package rtmp import ( "fmt" "github.com/aler9/gortsplib" "github.com/aler9/gortsplib/pkg/aac" "github.com/notedit/rtmp/av" nh264 "github.com/notedit/rtmp/codec/h264" "github.com/notedit/rtmp/format/flv/flvio" ) const ( codecH264 = 7 codecAAC = 10 ) // ReadMetadata reads track informations. func (c *Conn) ReadMetadata() (*gortsplib.Track, *gortsplib.Track, error) { var videoTrack *gortsplib.Track var audioTrack *gortsplib.Track md, err := func() (flvio.AMFMap, error) { pkt, err := c.ReadPacket() if err != nil { return nil, err } if pkt.Type != av.Metadata { return nil, fmt.Errorf("first packet must be metadata") } arr, err := flvio.ParseAMFVals(pkt.Data, false) if err != nil { return nil, err } if len(arr) != 1 { return nil, fmt.Errorf("invalid metadata") } ma, ok := arr[0].(flvio.AMFMap) if !ok { return nil, fmt.Errorf("invalid metadata") } return ma, nil }() if err != nil { return nil, nil, err } hasVideo, err := func() (bool, error) { v, ok := md.GetV("videocodecid") if !ok { return false, nil } switch vt := v.(type) { case float64: switch vt { case 0: return false, nil case codecH264: return true, nil } case string: if vt == "avc1" { return true, nil } } return false, fmt.Errorf("unsupported video codec %v", v) }() if err != nil { return nil, nil, err } hasAudio, err := func() (bool, error) { v, ok := md.GetV("audiocodecid") if !ok { return false, nil } switch vt := v.(type) { case float64: switch vt { case 0: return false, nil case codecAAC: return true, nil } case string: if vt == "mp4a" { return true, nil } } return false, fmt.Errorf("unsupported audio codec %v", v) }() if err != nil { return nil, nil, err } if !hasVideo && !hasAudio { return nil, nil, fmt.Errorf("stream doesn't contain tracks with supported codecs (H264 or AAC)") } for { var pkt av.Packet pkt, err = c.ReadPacket() if err != nil { return nil, nil, err } switch pkt.Type { case av.H264DecoderConfig: if !hasVideo { return nil, nil, fmt.Errorf("unexpected video packet") } if videoTrack != nil { return nil, nil, fmt.Errorf("video track setupped twice") } codec, err := nh264.FromDecoderConfig(pkt.Data) if err != nil { return nil, nil, err } videoTrack, err = gortsplib.NewTrackH264(96, &gortsplib.TrackConfigH264{SPS: codec.SPS[0], PPS: codec.PPS[0]}) if err != nil { return nil, nil, err } case av.AACDecoderConfig: if !hasAudio { return nil, nil, fmt.Errorf("unexpected audio packet") } if audioTrack != nil { return nil, nil, fmt.Errorf("audio track setupped twice") } var mpegConf aac.MPEG4AudioConfig err := mpegConf.Decode(pkt.Data) if err != nil { return nil, nil, err } audioTrack, err = gortsplib.NewTrackAAC(96, &gortsplib.TrackConfigAAC{ Type: int(mpegConf.Type), SampleRate: mpegConf.SampleRate, ChannelCount: mpegConf.ChannelCount, AOTSpecificConfig: mpegConf.AOTSpecificConfig, }) if err != nil { return nil, nil, err } } if (!hasVideo || videoTrack != nil) && (!hasAudio || audioTrack != nil) { return videoTrack, audioTrack, nil } } } // WriteMetadata writes track informations. func (c *Conn) WriteMetadata(videoTrack *gortsplib.Track, audioTrack *gortsplib.Track) error { err := c.WritePacket(av.Packet{ Type: av.Metadata, Data: flvio.FillAMF0ValMalloc(flvio.AMFMap{ { K: "videodatarate", V: float64(0), }, { K: "videocodecid", V: func() float64 { if videoTrack != nil { return codecH264 } return 0 }(), }, { K: "audiodatarate", V: float64(0), }, { K: "audiocodecid", V: func() float64 { if audioTrack != nil { return codecAAC } return 0 }(), }, }), }) if err != nil { return err } if videoTrack != nil { conf, err := videoTrack.ExtractConfigH264() if err != nil { return err } codec := nh264.Codec{ SPS: map[int][]byte{ 0: conf.SPS, }, PPS: map[int][]byte{ 0: conf.PPS, }, } b := make([]byte, 128) var n int codec.ToConfig(b, &n) b = b[:n] err = c.WritePacket(av.Packet{ Type: av.H264DecoderConfig, Data: b, }) if err != nil { return err } } if audioTrack != nil { conf, err := audioTrack.ExtractConfigAAC() if err != nil { return err } enc, err := aac.MPEG4AudioConfig{ Type: aac.MPEG4AudioType(conf.Type), SampleRate: conf.SampleRate, ChannelCount: conf.ChannelCount, AOTSpecificConfig: conf.AOTSpecificConfig, }.Encode() if err != nil { return err } err = c.WritePacket(av.Packet{ Type: av.AACDecoderConfig, Data: enc, }) if err != nil { return err } } return nil }