typefindfunctions: make h264 typefinder more picky when returning "likely" probability

Only return LIKELY probability if we've seen an SPS, PPS and an
IDR slice nal, i.e. try harder to avoid false positives such
as with certain VC-1 files.

https://bugzilla.gnome.org/show_bug.cgi?id=668565

diff --git a/gst/typefind/gsttypefindfunctions.c b/gst/typefind/gsttypefindfunctions.c
index bd8f97c..1bf32cb 100644 (file)
--- a/gst/typefind/gsttypefindfunctions.c
+++ b/gst/typefind/gsttypefindfunctions.c
@@ -2402,6 +2402,9 @@ h264_video_type_find (GstTypeFind * tf, gpointer unused)
   /* Stream consists of: a series of sync codes (00 00 00 01) followed 
    * by NALs
    */
+  gboolean seen_idr = FALSE;
+  gboolean seen_sps = FALSE;
+  gboolean seen_pps = FALSE;
   int nut, ref;
   int good = 0;
   int bad = 0;
@@ -2426,6 +2429,13 @@ h264_video_type_find (GstTypeFind * tf, gpointer unused)
             ((nut == 6 || (nut >= 9 && nut <= 12)) && ref != 0)) {
           bad++;
         } else {
+          if (nut == 7)
+            seen_sps = TRUE;
+          else if (nut == 8)
+            seen_pps = TRUE;
+          else if (nut == 5)
+            seen_idr = TRUE;
+
           good++;
         }
       } else if (nut >= 14 && nut <= 33) {
@@ -2439,9 +2449,10 @@ h264_video_type_find (GstTypeFind * tf, gpointer unused)
         /* don't consider these bad */
       }
 
-      GST_DEBUG ("good %d bad %d", good, bad);
+      GST_LOG ("good:%d, bad:%d, pps:%d, sps:%d, idr:%d", good, bad, seen_pps,
+          seen_sps, seen_idr);
 
-      if (good >= 10 && bad < 4) {
+      if (seen_sps && seen_pps && seen_idr && good >= 10 && bad < 4) {
         gst_type_find_suggest (tf, GST_TYPE_FIND_LIKELY, H264_VIDEO_CAPS);
         return;
       }
@@ -2451,6 +2462,9 @@ h264_video_type_find (GstTypeFind * tf, gpointer unused)
     data_scan_ctx_advance (tf, &c, 1);
   }
 
+  GST_LOG ("good:%d, bad:%d, pps:%d, sps:%d, idr:%d", good, bad, seen_pps,
+      seen_sps, seen_idr);
+
   if (good >= 2 && bad == 0) {
     gst_type_find_suggest (tf, GST_TYPE_FIND_POSSIBLE, H264_VIDEO_CAPS);
   }