Add support to play src on cameras with speaker

cmd/streams/play.go

@@ -0,0 +1,116 @@
+package streams
+
+import (
+	"errors"
+	"github.com/AlexxIT/go2rtc/pkg/streamer"
+)
+
+func (s *Stream) Play(source string) error {
+	s.mu.Lock()
+	for _, producer := range s.producers {
+		if producer.state == stateInternal && producer.element != nil {
+			_ = producer.element.Stop()
+		}
+	}
+	s.mu.Unlock()
+
+	if source == "" {
+		return nil
+	}
+
+	for _, producer := range s.producers {
+		// start new client
+		client, err := GetProducer(producer.url)
+		if err != nil {
+			return err
+		}
+
+		// check if client support consumer interface
+		cons := client.(streamer.Consumer)
+		if cons == nil {
+			continue
+		}
+
+		// start new producer
+		prod, err := GetProducer(source)
+		if err != nil {
+			return err
+		}
+
+		if !matchMedia(prod, cons) {
+			return errors.New("can't match media")
+		}
+
+		s.AddInternalProducer(prod)
+		s.AddInternalConsumer(cons)
+
+		go func() {
+			_ = prod.Start()
+			_ = client.Stop()
+			s.RemoveProducer(prod)
+		}()
+
+		go func() {
+			_ = client.Start()
+			_ = prod.Stop()
+			s.RemoveInternalConsumer(cons)
+		}()
+
+		return nil
+	}
+
+	return errors.New("can't find consumer")
+}
+
+func (s *Stream) AddInternalProducer(prod streamer.Producer) {
+	producer := &Producer{element: prod, state: stateInternal}
+	s.mu.Lock()
+	s.producers = append(s.producers, producer)
+	s.mu.Unlock()
+}
+
+func (s *Stream) AddInternalConsumer(cons streamer.Consumer) {
+	consumer := &Consumer{element: cons}
+	s.mu.Lock()
+	s.consumers = append(s.consumers, consumer)
+	s.mu.Unlock()
+}
+
+func (s *Stream) RemoveInternalConsumer(cons streamer.Consumer) {
+	s.mu.Lock()
+	for i, consumer := range s.consumers {
+		if consumer.element == cons {
+			s.removeConsumer(i)
+			break
+		}
+	}
+	s.mu.Unlock()
+}
+
+func matchMedia(prod streamer.Producer, cons streamer.Consumer) bool {
+	for _, consMedia := range cons.GetMedias() {
+		for _, prodMedia := range prod.GetMedias() {
+			// codec negotiation
+			prodCodec := prodMedia.MatchMedia(consMedia)
+			if prodCodec == nil {
+				continue
+			}
+
+			// setup producer track
+			prodTrack := prod.GetTrack(prodMedia, prodCodec)
+			if prodTrack == nil {
+				return false
+			}
+
+			// setup consumer track
+			consTrack := cons.AddTrack(consMedia, prodTrack)
+			if consTrack == nil {
+				return false
+			}
+
+			return true
+		}
+	}
+
+	return false
+}