libgphoto2 photo camera library (libgphoto2) API 2.5.29

Data Structures | Macros | Functions
gphoto2-camera.c File Reference
`#include "config.h"`
`#include <gphoto2/gphoto2-camera.h>`
`#include <stdlib.h>`
`#include <string.h>`
`#include <stdarg.h>`
`#include <stdio.h>`
`#include <ltdl.h>`
`#include <gphoto2/gphoto2-result.h>`
`#include <gphoto2/gphoto2-library.h>`
`#include <gphoto2/gphoto2-port-log.h>`
`#include "libgphoto2/i18n.h"`

## Data Structures
struct | _CameraPrivateCore

## Macros
#define | CAMERA_UNUSED(c, ctx)
#define | CR(c, result, ctx)
#define | CHECK_OPEN(c, ctx)
#define | CHECK_CLOSE(c, ctx)
#define | CRS(c, res, ctx)
#define | CRSL(c, res, ctx, list)
#define | CHECK_RESULT_OPEN_CLOSE(c, result, ctx)
#define | CHECK_INIT(c, ctx)

## Functions
int | gp_camera_exit (Camera *camera, GPContext *context)
int | gp_camera_new (Camera **camera)
int | gp_camera_set_abilities (Camera *camera, CameraAbilities abilities)
| Sets the camera abilities. More...
int | gp_camera_get_abilities (Camera *camera, CameraAbilities *abilities)
int | gp_camera_get_port_info (Camera *camera, GPPortInfo *info)
int | gp_camera_set_port_info (Camera *camera, GPPortInfo info)
int | gp_camera_set_port_speed (Camera *camera, int speed)
int | gp_camera_get_port_speed (Camera *camera)
int | gp_camera_ref (Camera *camera)
int | gp_camera_unref (Camera *camera)
int | gp_camera_free (Camera *camera)
int | gp_camera_autodetect (CameraList *list, GPContext *context)
int | gp_camera_init (Camera *camera, GPContext *context)
int | gp_camera_get_config (Camera *camera, CameraWidget **window, GPContext *context)
int | gp_camera_get_single_config (Camera *camera, const char *name, CameraWidget **widget, GPContext *context)
int | gp_camera_list_config (Camera *camera, CameraList *list, GPContext *context)
int | gp_camera_set_config (Camera *camera, CameraWidget *window, GPContext *context)
int | gp_camera_set_single_config (Camera *camera, const char *name, CameraWidget *widget, GPContext *context)
int | gp_camera_get_summary (Camera *camera, CameraText *summary, GPContext *context)
int | gp_camera_get_manual (Camera *camera, CameraText *manual, GPContext *context)
int | gp_camera_get_about (Camera *camera, CameraText *about, GPContext *context)
int | gp_camera_capture (Camera *camera, CameraCaptureType type, CameraFilePath *path, GPContext *context)
int | gp_camera_trigger_capture (Camera *camera, GPContext *context)
int | gp_camera_capture_preview (Camera *camera, CameraFile *file, GPContext *context)
int | gp_camera_wait_for_event (Camera *camera, int timeout, CameraEventType *eventtype, void **eventdata, GPContext *context)
int | gp_camera_folder_list_files (Camera *camera, const char *folder, CameraList *list, GPContext *context)
int | gp_camera_folder_list_folders (Camera *camera, const char *folder, CameraList *list, GPContext *context)
int | gp_camera_folder_delete_all (Camera *camera, const char *folder, GPContext *context)
int | gp_camera_folder_put_file (Camera *camera, const char *folder, const char *filename, CameraFileType type, CameraFile *file, GPContext *context)
int | gp_camera_file_get_info (Camera *camera, const char *folder, const char *file, CameraFileInfo *info, GPContext *context)
int | gp_camera_file_set_info (Camera *camera, const char *folder, const char *file, CameraFileInfo info, GPContext *context)
int | gp_camera_file_get (Camera *camera, const char *folder, const char *file, CameraFileType type, CameraFile *camera_file, GPContext *context)
int | gp_camera_file_read (Camera *camera, const char *folder, const char *file, CameraFileType type, uint64_t offset, char *buf, uint64_t *size, GPContext *context)
int | gp_camera_file_delete (Camera *camera, const char *folder, const char *file, GPContext *context)
int | gp_camera_folder_make_dir (Camera *camera, const char *folder, const char *name, GPContext *context)
int | gp_camera_folder_remove_dir (Camera *camera, const char *folder, const char *name, GPContext *context)
int | gp_camera_get_storageinfo (Camera *camera, CameraStorageInformation **sifs, int *nrofsifs, GPContext *context)
| Gets information on the camera attached storage. More...
void | gp_camera_set_timeout_funcs (Camera *camera, CameraTimeoutStartFunc start_func, CameraTimeoutStopFunc stop_func, void *data)
int | gp_camera_start_timeout (Camera *camera, unsigned int timeout, CameraTimeoutFunc func)
void | gp_camera_stop_timeout (Camera *camera, unsigned int id)

## Detailed Description

Implement Camera object representing a camera attached to the system.

Author
  Copyright 2000 Scott Fritzinger
  Copyright 2001-2002 Lutz Mueller lutz@.nosp@m.user.nosp@m.s.sf..nosp@m.net

Note
  This library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.
  This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.
  You should have received a copy of the GNU Lesser General Public License along with this library; if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

## Macro Definition Documentation

## ◆ CAMERA_UNUSED

#define CAMERA_UNUSED | ( |  | c,
|  |  | ctx
| ) |  |

Value:
{ \
(c)->pc->used--; \
if (!(c)->pc->used) { \
if ((c)->pc->exit_requested) \
gp_camera_exit ((c), (ctx)); \
if (!(c)->pc->ref_count) \
gp_camera_free (c); \
} \
}

## ◆ CHECK_CLOSE

#define CHECK_CLOSE | ( |  | c,
|  |  | ctx
| ) |  |

Value:
{ \
if ((c)->functions->post_func) { \
int r3 = (c)->functions->post_func (c,ctx); \
if (r3 < 0) { \
CAMERA_UNUSED (c,ctx); \
return (r3); \
} \
} \
}

## ◆ CHECK_INIT

#define CHECK_INIT | ( |  | c,
|  |  | ctx
| ) |  |

Value:
{ \
if ((c)->pc->used) \
return (GP_ERROR_CAMERA_BUSY); \
(c)->pc->used++; \
if (!(c)->pc->lh) \
CR((c), gp_camera_init (c, ctx), ctx); \
}
gp_camera_init
int gp_camera_init(Camera *camera, GPContext *context)
Definition: gphoto2-camera.c:668
GP_ERROR_CAMERA_BUSY
#define GP_ERROR_CAMERA_BUSY
The camera is already busy.
Definition: gphoto2-result.h:90

## ◆ CHECK_OPEN

#define CHECK_OPEN | ( |  | c,
|  |  | ctx
| ) |  |

Value:
{ \
if ((c)->functions->pre_func) { \
int r2 = (c)->functions->pre_func (c,ctx); \
if (r2 < 0) { \
CAMERA_UNUSED (c,ctx); \
return (r2); \
} \
} \
}

## ◆ CHECK_RESULT_OPEN_CLOSE

#define CHECK_RESULT_OPEN_CLOSE | ( |  | c,
|  |  | result,
|  |  | ctx
| ) |  |

Value:
{ \
int r6; \
\
CHECK_OPEN (c,ctx); \
r6 = (result); \
if (r6 < 0) { \
GP_LOG_E ("'%s' failed: %d", #result, r6); \
CHECK_CLOSE (c,ctx); \
CAMERA_UNUSED (c,ctx); \
return (r6); \
} \
CHECK_CLOSE (c,ctx); \
}

## ◆ CR

#define CR | ( |  | c,
|  |  | result,
|  |  | ctx
| ) |  |

Value:
{ \
int r1 = (result); \
\
if (r1 < 0) { \
/* libgphoto2_port doesn't have a GPContext */ \
gp_context_error ((ctx), _("An error occurred " \
"in the io-library ('%s'): %s"), \
gp_port_result_as_string (r1), \
gp_port_get_error ((c) ? (c)->port : NULL)); \
if (c) \
CAMERA_UNUSED (c,ctx); \
return (r1); \
} \
}
gp_port_result_as_string
const char * gp_port_result_as_string(int result)
Definition: gphoto2-port-result.c:38
gp_port_get_error
const char * gp_port_get_error(GPPort *port)
Get verbose port error message.
Definition: gphoto2-port.c:1197

## ◆ CRS

#define CRS | ( |  | c,
|  |  | res,
|  |  | ctx
| ) |  |

Value:
{ \
int r4 = (res); \
\
if (r4 < 0) { \
CAMERA_UNUSED (c,ctx); \
return (r4); \
} \
}

## ◆ CRSL

#define CRSL | ( |  | c,
|  |  | res,
|  |  | ctx,
|  |  | list
| ) |  |

Value:
{ \
int r5 = (res); \
\
if (r5 < 0) { \
CAMERA_UNUSED (c,ctx); \
gp_list_free (list); \
return (r5); \
} \
}

## Function Documentation

## ◆ gp_camera_autodetect()

int gp_camera_autodetect | ( | CameraList * | list,
|  | GPContext * | context
| ) |  |

Autodetect all detectable camera

Parameters

  list | a CameraList that receives the autodetected cameras
  context | a GPContext

Returns
  the number of cameras detected (0 to n) or a gphoto2 error code (<0)

This camera will autodetected all cameras that can be autodetected. This will for instance detect all USB cameras.

CameraList *list; gp_list_new (&list); gp_camera_autodetect (list, context); ... done! ...

References gp_abilities_list_detect(), gp_abilities_list_free(), gp_abilities_list_load(), gp_abilities_list_new(), gp_list_append(), gp_list_count(), gp_list_free(), gp_list_get_name(), gp_list_get_value(), gp_list_new(), GP_OK, gp_port_info_list_count(), gp_port_info_list_free(), gp_port_info_list_load(), and gp_port_info_list_new().

## ◆ gp_camera_capture()

int gp_camera_capture | ( | Camera * | camera,
|  | CameraCaptureType | type,
|  | CameraFilePath * | path,
|  | GPContext * | context
| ) |  |

Captures an image, movie, or sound clip depending on the given `type`.

Parameters

  camera | a Camera
  type | a CameraCaptureType
  path | a CameraFilePath
  context | a GPContext

Returns
  a gphoto2 error code

The resulting file will be stored on the camera. The location gets stored in `path`. The file can then be downloaded using gp_camera_file_get.

## ◆ gp_camera_capture_preview()

int gp_camera_capture_preview | ( | Camera * | camera,
|  | CameraFile * | file,
|  | GPContext * | context
| ) |  |

Captures a preview that won't be stored on the camera but returned in supplied file.

Parameters

  camera | a Camera
  file | a CameraFile
  context | a GPContext

Returns
  a gphoto2 error code

For example, you could use gp_capture_preview() for taking some sample pictures before calling gp_capture().

## ◆ gp_camera_exit()

int gp_camera_exit | ( | Camera * | camera,
|  | GPContext * | context
| ) |  |

Close connection to camera.

Parameters

  camera | a Camera object
  context | a GPContext object

Returns
  a gphoto2 error code.

Closes a connection to the camera and therefore gives other application the possibility to access the camera, too.

It is recommended that you call this function when you currently don't need the camera. The camera will get reinitialized by gp_camera_init() automatically if you try to access the camera again.

References _CameraFunctions::exit, gp_camera_stop_timeout(), gp_filesystem_reset(), GP_OK, gp_port_close(), gp_port_open(), CameraAbilities::model, and _Camera::pc.

Referenced by gp_camera_free(), gp_camera_set_abilities(), and gp_camera_set_port_speed().

## ◆ gp_camera_file_delete()

int gp_camera_file_delete | ( | Camera * | camera,
|  | const char * | folder,
|  | const char * | file,
|  | GPContext * | context
| ) |  |

Deletes the file from `folder`.

Parameters

  camera | a Camera
  folder | a folder
  file | the name of a file
  context | a GPContext

Returns
  a gphoto2 error code

## ◆ gp_camera_file_get()

int gp_camera_file_get | ( | Camera * | camera,
|  | const char * | folder,
|  | const char * | file,
|  | CameraFileType | type,
|  | CameraFile * | camera_file,
|  | GPContext * | context
| ) |  |

Retrieves a file from the Camera.

Parameters

  camera | a Camera
  folder | a folder
  file | the name of a file
  type | the CameraFileType
  camera_file | a CameraFile
  context | a GPContext

Returns
  a gphoto2 error code

## ◆ gp_camera_file_get_info()

int gp_camera_file_get_info | ( | Camera * | camera,
|  | const char * | folder,
|  | const char * | file,
|  | CameraFileInfo * | info,
|  | GPContext * | context
| ) |  |

Retrieves information about a file.

Parameters

  camera | a Camera
  folder | a folder
  file | the name of the file
  info |
  context | a GPContext

Returns
  a gphoto2 error code

## ◆ gp_camera_file_read()

int gp_camera_file_read | ( | Camera * | camera,
|  | const char * | folder,
|  | const char * | file,
|  | CameraFileType | type,
|  | uint64_t | offset,
|  | char * | buf,
|  | uint64_t * | size,
|  | GPContext * | context
| ) |  |

Reads a file partially from the Camera.

Parameters

  camera | a Camera
  folder | a folder
  file | the name of a file
  type | the CameraFileType
  offset | the offset into the camera file
  data | the buffer receiving the data
  size | the size to be read and that was read. (Note: size should not exceed 32 bits)
  context | a GPContext

Returns
  a gphoto2 error code

## ◆ gp_camera_file_set_info()

int gp_camera_file_set_info | ( | Camera * | camera,
|  | const char * | folder,
|  | const char * | file,
|  | CameraFileInfo | info,
|  | GPContext * | context
| ) |  |

Sets some file properties like name or permissions.

Parameters

  camera | a Camera
  folder | a folder
  file | the name of a file
  info | the CameraFileInfo
  context | a GPContext

Returns
  a gphoto2 error code

## ◆ gp_camera_folder_delete_all()

int gp_camera_folder_delete_all | ( | Camera * | camera,
|  | const char * | folder,
|  | GPContext * | context
| ) |  |

Deletes all files in a given `folder`.

Parameters

  camera | a Camera
  folder | a folder
  context | a GPContext

Returns
  a gphoto2 error code

## ◆ gp_camera_folder_list_files()

int gp_camera_folder_list_files | ( | Camera * | camera,
|  | const char * | folder,
|  | CameraList * | list,
|  | GPContext * | context
| ) |  |

Lists the files in supplied `folder`.

Parameters

  camera | a Camera
  folder | a folder
  list | a CameraList
  context | a GPContext

Returns
  a gphoto2 error code

## ◆ gp_camera_folder_list_folders()

int gp_camera_folder_list_folders | ( | Camera * | camera,
|  | const char * | folder,
|  | CameraList * | list,
|  | GPContext * | context
| ) |  |

Lists the folders in supplied `folder`.

Parameters

  camera | a Camera
  folder | a folder
  list | a CameraList
  context | a GPContext

Returns
  a gphoto2 error code

## ◆ gp_camera_folder_make_dir()

int gp_camera_folder_make_dir | ( | Camera * | camera,
|  | const char * | folder,
|  | const char * | name,
|  | GPContext * | context
| ) |  |

Creates a new directory called `name` in the given `folder`.

Parameters

  camera | a Camera
  folder | the location where to create the new directory
  name | the name of the directory to be created
  context | a GPContext

Returns
  a gphoto2 error code

## ◆ gp_camera_folder_put_file()

int gp_camera_folder_put_file | ( | Camera * | camera,
|  | const char * | folder,
|  | const char * | filename,
|  | CameraFileType | type,
|  | CameraFile * | file,
|  | GPContext * | context
| ) |  |

Uploads a file into given `folder`.

Parameters

  camera | a Camera
  folder | a folder
  file | a CameraFile
  context | a GPContext

Returns
  a gphoto2 error code

## ◆ gp_camera_folder_remove_dir()

int gp_camera_folder_remove_dir | ( | Camera * | camera,
|  | const char * | folder,
|  | const char * | name,
|  | GPContext * | context
| ) |  |

Removes an (empty) directory called `name` from the given `folder`.

Parameters

  camera | a Camera
  folder | the folder from which to remove the directory
  name | the name of the directory to be removed
  context | a GPContext

Returns
  a gphoto2 error code

## ◆ gp_camera_free()

int gp_camera_free | ( | Camera * | camera | ) |

Free the `camera`.

Parameters

  camera | a Camera

Returns
  a gphoto2 error code

Deprecated:
  This function should never be used. Please use gp_camera_unref instead.

References gp_camera_exit(), gp_filesystem_free(), GP_OK, gp_port_free(), and _Camera::pc.

Referenced by gp_camera_unref().

## ◆ gp_camera_get_abilities()

int gp_camera_get_abilities | ( | Camera * | camera,
|  | CameraAbilities * | abilities
| ) |  |

Retrieve the `abilities` of the `camera`.

Parameters

  camera | a Camera
  abilities |

Returns
  a gphoto2 error code

References GP_OK, and _Camera::pc.

## ◆ gp_camera_get_about()

int gp_camera_get_about | ( | Camera * | camera,
|  | CameraText * | about,
|  | GPContext * | context
| ) |  |

Retrieves information about the camera driver.

Parameters

  camera | a Camera
  about | a CameraText
  context | a GPContext

Returns
  a gphoto2 error code

Typically, this information contains name and address of the author, acknowledgements, etc.

## ◆ gp_camera_get_config()

int gp_camera_get_config | ( | Camera * | camera,
|  | CameraWidget ** | window,
|  | GPContext * | context
| ) |  |

Retrieve a configuration `window` for the `camera`.

Parameters

  camera | a Camera
  window | a CameraWidget
  context | a GPContext

Returns
  gphoto2 error code

This `window` can be used for construction of a configuration dialog.

## ◆ gp_camera_get_manual()

int gp_camera_get_manual | ( | Camera * | camera,
|  | CameraText * | manual,
|  | GPContext * | context
| ) |  |

Retrieves the `manual` for given `camera`.

Parameters

  camera | a Camera
  manual | a CameraText
  context | a GPContext

Returns
  a gphoto2 error code

This manual typically contains information about using the camera.

## ◆ gp_camera_get_port_speed()

int gp_camera_get_port_speed | ( | Camera * | camera | ) |

Retrieve the current speed.

Parameters

  camera | a Camera

Returns
  The current speed or a gphoto2 error code

References _Camera::pc.

## ◆ gp_camera_get_single_config()

int gp_camera_get_single_config | ( | Camera * | camera,
|  | const char * | name,
|  | CameraWidget ** | widget,
|  | GPContext * | context
| ) |  |

Retrieve a single configuration `widget` for the `camera`.

Parameters

  camera | a Camera
  name | the name of a configuration widget
  widget | a CameraWidget
  context | a GPContext

Returns
  gphoto2 error code

This `widget` will then contain the current and the possible values and the type.

## ◆ gp_camera_get_storageinfo()

int gp_camera_get_storageinfo | ( | Camera * | camera,
|  | CameraStorageInformation ** | sifs,
|  | int * | nrofsifs,
|  | GPContext * | context
| ) |  |

Gets information on the camera attached storage.

Parameters

  camera | a Camera
  sifs | Pointer to receive a pointer to/array of storage info items
  nrofsifs | Pointer to receive number of array entries
  context | a GPContext

Returns
  a gphoto2 error code

Retrieves the storage information, like maximum and free space, for the specified filesystem, if supported by the device. The storage information is returned in an newly allocated array of CameraStorageInformation objects, to which the pointer pointed to by #sifs will be set.

The variable pointed to by #nrofsifs will be set to the number of elements in that array.

It is the caller's responsibility to free the memory of the array.

## ◆ gp_camera_get_summary()

int gp_camera_get_summary | ( | Camera * | camera,
|  | CameraText * | summary,
|  | GPContext * | context
| ) |  |

Retrieves a camera summary.

Parameters

  camera | a Camera
  summary | a CameraText
  context | a GPContext

Returns
  a gphoto2 error code

This summary typically contains information like manufacturer, pictures taken, or generally information that is not configurable.

## ◆ gp_camera_init()

int gp_camera_init | ( | Camera * | camera,
|  | GPContext * | context
| ) |  |

Initiate a connection to the `camera`.

Parameters

  camera | a Camera
  context | a GPContext

Returns
  a gphoto2 error code

Before calling this function, the `camera` should be set up using gp_camera_set_port_path() or gp_camera_set_port_name() and gp_camera_set_abilities(). If that has been omitted, gphoto2 tries to autodetect any cameras and chooses the first one if any cameras are found. It is generally a good idea to call gp_camera_exit() after transactions have been completed in order to give other applications the chance to access the camera, too.

## ◆ gp_camera_new()

int gp_camera_new | ( | Camera ** | camera | ) |

Allocates the memory for a Camera.

Parameters

  camera | the Camera object to initialize.

Returns
  a gphoto2 error code

## ◆ gp_camera_ref()

int gp_camera_ref | ( | Camera * | camera | ) |

Increment the reference count of a `camera`.

Parameters

  camera | a Camera

Returns
  a gphoto2 error code

References GP_OK, and _Camera::pc.

## ◆ gp_camera_set_abilities()

int gp_camera_set_abilities | ( | Camera * | camera,
|  | CameraAbilities | abilities
| ) |  |

Sets the camera abilities.

Parameters

  camera | a Camera
  abilities | the CameraAbilities to be set

Returns
  a gphoto2 error code

You need to call this function before calling gp_camera_init the first time unless you want gphoto2 to autodetect cameras and choose the first detected one. By setting the `abilities`, you tell gphoto2 what model the `camera` is and what camera driver should be used for accessing the `camera`. You can get `abilities` by calling gp_abilities_list_get_abilities.

References gp_camera_exit(), GP_OK, CameraAbilities::model, and _Camera::pc.

## ◆ gp_camera_set_config()

int gp_camera_set_config | ( | Camera * | camera,
|  | CameraWidget * | window,
|  | GPContext * | context
| ) |  |

Sets the configuration.

Parameters

  camera | a Camera
  window | a CameraWidget
  context | a GPContext

Returns
  a gphoto2 error code

Typically, a `window` is retrieved using gp_camera_get_config and passed to this function in order to adjust the settings on the camera.

## ◆ gp_camera_set_port_speed()

int gp_camera_set_port_speed | ( | Camera * | camera,
|  | int | speed
| ) |  |

Set the camera speed.

Parameters

  camera | a Camera
  speed | the speed

Returns
  a gphoto2 error code

This function is typically used prior first initialization using gp_camera_init for debugging purposes. Normally, a camera driver will try to figure out the current speed of the camera and set the speed to the optimal one automatically. Note that this function only works with serial ports. In other words, you have to set the camera's port to a serial one (using #gp_camera_set_port_path or #gp_camera_set_port_name) prior calling this function.

References gp_camera_exit(), GP_PORT_SERIAL, _Camera::pc, and _GPPort::type.

## ◆ gp_camera_set_single_config()

int gp_camera_set_single_config | ( | Camera * | camera,
|  | const char * | name,
|  | CameraWidget * | widget,
|  | GPContext * | context
| ) |  |

Set a single configuration `widget` for the `camera`.

Parameters

  camera | a Camera
  name | the name of a configuration widget
  widget | a CameraWidget
  context | a GPContext

Returns
  gphoto2 error code

This `widget` contains the new value of the widget to set.

## ◆ gp_camera_set_timeout_funcs()

void gp_camera_set_timeout_funcs | ( | Camera * | camera,
|  | CameraTimeoutStartFunc | start_func,
|  | CameraTimeoutStopFunc | stop_func,
|  | void * | data
| ) |  |

Parameters

  camera | a Camera
  start_func |
  stop_func |
  data |

Returns
  a gphoto2 error code

If your frontend has something like idle loops, it is recommended you use gp_camera_set_timeout_funcs in order to give the camera driver the possibility to keep up the connection to the camera.

## ◆ gp_camera_start_timeout()

int gp_camera_start_timeout | ( | Camera * | camera,
|  | unsigned int | timeout,
|  | CameraTimeoutFunc | func
| ) |  |

Parameters

  camera | a Camera
  timeout | number of seconds that should pass between each call to `func`
  func | the function that should be called each `timeout` seconds

Returns
  The id of the background process or a gphoto2 error code

This function should be called by the camera driver during camera_init() if the camera needs to be sent messages periodically in order to prevent it from shutting down.

## ◆ gp_camera_stop_timeout()

void gp_camera_stop_timeout | ( | Camera * | camera,
|  | unsigned int | id
| ) |  |

Stop periodic calls to keepalive function.

Parameters

  camera | a Camera
  id | the id of the background process previously returned by gp_camera_start_timeout

Call this function in the camera driver if you want to stop a periodic call to a function that has been started using gp_camera_start_timeout.

References _Camera::pc.

Referenced by gp_camera_exit().

## ◆ gp_camera_trigger_capture()

int gp_camera_trigger_capture | ( | Camera * | camera,
|  | GPContext * | context
| ) |  |

Triggers capture of one or more images.

Parameters

  camera | a Camera
  context | a GPContext

Returns
  a gphoto2 error code

This functions just remotely causes the shutter release and returns immediately. You will want to run #gp_camera_wait_event until a image is added which can be downloaded using gp_camera_file_get.

## ◆ gp_camera_unref()

int gp_camera_unref | ( | Camera * | camera | ) |

Decrements the reference count of a Camera.

Parameters

  camera | a Camera

Returns
  a gphoto2 error code

If the reference count reaches %0, the `camera` will be freed automatically.

References gp_camera_free(), GP_ERROR, GP_OK, and _Camera::pc.

## ◆ gp_camera_wait_for_event()

int gp_camera_wait_for_event | ( | Camera * | camera,
|  | int | timeout,
|  | CameraEventType * | eventtype,
|  | void ** | eventdata,
|  | GPContext * | context
| ) |  |

Wait and retrieve an event from the camera.

Parameters

  camera | a Camera
  timeout | amount of time to wait in 1/1000 seconds
  eventtype | received CameraEventType [out]
  eventdata | received event specific data [out]
  context | a GPContext

Returns
  gphoto2 error code

This function blocks and waits for an event to come from the camera. If a timeout occurs before an event is received then eventtype will be GP_EVENT_TIMEOUT and eventdata is left unchanged.

If an event is received then eventtype is set to the type of event, and eventdata is set to event specific data. See the CameraEventType enum to see which eventtypes match to which types of eventdata.

Note that this function will return one event after each other, you need to be able to call it multiple times, e.g. in a loop, when waiting for specific events.