reset retries after stable playback

internal/playback/supervisor.go

@@ -5,7 +5,8 @@ import (
 	"time"
 )
 
-type attemptFunc func(context.Context) error
+// attemptFunc returns whether useful media was received before the attempt ended.
+type attemptFunc func(context.Context) (becameStable bool, err error)
 type retryDecider func(error) bool
 type waitFunc func(context.Context, time.Duration) error
 
@@ -32,7 +33,7 @@ func runWithRetry(
 	failedAttempts := 0
 
 	for {
-		err := attempt(ctx)
+		becameStable, err := attempt(ctx)
 		if err == nil {
 			return nil
 		}
@@ -40,6 +41,10 @@ func runWithRetry(
 			return ctx.Err()
 		}
 
+		if becameStable {
+			failedAttempts = 0
+		}
+
 		failedAttempts++
 		willRetry := shouldRetry(err) && policy.canRetry(failedAttempts)
 		if !willRetry {