hls: fix intermittent audio on iOS

internal/hls/muxer_test.go

@@ -114,14 +114,18 @@ func TestMuxer(t *testing.T) {
 
 	// PES (AAC)
 	checkTSPacket(t, byts, 257, 3)
-	byts = byts[177:]
-	aus, err := aac.DecodeADTS(byts[:11])
+	byts = byts[166:]
+	aus, err := aac.DecodeADTS(byts[:22])
 	require.NoError(t, err)
-	require.Equal(t, 1, len(aus))
+	require.Equal(t, 2, len(aus))
 	require.Equal(t, 2, aus[0].Type)
 	require.Equal(t, 44100, aus[0].SampleRate)
 	require.Equal(t, 2, aus[0].ChannelCount)
 	require.Equal(t, []byte{0x01, 0x02, 0x03, 0x04}, aus[0].AU)
+	require.Equal(t, 2, aus[1].Type)
+	require.Equal(t, 44100, aus[1].SampleRate)
+	require.Equal(t, 2, aus[1].ChannelCount)
+	require.Equal(t, []byte{0x05, 0x06, 0x07, 0x08}, aus[1].AU)
 }
 
 func TestMuxerCloseBeforeFirstSegment(t *testing.T) {

internal/hls/muxer_ts_generator.go

@@ -145,15 +145,18 @@ func (m *muxerTSGenerator) writeAAC(pts time.Duration, aus [][]byte) error {
 		}
 	}
 
-	for _, au := range aus {
-		enc, err := aac.EncodeADTS([]*aac.ADTSPacket{
-			{
+	pkts := make([]*aac.ADTSPacket, len(aus))
+
+	for i, au := range aus {
+		pkts[i] = &aac.ADTSPacket{
 			Type:         m.aacConf.Type,
 			SampleRate:   m.aacConf.SampleRate,
 			ChannelCount: m.aacConf.ChannelCount,
 			AU:           au,
-			},
-		})
+		}
+	}
+
+	enc, err := aac.EncodeADTS(pkts)
 	if err != nil {
 		return err
 	}
@@ -164,10 +167,7 @@ func (m *muxerTSGenerator) writeAAC(pts time.Duration, aus [][]byte) error {
 	}
 
 	if m.videoTrack == nil {
-			m.audioAUCount++
-		}
-
-		pts += 1000 * time.Second / time.Duration(m.aacConf.SampleRate)
+		m.audioAUCount += len(aus)
 	}
 
 	return nil