avformat/aea: reduce false positives in probing

Fixes probetest failure

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

libavformat/aea.c

@@ -34,12 +34,8 @@ static int aea_read_probe(AVProbeData *p)
 
     /* Magic is '00 08 00 00' in Little Endian*/
     if (AV_RL32(p->buf)==0x800) {
-        int bsm_s, bsm_e, inb_s, inb_e, ch;
+        int ch, i;
         ch = p->buf[264];
-        bsm_s = p->buf[2048];
-        inb_s = p->buf[2048+1];
-        inb_e = p->buf[2048+210];
-        bsm_e = p->buf[2048+211];
 
         if (ch != 1 && ch != 2)
             return 0;
@@ -48,7 +44,16 @@ static int aea_read_probe(AVProbeData *p)
          * the block size mode bytes have to be the same
          * the info bytes have to be the same
          */
-        if (bsm_s == bsm_e && inb_s == inb_e)
+        for (i = 2048; i + 211 < p->buf_size; i+= 212) {
+            int bsm_s, bsm_e, inb_s, inb_e;
+            bsm_s = p->buf[0];
+            inb_s = p->buf[1];
+            inb_e = p->buf[210];
+            bsm_e = p->buf[211];
+
+            if (bsm_s != bsm_e || inb_s != inb_e)
+                return 0;
+        }
         return AVPROBE_SCORE_MAX / 4 + 1;
     }
     return 0;