feat: doubao tts support streaming realtime audio

relay/channel/volcengine/tts.go

@@ -1,9 +1,11 @@
 package volcengine
 
 import (
+	"context"
 	"encoding/base64"
 	"encoding/json"
 	"errors"
+	"fmt"
 	"io"
 	"net/http"
 	"strings"
@@ -13,6 +15,7 @@ import (
 	"github.com/QuantumNous/new-api/types"
 	"github.com/gin-gonic/gin"
 	"github.com/google/uuid"
+	"github.com/gorilla/websocket"
 )
 
 type VolcengineTTSRequest struct {
@@ -192,3 +195,129 @@ func handleTTSResponse(c *gin.Context, resp *http.Response, info *relaycommon.Re
 func generateRequestID() string {
 	return uuid.New().String()
 }
+
+// handleTTSWebSocketResponse handles streaming TTS response via WebSocket
+func handleTTSWebSocketResponse(c *gin.Context, requestURL string, volcRequest VolcengineTTSRequest, info *relaycommon.RelayInfo, encoding string) (usage any, err *types.NewAPIError) {
+	// Parse API key for auth
+	_, token, parseErr := parseVolcengineAuth(info.ApiKey)
+	if parseErr != nil {
+		return nil, types.NewErrorWithStatusCode(
+			parseErr,
+			types.ErrorCodeChannelInvalidKey,
+			http.StatusUnauthorized,
+		)
+	}
+
+	// Setup WebSocket headers
+	header := http.Header{}
+	header.Set("Authorization", fmt.Sprintf("Bearer;%s", token))
+
+	// Dial WebSocket connection
+	conn, resp, dialErr := websocket.DefaultDialer.DialContext(context.Background(), requestURL, header)
+	if dialErr != nil {
+		if resp != nil {
+			return nil, types.NewErrorWithStatusCode(
+				fmt.Errorf("failed to connect to websocket: %w, status: %d", dialErr, resp.StatusCode),
+				types.ErrorCodeBadResponseStatusCode,
+				http.StatusBadGateway,
+			)
+		}
+		return nil, types.NewErrorWithStatusCode(
+			fmt.Errorf("failed to connect to websocket: %w", dialErr),
+			types.ErrorCodeBadResponseStatusCode,
+			http.StatusBadGateway,
+		)
+	}
+	defer conn.Close()
+
+	// Update request operation to "submit" for WebSocket
+	volcRequest.Request.Operation = "submit"
+
+	// Marshal request payload
+	payload, marshalErr := json.Marshal(volcRequest)
+	if marshalErr != nil {
+		return nil, types.NewErrorWithStatusCode(
+			fmt.Errorf("failed to marshal request: %w", marshalErr),
+			types.ErrorCodeBadRequestBody,
+			http.StatusInternalServerError,
+		)
+	}
+
+	// Send full client request
+	if sendErr := FullClientRequest(conn, payload); sendErr != nil {
+		return nil, types.NewErrorWithStatusCode(
+			fmt.Errorf("failed to send request: %w", sendErr),
+			types.ErrorCodeBadRequestBody,
+			http.StatusInternalServerError,
+		)
+	}
+
+	// Set response headers
+	contentType := getContentTypeByEncoding(encoding)
+	c.Header("Content-Type", contentType)
+	c.Header("Transfer-Encoding", "chunked")
+
+	// Stream audio data
+	var audioBuffer []byte
+	for {
+		msg, recvErr := ReceiveMessage(conn)
+		if recvErr != nil {
+			if websocket.IsCloseError(recvErr, websocket.CloseNormalClosure, websocket.CloseGoingAway) {
+				break
+			}
+			return nil, types.NewErrorWithStatusCode(
+				fmt.Errorf("failed to receive message: %w", recvErr),
+				types.ErrorCodeBadResponse,
+				http.StatusInternalServerError,
+			)
+		}
+
+		switch msg.MsgType {
+		case MsgTypeError:
+			return nil, types.NewErrorWithStatusCode(
+				fmt.Errorf("received error from server: code=%d, %s", msg.ErrorCode, string(msg.Payload)),
+				types.ErrorCodeBadResponse,
+				http.StatusBadRequest,
+			)
+		case MsgTypeFrontEndResultServer:
+			// Metadata response, can be logged or processed
+			continue
+		case MsgTypeAudioOnlyServer:
+			// Stream audio chunk to client
+			if len(msg.Payload) > 0 {
+				audioBuffer = append(audioBuffer, msg.Payload...)
+				if _, writeErr := c.Writer.Write(msg.Payload); writeErr != nil {
+					return nil, types.NewErrorWithStatusCode(
+						fmt.Errorf("failed to write audio data: %w", writeErr),
+						types.ErrorCodeBadResponse,
+						http.StatusInternalServerError,
+					)
+				}
+				c.Writer.Flush()
+			}
+
+			// Check if this is the last packet (negative sequence)
+			if msg.Sequence < 0 {
+				c.Status(http.StatusOK)
+				usage = &dto.Usage{
+					PromptTokens:     info.PromptTokens,
+					CompletionTokens: 0,
+					TotalTokens:      info.PromptTokens,
+				}
+				return usage, nil
+			}
+		default:
+			// Unknown message type, log and continue
+			continue
+		}
+	}
+
+	// If we reach here, connection closed without final packet
+	c.Status(http.StatusOK)
+	usage = &dto.Usage{
+		PromptTokens:     info.PromptTokens,
+		CompletionTokens: 0,
+		TotalTokens:      info.PromptTokens,
+	}
+	return usage, nil
+}