Added a configurable Opus bitrate for audio transcription (#981)

Co-authored-by: Thorsten Sommer <SommerEngineering@users.noreply.github.com>

app/MindWork AI Studio/Tools/PluginSystem/PluginConfiguration.cs

@@ -398,6 +398,9 @@ public sealed class PluginConfiguration(bool isInternal, LuaState state, PluginT
         // Config: transcription provider?
         ManagedConfiguration.TryProcessConfiguration(x => x.App, x => x.UseTranscriptionProvider, Guid.Empty, this.Id, settingsTable, dryRun);
 
+        // Config: transcription Opus bitrate?
+        ManagedConfiguration.TryProcessConfiguration(x => x.App, x => x.OpusBitrate, this.Id, settingsTable, dryRun);
+
         message = string.Empty;
         return true;
     }

app/MindWork AI Studio/Tools/Rust/CreateMediaJobRequest.cs

@@ -4,4 +4,5 @@ namespace AIStudio.Tools.Rust;
 /// <param name="InputPath">Absolute source media path.</param>
 /// <param name="OutputPath">Absolute operation-owned output path.</param>
 /// <param name="MaxPassThroughBytes">Optional pass-through size ceiling.</param>
-public sealed record CreateMediaJobRequest(string InputPath, string OutputPath, ulong? MaxPassThroughBytes = null);
+/// <param name="OpusBitrateBps">Optional target Opus encoder bitrate in bits per second.</param>
+public sealed record CreateMediaJobRequest(string InputPath, string OutputPath, ulong? MaxPassThroughBytes = null, uint? OpusBitrateBps = null);

app/MindWork AI Studio/Tools/Services/MediaTranscriptionService.cs

@@ -1,6 +1,7 @@
 using AIStudio.Chat;
 using AIStudio.Provider;
 using AIStudio.Settings;
+using AIStudio.Settings.DataModel;
 using AIStudio.Tools.Media;
 using AIStudio.Tools.PluginSystem;
 using AIStudio.Tools.Rust;
@@ -646,9 +647,23 @@ public sealed class MediaTranscriptionService(
         MediaOperation operation,
         bool updateImportState)
     {
+        // The bitrate governs re-encoding, not every upload: the runtime hands a file through
+        // unchanged when it already is a single mono 48 kHz Opus track in a WebM container and small
+        // enough. Such a file keeps whatever bitrate it was made with, which is the better outcome --
+        // re-encoding it could only take quality away, never add any.
+        var opusBitrateBps = settingsManager.ConfigurationData.App.OpusBitrate.GetBitsPerSecond();
+
+        // Which quality an upload was produced with is the first question to ask when a transcript
+        // comes back missing something, so it has to be in the log of the job it belongs to:
+        logger.LogInformation(
+            "Normalizing media for operation {OperationId}; re-encoding uses the Opus bitrate {OpusBitrate} ({OpusBitrateBps} bps).",
+            operation.Id,
+            settingsManager.ConfigurationData.App.OpusBitrate,
+            opusBitrateBps);
+
         // The quick POST is intentionally not cancelled: losing its response could orphan a job
         // whose ID the client never received. Cancellation is applied immediately after ownership.
-        var jobId = await rustService.StartMediaJobAsync(mediaPath, normalizedPath, CancellationToken.None);
+        var jobId = await rustService.StartMediaJobAsync(mediaPath, normalizedPath, opusBitrateBps, CancellationToken.None);
         operation.JobId = jobId;
 
         try

app/MindWork AI Studio/Tools/Services/RustService.Media.cs

@@ -10,13 +10,14 @@ public partial class RustService
     /// <summary>Starts a Rust media normalization job.</summary>
     /// <param name="inputPath">Absolute source path.</param>
     /// <param name="outputPath">Absolute operation-owned output path.</param>
+    /// <param name="opusBitrateBps">Target Opus encoder bitrate in bits per second.</param>
     /// <param name="token">Request cancellation token.</param>
     /// <returns>The opaque runtime job identifier.</returns>
-    public async Task<string> StartMediaJobAsync(string inputPath, string outputPath, CancellationToken token = default)
+    public async Task<string> StartMediaJobAsync(string inputPath, string outputPath, uint opusBitrateBps, CancellationToken token = default)
     {
         using var response = await this.http.PostAsJsonAsync(
             "/media/jobs",
-            new CreateMediaJobRequest(inputPath, outputPath),
+            new CreateMediaJobRequest(inputPath, outputPath, OpusBitrateBps: opusBitrateBps),
             this.jsonRustSerializerOptions,
             token);