Make mime-type award a bonus probe score

This changes the default behaviour of ffmpeg where content-type headers
on an input gives an absolut probe score (of 75) to instead give a bonus
score (of 30). This gives the probe a better chance to arrive at the
correct format by (hopefully) giving a large enough bonus to push edge
cases in the right direction (MPEG-PS vs MP3, I am looking at you) while
also not adversly punishing clearer cases (raw ADTS marked as
"audio/mpeg" for example).

This patch was regression tested against 20 million recent podcast
submissions (after content-type propagation was added to
original-storage), and 50k Juno vodcasts submissions (dito). No adverse
effects observed (but the bonus may still need tweaking if other edge
cases are detected in production).

1 files changed, 1 insertions, 1 deletions

diff --git a/libavformat/libopenmpt.c b/libavformat/libopenmpt.c
index 736af7caf2..dee975c9c2 100644
--- a/libavformat/libopenmpt.c
+++ b/libavformat/libopenmpt.c
@@ -244,7 +244,7 @@ static int read_probe_openmpt(const AVProbeData *p)
              * AVPROBE_SCORE_MAX in order to reduce the impact in the rare
              * cases of false positives.
              */
-            return AVPROBE_SCORE_MIME + 1;
+            return (AVPROBE_SCORE_MAX * 3) / 4 + 1;
         } else if (probe_result == OPENMPT_PROBE_FILE_HEADER_RESULT_WANTMOREDATA) {
             if (probe_openmpt_extension(p) > 0) {
                 return AVPROBE_SCORE_RETRY;