Media: Improve display and accessibility of meta data in detail view.

* Add a `human_readable_duration` function including tests.
* Add 'pixels' after image width/height.
* Add screen reader text for durations.

Props Presskopp, kiranpotphode, milindmore22, stormrockwell, afercia.
Fixes #39667. 



git-svn-id: https://develop.svn.wordpress.org/trunk@43633 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-includes/functions.php

@@ -322,6 +322,62 @@ function size_format( $bytes, $decimals = 0 ) {
 	return false;
 }
 
+/**
+ * Convert a filelength to human readable format.
+ *
+ * @since 5.0
+ *
+ * @param string $filelength Duration will be in string format (HH:ii:ss) OR (ii:ss).
+ * @return boolean|string A human readable filelength string, false on failure.
+ */
+function human_readable_duration( $filelength = '' ) {
+	// Return false if filelength is empty or not in format.
+	if ( ( empty( $filelength ) || ! is_string( $filelength ) ) ) {
+		return false;
+	}
+
+	// Validate filelength format.
+	if ( ! ( (bool) preg_match( '/^(([0-3]?[0-9])|([2][0-3])):([0-5]?[0-9])(:([0-5]?[0-9]))?$/', $filelength ) ) ) {
+		return false;
+	}
+
+	$human_readable_duration = array();
+
+	// Extract duration.
+	$durations      = array_reverse( explode( ':', $filelength ) );
+	$duration_count = count( $durations );
+
+	if ( 3 === $duration_count ) {
+		// Three parts: hours, minutes & seconds.
+		list( $second, $minute, $hour ) = $durations;
+	} elseif ( 2 === $duration_count ) {
+		// Two parts: minutes & seconds.
+		list( $second, $minute ) = $durations;
+	} else {
+		return false;
+	}
+
+	// Add the hour part to the string.
+	if ( ! empty( $hour ) && is_numeric( $hour ) ) {
+		/* translators: Time duration in hour or hours. */
+		$human_readable_duration[] = sprintf( _n( '%s hour', '%s hours', $hour ), (int) $hour );
+	}
+
+	// Add the minute part to the string.
+	if ( ! empty( $minute ) && is_numeric( $minute ) ) {
+		/* translators: Time duration in minute or minutes. */
+		$human_readable_duration[] = sprintf( _n( '%s minute', '%s minutes', $minute ), (int) $minute );
+	}
+
+	// Add the second part to the string.
+	if ( ! empty( $second ) && is_numeric( $second ) ) {
+		/* translators: Time duration in second or seconds. */
+		$human_readable_duration[] = sprintf( _n( '%s second', '%s seconds', $second ), (int) $second );
+	}
+
+	return implode( ', ', $human_readable_duration );
+}
+
 /**
  * Get the week start and end from the datetime or date string from MySQL.
  *