ActiveStorage: fix default video_preview_arguments

Author: crawler

guides/source/configuring.md

@@ -1068,7 +1068,7 @@ text/javascript image/svg+xml application/postscript application/x-shockwave-fla
 
 * `config.active_storage.video_preview_arguments` can be used to alter the way ffmpeg generates video preview images.
 
-    The default is `"-vf select=eq(n\,0)+eq(key\,1)+gt(scene\,0.015),loop=loop=-1:size=2,trim=start_frame=1 -frames:v 1 -f image2"`
+    The default is `"-vf 'select=eq(n\\,0)+eq(key\\,1)+gt(scene\\,0.015),loop=loop=-1:size=2,trim=start_frame=1' -frames:v 1 -f image2"`
 
     1. `select=eq(n\,0)+eq(key\,1)+gt(scene\,0.015)`: Select the first video frame, plus keyframes, plus frames that meet the scene change threshold.
     2. `loop=loop=-1:size=2,trim=start_frame=1`: To use the first video frame as a fallback when no other frames meet the criteria, loop the first (one or) two selected frames, then drop the first looped frame.
@@ -1090,7 +1090,7 @@ text/javascript image/svg+xml application/postscript application/x-shockwave-fla
 - `config.active_support.cache_format_version`: `7.0`
 - `config.action_dispatch.return_only_request_media_type_on_content_type`: `false`
 - `config.action_mailer.smtp_timeout`: `5`
-- `config.active_storage.video_preview_arguments`: `"-vf select=eq(n\,0)+eq(key\,1)+gt(scene\,0.015),loop=loop=-1:size=2,trim=start_frame=1 -frames:v 1 -f image2"`
+- `config.active_storage.video_preview_arguments`: `"-vf 'select=eq(n\\,0)+eq(key\\,1)+gt(scene\\,0.015),loop=loop=-1:size=2,trim=start_frame=1' -frames:v 1 -f image2"`
 
 #### For '6.1', defaults from previous versions below and:
 

railties/lib/rails/application/configuration.rb

@@ -223,7 +223,8 @@ def load_defaults(target_version)
 
           if respond_to?(:active_storage)
             active_storage.video_preview_arguments =
-              "-vf select=eq(n\,0)+eq(key\,1)+gt(scene\,0.015),loop=loop=-1:size=2,trim=start_frame=1 -frames:v 1 -f image2"
+              "-vf 'select=eq(n\\,0)+eq(key\\,1)+gt(scene\\,0.015),loop=loop=-1:size=2,trim=start_frame=1'" \
+              " -frames:v 1 -f image2"
           end
         else
           raise "Unknown version #{target_version.to_s.inspect}"

railties/lib/rails/generators/rails/app/templates/config/initializers/new_framework_defaults_7_0.rb.tt

@@ -42,4 +42,4 @@
 # better preview images (rather than the previous default of using the first frame
 # of the video).
 # Rails.application.config.active_storage.video_preview_arguments =
-#   "-vf select=eq(n\,0)+eq(key\,1)+gt(scene\,0.015),loop=loop=-1:size=2,trim=start_frame=1 -frames:v 1 -f image2"
+#   "-vf 'select=eq(n\\,0)+eq(key\\,1)+gt(scene\\,0.015),loop=loop=-1:size=2,trim=start_frame=1' -frames:v 1 -f image2"

railties/test/application/configuration_test.rb

@@ -3032,7 +3032,8 @@ class MyLogger < ::Logger
       app "development"
 
       assert_equal ActiveStorage.video_preview_arguments,
-        "-vf select=eq(n\,0)+eq(key\,1)+gt(scene\,0.015),loop=loop=-1:size=2,trim=start_frame=1 -frames:v 1 -f image2"
+        "-vf 'select=eq(n\\,0)+eq(key\\,1)+gt(scene\\,0.015),loop=loop=-1:size=2,trim=start_frame=1'" \
+        " -frames:v 1 -f image2"
     end
 
     test "hosts include .localhost in development" do