wp-includes/class-wp-customize-manager.php:6087Callback for validating the header_video value.
$validityWP_Error$valuemixedmixed public function _validate_header_video( $validity, $value ) { $video = get_attached_file( absint( $value ) ); if ( $video ) { $size = filesize( $video ); if ( $size > 8 * MB_IN_BYTES ) { $validity->add( 'size_too_large', __( 'This video file is too large to use as a header video. Try a shorter video or optimize the compression settings and re-upload a file that is less than 8MB. Or, upload your video to YouTube and link it with the option below.' ) ); } if ( ! str_ends_with( $video, '.mp4' ) && ! str_ends_with( $video, '.mov' ) ) { // Check for .mp4 or .mov format, which (assuming h.264 encoding) are the only cross-browser-supported formats. $validity->add( 'invalid_file_type', sprintf( /* translators: 1: .mp4, 2: .mov */ __( 'Only %1$s or %2$s files may be used for header video. Please convert your video file and try again, or, upload your video to YouTube and link it with the option below.' ), '<code>.mp4</code>', '<code>.mov</code>' ) ); } } return $validity; }Introduced in 4.7.0. Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
src/wp-includes/class-wp-customize-manager.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.