Change audio format from ogg to mp3 for wider compatibility (#11141)

* Change audio format from ogg to mp3 for wider compatibility

* Add media description as title to links of unknown media attachments

app/javascript/mastodon/components/media_gallery.js

@@ -157,7 +157,7 @@ class Item extends React.PureComponent {
     if (attachment.get('type') === 'unknown') {
       return (
         <div className={classNames('media-gallery__item', { standalone })} key={attachment.get('id')} style={{ left: left, top: top, right: right, bottom: bottom, width: `${width}%`, height: `${height}%` }}>
-          <a className='media-gallery__item-thumbnail' href={attachment.get('remote_url')} target='_blank' style={{ cursor: 'pointer' }}>
+          <a className='media-gallery__item-thumbnail' href={attachment.get('remote_url')} target='_blank' style={{ cursor: 'pointer' }} title={attachment.get('description')}>
             <canvas width={32} height={32} ref={this.setCanvasRef} className='media-gallery__preview' />
           </a>
         </div>

app/javascript/styles/mastodon/components.scss

@@ -557,6 +557,7 @@
 
     .compose-form__upload-thumbnail {
       border-radius: 4px;
+      background-color: $base-shadow-color;
       background-position: center;
       background-size: cover;
       background-repeat: no-repeat;

app/models/media_attachment.rb

@@ -69,9 +69,13 @@ class MediaAttachment < ApplicationRecord
 
   AUDIO_STYLES = {
     original: {
-      format: 'ogg',
-      content_type: 'audio/ogg',
-      convert_options: {},
+      format: 'mp3',
+      content_type: 'audio/mpeg',
+      convert_options: {
+        output: {
+          'q:a' => 2,
+        },
+      },
     },
   }.freeze