_t);
@@ -93,6 +94,16 @@ static int mp3_read_probe(const AVProbeData *p)
             ret = avpriv_mpegaudio_decode_header(&h, header);
             if (ret != 0)
                 break;
+
+            buf3 = buf2 + 4;
+            while (buf3 < end) {
+                next_sync = AV_RB32(buf3);
+                if ((next_sync & MP3_MASK) == (header & MP3_MASK))
+                    break;
+                buf3++;
+            }
+            if (buf3 - buf2 != h.frame_size)
+                break;
             buf2 += h.frame_size;
             framesizes += h.frame_size;
         }
-- 
2.6.4