dropped-frame tracke

internal/playback/sync_attempt.go

@@ -14,6 +14,7 @@ func runSyncAttempt(
 	videoConfig FeedConfig,
 	audioConfig FeedConfig,
 ) (resultErr error) {
+	videoCtx := withVideoSource(ctx, videoConfig)
 	reader, err := factory.OpenSync(
 		ctx,
 		videoConfig,
@@ -39,7 +40,7 @@ func runSyncAttempt(
 			return fmt.Errorf("read sync group: %w", err)
 		}
 
-		if err := videoSink.ConsumeVideo(ctx, frame.Video); err != nil {
+		if err := videoSink.ConsumeVideo(videoCtx, frame.Video); err != nil {
 			if ctx.Err() != nil {
 				return ctx.Err()
 			}

internal/playback/video.go

@@ -2,6 +2,17 @@ package playback
 
 import "context"
 
+type videoSourceContextKey struct{}
+
+func withVideoSource(ctx context.Context, source FeedConfig) context.Context {
+	return context.WithValue(ctx, videoSourceContextKey{}, source)
+}
+
+func videoSourceFromContext(ctx context.Context) FeedConfig {
+	source, _ := ctx.Value(videoSourceContextKey{}).(FeedConfig)
+	return source
+}
+
 // VideoFrame contains metadata and borrowed source payload.
 //
 // Payload is valid only until the next VideoReader.ReadVideo call or until the

internal/playback/video_attempt.go

@@ -24,6 +24,7 @@ func runVideoAttempt(
 	sink VideoSink,
 	config FeedConfig,
 ) (resultErr error) {
+	ctx = withVideoSource(ctx, config)
 	reader, err := factory.OpenVideo(ctx, config)
 	if err != nil {
 		return fmt.Errorf("open video: %w", err)

internal/playback/video_bridge.go

@@ -6,7 +6,9 @@ import (
 )
 
 type PendingVideoFrame struct {
-	Frame VideoFrame
+	Frame      VideoFrame
+	Generation uint64
+	Source     FeedConfig
 
 	completeOnce sync.Once
 	result       chan error
@@ -27,8 +29,10 @@ func (b *VideoBridge) ConsumeVideo(
 	frame VideoFrame,
 ) error {
 	pending := &PendingVideoFrame{
-		Frame:  frame,
-		result: make(chan error, 1),
+		Frame:      frame,
+		Generation: generationFromContext(ctx),
+		Source:     videoSourceFromContext(ctx),
+		result:     make(chan error, 1),
 	}
 
 	select {

internal/playback/video_bridge_test.go

@@ -21,8 +21,10 @@ func TestVideoBridgeDeliversFrameAndCompletionResult(t *testing.T) {
 	}
 	consumeResult := make(chan error, 1)
 
+	wantSource := FeedConfig{Domain: "/video", UUID: "video", Active: true}
 	go func() {
-		consumeResult <- bridge.ConsumeVideo(context.Background(), wantFrame)
+		ctx := withGeneration(context.Background(), 17)
+		consumeResult <- bridge.ConsumeVideo(withVideoSource(ctx, wantSource), wantFrame)
 	}()
 
 	ctx, cancel := context.WithTimeout(context.Background(), videoBridgeTestTimeout)
@@ -34,6 +36,12 @@ func TestVideoBridgeDeliversFrameAndCompletionResult(t *testing.T) {
 	if pending.Frame.Index != wantFrame.Index {
 		t.Fatalf("Next() frame index = %d, want %d", pending.Frame.Index, wantFrame.Index)
 	}
+	if pending.Generation != 17 {
+		t.Fatalf("Next() generation = %d, want 17", pending.Generation)
+	}
+	if pending.Source != wantSource {
+		t.Fatalf("Next() source = %#v, want %#v", pending.Source, wantSource)
+	}
 	if &pending.Frame.Payload[0] != &wantFrame.Payload[0] {
 		t.Fatal("Next() copied the borrowed payload")
 	}