install go2rtc on bob

installs_on_host/go2rtc/internal/streams/add_consumer.go

@@ -0,0 +1,166 @@
+package streams
+
+import (
+	"errors"
+	"strings"
+
+	"github.com/AlexxIT/go2rtc/pkg/core"
+)
+
+func (s *Stream) AddConsumer(cons core.Consumer) (err error) {
+	// support for multiple simultaneous pending from different consumers
+	consN := s.pending.Add(1) - 1
+
+	var prodErrors = make([]error, len(s.producers))
+	var prodMedias []*core.Media
+	var prodStarts []*Producer
+
+	// Step 1. Get consumer medias
+	consMedias := cons.GetMedias()
+	for _, consMedia := range consMedias {
+		log.Trace().Msgf("[streams] check cons=%d media=%s", consN, consMedia)
+
+	producers:
+		for prodN, prod := range s.producers {
+			// check for loop request, ex. `camera1: ffmpeg:camera1`
+			if info, ok := cons.(core.Info); ok && prod.url == info.GetSource() {
+				log.Trace().Msgf("[streams] skip cons=%d prod=%d", consN, prodN)
+				continue
+			}
+
+			if prodErrors[prodN] != nil {
+				log.Trace().Msgf("[streams] skip cons=%d prod=%d", consN, prodN)
+				continue
+			}
+
+			if err = prod.Dial(); err != nil {
+				log.Trace().Err(err).Msgf("[streams] dial cons=%d prod=%d", consN, prodN)
+				prodErrors[prodN] = err
+				continue
+			}
+
+			// Step 2. Get producer medias (not tracks yet)
+			for _, prodMedia := range prod.GetMedias() {
+				log.Trace().Msgf("[streams] check cons=%d prod=%d media=%s", consN, prodN, prodMedia)
+				prodMedias = append(prodMedias, prodMedia)
+
+				// Step 3. Match consumer/producer codecs list
+				prodCodec, consCodec := prodMedia.MatchMedia(consMedia)
+				if prodCodec == nil {
+					continue
+				}
+
+				var track *core.Receiver
+
+				switch prodMedia.Direction {
+				case core.DirectionRecvonly:
+					log.Trace().Msgf("[streams] match cons=%d <= prod=%d", consN, prodN)
+
+					// Step 4. Get recvonly track from producer
+					if track, err = prod.GetTrack(prodMedia, prodCodec); err != nil {
+						log.Info().Err(err).Msg("[streams] can't get track")
+						prodErrors[prodN] = err
+						continue
+					}
+					// Step 5. Add track to consumer
+					if err = cons.AddTrack(consMedia, consCodec, track); err != nil {
+						log.Info().Err(err).Msg("[streams] can't add track")
+						continue
+					}
+
+				case core.DirectionSendonly:
+					log.Trace().Msgf("[streams] match cons=%d => prod=%d", consN, prodN)
+
+					// Step 4. Get recvonly track from consumer (backchannel)
+					if track, err = cons.(core.Producer).GetTrack(consMedia, consCodec); err != nil {
+						log.Info().Err(err).Msg("[streams] can't get track")
+						continue
+					}
+					// Step 5. Add track to producer
+					if err = prod.AddTrack(prodMedia, prodCodec, track); err != nil {
+						log.Info().Err(err).Msg("[streams] can't add track")
+						prodErrors[prodN] = err
+						continue
+					}
+				}
+
+				prodStarts = append(prodStarts, prod)
+
+				if !consMedia.MatchAll() {
+					break producers
+				}
+			}
+		}
+	}
+
+	// stop producers if they don't have readers
+	if s.pending.Add(-1) == 0 {
+		s.stopProducers()
+	}
+
+	if len(prodStarts) == 0 {
+		return formatError(consMedias, prodMedias, prodErrors)
+	}
+
+	s.mu.Lock()
+	s.consumers = append(s.consumers, cons)
+	s.mu.Unlock()
+
+	// there may be duplicates, but that's not a problem
+	for _, prod := range prodStarts {
+		prod.start()
+	}
+
+	return nil
+}
+
+func formatError(consMedias, prodMedias []*core.Media, prodErrors []error) error {
+	// 1. Return errors if any not nil
+	var text string
+
+	for _, err := range prodErrors {
+		if err != nil {
+			text = appendString(text, err.Error())
+		}
+	}
+
+	if len(text) != 0 {
+		return errors.New("streams: " + text)
+	}
+
+	// 2. Return "codecs not matched"
+	if prodMedias != nil {
+		var prod, cons string
+
+		for _, media := range prodMedias {
+			if media.Direction == core.DirectionRecvonly {
+				for _, codec := range media.Codecs {
+					prod = appendString(prod, media.Kind+":"+codec.PrintName())
+				}
+			}
+		}
+
+		for _, media := range consMedias {
+			if media.Direction == core.DirectionSendonly {
+				for _, codec := range media.Codecs {
+					cons = appendString(cons, media.Kind+":"+codec.PrintName())
+				}
+			}
+		}
+
+		return errors.New("streams: codecs not matched: " + prod + " => " + cons)
+	}
+
+	// 3. Return unknown error
+	return errors.New("streams: unknown error")
+}
+
+func appendString(s, elem string) string {
+	if strings.Contains(s, elem) {
+		return s
+	}
+	if len(s) == 0 {
+		return elem
+	}
+	return s + ", " + elem
+}