codec/h264/parse.go: skip over access unit delimiters when getting nalType

codec/h264/h264dec/frame.go

@@ -11,7 +11,7 @@ const (
 	naluTypeSEI
 	NALTypeSPS
 	naluTypePPS
-	naluTypeAccessUnitDelimiter
+	NALTypeAccessUnitDelimiter
 	naluTypeEndOfSequence
 	naluTypeEndOfStream
 	naluTypeFillerData

codec/h264/parse.go

@@ -26,14 +26,20 @@ LICENSE
 
 package h264
 
-import "errors"
+import (
+	"errors"
+
+	"bitbucket.org/ausocean/av/codec/h264/h264dec"
+)
 
 var errNotEnoughBytes = errors.New("not enough bytes to read")
 
 // NALType returns the NAL type of the given NAL unit bytes. The given NAL unit
 // may be in byte stream or packet format.
+// NB: access unit delimiters are skipped.
 func NALType(n []byte) (int, error) {
 	sc := frameScanner{buf: n}
+	for {
 		b, ok := sc.readByte()
 		if !ok {
 			return 0, errNotEnoughBytes
@@ -51,9 +57,12 @@ func NALType(n []byte) (int, error) {
 			if !ok {
 				return 0, errNotEnoughBytes
 			}
-		return int(b & 0x1f), nil
+			nalType := int(b & 0x1f)
+			if nalType != h264dec.NALTypeAccessUnitDelimiter {
+				return nalType, nil
+			}
+		}
 	}
-	return int(b & 0x1f), nil
 }
 
 type frameScanner struct {