Do not try to parse empty strf tags.

diff --git a/libavformat/avidec.c b/libavformat/avidec.c
index 9e75ee2cd21716e60f5187b0fccac04880d0aa05..05602d8bc15a7b61ea487d9fe6d417fb650e1b4d 100644 (file)
--- a/libavformat/avidec.c
+++ b/libavformat/avidec.c
@@ -570,6 +570,8 @@ static int avi_read_header(AVFormatContext *s, AVFormatParameters *ap)
             break;
         case MKTAG('s', 't', 'r', 'f'):
             /* stream header */
+            if (!size)
+                break;
             if (stream_index >= (unsigned)s->nb_streams || avi->dv_demux) {
                 avio_skip(pb, size);
             } else {