diff --git a/main.js b/main.js
index fa65519..4c0bcbe 100644
--- a/main.js
+++ b/main.js
@@ -310,9 +310,12 @@ function transcodeToMp4(input, output, opts) {
   // Cover the target frame then centre-crop, so the chosen aspect is filled
   // without distortion.
   const vf = `scale=${w}:${h}:force_original_aspect_ratio=increase,crop=${w}:${h}`;
-  const args = ['-y', '-i', input, '-vf', vf,
-    '-c:v', 'libx264', '-preset', 'veryfast', '-crf', '20', '-pix_fmt', 'yuv420p',
-    '-c:a', 'aac', '-b:a', '192k', '-movflags', '+faststart', output];
+  // Post-processing, not realtime: spend encode time on quality. CRF 18 +
+  // medium is visually transparent for VJ motion; -r 30 turns the recorder's
+  // variable frame timing into constant 30fps (players and socials want CFR).
+  const args = ['-y', '-i', input, '-vf', vf, '-r', '30',
+    '-c:v', 'libx264', '-preset', 'medium', '-crf', '18', '-pix_fmt', 'yuv420p',
+    '-c:a', 'aac', '-b:a', '256k', '-movflags', '+faststart', output];
   return new Promise((resolve, reject) => {
     execFile(ffmpegPath(), args, { maxBuffer: 1 << 24 }, (err, stdout, stderr) => {
       if (err) reject(new Error('ffmpeg: ' + String(stderr || err.message).slice(-500)));
diff --git a/src/output.js b/src/output.js
index 0e3b168..9833fde 100644
--- a/src/output.js
+++ b/src/output.js
@@ -173,7 +173,15 @@ async function startRecording(opts) {
     const vstream = recCanvas.captureStream(30);
     const astream = audio.recordDest.stream;
     const stream = new MediaStream([...vstream.getVideoTracks(), ...astream.getAudioTracks()]);
-    recorder = new MediaRecorder(stream, { mimeType: pickMime(), videoBitsPerSecond: 12e6 });
+    // Generous bitrate: this WebM is only an intermediate (deleted after the
+    // MP4 mux) and the realtime VP9 encoder needs headroom on full-screen
+    // abstract motion — 12 Mbps left visible blocking, the ffmpeg pass can
+    // only preserve what survives this first encode.
+    recorder = new MediaRecorder(stream, {
+      mimeType: pickMime(),
+      videoBitsPerSecond: 30e6,
+      audioBitsPerSecond: 192e3
+    });
     // Serialise chunk delivery: ondataavailable is async, so without a chain the
     // header chunk could be sent after a later one and corrupt the WebM.
     let chain = Promise.resolve();