feat: improve transcription with language hints and batch UX (#647)

src/extension.ts

@@ -1180,12 +1180,16 @@ export async function activate(context: vscode.ExtensionContext) {
     context.subscriptions.push(
         vscode.commands.registerCommand("codex-editor-extension.generateTranscriptions", async () => {
             const countInput = await vscode.window.showInputBox({
-                prompt: "How many cells to transcribe?",
-                placeHolder: "e.g., 5",
-                validateInput: (val) => (val && !isNaN(Number(val)) && Number(val) >= 1 ? undefined : "Enter a positive number"),
+                prompt: "How many cells to transcribe? (0 or blank = all untranscribed cells)",
+                placeHolder: "0 for all, or a specific number",
+                value: "0",
+                validateInput: (val) => {
+                    if (!val || val.trim() === "") return undefined;
+                    return !isNaN(Number(val)) && Number(val) >= 0 ? undefined : "Enter 0 for all, or a positive number";
+                },
             });
-            if (!countInput) return;
-            const count = Math.max(1, Math.floor(Number(countInput)));
+            if (countInput === undefined) return; // user cancelled
+            const count = Math.max(0, Math.floor(Number(countInput || 0)));
 
             const provider = GlobalProvider.getInstance().getProvider("codex-cell-editor") as CodexCellEditorProvider | undefined;
             if (!provider) {
@@ -1194,7 +1198,10 @@ export async function activate(context: vscode.ExtensionContext) {
             }
 
             provider.postMessageToWebviews({ type: "startBatchTranscription", content: { count } } as any);
-            vscode.window.showInformationMessage(`Starting transcription for up to ${count} cells...`);
+            const label = count > 0 ? `up to ${count}` : "all untranscribed";
+            vscode.window.showInformationMessage(
+                `Starting transcription for ${label} cells... First request may take ~45s to warm up.`
+            );
         })
     );
 

src/providers/codexCellEditorProvider/codexCellEditorMessagehandling.ts

@@ -406,10 +406,11 @@ const messageHandlers: Record<string, (ctx: MessageHandlerContext) => Promise<vo
                 console.error(`[getAsrConfig] This will cause transcription to fail. Please check authentication status.`);
             }
 
-            debug(`[getAsrConfig] Sending config: endpoint=${endpoint}, hasToken=${!!authToken}`);
+            const language = vscode.workspace.getConfiguration("codex-editor-extension").get<string>("asrLanguage", "eng");
+            debug(`[getAsrConfig] Sending config: endpoint=${endpoint}, hasToken=${!!authToken}, language=${language}`);
             safePostMessageToPanel(webviewPanel, {
                 type: "asrConfig",
-                content: { endpoint, authToken }
+                content: { endpoint, authToken, language }
             });
         } catch (error) {
             console.error("Error sending ASR config:", error);
@@ -429,6 +430,19 @@ const messageHandlers: Record<string, (ctx: MessageHandlerContext) => Promise<vo
         }
     },
 
+    requestBatchTranscription: async ({ event, webviewPanel, provider }) => {
+        const count = (event as any).content?.count ?? 0;
+        // Forward to the webview as a startBatchTranscription message
+        safePostMessageToPanel(webviewPanel, {
+            type: "startBatchTranscription",
+            content: { count },
+        } as any);
+        const label = count > 0 ? `up to ${count}` : "all untranscribed";
+        vscode.window.showInformationMessage(
+            `Starting transcription for ${label} cells... First request may take ~45s to warm up.`
+        );
+    },
+
     updateCellAfterTranscription: async ({ event, document, webviewPanel, provider }) => {
         const typedEvent = event as Extract<EditorPostMessages, { command: "updateCellAfterTranscription"; }>;
         const { cellId, transcribedText, language } = typedEvent.content;

webviews/codex-webviews/src/CodexCellEditor/AudioWaveformWithTranscription.tsx

@@ -33,6 +33,7 @@ interface AudioWaveformWithTranscriptionProps {
     isTranscribing: boolean;
     transcriptionProgress: number;
     onTranscribe: () => void;
+    onTranscribeAll?: () => void;
     onInsertTranscription: () => void;
     disabled?: boolean;
     onRequestRemove?: () => void;
@@ -50,6 +51,7 @@ const AudioWaveformWithTranscription: React.FC<AudioWaveformWithTranscriptionPro
     isTranscribing,
     transcriptionProgress,
     onTranscribe,
+    onTranscribeAll,
     onInsertTranscription,
     disabled = false,
     onRequestRemove,
@@ -341,16 +343,30 @@ const AudioWaveformWithTranscription: React.FC<AudioWaveformWithTranscriptionPro
             {/* Action buttons at bottom */}
             <div className="flex flex-wrap items-center justify-center gap-2 px-2">
                 {!transcription && !isTranscribing && (
-                    <Button
-                        onClick={onTranscribe}
-                        disabled={disabled || (!audioUrl && !audioBlob)}
-                        variant="outline"
-                        className="h-8 px-2 text-xs text-[var(--vscode-button-background)] border-[var(--vscode-button-background)]/20 hover:bg-[var(--vscode-button-background)]/10"
-                        title="Transcribe Audio"
-                    >
-                        <MessageCircle className="h-3 w-3" />
-                        <span className="ml-1">Transcribe</span>
-                    </Button>
+                    <>
+                        <Button
+                            onClick={onTranscribe}
+                            disabled={disabled || (!audioUrl && !audioBlob)}
+                            variant="outline"
+                            className="h-8 px-2 text-xs text-[var(--vscode-button-background)] border-[var(--vscode-button-background)]/20 hover:bg-[var(--vscode-button-background)]/10"
+                            title="Transcribe this cell"
+                        >
+                            <MessageCircle className="h-3 w-3" />
+                            <span className="ml-1">Transcribe</span>
+                        </Button>
+                        {onTranscribeAll && (
+                            <Button
+                                onClick={onTranscribeAll}
+                                disabled={disabled}
+                                variant="outline"
+                                className="h-8 px-2 text-xs text-[var(--vscode-button-background)] border-[var(--vscode-button-background)]/20 hover:bg-[var(--vscode-button-background)]/10"
+                                title="Transcribe all untranscribed cells (recommended — avoids repeated cold starts)"
+                            >
+                                <MessageCircle className="h-3 w-3" />
+                                <span className="ml-1">Transcribe All</span>
+                            </Button>
+                        )}
+                    </>
                 )}
                 <Button
                     variant="outline"

webviews/codex-webviews/src/CodexCellEditor/CodexCellEditor.tsx

@@ -450,6 +450,11 @@ const CodexCellEditor: React.FC = () => {
                     const targetCount = Math.max(0, message.content.count | 0);
                     const specificCellId: string | undefined = (message as any)?.content?.cellId;
                     let completed = 0;
+                    // Create a single client for the entire batch to reuse the warmed Modal container
+                    const client = new WhisperTranscriptionClient(
+                        wsEndpoint,
+                        asrConfig.authToken
+                    );
                     for (const unit of translationUnits) {
                         if (targetCount > 0 && completed >= targetCount) break;
                         const cellId = unit.cellMarkers[0];
@@ -501,11 +506,7 @@ const CodexCellEditor: React.FC = () => {
                         // Transcribe
                         debug(
                             "batchTranscription",
-                            `Creating client for cell ${cellId}: endpoint=${wsEndpoint}, hasToken=${!!asrConfig.authToken}`
-                        );
-                        const client = new WhisperTranscriptionClient(
-                            wsEndpoint,
-                            asrConfig.authToken
+                            `Transcribing cell ${cellId}: endpoint=${wsEndpoint}, hasToken=${!!asrConfig.authToken}`
                         );
                         try {
                             // Mark cell as transcribing for UI feedback
@@ -514,15 +515,15 @@ const CodexCellEditor: React.FC = () => {
                                 next.add(cellId);
                                 return next;
                             });
-                            const result = await client.transcribe(blob);
+                            const result = await client.transcribe(blob, 60000, asrConfig.language);
                             const text = (result.text || "").trim();
                             if (text) {
                                 vscode.postMessage({
                                     command: "updateCellAfterTranscription",
                                     content: {
                                         cellId,
                                         transcribedText: text,
-                                        language: "unknown",
+                                        language: asrConfig.language || "unknown",
                                     },
                                 } as unknown as EditorPostMessages);
 

webviews/codex-webviews/src/CodexCellEditor/TextCellEditor.tsx

@@ -1368,6 +1368,14 @@ const CellEditor: React.FC<CellEditorProps> = ({
         }
     });
 
+    const handleTranscribeAll = () => {
+        // Trigger batch transcription for all untranscribed cells via the extension
+        window.vscodeApi.postMessage({
+            command: "requestBatchTranscription",
+            content: { count: 0 }, // 0 = all untranscribed cells
+        });
+    };
+
     const handleTranscribeAudio = async () => {
         // Check connectivity first
         if (!navigator.onLine) {
@@ -1415,8 +1423,8 @@ const CellEditor: React.FC<CellEditorProps> = ({
                 setTranscriptionStatus(`Error: ${error}`);
             };
 
-            // Perform transcription
-            const result = await client.transcribe(audioBlob);
+            // Perform transcription with language hint
+            const result = await client.transcribe(audioBlob, 60000, asrConfig?.language);
 
             // Success - save transcription but don't automatically insert
             const transcribedText = result.text.trim();
@@ -1435,7 +1443,7 @@ const CellEditor: React.FC<CellEditorProps> = ({
                         content: {
                             cellId: cellMarkers[0],
                             transcribedText: transcribedText,
-                            language: "unknown",
+                            language: asrConfig?.language || "unknown",
                         },
                     };
                     window.vscodeApi.postMessage(messageContent);
@@ -2911,6 +2919,7 @@ const CellEditor: React.FC<CellEditorProps> = ({
                                             isTranscribing={isTranscribing}
                                             transcriptionProgress={transcriptionProgress}
                                             onTranscribe={handleTranscribeAudio}
+                                            onTranscribeAll={handleTranscribeAll}
                                             onInsertTranscription={handleInsertTranscription}
                                             onRequestRemove={() => setConfirmingDiscard(true)}
                                             onShowHistory={() => setShowAudioHistory(true)}

webviews/codex-webviews/src/CodexCellEditor/WhisperTranscriptionClient.ts

@@ -11,7 +11,8 @@ export class WhisperTranscriptionClient {
 
     async transcribe(
         audioBlob: Blob,
-        timeoutMs: number = 60000
+        timeoutMs: number = 60000,
+        language?: string
     ): Promise<{ text: string; }> {
         try {
             // Create FormData with audio file
@@ -25,6 +26,9 @@ export class WhisperTranscriptionClient {
             if (this.authToken) {
                 url.searchParams.set("token", this.authToken);
             }
+            if (language) {
+                url.searchParams.set("lang", language);
+            }
 
             // Prepare headers
             const headers: HeadersInit = {};