Total rework FLV client

pkg/flv/client.go

@@ -0,0 +1,162 @@
+package flv
+
+import (
+	"bytes"
+	"io"
+	"time"
+
+	"github.com/AlexxIT/go2rtc/pkg/aac"
+	"github.com/AlexxIT/go2rtc/pkg/core"
+	"github.com/AlexxIT/go2rtc/pkg/h264/avc"
+	"github.com/pion/rtp"
+)
+
+type Client struct {
+	URL string
+
+	rd io.Reader
+
+	medias    []*core.Media
+	receivers []*core.Receiver
+
+	recv int
+}
+
+func NewClient(rd io.Reader) *Client {
+	return &Client{rd: rd}
+}
+
+func (c *Client) Describe() error {
+	if err := c.ReadHeader(); err != nil {
+		return err
+	}
+
+	// Normal software sends:
+	// 1. Video/audio flag in header
+	// 2. MetaData as first tag (with video/audio codec info)
+	// 3. Video/audio headers in 2nd and 3rd tag
+
+	// Reolink camera sends:
+	// 1. Empty video/audio flag
+	// 2. MedaData without stereo key for AAC
+	// 3. Audio header after Video keyframe tag
+	waitVideo := true
+	waitAudio := true
+	timeout := time.Now().Add(core.ProbeTimeout)
+
+	for (waitVideo || waitAudio) && time.Now().Before(timeout) {
+		tagType, _, b, err := c.ReadTag()
+		if err != nil {
+			return err
+		}
+
+		c.recv += len(b)
+
+		switch tagType {
+		case TagAudio:
+			if !waitAudio {
+				continue
+			}
+
+			waitAudio = false
+
+			codecID := b[0] >> 4 // SoundFormat
+			_ = b[0] & 0b1100    // SoundRate
+			_ = b[0] & 0b0010    // SoundSize
+			_ = b[0] & 0b0001    // SoundType
+
+			if codecID != CodecAAC {
+				continue
+			}
+
+			if b[1] != 0 { // check if header
+				continue
+			}
+
+			codec := aac.ConfigToCodec(b[2:])
+			media := &core.Media{
+				Kind:      core.KindAudio,
+				Direction: core.DirectionRecvonly,
+				Codecs:    []*core.Codec{codec},
+			}
+			c.medias = append(c.medias, media)
+
+		case TagVideo:
+			if !waitVideo {
+				continue
+			}
+
+			waitVideo = false
+
+			_ = b[0] >> 4            // FrameType
+			codecID := b[0] & 0b1111 // CodecID
+
+			if codecID != CodecAVC {
+				continue
+			}
+
+			if b[1] != 0 { // check if header
+				continue
+			}
+
+			codec := avc.ConfigToCodec(b[5:])
+			media := &core.Media{
+				Kind:      core.KindVideo,
+				Direction: core.DirectionRecvonly,
+				Codecs:    []*core.Codec{codec},
+			}
+			c.medias = append(c.medias, media)
+
+		case TagData:
+			if !bytes.Contains(b, []byte("onMetaData")) {
+				continue
+			}
+			waitVideo = bytes.Contains(b, []byte("videocodecid"))
+			waitAudio = bytes.Contains(b, []byte("audiocodecid"))
+		}
+	}
+
+	return nil
+}
+
+func (c *Client) Play() error {
+	video, audio := core.VA(c.receivers)
+
+	for {
+		tagType, timeMS, b, err := c.ReadTag()
+		if err != nil {
+			return err
+		}
+
+		c.recv += len(b)
+
+		switch tagType {
+		case TagAudio:
+			if audio == nil || b[1] == 0 {
+				continue
+			}
+
+			pkt := &rtp.Packet{
+				Header: rtp.Header{
+					Timestamp: TimeToRTP(timeMS, audio.Codec.ClockRate),
+				},
+				Payload: b[2:],
+			}
+			audio.WriteRTP(pkt)
+
+		case TagVideo:
+			// frame type 4b, codecID 4b, avc packet type 8b, composition time 24b
+			if video == nil || b[1] == 0 {
+				continue
+			}
+
+			pkt := &rtp.Packet{
+				Header: rtp.Header{
+					Timestamp: TimeToRTP(timeMS, video.Codec.ClockRate),
+				},
+				Payload: b[5:],
+			}
+			video.WriteRTP(pkt)
+		}
+	}
+}