avformat/thp: Require a video stream

The demuxer code assumes the existence of a video stream

Fixes: assertion failure
Fixes: 21512/clusterfuzz-testcase-minimized-ffmpeg_DEMUXER_fuzzer-5699660783288320

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
(cherry picked from commit 97c78caf3e8f7ec4df3d3123b5e8d0e7541319e6)
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

1 files changed, 3 insertions, 0 deletions

diff --git a/libavformat/thp.c b/libavformat/thp.c
index 76b9b3820c..38db4da89a 100644
--- a/libavformat/thp.c
+++ b/libavformat/thp.c
@@ -145,6 +145,9 @@ static int thp_read_header(AVFormatContext *s)
         }
     }
 
+    if (!thp->vst)
+        return AVERROR_INVALIDDATA;
+
     return 0;
 }