libmtp.c

来自「Media transfer protocol implementation o」· C语言 代码 · 共 2,016 行 · 第 1/5 页

/**
 * Helper function to extract a unicode property off a device.
 * This is the standard way of retrieveing unicode device
 * properties as described by the PTP spec.
 * @param device a pointer to the device to get the property from.
 * @param unicstring a pointer to a pointer that will hold the
 *        property after this call is completed.
 * @param property the property to retrieve.
 * @return 0 on success, any other value means failure.
 */
static int get_device_unicode_property(LIBMTP_mtpdevice_t *device,
				       char **unicstring, uint16_t property)
{
  PTPPropertyValue propval;
  PTPParams *params = (PTPParams *) device->params;
  uint16_t *tmp;
  int i;

  if (!ptp_property_issupported(params, property)) {
    return -1;
  }

  // Unicode strings are 16bit unsigned integer arrays.
  if (ptp_getdevicepropvalue(params,
			     property,
			     &propval,
			     PTP_DTC_AUINT16) != PTP_RC_OK) {
    return -1;
  }

  // Extract the actual array.
  // printf("Array of %d elements\n", propval.a.count);
  tmp = malloc((propval.a.count + 1)*sizeof(uint16_t));
  for (i = 0; i < propval.a.count; i++) {
    tmp[i] = propval.a.v[i].u16;
    // printf("%04x ", tmp[i]);
  }
  tmp[propval.a.count] = 0x0000U;
  free(propval.a.v);

  *unicstring = utf16_to_utf8(device, tmp);

  free(tmp);

  return 0;
}

/**
 * This function returns the secure time as an XML document string from
 * the device.
 * @param device a pointer to the device to get the secure time for.
 * @param sectime the secure time string as an XML document or NULL if the call
 *         failed or the secure time property is not supported. This string
 *         must be <code>free()</code>:ed by the caller after use.
 * @return 0 on success, any other value means failure.
 */
int LIBMTP_Get_Secure_Time(LIBMTP_mtpdevice_t *device, char ** const sectime)
{
  return get_device_unicode_property(device, sectime, PTP_DPC_MTP_SecureTime);
}

/**
 * This function returns the device (public key) certificate as an
 * XML document string from the device.
 * @param device a pointer to the device to get the device certificate for.
 * @param devcert the device certificate as an XML string or NULL if the call
 *        failed or the device certificate property is not supported. This
 *        string must be <code>free()</code>:ed by the caller after use.
 * @return 0 on success, any other value means failure.
 */
int LIBMTP_Get_Device_Certificate(LIBMTP_mtpdevice_t *device, char ** const devcert)
{
  return get_device_unicode_property(device, devcert, PTP_DPC_MTP_DeviceCertificate);
}

/**
 * This function retrieves a list of supported file types, i.e. the file
 * types that this device claims it supports, e.g. audio file types that
 * the device can play etc. This list is mitigated to
 * inlcude the file types that libmtp can handle, i.e. it will not list
 * filetypes that libmtp will handle internally like playlists and folders.
 * @param device a pointer to the device to get the filetype capabilities for.
 * @param filetypes a pointer to a pointer that will hold the list of
 *        supported filetypes if the call was successful. This list must
 *        be <code>free()</code>:ed by the caller after use.
 * @param length a pointer to a variable that will hold the length of the
 *        list of supported filetypes if the call was successful.
 * @return 0 on success, any other value means failure.
 * @see LIBMTP_Get_Filetype_Description()
 */
int LIBMTP_Get_Supported_Filetypes(LIBMTP_mtpdevice_t *device, uint16_t ** const filetypes,
				  uint16_t * const length)
{
  PTPParams *params = (PTPParams *) device->params;
  uint16_t *localtypes;
  uint16_t localtypelen;
  uint32_t i;

  // This is more memory than needed if there are unknown types, but what the heck.
  localtypes = (uint16_t *) malloc(params->deviceinfo.ImageFormats_len * sizeof(uint16_t));
  localtypelen = 0;

  for (i=0;i<params->deviceinfo.ImageFormats_len;i++) {
    uint16_t localtype = map_ptp_type_to_libmtp_type(params->deviceinfo.ImageFormats[i]);
    if (localtype != LIBMTP_FILETYPE_UNKNOWN) {
      localtypes[localtypelen] = localtype;
      localtypelen++;
    }
  }

  *filetypes = localtypes;
  *length = localtypelen;

  return 0;
}

/**
 * This creates a new file metadata structure and allocates memory
 * for it. Notice that if you add strings to this structure they
 * will be freed by the corresponding <code>LIBMTP_destroy_file_t</code>
 * operation later, so be careful of using strdup() when assigning
 * strings, e.g.:
 *
 * <pre>
 * LIBMTP_file_t *file = LIBMTP_new_file_t();
 * file->filename = strdup(namestr);
 * ....
 * LIBMTP_destroy_file_t(file);
 * </pre>
 *
 * @return a pointer to the newly allocated metadata structure.
 * @see LIBMTP_destroy_file_t()
 */
LIBMTP_file_t *LIBMTP_new_file_t(void)
{
  LIBMTP_file_t *new = (LIBMTP_file_t *) malloc(sizeof(LIBMTP_file_t));
  if (new == NULL) {
    return NULL;
  }
  new->filename = NULL;
  new->filesize = 0;
  new->filetype = LIBMTP_FILETYPE_UNKNOWN;
  new->next = NULL;
  return new;
}

/**
 * This destroys a file metadata structure and deallocates the memory
 * used by it, including any strings. Never use a file metadata
 * structure again after calling this function on it.
 * @param file the file metadata to destroy.
 * @see LIBMTP_new_file_t()
 */
void LIBMTP_destroy_file_t(LIBMTP_file_t *file)
{
  if (file == NULL) {
    return;
  }
  if (file->filename != NULL)
    free(file->filename);
  free(file);
  return;
}

/**
* THIS FUNCTION IS DEPRECATED. PLEASE UPDATE YOUR CODE IN ORDER
 * NOT TO USE IT.
 * @see LIBMTP_Get_Filelisting_With_Callback()
 */
LIBMTP_file_t *LIBMTP_Get_Filelisting(LIBMTP_mtpdevice_t *device)
{
  printf("WARNING: LIBMTP_Get_Filelisting() is deprecated.\n");
  printf("WARNING: please update your code to use LIBMTP_Get_Filelisting_With_Callback()\n");
  return LIBMTP_Get_Filelisting_With_Callback(device, NULL, NULL);
}

/**
 * This returns a long list of all files available
 * on the current MTP device. Typical usage:
 *
 * <pre>
 * LIBMTP_file_t *filelist;
 *
 * filelist = LIBMTP_Get_Filelisting_With_Callback(device, callback, data);
 * while (filelist != NULL) {
 *   LIBMTP_file_t *tmp;
 *
 *   // Do something on each element in the list here...
 *   tmp = filelist;
 *   filelist = filelist->next;
 *   LIBMTP_destroy_file_t(tmp);
 * }
 * </pre>
 *
 * @param device a pointer to the device to get the file listing for.
 * @param callback a function to be called during the tracklisting retrieveal
 *               for displaying progress bars etc, or NULL if you don't want
 *               any callbacks.
 * @param data a user-defined pointer that is passed along to
 *             the <code>progress</code> function in order to
 *             pass along some user defined data to the progress
 *             updates. If not used, set this to NULL.
 * @return a list of files that can be followed using the <code>next</code>
 *         field of the <code>LIBMTP_file_t</code> data structure.
 *         Each of the metadata tags must be freed after use, and may
 *         contain only partial metadata information, i.e. one or several
 *         fields may be NULL or 0.
 * @see LIBMTP_Get_Filemetadata()
 */
LIBMTP_file_t *LIBMTP_Get_Filelisting_With_Callback(LIBMTP_mtpdevice_t *device,
                                                    LIBMTP_progressfunc_t const callback,
                                                    void const * const data)
{
  uint32_t i = 0;
  LIBMTP_file_t *retfiles = NULL;
  LIBMTP_file_t *curfile = NULL;
  PTPParams *params = (PTPParams *) device->params;

  // Get all the handles if we haven't already done that
  if (params->handles.Handler == NULL) {
    flush_handles(device);
  }

  for (i = 0; i < params->handles.n; i++) {

    if (callback != NULL)
      callback(i, params->handles.n, data);

    LIBMTP_file_t *file;
    PTPObjectInfo oi;

    if (ptp_getobjectinfo(params, params->handles.Handler[i], &oi) == PTP_RC_OK) {

      if (oi.ObjectFormat == PTP_OFC_Association) {
	// MTP use thesis object format for folders which means
	// these "files" will turn up on a folder listing instead.
	continue;
      }

      // Allocate a new file type
      file = LIBMTP_new_file_t();

      file->parent_id = oi.ParentObject;

      // Set the filetype
      file->filetype = map_ptp_type_to_libmtp_type(oi.ObjectFormat);

      // Original file-specific properties
      file->filesize = oi.ObjectCompressedSize;
      if (oi.Filename != NULL) {
	file->filename = strdup(oi.Filename);
      }

      // This is some sort of unique ID so we can keep track of the track.
      file->item_id = params->handles.Handler[i];

      // Add track to a list that will be returned afterwards.
      if (retfiles == NULL) {
	retfiles = file;
	curfile = file;
      } else {
	curfile->next = file;
	curfile = file;
      }

      // Call listing callback
      // double progressPercent = (double)i*(double)100.0 / (double)params->handles.n;

    } else {
      printf("LIBMTP panic: Found a bad handle, trying to ignore it.\n");
    }

  } // Handle counting loop
  return retfiles;
}

/**
 * This function retrieves the metadata for a single file off
 * the device.
 *
 * Do not call this function repeatedly! The file handles are linearly
 * searched O(n) and the call may involve (slow) USB traffic, so use
 * <code>LIBMTP_Get_Filelisting()</code> and cache the file, preferably
 * as an efficient data structure such as a hash list.
 *
 * @param device a pointer to the device to get the file metadata from.
 * @param fileid the object ID of the file that you want the metadata for.
 * @return a metadata entry on success or NULL on failure.
 * @see LIBMTP_Get_Filelisting()
 */
LIBMTP_file_t *LIBMTP_Get_Filemetadata(LIBMTP_mtpdevice_t *device, uint32_t const fileid)
{
  uint32_t i = 0;
  PTPParams *params = (PTPParams *) device->params;

  // Get all the handles if we haven't already done that
  if (params->handles.Handler == NULL) {
    flush_handles(device);
  }

  for (i = 0; i < params->handles.n; i++) {
    LIBMTP_file_t *file;
    PTPObjectInfo oi;

    // Is this the file we're looking for?
    if (params->handles.Handler[i] != fileid) {
      continue;
    }

    if (ptp_getobjectinfo(params, params->handles.Handler[i], &oi) == PTP_RC_OK) {

      if (oi.ObjectFormat == PTP_OFC_Association) {
	// MTP use thesis object format for folders which means
	// these "files" will turn up on a folder listing instead.
	return NULL;
      }

      // Allocate a new file type
      file = LIBMTP_new_file_t();

      file->parent_id = oi.ParentObject;

      // Set the filetype
      file->filetype = map_ptp_type_to_libmtp_type(oi.ObjectFormat);

      // Original file-specific properties
      file->filesize = oi.ObjectCompressedSize;
      if (oi.Filename != NULL) {
	file->filename = strdup(oi.Filename);
      }

      // This is some sort of unique ID so we can keep track of the track.
      file->item_id = params->handles.Handler[i];

      return file;
    } else {
      return NULL;
    }

  }
  return NULL;
}

/**
 * This creates a new track metadata structure and allocates memory
 * for it. Notice that if you add strings to this structure they
 * will be freed by the corresponding <code>LIBMTP_destroy_track_t</code>
 * operation later, so be careful of using strdup() when assigning
 * strings, e.g.:
 *
 * <pre>
 * LIBMTP_track_t *track = LIBMTP_new_track_t();
 * track->title = strdup(titlestr);
 * ....
 * LIBMTP_destroy_track_t(track);
 * </pre>
 *
 * @return a pointer to the newly allocated metadata structure.
 * @see LIBMTP_destroy_track_t()
 */
LIBMTP_track_t *LIBMTP_new_track_t(void)
{
  LIBMTP_track_t *new = (LIBMTP_track_t *) malloc(sizeof(LIBMTP_track_t));
  if (new == NULL) {
    return NULL;
  }
  new->title = NULL;
  new->artist = NULL;
  new->album = NULL;
  new->genre = NULL;
  new->date = NULL;
  new->filename = NULL;
  new->duration = 0;
  new->tracknumber = 0;
  new->filesize = 0;
  new->filetype = LIBMTP_FILETYPE_UNKNOWN;
  new->samplerate = 0;
  new->nochannels = 0;
  new->wavecodec = 0;
  new->bitrate = 0;
  new->bitratetype = 0;
  new->rating = 0;
  new->usecount = 0;
  new->next = NULL;
  return new;
}

/**
 * This destroys a track metadata structure and deallocates the memory
 * used by it, including any strings. Never use a track metadata
 * structure again after calling this function on it.
 * @param track the track metadata to destroy.
 * @see LIBMTP_new_track_t()
 */
void LIBMTP_destroy_track_t(LIBMTP_track_t *track)
{
  if (track == NULL) {
    return;
  }
  if (track->title != NULL)
    free(track->title);
  if (track->artist != NULL)
    free(track->artist);
  if (track->album != NULL)