diff --git a/pack-vid b/pack-vid
index 5648646..7d02e18 100755
--- a/pack-vid
+++ b/pack-vid
@@ -2,8 +2,8 @@
 <?php
 
 // Squishes given video input into sub-4000kb .mp4
-// Crops or pads to 16:9 (crop default; --letterbox to pad)
-// Strips audio (to override, pass --audio for 96 kbps AAC)
+// Crops or pads to 16:9 (letterbox default; --crop to crop)
+// Includes stereo audio (to strip, pass --no-audio)
 // HDR to SDR tonemapping
 // Picks bitrate to match
 // Picks resolution based on bitrate target
@@ -16,10 +16,10 @@ $maxBytes = 4000 * 1000; // fit in 4MB
 $maxBytes = $maxBytes * 15 / 16; // leave some headroom
 
 $options = [
-    'letterbox' => false,
-    'audio' => false,
-    'exposure' => '0',
-    'peak' => '10000',
+    'crop' => false,
+    'no-audio' => false,
+    'exposure' => '-0.5', // half stop down
+    'peak' => '1000', // '10000' is max
     'fps' => '60',
     'size' => $maxBytes,
     'quality' => 0.75,
@@ -40,8 +40,8 @@ if ( count ( $args ) < 2 ) {
     die(
         "Usage: $self [options...] <srcfile.mp4> <destfile.mp4>\n" .
         "Options:\n" .
-        "  --letterbox    pad instead of cropping\n" .
-        "  --audio        include audio\n" .
+        "  --crop         crop instead of padding\n" .
+        "  --no-audio     strip audio\n" .
         "  --exposure=n   adjust exposure\n" .
         "  --peak=n       set HDR peak nits\n" .
         "  --fps=n        frame rate limit\n" .
@@ -141,16 +141,21 @@ function convert( $src, $dest, $options ) {
     $bitrate = floor( $maxBits / $duration );
 
 
-    if ( $options[ 'audio' ] ) {
-        $audioBitrate = 96 * 1000;
-        $audio = [ '-b:a', $audioBitrate ];
-        $bitrate -= $audioBitrate;
-    } else {
+    if ( $options[ 'no-audio' ] ) {
         $audio = [ '-an' ];
+    } else {
+        $audioBitrate = 96 * 1000;
+        $audio = [
+            '-ac', 2,
+            '-b:a', $audioBitrate,
+        ];
+        $bitrate -= $audioBitrate;
     }
 
+    $bitrate = max( $bitrate, 16000 );
+
     $mbits = 1000 * 1000;
-    $base = intval( $mbits * $options['quality'] );
+    $base = intval( $mbits * floatval( $options['quality'] ) );
     if ( $bitrate < 1 * $base || $height < 480 ) {
         $frameWidth = 640;
         $frameHeight = 360;
@@ -167,22 +172,22 @@ function convert( $src, $dest, $options ) {
 
     $aspect = $width / $height;
     $wide = $aspect > ( $frameWidth / $frameHeight );
-    $pad = boolval( $options['letterbox'] );
-    if ( $pad ) {
+    $crop = boolval( $options['crop'] );
+    if ( $crop ) {
         if ( $wide ) {
-            $scaleWidth = $frameWidth;
-            $scaleHeight = evenize( $frameWidth / $aspect );
-        } else {
             $scaleHeight = $frameHeight;
             $scaleWidth = evenize( $frameHeight * $aspect );
+        } else {
+            $scaleWidth = $frameWidth;
+            $scaleHeight = evenize( $frameWidth / $aspect );
         }
     } else {
         if ( $wide ) {
-            $scaleHeight = $frameHeight;
-            $scaleWidth = evenize( $frameHeight * $aspect );
-        } else {
             $scaleWidth = $frameWidth;
             $scaleHeight = evenize( $frameWidth / $aspect );
+        } else {
+            $scaleHeight = $frameHeight;
+            $scaleWidth = evenize( $frameHeight * $aspect );
         }
     }
 
@@ -201,12 +206,12 @@ function convert( $src, $dest, $options ) {
         $filters[] = "zscale=t=bt709:m=bt709:r=full";
     }
     $filters[] = "format=yuv420p";
-    if ( $options['letterbox'] ) {
+    if ( $crop ) {
+        $filters[] = "crop=w=$frameWidth:h=$frameHeight";
+    } else {
         $offsetX = round( ( $frameWidth - $scaleWidth) / 2 );
         $offsetY = round( ( $frameHeight - $scaleHeight) / 2 );
         $filters[] = "pad=w=$frameWidth:h=$frameHeight:x=$offsetX:y=$offsetY";
-    } else {
-        $filters[] = "crop=w=$frameWidth:h=$frameHeight";
     }
     $vf = implode( ',', $filters );