Change video uploads to always be converted to H264/MP4 (#13220)

Even if the container format is the same (.mp4), the codec could
be different and not playable in web browsers

app/models/media_attachment.rb

@@ -57,6 +57,26 @@ class MediaAttachment < ApplicationRecord
     },
   }.freeze
 
+  VIDEO_FORMAT = {
+    format: 'mp4',
+    content_type: 'video/mp4',
+    convert_options: {
+      output: {
+        'loglevel' => 'fatal',
+        'movflags' => 'faststart',
+        'pix_fmt' => 'yuv420p',
+        'vf' => 'scale=\'trunc(iw/2)*2:trunc(ih/2)*2\'',
+        'vsync' => 'cfr',
+        'c:v' => 'h264',
+        'maxrate' => '1300K',
+        'bufsize' => '1300K',
+        'frames:v' => 60 * 60 * 3,
+        'crf' => 18,
+        'map_metadata' => '-1',
+      },
+    },
+  }.freeze
+
   VIDEO_STYLES = {
     small: {
       convert_options: {
@@ -71,17 +91,7 @@ class MediaAttachment < ApplicationRecord
       blurhash: BLURHASH_OPTIONS,
     },
 
-    original: {
-      keep_same_format: true,
-      convert_options: {
-        output: {
-          'loglevel' => 'fatal',
-          'map_metadata' => '-1',
-          'c:v' => 'copy',
-          'c:a' => 'copy',
-        },
-      },
-    },
+    original: VIDEO_FORMAT,
   }.freeze
 
   AUDIO_STYLES = {
@@ -98,26 +108,6 @@ class MediaAttachment < ApplicationRecord
     },
   }.freeze
 
-  VIDEO_FORMAT = {
-    format: 'mp4',
-    content_type: 'video/mp4',
-    convert_options: {
-      output: {
-        'loglevel' => 'fatal',
-        'movflags' => 'faststart',
-        'pix_fmt' => 'yuv420p',
-        'vf' => 'scale=\'trunc(iw/2)*2:trunc(ih/2)*2\'',
-        'vsync' => 'cfr',
-        'c:v' => 'h264',
-        'maxrate' => '1300K',
-        'bufsize' => '1300K',
-        'frames:v' => 60 * 60 * 3,
-        'crf' => 18,
-        'map_metadata' => '-1',
-      },
-    },
-  }.freeze
-
   VIDEO_CONVERTED_STYLES = {
     small: VIDEO_STYLES[:small],
     original: VIDEO_FORMAT,