Add LIBMTP_Get_Thumbnail_Format to get thumbnail format of a file.

src/libmtp.c

 /**
  * \file libmtp.c
  *
  * Copyright (C) 2005-2011 Linus Walleij <triad@df.lth.se>
  * Copyright (C) 2005-2008 Richard A. Low <richard@wentnet.com>
  * Copyright (C) 2007 Ted Bullock <tbullock@canada.com>
  * Copyright (C) 2007 Tero Saarni <tero.saarni@gmail.com>
  * Copyright (C) 2008 Florent Mertens <flomertens@gmail.com>
  *
  * This library is free software; you can redistribute it and/or
@@ skipping 8944 matching lines @@
   PTPParams *params = (PTPParams *) device->params;
   uint16_t ret;
 
   ret = ptp_getthumb(params, id, data, size);
   if (ret == PTP_RC_OK)
       return 0;
   return -1;
 }
 
 /**
+ * Get thumbnail format of a file.
+ * @param device a pointer to the device to get thumbnail format of.
+ * @param id the object ID of the file to get thumbnail format of.
+ * @return 0 on success, any other value means failure.
+ */
+int LIBMTP_Get_Thumbnail_Format(LIBMTP_mtpdevice_t *device, uint32_t const id,
+                                uint16_t *format)
+{
+  PTPParams *params = (PTPParams *) device->params;
+  uint16_t ret;
+
+  PTPObjectInfo object_info;
+  ret = ptp_getobjectinfo(params, id, &object_info);
+  if (ret != PTP_RC_OK)
+    return -1;
+
+  *format = object_info.ThumbFormat;
+  return 0;
+}
+
+/**
  * This routine updates an album based on the metadata
  * supplied. If the <code>tracks</code> field of the metadata
  * contains a track listing, these tracks will be added to the
  * album in place of those already present, i.e. the
  * previous track listing will be deleted.
  * @param device a pointer to the device to create the new album on.
  * @param metadata the metadata for the album to be updated.
  *                 notice that the field <code>album_id</code>
  *                 must contain the apropriate album ID.
  * @return 0 on success, any other value means failure.
@@ skipping 44 matching lines @@
  * @param device the device which may have a cache to which the object should be updated.
  * @param object_id the object to update.
  */
 static void update_metadata_cache(LIBMTP_mtpdevice_t *device, uint32_t object_id)
 {
   PTPParams *params = (PTPParams *)device->params;
 
   ptp_remove_object_from_cache(params, object_id);
   add_object_to_cache(device, object_id);
 }