feat: sync group call livestream support

internal/app/livestream/rtmp.go

@@ -0,0 +1,68 @@
+package livestream
+
+import (
+	"context"
+	"io"
+	"net"
+
+	rtmp "github.com/yutopp/go-rtmp"
+	rtmpmsg "github.com/yutopp/go-rtmp/message"
+	"go.uber.org/zap"
+)
+
+// rtmpHandler 是单条 RTMP 连接的回调：publish 时用 stream key 鉴权并绑定
+// channel，media tag 直通 FLV → ffmpeg。一条连接只允许一路 publish。
+type rtmpHandler struct {
+	rtmp.DefaultHandler
+	svc    *Service
+	conn   net.Conn
+	stream *stream
+}
+
+func (h *rtmpHandler) OnPublish(_ *rtmp.StreamContext, _ uint32, cmd *rtmpmsg.NetStreamPublish) error {
+	if h.stream != nil {
+		return errPublishRejected
+	}
+	st, err := h.svc.startPublish(context.Background(), cmd.PublishingName, h.conn)
+	if err != nil {
+		h.svc.log.Warn("rtmp publish rejected", zap.Error(err))
+		return errPublishRejected
+	}
+	h.stream = st
+	return nil
+}
+
+func (h *rtmpHandler) OnSetDataFrame(timestamp uint32, data *rtmpmsg.NetStreamSetDataFrame) error {
+	if h.stream == nil {
+		return nil
+	}
+	// onMetaData 原样透传给 ffmpeg（可选信息，写失败不断流）。
+	_ = h.stream.writeTag(18, timestamp, data.Payload)
+	return nil
+}
+
+func (h *rtmpHandler) OnAudio(timestamp uint32, payload io.Reader) error {
+	return h.writeMedia(8, timestamp, payload)
+}
+
+func (h *rtmpHandler) OnVideo(timestamp uint32, payload io.Reader) error {
+	return h.writeMedia(9, timestamp, payload)
+}
+
+func (h *rtmpHandler) writeMedia(tagType byte, timestamp uint32, payload io.Reader) error {
+	if h.stream == nil {
+		return nil
+	}
+	body, err := io.ReadAll(payload)
+	if err != nil {
+		return err
+	}
+	return h.stream.writeTag(tagType, timestamp, body)
+}
+
+func (h *rtmpHandler) OnClose() {
+	if h.stream != nil {
+		h.svc.endPublish(h.stream)
+		h.stream = nil
+	}
+}