Media: Allow filtering audio file metadata in wp_read_audio_metadata().

This changeset introduces the `wp_read_audio_metadata` hook which allows to filter metadata extracted from an uploaded audio file.

This brings consistency with corresponding filters available for image and video file types:

- `wp_read_image_metadata` added in [6313] / #5162.
- `wp_read_video_metadata` added in [41746] / #35218.

Props luigipulcini, SergeyBiryukov, mukesh27.
Fixes #55828.


git-svn-id: https://develop.svn.wordpress.org/trunk@53764 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-admin/includes/media.php

@@ -3697,7 +3697,22 @@ function wp_read_audio_metadata( $file ) {
 
 	wp_add_id3_tag_data( $metadata, $data );
 
-	return $metadata;
+	$file_format = isset( $metadata['fileformat'] ) ? $metadata['fileformat'] : null;
+
+	/**
+	 * Filters the array of metadata retrieved from an audio file.
+	 *
+	 * In core, usually this selection is what is stored.
+	 * More complete data can be parsed from the `$data` parameter.
+	 *
+	 * @since 6.1.0
+	 *
+	 * @param array  $metadata       Filtered Audio metadata.
+	 * @param string $file           Path to audio file.
+	 * @param string $file_format    File format of audio, as analyzed by getID3.
+	 * @param array  $data           Raw metadata from getID3.
+	 */
+	return apply_filters( 'wp_read_audio_metadata', $metadata, $file, $file_format, $data );
 }
 
 /**