Method Example3Async

tts/tts-dotnet-quickstart/Program.cs:194–243

Example 3: Bidirectional streaming. Demonstrates how to use WebSocket-based streaming for real-time text-to-speech. This allows you to send text incrementally and receive audio chunks as they're generated, enabling low-latency conversational experiences.

()

    /// enabling low-latency conversational experiences.
    /// </summary>
    static async Task Example3Async()
    {
        Console.WriteLine("Example 3: Bidirectional streaming...");

        using var streamingTtsClient = new StreamingTtsClient(_apiKey!);
        await streamingTtsClient.ConnectAsync();

        // Start audio player for raw PCM playback
        using var player = StartAudioPlayer(usePcmFormat: true);
        await player.StartAsync();

        // Use silence filler to handle gaps between utterances (like TypeScript's createSilenceFiller)
        using var silenceFiller = new SilenceFiller(player.Stdin!);

        // Task 1: Send text input to the TTS service
        var sendInputTask = Task.Run(async () =>
        {
            await streamingTtsClient.SendAsync(new { text = "Hello" });
            await streamingTtsClient.SendAsync(new { text = " world." });
            // The whitespace    ^ is important, otherwise the model would see
            // "Helloworld." and not "Hello world."
            await streamingTtsClient.SendFlushAsync();
            
            // Simulate a delay before continuing the conversation
            Console.WriteLine("Waiting 8 seconds...");
            await Task.Delay(TimeSpan.FromSeconds(VoiceCreationDelaySeconds));
            
            await streamingTtsClient.SendAsync(new { text = "Goodbye, world." });
            await streamingTtsClient.SendFlushAsync();

            await streamingTtsClient.SendCloseAsync();
        });

        // Task 2: Receive and play audio chunks as they arrive
        var handleMessagesTask = Task.Run(async () =>
        {
            Console.WriteLine("Playing audio: Example 3 - Bidirectional streaming");
            await foreach (var chunk in streamingTtsClient.ReceiveAudioChunksAsync())
            {
                var audioBytes = Convert.FromBase64String(chunk.Audio);
                silenceFiller.WriteAudio(audioBytes);
            }
            await silenceFiller.EndStreamAsync();
            await player.StopAsync();
        });

        await Task.WhenAll(sendInputTask, handleMessagesTask);

        Console.WriteLine("Done!");
    }

    /// <summary>
    /// Helper method to stream audio chunks from a TTS response to an audio player.