Added length check to IndexPid.

container/mts/mpegts.go

@@ -180,6 +180,7 @@ func FindPat(d []byte) ([]byte, int, error) {
 var (
 	errInvalidLen     = errors.New("MPEG-TS data not of valid length")
 	errCouldNotFind   = errors.New("could not find packet with given PID")
+	errNotConsecutive = errors.New("could not find consecutive PIDs")
 )
 
 // FindPid will take a clip of MPEG-TS and try to find a packet with given PID - if one
@@ -223,10 +224,12 @@ func LastPid(d []byte, pid uint16) (pkt []byte, i int, err error) {
 func IndexPid(d []byte, pids ...uint16) (idx int, m map[string]string, err error) {
 	idx = -1
 	for _, pid := range pids {
-		pkt, i, _err := FindPid(d, pid)
+		if len(d) < PacketSize {
+			return idx, m, errInvalidLen
+		}
+		pkt, i, err := FindPid(d, pid)
 		if err != nil {
-			err = errors.Wrap(_err, "could not find PID")
-			return
+			return idx, m, errCouldNotFind
 		}
 		if pid == PmtPid {
 			m, _ = metaFromPMT(pkt)
@@ -234,8 +237,7 @@ func IndexPid(d []byte, pids ...uint16) (idx int, m map[string]string, err error
 		if idx == -1 {
 			idx = i
 		} else if i != 0 {
-			err = errors.New("PIDs not consecutive")
-			return
+			return idx, m, errNotConsecutive
 		}
 		d = d[i+PacketSize:]
 	}