typefinding: don't detect mp3 based on just a few bits1.0

Remove dodgy code that detects mp3 with as little as
a valid frame sync at the beginning. This was only used
in some unit tests in -good where there were only a few
bytes after the id3 tag. We now require at least two
frame headers.

Fixes mis-dection of text files with UTF-16 LE BOM as mp3.

https://bugzilla.gnome.org/show_bug.cgi?id=681368

1 files changed, 8 insertions, 8 deletions

diff --git a/gst/typefind/gsttypefindfunctions.c b/gst/typefind/gsttypefindfunctions.c
index 82accf7bb..a1167015a 100644
--- a/gst/typefind/gsttypefindfunctions.c
+++ b/gst/typefind/gsttypefindfunctions.c
@@ -1401,14 +1401,14 @@ mp3_type_find (GstTypeFind * tf, gpointer unused)
     goto suggest;
   }
 
-  /* let's see if there's a valid header right at the start */
-  data = gst_type_find_peek (tf, 0, 4); /* use min. frame size? */
-  if (data && mp3_type_frame_length_from_header (GST_READ_UINT32_BE (data),
-          &layer, NULL, NULL, NULL, NULL, 0) != 0) {
-    if (prob == 0)
-      prob = GST_TYPE_FIND_POSSIBLE - 10;
-    else
-      prob = MAX (GST_TYPE_FIND_POSSIBLE - 10, prob + 10);
+  /* a valid header right at the start makes it more likely
+   * that this is actually plain mpeg-1 audio */
+  if (prob > 0) {
+    data = gst_type_find_peek (tf, 0, 4);       /* use min. frame size? */
+    if (data && mp3_type_frame_length_from_header (GST_READ_UINT32_BE (data),
+            &layer, NULL, NULL, NULL, NULL, 0) != 0) {
+      prob = MIN (prob + 10, GST_TYPE_FIND_MAXIMUM);
+    }
   }
 
   if (prob > 0)