Added a fictive parameter "-source-frame-range" for selecting one or …

…more

image frames in transcoding multi-image file formats. The parameter is
translated in actual frame selection syntax supported by ImageMagick.

Use the more portable "escapeshellarg" function in selecting the first
image frame in still generation.

sites/all/modules/mediamosa_tool_image/mediamosa_tool_image.class.inc

@@ -73,9 +73,9 @@ class mediamosa_tool_image {
       // Source.
       $mediafile_source = mediamosa_storage::get_realpath_mediafile($mediafile_id_source);
 
-      // Select the first image in a multi-image file format such as tiff. (mind the shell escaping for [])
-      // This is a nop for single-image file formats.
-      $mediafile_source .= '"[0]"';
+      // Select the first image frame in a multi-image file format such as tiff.
+      // This is a no-op for single-image file formats.
+      $mediafile_source .= escapeshellarg('[0]');
 
       // Dest.
       $mediafile_dest = mediamosa_storage::get_realpath_temporary_file($job_info['job_id'] . sprintf(mediamosa_settings::STILL_EXTENSION, 1) . '.jpeg');
@@ -105,11 +105,27 @@ class mediamosa_tool_image {
    */
   public static function get_transcode_exec($options) {
 
+    $parameter_string = $options['parameter_string'];
+
+    // Convert a fictive "-source-frame-range" parameter to an actual frame range selection.
+    $optional_source_frame_range = '';
+
+    $parameters = explode(' ',$options['parameter_string']);
+    $range_index = array_search('-source-frame-range',$parameters);
+
+    if ($range_index !== False) {
+      list(,$range_value) = array_splice($parameters,$range_index,2);
+
+      $optional_source_frame_range = escapeshellarg('[' . $range_value . ']');
+
+      $parameter_string = implode(' ',$parameters);
+    }
+
     // Build the values.
     $execution_string_options = array(
-      '@mediafile_source' => $options['location_source_file'],
+      '@mediafile_source' => $options['location_source_file'] . $optional_source_frame_range,
       '@mediafile_dest' => $options['location_dest_file'] . '.' . $options['file_extension'],
-      '@parameter_string' => $options['parameter_string'],
+      '@parameter_string' => $parameter_string,
       '@status_file' => $options['status_file'],
       '@working_dir' => dirname($options['location_dest_file']),
     );