Improved audio recording error handling and chunk processing

app/MindWork AI Studio/Components/VoiceRecorder.razor.cs

@@ -137,6 +137,7 @@ public partial class VoiceRecorder : MSGComponentBase
             var mimeTypes = GetPreferredMimeTypes(
                 Builder.Create().UseAudio().UseSubtype(AudioSubtype.WEBM).Build(),
                 Builder.Create().UseAudio().UseSubtype(AudioSubtype.OGG).Build(),
+                Builder.Create().UseAudio().UseSubtype(AudioSubtype.MP4).Build(),
                 Builder.Create().UseAudio().UseSubtype(AudioSubtype.AAC).Build(),
                 Builder.Create().UseAudio().UseSubtype(AudioSubtype.MP3).Build(),
                 Builder.Create().UseAudio().UseSubtype(AudioSubtype.AIFF).Build(),
@@ -171,6 +172,7 @@ public partial class VoiceRecorder : MSGComponentBase
 
                 // Clean up the recording stream if starting failed:
                 await this.FinalizeRecordingStream();
+                await this.ReleaseMicrophoneAsync();
             }
             finally
             {
@@ -179,11 +181,13 @@ public partial class VoiceRecorder : MSGComponentBase
         }
         else
         {
+            var recordingStoppedSuccessfully = false;
             try
             {
                 var result = await this.JsRuntime.InvokeAsync<AudioRecordingResult>("audioRecorder.stop");
                 if (result.ChangedMimeType)
                     this.Logger.LogWarning("The recorded audio MIME type was changed to '{ResultMimeType}'.", result.MimeType);
+                recordingStoppedSuccessfully = true;
             }
             catch (Exception e)
             {
@@ -197,8 +201,19 @@ public partial class VoiceRecorder : MSGComponentBase
             this.isRecording = false;
             this.StateHasChanged();
 
-            // Start transcription if we have a recording and a configured provider:
+            if (!recordingStoppedSuccessfully || this.finalRecordingPath is null)
-            if (this.finalRecordingPath is not null)
+            {
+                if (recordingStoppedSuccessfully)
+                {
+                    this.Logger.LogWarning("The audio recorder did not produce any data.");
+                    await this.MessageBus.SendError(new(Icons.Material.Filled.MicOff, this.T("Failed to stop audio recording.")));
+                }
+
+                this.DeleteFinalRecording();
+                await this.ReleaseMicrophoneAsync();
+                return;
+            }
+
             await this.TranscribeRecordingAsync();
         }
     }
@@ -256,6 +271,7 @@ public partial class VoiceRecorder : MSGComponentBase
         catch (Exception ex)
         {
             this.Logger.LogError(ex, "Error writing audio chunk to stream.");
+            throw;
         }
     }
 
@@ -268,17 +284,23 @@ public partial class VoiceRecorder : MSGComponentBase
             await this.currentRecordingStream.DisposeAsync();
             this.currentRecordingStream = null;
 
-            // Rename the file with the correct extension based on MIME type:
+            if (this.currentRecordingPath is not null && File.Exists(this.currentRecordingPath))
-            if (this.currentRecordingPath is not null && this.currentRecordingMimeType is not null)
+            {
+                var fileSize = new FileInfo(this.currentRecordingPath).Length;
+
+                // Rename non-empty recordings with the correct extension based on MIME type:
+                if (fileSize > 0 && this.currentRecordingMimeType is not null)
                 {
                     var extension = GetFileExtension(this.currentRecordingMimeType);
                     var newPath = Path.ChangeExtension(this.currentRecordingPath, extension);
-
-                if (File.Exists(this.currentRecordingPath))
-                {
                     File.Move(this.currentRecordingPath, newPath, overwrite: true);
                     this.finalRecordingPath = newPath;
-                    this.Logger.LogInformation("Finalized audio recording over {NumChunks} streamed audio chunks to the file '{RecordingPath}'.", this.numReceivedChunks, newPath);
+                    this.Logger.LogInformation("Finalized audio recording over {NumChunks} streamed audio chunks to the file '{RecordingPath}' with {FileSize} bytes.", this.numReceivedChunks, newPath, fileSize);
+                }
+                else
+                {
+                    this.Logger.LogWarning("Discarding an audio recording with {FileSize} bytes and MIME type '{MimeType}'.", fileSize, this.currentRecordingMimeType);
+                    File.Delete(this.currentRecordingPath);
                 }
             }
         }
@@ -375,19 +397,28 @@ public partial class VoiceRecorder : MSGComponentBase
         finally
         {
             await this.ReleaseMicrophoneAsync();
+            this.DeleteFinalRecording();
+            this.isTranscribing = false;
+            this.StateHasChanged();
+        }
+    }
+
+    private void DeleteFinalRecording()
+    {
+        var recordingPath = this.finalRecordingPath;
+        this.finalRecordingPath = null;
+
+        if (recordingPath is null)
+            return;
 
         try
         {
-                if (File.Exists(this.finalRecordingPath))
+            if (File.Exists(recordingPath))
-                    File.Delete(this.finalRecordingPath);
+                File.Delete(recordingPath);
         }
         catch (Exception ex)
         {
-                this.Logger.LogError(ex, "Failed to delete the recording file '{RecordingPath}'.", this.finalRecordingPath);
+            this.Logger.LogError(ex, "Failed to delete the recording file '{RecordingPath}'.", recordingPath);
-            }
-            this.finalRecordingPath = null;
-            this.isTranscribing = false;
-            this.StateHasChanged();
         }
     }
 

app/MindWork AI Studio/wwwroot/audio.js

@@ -184,6 +184,9 @@ let mediaRecorder;
 let actualRecordingMimeType;
 let changedMimeType = false;
 let pendingChunkUploads = 0;
+let chunkUploadPromise = Promise.resolve();
+let chunkUploadError = null;
+let recordingError = null;
 
 // Store the media stream so we can close the microphone later:
 let activeMediaStream = null;
@@ -246,48 +249,65 @@ window.audioRecorder = {
         actualRecordingMimeType = mediaRecorder.mimeType;
         console.log('Audio recording - actual mime type used by the browser: ', actualRecordingMimeType);
 
+        const actualBaseMimeType = actualRecordingMimeType.split(';')[0].trim().toLowerCase();
+
         // Check the list of desired mime types against the actual one:
-        if (!desiredMimeTypes.includes(actualRecordingMimeType)) {
+        if (!desiredMimeTypes.some(type => type.split(';')[0].trim().toLowerCase() === actualBaseMimeType)) {
             changedMimeType = true;
             console.warn(`Audio recording - requested mime types ('${desiredMimeTypes.join(', ')}') do not include the actual mime type used by the browser ('${actualRecordingMimeType}').`);
         } else {
             changedMimeType = false;
         }
 
-        // Reset the pending uploads counter:
+        // Reset the upload and recorder state:
         pendingChunkUploads = 0;
+        chunkUploadPromise = Promise.resolve();
+        chunkUploadError = null;
+        recordingError = null;
 
-        // Stream each chunk directly to .NET as it becomes available:
+        // Stream each chunk directly to .NET in recording order as it becomes available:
-        mediaRecorder.ondataavailable = async (event) => {
+        mediaRecorder.ondataavailable = (event) => {
             if (event.data.size > 0) {
                 pendingChunkUploads++;
-                try {
+                chunkUploadPromise = chunkUploadPromise
+                    .then(async () => {
                         const arrayBuffer = await event.data.arrayBuffer();
                         const uint8Array = new Uint8Array(arrayBuffer);
                         await dotnetRef.invokeMethodAsync('OnAudioChunkReceived', uint8Array);
-                } catch (error) {
+                    })
+                    .catch(error => {
+                        chunkUploadError ??= error;
                         console.error('Error sending audio chunk to .NET:', error);
-                } finally {
+                    })
-                    pendingChunkUploads--;
+                    .finally(() => pendingChunkUploads--);
-                }
             }
         };
 
+        mediaRecorder.onerror = event => {
+            recordingError ??= event.error || new Error('The media recorder failed.');
+            console.error('Audio recording - MediaRecorder error:', recordingError);
+        };
+
+        if (actualBaseMimeType === 'audio/mp4') {
+            // WebKitGTK does not reliably produce MP4 data when a timeslice is used. Let it
+            // finalize one complete M4A blob when stop() is called instead.
+            mediaRecorder.start();
+        } else {
             mediaRecorder.start(3000); // read the recorded data in 3-second chunks
+        }
+
         return actualRecordingMimeType;
     },
 
     stop: async function () {
-        return new Promise((resolve) => {
+        return new Promise((resolve, reject) => {
 
             // Add an event listener to handle the stop event:
             mediaRecorder.onstop = async () => {
 
                 // Wait for all pending chunk uploads to complete before finalizing:
                 console.log(`Audio recording - waiting for ${pendingChunkUploads} pending uploads.`);
-                while (pendingChunkUploads > 0) {
+                await chunkUploadPromise;
-                    await new Promise(r => setTimeout(r, 10)); // wait 10 ms before checking again
-                }
 
                 console.log('Audio recording - all chunks uploaded, finalizing.');
 
@@ -303,6 +323,12 @@ window.audioRecorder = {
                 // Call window.audioRecorder.releaseMicrophone() after the last sound has played.
                 //
 
+                const error = recordingError || chunkUploadError;
+                if (error) {
+                    reject(error);
+                    return;
+                }
+
                 // No need to process data here anymore, just signal completion:
                 resolve({
                     mimeType: actualRecordingMimeType,

app/MindWork AI Studio/wwwroot/changelog/v26.7.3.md

@@ -5,7 +5,7 @@
 - Improved update guidance for Flatpak installations and added an enterprise option that lets organizations manage updates entirely through their IT department.
 - Fixed an issue that could leave AI Studio unresponsive after waking the computer from sleep. Yes, we know this was an annoying bug, and we apologize for the inconvenience.
 - Fixed enterprise configuration plugins from Windows-created ZIP files may not load correctly on Linux when the ZIP contained plugin files inside a folder.
-- Fixed voice recording not starting on Linux.
+- Fixed voice recording and transcription on Linux.
 - Fixed being able to switch document analysis policies while an analysis or media transcription was still in progress.
 - Upgraded Rust to v1.97.0.
 - Upgraded Tauri to v2.11.5.