Utility Macros

Details

CHECK_PARAM_NULL()

#define     CHECK_PARAM_NULL(param)

Checks if the given parameter is NULL. If so, returns GP_ERROR_BAD_PARAMETERS from the enclosing function.

param :

value to check for NULL

CON_CHECK_PARAM_NULL()

#define     CON_CHECK_PARAM_NULL(param)

Checks if the given parameter is NULL. If so, reports through gp_context_error() (assuming that "context" is defined) and returns GP_ERROR_BAD_PARAMETERS from the enclosing function.

param :

value to check for NULL

GP_PORT_DEFAULT

#define GP_PORT_DEFAULT                GP_PORT_DEFAULT_RETURN(GP_ERROR_BAD_PARAMETERS)

Return as a default case in switch (camera->port->type) statements in functions returning a gphoto2 error code where this value of camera->port->type is unexpected.

GP_PORT_DEFAULT_RETURN()

#define GP_PORT_DEFAULT_RETURN(RETVAL) GP_PORT_DEFAULT_RETURN_INTERNAL(return RETVAL)

Return as a default case in switch (camera->port->type) statements in functions returning a value.

RETVAL :

Value to return from this function

GP_PORT_DEFAULT_RETURN_EMPTY

#define GP_PORT_DEFAULT_RETURN_EMPTY   GP_PORT_DEFAULT_RETURN_INTERNAL(return)

Return as a default case in switch (camera->port->type) statements in functions returning void.

GP_PORT_DEFAULT_RETURN_INTERNAL()

#define     GP_PORT_DEFAULT_RETURN_INTERNAL(return_statement)

Used only by GP_PORT_DEFAULT_RETURN_EMPTY(), GP_PORT_DEFAULT_RETURN(), and GP_PORT_DEFAULT()

return_statement :

Statement to use for return

enum canonJpegMarkerCode

typedef enum {
	JPEG_ESC     = 0xFF,
	JPEG_A50_SOS = 0xC4,
	JPEG_BEG     = 0xD8,
	JPEG_SOI     = 0xD8,
	JPEG_END     = 0xD9,
	JPEG_SOS     = 0xDB,
	JPEG_APP1    = 0xE1,
} canonJpegMarkerCode;

Flags to find important points in JFIF or EXIF files

`JPEG_ESC`	Byte value to flag possible JPEG code.
`JPEG_A50_SOS`	Byte value to flag a JPEG SOS marker in a file from a PowerShot A50 camera.
`JPEG_BEG`	Byte value which, immediately after `JPEG_ESC`, marks the start of JPEG image data in a JFIF file.
`JPEG_SOI`
`JPEG_END`	Byte code to mark the end of a JPEG image?
`JPEG_SOS`	Byte value to flag a JPEG SOS marker.
`JPEG_APP1`

enum canonDownloadImageType

typedef enum {
	CANON_DOWNLOAD_THUMB = 1,
	CANON_DOWNLOAD_FULL  = 2
} canonDownloadImageType;

Codes for "Download Captured Image" command to tell the camera to download either the thumbnail or the full image for the most recently captured image.

`CANON_DOWNLOAD_THUMB`	Get just the thumbnail for the image
`CANON_DOWNLOAD_FULL`	Get the full image

GP_MODULE

#define     GP_MODULE