[FFmpeg-cvslog] avformat/vividas: Check and require 1 video stream

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michael at niedermayer.cc> | Tue Nov  5 21:52:41 2019 +0100| [3e5a528bbe85a3a00640bc2739c11ee07eb05485] | committer: Michael Niedermayer

avformat/vividas: Check and require 1 video stream

The decoder hardcodes that audio is stream_id = 1 so it does not
currently work with more or less than 1 video stream at st=0

Fixes: assertion failure
Fixes: 18602/clusterfuzz-testcase-minimized-ffmpeg_DEMUXER_fuzzer-6259277199310848

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=3e5a528bbe85a3a00640bc2739c11ee07eb05485
---

 libavformat/vividas.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/libavformat/vividas.c b/libavformat/vividas.c
index a55f5c0ead..bf19b55f51 100644
--- a/libavformat/vividas.c
+++ b/libavformat/vividas.c
@@ -311,8 +311,10 @@ static int track_header(VividasDemuxContext *viv, AVFormatContext *s,  uint8_t *
     num_video = avio_r8(pb);
 
     avio_seek(pb, off, SEEK_SET);
-    if (num_video != 1)
-        av_log(s, AV_LOG_WARNING, "number of video tracks %d is not 1\n", num_video);
+    if (num_video != 1) {
+        av_log(s, AV_LOG_ERROR, "number of video tracks %d is not 1\n", num_video);
+        return AVERROR_PATCHWELCOME;
+    }
 
     for (i = 0; i < num_video; i++) {
         AVStream *st = avformat_new_stream(s, NULL);