wpseek.com
A WordPress-centric search engine for devs and theme authors



wp_get_image_mime › WordPress Function

Since4.7.1
Deprecatedn/a
wp_get_image_mime ( $file )
Parameters:
  • (string) $file Full path to the file.
    Required: Yes
Returns:
  • (string|false) The actual mime type or false if the type cannot be determined.
Defined at:
Codex:
Change Log:
  • 5.8.0
  • 6.5.0

Returns the real mime type of an image file.

This depends on exif_imagetype() or getimagesize() to determine real mime types.


Source

function wp_get_image_mime( $file ) {
	/*
	 * Use exif_imagetype() to check the mimetype if available or fall back to
	 * getimagesize() if exif isn't available. If either function throws an Exception
	 * we assume the file could not be validated.
	 */
	try {
		if ( is_callable( 'exif_imagetype' ) ) {
			$imagetype = exif_imagetype( $file );
			$mime      = ( $imagetype ) ? image_type_to_mime_type( $imagetype ) : false;
		} elseif ( function_exists( 'getimagesize' ) ) {
			// Don't silence errors when in debug mode, unless running unit tests.
			if ( defined( 'WP_DEBUG' ) && WP_DEBUG
				&& ! defined( 'WP_RUN_CORE_TESTS' )
			) {
				// Not using wp_getimagesize() here to avoid an infinite loop.
				$imagesize = getimagesize( $file );
			} else {
				$imagesize = @getimagesize( $file );
			}

			$mime = ( isset( $imagesize['mime'] ) ) ? $imagesize['mime'] : false;
		} else {
			$mime = false;
		}

		if ( false !== $mime ) {
			return $mime;
		}

		$magic = file_get_contents( $file, false, null, 0, 12 );

		if ( false === $magic ) {
			return false;
		}

		/*
		 * Add WebP fallback detection when image library doesn't support WebP.
		 * Note: detection values come from LibWebP, see
		 * https://github.com/webmproject/libwebp/blob/master/imageio/image_dec.c#L30
		 */
		$magic = bin2hex( $magic );
		if (
			// RIFF.
			( str_starts_with( $magic, '52494646' ) ) &&
			// WEBP.
			( 16 === strpos( $magic, '57454250' ) )
		) {
			$mime = 'image/webp';
		}

		/**
		 * Add AVIF fallback detection when image library doesn't support AVIF.
		 *
		 * Detection based on section 4.3.1 File-type box definition of the ISO/IEC 14496-12
		 * specification and the AV1-AVIF spec, see https://aomediacodec.github.io/av1-avif/v1.1.0.html#brands.
		 */

		// Divide the header string into 4 byte groups.
		$magic = str_split( $magic, 8 );

		if (
			isset( $magic[1] ) &&
			isset( $magic[2] ) &&
			'ftyp' === hex2bin( $magic[1] ) &&
			( 'avif' === hex2bin( $magic[2] ) || 'avis' === hex2bin( $magic[2] ) )
		) {
			$mime = 'image/avif';
		}
	} catch ( Exception $e ) {
		$mime = false;
	}

	return $mime;
}