mpegts_probe: detect files with garbage at the begin.

Fixes Ticket1811

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

diff --git a/libavformat/mpegts.c b/libavformat/mpegts.c
index 33a0eaf08c5b1ae233eb6d7c923a49f6e32b55de..5b04b63da6ac9b8cf539d916fdadfb2dfaa1af4d 100644 (file)
--- a/libavformat/mpegts.c
+++ b/libavformat/mpegts.c
@@ -1880,24 +1880,34 @@ static int handle_packets(MpegTSContext *ts, int nb_packets)
 static int mpegts_probe(AVProbeData *p)
 {
     const int size= p->buf_size;
-    int score, fec_score, dvhs_score;
+    int maxscore=0;
+    int sumscore=0;
+    int i;
     int check_count= size / TS_FEC_PACKET_SIZE;
 #define CHECK_COUNT 10
+#define CHECK_BLOCK 100
 
     if (check_count < CHECK_COUNT)
         return -1;
 
-    score     = analyze(p->buf, TS_PACKET_SIZE     *check_count, TS_PACKET_SIZE     , NULL)*CHECK_COUNT/check_count;
-    dvhs_score= analyze(p->buf, TS_DVHS_PACKET_SIZE*check_count, TS_DVHS_PACKET_SIZE, NULL)*CHECK_COUNT/check_count;
-    fec_score = analyze(p->buf, TS_FEC_PACKET_SIZE *check_count, TS_FEC_PACKET_SIZE , NULL)*CHECK_COUNT/check_count;
-    av_dlog(NULL, "score: %d, dvhs_score: %d, fec_score: %d \n",
-            score, dvhs_score, fec_score);
+    for (i=0; i<check_count; i+=CHECK_BLOCK){
+        int left = FFMIN(check_count - i, CHECK_BLOCK);
+        int score     = analyze(p->buf + TS_PACKET_SIZE     *i, TS_PACKET_SIZE     *left, TS_PACKET_SIZE     , NULL);
+        int dvhs_score= analyze(p->buf + TS_DVHS_PACKET_SIZE*i, TS_DVHS_PACKET_SIZE*left, TS_DVHS_PACKET_SIZE, NULL);
+        int fec_score = analyze(p->buf + TS_FEC_PACKET_SIZE *i, TS_FEC_PACKET_SIZE *left, TS_FEC_PACKET_SIZE , NULL);
+        score = FFMAX3(score, dvhs_score, fec_score);
+        sumscore += score;
+        maxscore = FFMAX(maxscore, score);
+    }
+
+    sumscore = sumscore*CHECK_COUNT/check_count;
+    maxscore = maxscore*CHECK_COUNT/CHECK_BLOCK;
+
+    av_dlog(0, "TS score: %d %d\n", sumscore, maxscore);
 
-// we need a clear definition for the returned score otherwise things will become messy sooner or later
-    if     (score > fec_score && score > dvhs_score && score > 6) return AVPROBE_SCORE_MAX + score     - CHECK_COUNT;
-    else if(dvhs_score > score && dvhs_score > fec_score && dvhs_score > 6) return AVPROBE_SCORE_MAX + dvhs_score  - CHECK_COUNT;
-    else if(                 fec_score > 6) return AVPROBE_SCORE_MAX + fec_score - CHECK_COUNT;
-    else                                    return -1;
+    if (sumscore > 6)           return AVPROBE_SCORE_MAX + sumscore - CHECK_COUNT;
+    else if (maxscore > 6)      return AVPROBE_SCORE_MAX/2 + sumscore - CHECK_COUNT;
+    else                        return -1;
 }
 
 /* return the 90kHz PCR and the extension for the 27MHz PCR. return