feat: 启用豆包二遍识别模式以提升实时性和准确率

- 切换到 bigmodel_async endpoint 并启用 enable_nonstream
- 第一遍流式识别提供实时文字预览
- VAD 分句后自动触发第二遍非流式识别提升准确率
- 修改文本处理逻辑从累加改为替换（适配 full 模式）
- 统一配置字段命名：app_key → app_id, access_key → access_token

config.example.yaml

@@ -3,8 +3,8 @@
 
 # 火山引擎豆包 ASR 配置
 doubao:
-  app_key: ""       # env: DOUBAO_APP_KEY
-  access_key: ""    # env: DOUBAO_ACCESS_KEY
+  app_id: ""          # env: DOUBAO_APP_ID
+  access_token: ""    # env: DOUBAO_ACCESS_TOKEN
   resource_id: "volc.seedasr.sauc.duration"  # env: DOUBAO_RESOURCE_ID
 
 # 服务配置

internal/asr/client.go

@@ -13,15 +13,15 @@ import (
 )
 
 const (
-	doubaoEndpoint = "wss://openspeech.bytedance.com/api/v3/sauc/bigmodel_nostream"
+	doubaoEndpoint = "wss://openspeech.bytedance.com/api/v3/sauc/bigmodel_async"
 	writeTimeout   = 10 * time.Second
 	readTimeout    = 30 * time.Second
 )
 
 // Config holds Doubao ASR connection parameters.
 type Config struct {
-	AppKey     string
-	AccessKey  string
+	AppID       string
+	AccessToken string
 	ResourceID string
 }
 
@@ -39,8 +39,8 @@ type Client struct {
 func Dial(cfg Config, resultCh chan<- wsMsg.ServerMsg) (*Client, error) {
 	connID := uuid.New().String()
 	headers := http.Header{
-		"X-Api-App-Key":    {cfg.AppKey},
-		"X-Api-Access-Key": {cfg.AccessKey},
+		"X-Api-App-Key":    {cfg.AppID},
+		"X-Api-Access-Key": {cfg.AccessToken},
 		"X-Api-Resource-Id": {cfg.ResourceID},
 		"X-Api-Connect-Id": {connID},
 	}
@@ -72,9 +72,10 @@ func Dial(cfg Config, resultCh chan<- wsMsg.ServerMsg) (*Client, error) {
 			EnableITN:         true,
 			EnablePUNC:        true,
 			EnableDDC:         true,
-			ShowUtterances: false,
-			ResultType:     "single",
-			EndWindowSize:  2000,
+			ShowUtterances:    true,
+			ResultType:        "full",
+			EnableNonstream:   true,
+			EndWindowSize:     800,
 		},
 	}
 	data, err := EncodeFullClientRequest(req)
@@ -132,13 +133,13 @@ func (c *Client) readLoop(resultCh chan<- wsMsg.ServerMsg) {
 			resultCh <- wsMsg.ServerMsg{Type: wsMsg.MsgError, Message: resp.ErrMsg}
 			return
 		}
-		// nostream mode: may return intermediate results every ~15s
+		// bigmodel_async with enable_nonstream: returns both streaming (partial) and definite (final) results
 		text := resp.Text
 		if text != "" {
 			if resp.IsLast {
 				resultCh <- wsMsg.ServerMsg{Type: wsMsg.MsgFinal, Text: text}
 			} else {
-				// Intermediate result (>15s audio) — preview only, don't paste
+				// Intermediate streaming result (first pass) — preview only
 				resultCh <- wsMsg.ServerMsg{Type: wsMsg.MsgPartial, Text: text}
 			}
 		}

internal/asr/protocol.go

@@ -110,6 +110,7 @@ type RequestMeta struct {
 	EnableDDC        bool   `json:"enable_ddc"`
 	ShowUtterances   bool   `json:"show_utterances"`
 	ResultType       string `json:"result_type,omitempty"`
+	EnableNonstream  bool   `json:"enable_nonstream,omitempty"`
 	EndWindowSize    int    `json:"end_window_size,omitempty"`
 }
 // EncodeFullClientRequest builds the binary message for the initial handshake.

internal/config/config.go

@@ -6,8 +6,8 @@ import (
 
 // DoubaoConfig holds 火山引擎豆包 ASR credentials.
 type DoubaoConfig struct {
-	AppKey     string `yaml:"app_key"`
-	AccessKey  string `yaml:"access_key"`
+	AppID       string `yaml:"app_id"`
+	AccessToken string `yaml:"access_token"`
 	ResourceID string `yaml:"resource_id"`
 }
 

internal/config/load.go

@@ -41,11 +41,11 @@ func Load(configPath string) (Config, error) {
 
 // applyEnv overrides config fields with environment variables.
 func applyEnv(cfg *Config) {
-	if v := os.Getenv("DOUBAO_APP_KEY"); v != "" {
-		cfg.Doubao.AppKey = v
+	if v := os.Getenv("DOUBAO_APP_ID"); v != "" {
+		cfg.Doubao.AppID = v
 	}
-	if v := os.Getenv("DOUBAO_ACCESS_KEY"); v != "" {
-		cfg.Doubao.AccessKey = v
+	if v := os.Getenv("DOUBAO_ACCESS_TOKEN"); v != "" {
+		cfg.Doubao.AccessToken = v
 	}
 	if v := os.Getenv("DOUBAO_RESOURCE_ID"); v != "" {
 		cfg.Doubao.ResourceID = v
@@ -62,11 +62,11 @@ func applyEnv(cfg *Config) {
 
 // validate checks required fields.
 func validate(cfg Config) error {
-	if cfg.Doubao.AppKey == "" {
-		return fmt.Errorf("doubao.app_key is required (set DOUBAO_APP_KEY or config.yaml)")
+	if cfg.Doubao.AppID == "" {
+		return fmt.Errorf("doubao.app_id is required (set DOUBAO_APP_ID or config.yaml)")
 	}
-	if cfg.Doubao.AccessKey == "" {
-		return fmt.Errorf("doubao.access_key is required (set DOUBAO_ACCESS_KEY or config.yaml)")
+	if cfg.Doubao.AccessToken == "" {
+		return fmt.Errorf("doubao.access_token is required (set DOUBAO_ACCESS_TOKEN or config.yaml)")
 	}
 	return nil
 }

internal/ws/handler.go

@@ -62,21 +62,21 @@ func (h *Handler) handleConn(c *websocket.Conn) {
   defer close(resultCh)
 
   // Writer goroutine: single writer to avoid concurrent writes
-  // Accumulates all result texts; paste is triggered by stop, not by ASR final.
+  // bigmodel_async with enable_nonstream: server returns full text each time (not incremental)
+  // We replace preview text on each update instead of accumulating.
   var wg sync.WaitGroup
-  var accMu sync.Mutex
-  var accText string
+  var previewMu sync.Mutex
+  var previewText string
   wg.Add(1)
   go func() {
     defer wg.Done()
     for msg := range resultCh {
-      // Accumulate text from both partial and final results
+      // Replace preview text with latest result (full mode)
       if msg.Type == MsgPartial || msg.Type == MsgFinal {
-        accMu.Lock()
-        accText += msg.Text
-        // Send accumulated preview to phone
-        preview := ServerMsg{Type: msg.Type, Text: accText}
-        accMu.Unlock()
+        previewMu.Lock()
+        previewText = msg.Text
+        preview := ServerMsg{Type: msg.Type, Text: previewText}
+        previewMu.Unlock()
         if err := c.WriteMessage(websocket.TextMessage, preview.Bytes()); err != nil {
           log.Warn("ws write error", "err", err)
           return
@@ -128,10 +128,10 @@ func (h *Handler) handleConn(c *websocket.Conn) {
         if active {
           continue
         }
-        // Reset accumulated text for new session
-        accMu.Lock()
-        accText = ""
-        accMu.Unlock()
+        // Reset preview text for new session
+        previewMu.Lock()
+        previewText = ""
+        previewMu.Unlock()
         sa, cl, err := h.asrFactory(resultCh)
         if err != nil {
           log.Error("asr start failed", "err", err)
@@ -154,11 +154,11 @@ func (h *Handler) handleConn(c *websocket.Conn) {
         }
         sendAudio = nil
         active = false
-        // Now paste the accumulated text
-        accMu.Lock()
-        finalText := accText
-        accText = ""
-        accMu.Unlock()
+        // Paste the final preview text
+        previewMu.Lock()
+        finalText := previewText
+        previewText = ""
+        previewMu.Unlock()
         if finalText != "" && h.pasteFunc != nil {
           if err := h.pasteFunc(finalText); err != nil {
             log.Error("auto-paste failed", "err", err)

main.go

@@ -110,8 +110,8 @@ func main() {
 	srv := server.New(token, lanIP, webContent, serverTLSCfg)
 	// Build ASR factory from config
 	asrCfg := asr.Config{
-		AppKey:     cfg.Doubao.AppKey,
-		AccessKey:  cfg.Doubao.AccessKey,
+		AppID:       cfg.Doubao.AppID,
+		AccessToken: cfg.Doubao.AccessToken,
 		ResourceID: cfg.Doubao.ResourceID,
 	}
 	asrFactory := func(resultCh chan<- ws.ServerMsg) (func([]byte), func(), error) {