Fix MP4 with PCM on Android Telegram

pkg/iso/atoms.go

@@ -39,8 +39,7 @@ const (
 
 	SampleVideoIFrame    = sampleDependsOn2
 	SampleVideoNonIFrame = sampleDependsOn1 | sampleIsNonSync
-	SampleAudio          = sampleIsNonSync
-	SampleAudioAAC       = sampleDependsOn2
+	SampleAudio          = sampleDependsOn2 //sampleIsNonSync
 )
 
 func (m *Movie) WriteFileType() {

pkg/mp4/muxer.go

@@ -173,10 +173,10 @@ func (m *Muxer) Marshal(trackID byte, packet *rtp.Packet) []byte {
 			flags = iso.SampleVideoNonIFrame
 		}
 	case core.CodecAAC:
-		duration = 1024            // important for Apple Finder and QuickTime
-		flags = iso.SampleAudioAAC // not important
+		duration = 1024         // important for Apple Finder and QuickTime
+		flags = iso.SampleAudio // not important?
 	default:
-		flags = iso.SampleAudio // not important
+		flags = iso.SampleAudio // important for FLAC on Android Telegram
 	}
 
 	// minumum duration important for MSE in Apple Safari