mpegts: allow interacting with streams with unsupported codecs

pkg/formats/mpegts/codec_unsupported.go

@@ -0,0 +1,19 @@
+package mpegts
+
+import (
+	"github.com/asticode/go-astits"
+)
+
+// CodecUnsupported is an unsupported codec.
+type CodecUnsupported struct{}
+
+// IsVideo implements Codec.
+func (CodecUnsupported) IsVideo() bool {
+	return false
+}
+
+func (*CodecUnsupported) isCodec() {}
+
+func (c CodecUnsupported) marshal(uint16) (*astits.PMTElementaryStream, error) {
+	panic("this should not happen")
+}

pkg/formats/mpegts/reader.go

@@ -78,19 +78,12 @@ func NewReader(br io.Reader) (*Reader, error) {
 		var track Track
 		err := track.unmarshal(dem, es)
 		if err != nil {
-			if errors.Is(err, errUnsupportedCodec) {
-				continue
-			}
 			return nil, err
 		}
 
 		tracks = append(tracks, &track)
 	}
 
-	if tracks == nil {
-		return nil, fmt.Errorf("no tracks with supported codecs found")
-	}
-
 	// rewind demuxer
 	dem = astits.NewDemuxer(
 		context.Background(),

pkg/formats/mpegts/track.go

@@ -1,7 +1,6 @@
 package mpegts
 
 import (
-	"errors"
 	"fmt"
 
 	"github.com/asticode/go-astits"
@@ -15,8 +14,6 @@
 	opusIdentifier = 'O'<<24 | 'p'<<16 | 'u'<<8 | 's'
 )
 
-var errUnsupportedCodec = errors.New("unsupported codec")
-
 func findMPEG4AudioConfig(dem *astits.Demuxer, pid uint16) (*mpeg4audio.Config, error) {
 	for {
 		data, err := dem.NextData()
@@ -125,19 +122,15 @@
 	switch es.StreamType {
 	case astits.StreamTypeH265Video:
 		t.Codec = &CodecH265{}
-		return nil
 
 	case astits.StreamTypeH264Video:
 		t.Codec = &CodecH264{}
-		return nil
 
 	case astits.StreamTypeMPEG4Video:
 		t.Codec = &CodecMPEG4Video{}
-		return nil
 
 	case astits.StreamTypeMPEG2Video, astits.StreamTypeMPEG1Video:
 		t.Codec = &CodecMPEG1Video{}
-		return nil
 
 	case astits.StreamTypeAACAudio:
 		conf, err := findMPEG4AudioConfig(dem, es.ElementaryPID)
@@ -148,11 +141,9 @@
 		t.Codec = &CodecMPEG4Audio{
 			Config: *conf,
 		}
-		return nil
 
 	case astits.StreamTypeMPEG1Audio:
 		t.Codec = &CodecMPEG1Audio{}
-		return nil
 
 	case astits.StreamTypeAC3Audio:
 		sampleRate, channelCount, err := findAC3Parameters(dem, es.ElementaryPID)
@@ -164,15 +155,18 @@
 			SampleRate:   sampleRate,
 			ChannelCount: channelCount,
 		}
-		return nil
 
 	case astits.StreamTypePrivateData:
 		codec := findOpusCodec(es.ElementaryStreamDescriptors)
 		if codec != nil {
 			t.Codec = codec
-			return nil
+		} else {
+			t.Codec = &CodecUnsupported{}
 		}
+
+	default:
+		t.Codec = &CodecUnsupported{}
 	}
 
-	return errUnsupportedCodec
+	return nil
 }