add 30fps limiter

it's probably gonna get re-rendered anyway

pack-vid

@@ -108,10 +108,13 @@ function convert( $src, $dest, $options ) {
     }
 
     $mbits = 1000 * 1000;
-    if ( $bitrate < 2 * $mbits ) {
+    if ( $bitrate < $mbits ) {
+        $frameWidth = 640;
+        $frameHeight = 360;
+    } elseif ( $bitrate < 2 * $mbits ) {
         $frameWidth = 854;
         $frameHeight = 480;
-    } else if ( $bitrate <= 4 * $mbits ) {
+    } elseif ( $bitrate < 4 * $mbits ) {
         $frameWidth = 1280;
         $frameHeight = 720;
     } else {
@@ -142,10 +145,13 @@ function convert( $src, $dest, $options ) {
     }
     $vf = implode( ',', $filters );
 
+    $fps = 30;
+
     run( 'ffmpeg',
         array_merge( [
             '-i', $src,
             '-f', 'mp4',
+            '-r', $fps,
             '-vf', $vf,
             '-c:v', 'libx264',
             '-b:v', $bitrate,
@@ -160,6 +166,7 @@ function convert( $src, $dest, $options ) {
         array_merge( [
             '-i', $src,
             '-vf', $vf,
+            '-r', $fps,
             '-c:v', 'libx264',
             '-b:v', $bitrate,
             '-preset', 'veryslow',