fix(recording): silent recordings — capture + mux audio correctly

src-tauri/Cargo.toml

@@ -41,6 +41,6 @@ default = ["custom-protocol"]
 custom-protocol = ["tauri/custom-protocol"]
 
 [lints.rust]
-# The `objc` crate's msg_send! macro expands to a `cfg(cargo-clippy)` check;
-# declare it as a known cfg so it doesn't trip the unexpected_cfgs lint.
-unexpected_cfgs = { level = "warn", check-cfg = ['cfg(cargo-clippy)'] }
+# The `objc` crate's msg_send! macro references a `cargo-clippy` cfg that trips
+# the unexpected_cfgs lint — it's from the dependency macro, not our code.
+unexpected_cfgs = "allow"

src-tauri/src/audio.rs

@@ -76,13 +76,21 @@ impl AudioRecorder {
             output_path.display()
         );
 
+        // The captured audio is AAC, but the container dictates the codec:
+        // WebM (VP9) can't hold AAC — it needs Opus; MP4 takes AAC. Using the
+        // wrong codec makes the mux fail, leaving a silent video-only file.
+        let audio_codec = match format {
+            "mp4" => "aac",
+            _ => "libopus", // webm
+        };
+
         let status = Command::new(ffmpeg_path())
             .args([
                 "-y",
                 "-i", &video_path.to_string_lossy(),
                 "-i", &audio_path.to_string_lossy(),
                 "-c:v", "copy",
-                "-c:a", "aac",
+                "-c:a", audio_codec,
                 "-shortest",
                 &output_path.to_string_lossy(),
             ])

src/services/capture/tauri.ts

@@ -66,6 +66,10 @@ export class TauriCaptureService implements CaptureService {
           fps: options?.fps,
           displayId: options?.displayId,
           bounds: options?.bounds,
+          // Without these the Rust side never starts the audio recorder,
+          // so recordings came out silent.
+          includeAudio: options?.includeAudio,
+          systemAudio: options?.systemAudio,
         },
       });