Assume some TS packet size instead of failing completely.

Fixes ticket #68.

libavformat/mpegts.c

@@ -1468,8 +1468,10 @@ static int mpegts_read_header(AVFormatContext *s,
     if (len != sizeof(buf))
         goto fail;
     ts->raw_packet_size = get_packet_size(buf, sizeof(buf));
-    if (ts->raw_packet_size <= 0)
-        goto fail;
+    if (ts->raw_packet_size <= 0) {
+        av_log(s, AV_LOG_WARNING, "Could not detect TS packet size, defaulting to non-FEC/DVHS\n");
+        ts->raw_packet_size = TS_PACKET_SIZE;
+    }
     ts->stream = s;
     ts->auto_guess = 0;