WordPress/wp-admin/options-media.php

<?php
/**
 * Media settings administration panel.
 *
 * @package WordPress
 * @subpackage Administration
 */

/** WordPress Administration Bootstrap */
require_once( dirname( __FILE__ ) . '/admin.php' );

if ( ! current_user_can( 'manage_options' ) ) {
	wp_die( __( 'Sorry, you are not allowed to manage options for this site.' ) );
}

$title       = __( 'Media Settings' );
$parent_file = 'options-general.php';

$media_options_help = '<p>' . __( 'You can set maximum sizes for images inserted into your written content; you can also insert an image as Full Size.' ) . '</p>';

if ( ! is_multisite() && ( get_option( 'upload_url_path' ) || ( get_option( 'upload_path' ) != 'wp-content/uploads' && get_option( 'upload_path' ) ) ) ) {
	$media_options_help .= '<p>' . __( 'Uploading Files allows you to choose the folder and path for storing your uploaded files.' ) . '</p>';
}

$media_options_help .= '<p>' . __( 'You must click the Save Changes button at the bottom of the screen for new settings to take effect.' ) . '</p>';

get_current_screen()->add_help_tab(
	array(
		'id'      => 'overview',
		'title'   => __( 'Overview' ),
		'content' => $media_options_help,
	)
);

get_current_screen()->set_help_sidebar(
	'<p><strong>' . __( 'For more information:' ) . '</strong></p>' .
	'<p>' . __( '<a href="https://codex.wordpress.org/Settings_Media_Screen">Documentation on Media Settings</a>' ) . '</p>' .
	'<p>' . __( '<a href="https://wordpress.org/support/">Support</a>' ) . '</p>'
);

include( ABSPATH . 'wp-admin/admin-header.php' );

?>

<div class="wrap">
<h1><?php echo esc_html( $title ); ?></h1>

<form action="options.php" method="post">
<?php settings_fields( 'media' ); ?>

<h2 class="title"><?php _e( 'Image sizes' ); ?></h2>
<p><?php _e( 'The sizes listed below determine the maximum dimensions in pixels to use when adding an image to the Media Library.' ); ?></p>

<table class="form-table" role="presentation">
<tr>
<th scope="row"><?php _e( 'Thumbnail size' ); ?></th>
<td><fieldset><legend class="screen-reader-text"><span><?php _e( 'Thumbnail size' ); ?></span></legend>
<label for="thumbnail_size_w"><?php _e( 'Width' ); ?></label>
<input name="thumbnail_size_w" type="number" step="1" min="0" id="thumbnail_size_w" value="<?php form_option( 'thumbnail_size_w' ); ?>" class="small-text" />
<br />
<label for="thumbnail_size_h"><?php _e( 'Height' ); ?></label>
<input name="thumbnail_size_h" type="number" step="1" min="0" id="thumbnail_size_h" value="<?php form_option( 'thumbnail_size_h' ); ?>" class="small-text" />
</fieldset>
<input name="thumbnail_crop" type="checkbox" id="thumbnail_crop" value="1" <?php checked( '1', get_option( 'thumbnail_crop' ) ); ?>/>
<label for="thumbnail_crop"><?php _e( 'Crop thumbnail to exact dimensions (normally thumbnails are proportional)' ); ?></label>
</td>
</tr>

<tr>
<th scope="row"><?php _e( 'Medium size' ); ?></th>
<td><fieldset><legend class="screen-reader-text"><span><?php _e( 'Medium size' ); ?></span></legend>
<label for="medium_size_w"><?php _e( 'Max Width' ); ?></label>
<input name="medium_size_w" type="number" step="1" min="0" id="medium_size_w" value="<?php form_option( 'medium_size_w' ); ?>" class="small-text" />
<br />
<label for="medium_size_h"><?php _e( 'Max Height' ); ?></label>
<input name="medium_size_h" type="number" step="1" min="0" id="medium_size_h" value="<?php form_option( 'medium_size_h' ); ?>" class="small-text" />
</fieldset></td>
</tr>

<tr>
<th scope="row"><?php _e( 'Large size' ); ?></th>
<td><fieldset><legend class="screen-reader-text"><span><?php _e( 'Large size' ); ?></span></legend>
<label for="large_size_w"><?php _e( 'Max Width' ); ?></label>
<input name="large_size_w" type="number" step="1" min="0" id="large_size_w" value="<?php form_option( 'large_size_w' ); ?>" class="small-text" />
<br />
<label for="large_size_h"><?php _e( 'Max Height' ); ?></label>
<input name="large_size_h" type="number" step="1" min="0" id="large_size_h" value="<?php form_option( 'large_size_h' ); ?>" class="small-text" />
</fieldset></td>
</tr>

<?php do_settings_fields( 'media', 'default' ); ?>
</table>

<?php
/**
 * @global array $wp_settings
 */
if ( isset( $GLOBALS['wp_settings']['media']['embeds'] ) ) :
	?>
<h2 class="title"><?php _e( 'Embeds' ); ?></h2>
<table class="form-table" role="presentation">
	<?php do_settings_fields( 'media', 'embeds' ); ?>
</table>
<?php endif; ?>

<?php if ( ! is_multisite() ) : ?>
<h2 class="title"><?php _e( 'Uploading Files' ); ?></h2>
<table class="form-table" role="presentation">
	<?php
	// If upload_url_path is not the default (empty), and upload_path is not the default ('wp-content/uploads' or empty)
	if ( get_option( 'upload_url_path' ) || ( get_option( 'upload_path' ) != 'wp-content/uploads' && get_option( 'upload_path' ) ) ) :
		?>
<tr>
<th scope="row"><label for="upload_path"><?php _e( 'Store uploads in this folder' ); ?></label></th>
<td><input name="upload_path" type="text" id="upload_path" value="<?php echo esc_attr( get_option( 'upload_path' ) ); ?>" class="regular-text code" />
<p class="description">
		<?php
		/* translators: %s: wp-content/uploads */
		printf( __( 'Default is %s' ), '<code>wp-content/uploads</code>' );
		?>
</p>
</td>
</tr>

<tr>
<th scope="row"><label for="upload_url_path"><?php _e( 'Full URL path to files' ); ?></label></th>
<td><input name="upload_url_path" type="text" id="upload_url_path" value="<?php echo esc_attr( get_option( 'upload_url_path' ) ); ?>" class="regular-text code" />
<p class="description"><?php _e( 'Configuring this is optional. By default, it should be blank.' ); ?></p>
</td>
</tr>
<tr>
<td colspan="2" class="td-full">
<?php else : ?>
<tr>
<td class="td-full">
<?php endif; ?>
<label for="uploads_use_yearmonth_folders">
<input name="uploads_use_yearmonth_folders" type="checkbox" id="uploads_use_yearmonth_folders" value="1"<?php checked( '1', get_option( 'uploads_use_yearmonth_folders' ) ); ?> />
	<?php _e( 'Organize my uploads into month- and year-based folders' ); ?>
</label>
</td>
</tr>

	<?php do_settings_fields( 'media', 'uploads' ); ?>
</table>
<?php endif; ?>

<?php do_settings_sections( 'media' ); ?>

<?php submit_button(); ?>

</form>

</div>

<?php include( ABSPATH . 'wp-admin/admin-footer.php' ); ?>