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[英]How can I find the audio format of the selected voice of the SpeechSynthesizer
[英]How can I send audio to Nexmo Voice through websocket
我正在尝试在 .Net Core 2 web api 中使用 websockets 实现 Nexmo 的 Voice api。
这个 api 需要:现在,我正在绕过机器人步骤,因为我首先尝试连接到 websocket。 尝试回声方法(将收到的音频发送回 websocket)时,它可以正常工作。 但是当我尝试将语音从 Microsoft 文本发送到语音时,电话结束了。
我没有找到任何实现与回声不同的文档。
TextToSpeech 和 SpeechToText 方法在 websocket 之外使用时按预期工作。
这是带有语音到文本的 websocket:
public static async Task Echo(HttpContext context, WebSocket webSocket)
{
var buffer = new byte[1024 * 4];
WebSocketReceiveResult result = await webSocket.ReceiveAsync(new ArraySegment<byte>(buffer), CancellationToken.None);
while (!result.CloseStatus.HasValue)
{
var ttsAudio = await TextToSpeech.TransformTextToSpeechAsync("Hello, this is a test", "en-US");
await webSocket.SendAsync(new ArraySegment<byte>(ttsAudio, 0, ttsAudio.Length), WebSocketMessageType.Binary, true, CancellationToken.None);
result = await webSocket.ReceiveAsync(new ArraySegment<byte>(buffer), CancellationToken.None);
}
await webSocket.CloseAsync(result.CloseStatus.Value, result.CloseStatusDescription, CancellationToken.None);
}
这是带有 text-to-speech 的 websocket:
public static async Task Echo(HttpContext context, WebSocket webSocket) { var buffer = new byte[1024 * 4]; WebSocketReceiveResult result = await webSocket.ReceiveAsync(new ArraySegment<byte>(buffer), CancellationToken.None); while (!result.CloseStatus.HasValue) { var ttsAudio = await TextToSpeech.TransformTextToSpeechAsync("Hello, this is a test", "en-US"); await webSocket.SendAsync(new ArraySegment<byte>(ttsAudio, 0, ttsAudio.Length), WebSocketMessageType.Binary, true, CancellationToken.None); result = await webSocket.ReceiveAsync(new ArraySegment<byte>(buffer), CancellationToken.None); } await webSocket.CloseAsync(result.CloseStatus.Value, result.CloseStatusDescription, CancellationToken.None); }
2019 年 3 月 1 日更新
在回复Sam Machin的评论时,我尝试将数组拆分为每个 640 字节的块(我使用的是 16000khz 采样率),但是 nexmo 仍然挂断了电话,我仍然没有听到任何声音。
public static async Task NexmoTextToSpeech(HttpContext context, WebSocket webSocket) { var ttsAudio = await TextToSpeech.TransformTextToSpeechAsync("This is a test", "en-US"); var buffer = new byte[1024 * 4]; WebSocketReceiveResult result = await webSocket.ReceiveAsync(new ArraySegment<byte>(buffer), CancellationToken.None); while (!result.CloseStatus.HasValue) { await SendSpeech(context, webSocket, ttsAudio); result = await webSocket.ReceiveAsync(new ArraySegment<byte>(buffer), CancellationToken.None); } await webSocket.CloseAsync(WebSocketCloseStatus.NormalClosure, "Closing Socket", CancellationToken.None); } private static async Task SendSpeech(HttpContext context, WebSocket webSocket, byte[] ttsAudio) { const int chunkSize = 640; var chunkCount = 1; var offset = 0; var lastFullChunck = ttsAudio.Length < (offset + chunkSize); try { while(!lastFullChunck) { await webSocket.SendAsync(new ArraySegment<byte>(ttsAudio, offset, chunkSize), WebSocketMessageType.Binary, false, CancellationToken.None); offset = chunkSize * chunkCount; lastFullChunck = ttsAudio.Length < (offset + chunkSize); chunkCount++; } var lastMessageSize = ttsAudio.Length - offset; await webSocket.SendAsync(new ArraySegment<byte>(ttsAudio, offset, lastMessageSize), WebSocketMessageType.Binary, true, CancellationToken.None); } catch (Exception ex) { } }
这是有时出现在日志中的异常:
System.Net.WebSockets.WebSocketException (0x80004005): 远程方在没有完成关闭握手的情况下关闭了 WebSocket 连接。
看起来您正在将整个音频剪辑写入 websocket,Nexmo 接口要求音频在每条消息的 20 毫秒帧内,这意味着您需要将剪辑分成 320 或 640 字节(取决于您'正在使用 8Khz 或 16Khz)块并将每个块写入套接字。 如果您尝试将太大的文件写入套接字,它将如您所见地关闭。
有关详细信息,请参阅https://developer.nexmo.com/voice/voice-api/guides/websockets#writing-audio-to-the-websocket 。
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