[FFmpeg-devel] [PATCH v2 5/5] avformat/chromaprint: Avoid null pointer dereference

[Andriy Gelman]

From: Andriy Gelman <andriy.gelman at gmail.com>

As of commit 21b2442f in the chromaprint library, selecting "-algorithm 2" via the ffmpeg cli creates a null pointer dereference. This can be replicated by:
./ffmpeg -f lavfi -i sine=d=20,asetnsamples=n=1000 -f chromaprint -algorithm 2 -

Until this issue is resolved, this commit makes ffmpeg output an error when
"-algorithm 2" is selected for chromaprint versions > 1.2.0.
---
 libavformat/chromaprint.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/libavformat/chromaprint.c b/libavformat/chromaprint.c
index faa92ca0db..3ecce3e08a 100644
--- a/libavformat/chromaprint.c
+++ b/libavformat/chromaprint.c
@@ -70,6 +70,13 @@ static int write_header(AVFormatContext *s)
         return AVERROR(ENOMEM);
     }
 
+#if CPR_VERSION_INT > AV_VERSION_INT(1, 2, 0)
+    if (cpr->algorithm == CHROMAPRINT_ALGORITHM_TEST3) {
+        av_log(s, AV_LOG_ERROR, "Algorithm 2 cannot be used with chromaprint version > 1.2.0 because of a bug in the chromaprint library\n");
+        goto fail;
+    }
+#endif
+
     if (cpr->silence_threshold != -1) {
 #if CPR_VERSION_INT >= AV_VERSION_INT(0, 7, 0)
         if (!chromaprint_set_option(cpr->ctx, "silence_threshold", cpr->silence_threshold)) {
-- 
2.23.0