ptp.c

USB Host 开发中支持数码相机的源码。即Picture To Picture协议的完整实现

	*size=ptp.Param1;
	*rp2=ptp.Param2;
	return ret;
}

/**
 * ptp_canon_startshootingmode:
 * params:	PTPParams*
 * 
 * Starts shooting session. It emits a StorageInfoChanged
 * event via the interrupt pipe and pushes the StorageInfoChanged
 * and CANON_CameraModeChange events onto the event stack
 * (see operation PTP_OC_CANON_CheckEvent).
 *
 * Return values: Some PTP_RC_* code.
 *
 **/
uint16_t
ptp_canon_startshootingmode (PTPParams* params)
{
	PTPContainer ptp;
	
	PTP_CNT_INIT(ptp);
	ptp.Code=PTP_OC_CANON_StartShootingMode;
	ptp.Nparam=0;
	return ptp_transaction(params, &ptp, PTP_DP_NODATA, 0, NULL);
}

/**
 * ptp_canon_endshootingmode:
 * params:	PTPParams*
 * 
 * This operation is observed after pressing the Disconnect 
 * button on the Remote Capture app. It emits a StorageInfoChanged 
 * event via the interrupt pipe and pushes the StorageInfoChanged
 * and CANON_CameraModeChange events onto the event stack
 * (see operation PTP_OC_CANON_CheckEvent).
 *
 * Return values: Some PTP_RC_* code.
 *
 **/
uint16_t
ptp_canon_endshootingmode (PTPParams* params)
{
	PTPContainer ptp;
	
	PTP_CNT_INIT(ptp);
	ptp.Code=PTP_OC_CANON_EndShootingMode;
	ptp.Nparam=0;
	return ptp_transaction(params, &ptp, PTP_DP_NODATA, 0, NULL);
}

/**
 * ptp_canon_viewfinderon:
 * params:	PTPParams*
 * 
 * Prior to start reading viewfinder images, one  must call this operation.
 * Supposedly, this operation affects the value of the CANON_ViewfinderMode
 * property.
 *
 * Return values: Some PTP_RC_* code.
 *
 **/
uint16_t
ptp_canon_viewfinderon (PTPParams* params)
{
	PTPContainer ptp;
	
	PTP_CNT_INIT(ptp);
	ptp.Code=PTP_OC_CANON_ViewfinderOn;
	ptp.Nparam=0;
	return ptp_transaction(params, &ptp, PTP_DP_NODATA, 0, NULL);
}

/**
 * ptp_canon_viewfinderoff:
 * params:	PTPParams*
 * 
 * Before changing the shooting mode, or when one doesn't need to read
 * viewfinder images any more, one must call this operation.
 * Supposedly, this operation affects the value of the CANON_ViewfinderMode
 * property.
 *
 * Return values: Some PTP_RC_* code.
 *
 **/
uint16_t
ptp_canon_viewfinderoff (PTPParams* params)
{
	PTPContainer ptp;
	
	PTP_CNT_INIT(ptp);
	ptp.Code=PTP_OC_CANON_ViewfinderOff;
	ptp.Nparam=0;
	return ptp_transaction(params, &ptp, PTP_DP_NODATA, 0, NULL);
}

/**
 * ptp_canon_reflectchanges:
 * params:	PTPParams*
 * 		uint32_t p1 	- Yet unknown parameter,
 * 				  value 7 works
 * 
 * Make viewfinder reflect changes.
 * There is a button for this operation in the Remote Capture app.
 * What it does exactly I don't know. This operation is followed
 * by the CANON_GetChanges(?) operation in the log.
 *
 * Return values: Some PTP_RC_* code.
 *
 **/
uint16_t
ptp_canon_reflectchanges (PTPParams* params, uint32_t p1)
{
	PTPContainer ptp;
	
	PTP_CNT_INIT(ptp);
	ptp.Code=PTP_OC_CANON_ReflectChanges;
	ptp.Param1=p1;
	ptp.Nparam=1;
	return ptp_transaction(params, &ptp, PTP_DP_NODATA, 0, NULL);
}


/**
 * ptp_canon_checkevent:
 * params:	PTPParams*
 * 
 * The camera has a FIFO stack, in which it accumulates events.
 * Partially these events are communicated also via the USB interrupt pipe
 * according to the PTP USB specification, partially not.
 * This operation returns from the device a block of data, empty,
 * if the event stack is empty, or filled with an event's data otherwise.
 * The event is removed from the stack in the latter case.
 * The Remote Capture app sends this command to the camera all the time
 * of connection, filling with it the gaps between other operations. 
 *
 * Return values: Some PTP_RC_* code.
 * Upon success : PTPUSBEventContainer* event	- is filled with the event data
 *						  if any
 *                int *isevent			- returns 1 in case of event
 *						  or 0 otherwise
 **/
uint16_t
ptp_canon_checkevent (PTPParams* params, PTPUSBEventContainer* event, int* isevent)
{
	uint16_t ret;
	PTPContainer ptp;
	char *evdata = NULL;
	
	*isevent=0;
	PTP_CNT_INIT(ptp);
	ptp.Code=PTP_OC_CANON_CheckEvent;
	ptp.Nparam=0;
	ret=ptp_transaction(params, &ptp, PTP_DP_GETDATA, 0, &evdata);
	if (evdata!=NULL) {
		if (ret == PTP_RC_OK) {
        		ptp_unpack_EC(params, evdata, event);
    			*isevent=1;
        	}
		free(evdata);
	}
	return ret;
}


/**
 * ptp_canon_focuslock:
 *
 * This operation locks the focus. It is followed by the CANON_GetChanges(?)
 * operation in the log. 
 * It affects the CANON_MacroMode property. 
 *
 * params:	PTPParams*
 *
 * Return values: Some PTP_RC_* code.
 *
 **/
uint16_t
ptp_canon_focuslock (PTPParams* params)
{
	PTPContainer ptp;
	
	PTP_CNT_INIT(ptp);
	ptp.Code=PTP_OC_CANON_FocusLock;
	ptp.Nparam=0;
	return ptp_transaction(params, &ptp, PTP_DP_NODATA, 0, NULL);
}

/**
 * ptp_canon_focusunlock:
 *
 * This operation unlocks the focus. It is followed by the CANON_GetChanges(?)
 * operation in the log. 
 * It sets the CANON_MacroMode property value to 1 (where it occurs in the log).
 * 
 * params:	PTPParams*
 *
 * Return values: Some PTP_RC_* code.
 *
 **/
uint16_t
ptp_canon_focusunlock (PTPParams* params)
{
	PTPContainer ptp;
	
	PTP_CNT_INIT(ptp);
	ptp.Code=PTP_OC_CANON_FocusUnlock;
	ptp.Nparam=0;
	return ptp_transaction(params, &ptp, PTP_DP_NODATA, 0, NULL);
}

/**
 * ptp_canon_initiatecaptureinmemory:
 * 
 * This operation starts the image capture according to the current camera
 * settings. When the capture has happened, the camera emits a CaptureComplete
 * event via the interrupt pipe and pushes the CANON_RequestObjectTransfer,
 * CANON_DeviceInfoChanged and CaptureComplete events onto the event stack
 * (see operation CANON_CheckEvent). From the CANON_RequestObjectTransfer
 * event's parameter one can learn the just captured image's ObjectHandle.
 * The image is stored in the camera's own RAM.
 * On the next capture the image will be overwritten!
 *
 * params:	PTPParams*
 *
 * Return values: Some PTP_RC_* code.
 *
 **/
uint16_t
ptp_canon_initiatecaptureinmemory (PTPParams* params)
{
	PTPContainer ptp;
	
	PTP_CNT_INIT(ptp);
	ptp.Code=PTP_OC_CANON_InitiateCaptureInMemory;
	ptp.Nparam=0;
	return ptp_transaction(params, &ptp, PTP_DP_NODATA, 0, NULL);
}

/**
 * ptp_canon_getpartialobject:
 *
 * This operation is used to read from the device a data 
 * block of an object from a specified offset.
 *
 * params:	PTPParams*
 *      uint32_t handle - the handle of the requested object
 *      uint32_t offset - the offset in bytes from the beginning of the object
 *      uint32_t size - the requested size of data block to read
 *      uint32_t pos - 1 for the first block, 2 - for a block in the middle,
 *                  3 - for the last block
 *
 * Return values: Some PTP_RC_* code.
 *      char **block - the pointer to the block of data read
 *      uint32_t* readnum - the number of bytes read
 *
 **/
uint16_t
ptp_canon_getpartialobject (PTPParams* params, uint32_t handle, 
				uint32_t offset, uint32_t size,
				uint32_t pos, char** block, 
				uint32_t* readnum)
{
	uint16_t ret;
	PTPContainer ptp;
	char *data=NULL;
	
	PTP_CNT_INIT(ptp);
	ptp.Code=PTP_OC_CANON_GetPartialObject;
	ptp.Param1=handle;
	ptp.Param2=offset;
	ptp.Param3=size;
	ptp.Param4=pos;
	ptp.Nparam=4;
	ret=ptp_transaction(params, &ptp, PTP_DP_GETDATA, 0, &data);
	if (ret==PTP_RC_OK) {
		*block=data;
		*readnum=ptp.Param1;
	}
	return ret;
}

/**
 * ptp_canon_getviewfinderimage:
 *
 * This operation can be used to read the image which is currently
 * in the camera's viewfinder. The image size is 320x240, format is JPEG.
 * Of course, prior to calling this operation, one must turn the viewfinder
 * on with the CANON_ViewfinderOn command.
 * Invoking this operation many times, one can get live video from the camera!
 * 
 * params:	PTPParams*
 * 
 * Return values: Some PTP_RC_* code.
 *      char **image - the pointer to the read image
 *      unit32_t *size - the size of the image in bytes
 *
 **/
uint16_t
ptp_canon_getviewfinderimage (PTPParams* params, char** image, uint32_t* size)
{
	uint16_t ret;
	PTPContainer ptp;
	
	PTP_CNT_INIT(ptp);
	ptp.Code=PTP_OC_CANON_GetViewfinderImage;
	ptp.Nparam=0;
	ret=ptp_transaction(params, &ptp, PTP_DP_GETDATA, 0, image);
	if (ret==PTP_RC_OK) *size=ptp.Param1;
	return ret;
}

/**
 * ptp_canon_getchanges:
 *
 * This is an interesting operation, about the effect of which I am not sure.
 * This command is called every time when a device property has been changed 
 * with the SetDevicePropValue operation, and after some other operations.
 * This operation reads the array of Device Properties which have been changed
 * by the previous operation.
 * Probably, this operation is even required to make those changes work.
 *
 * params:	PTPParams*
 * 
 * Return values: Some PTP_RC_* code.
 *      uint16_t** props - the pointer to the array of changed properties
 *      uint32_t* propnum - the number of elements in the *props array
 *
 **/
uint16_t
ptp_canon_getchanges (PTPParams* params, uint16_t** props, uint32_t* propnum)
{
	uint16_t ret;
	PTPContainer ptp;
	char* data=NULL;
	
	PTP_CNT_INIT(ptp);
	ptp.Code=PTP_OC_CANON_GetChanges;
	ptp.Nparam=0;
	ret=ptp_transaction(params, &ptp, PTP_DP_GETDATA, 0, &data);
	if (ret == PTP_RC_OK)
        	*propnum=ptp_unpack_uint16_t_array(params,data,0,props);
	free(data);
	return ret;
}

/**
 * ptp_canon_getfolderentries:
 *
 * This command reads a specified object's record in a device's filesystem,
 * or the records of all objects belonging to a specified folder (association).
 *  
 * params:	PTPParams*
 *      uint32_t store - StorageID,
 *      uint32_t p2 - Yet unknown (0 value works OK)
 *      uint32_t parent - Parent Object Handle
 *                      # If Parent Object Handle is 0xffffffff, 
 *                      # the Parent Object is the top level folder.
 *      uint32_t handle - Object Handle
 *                      # If Object Handle is 0, the records of all objects 
 *                      # belonging to the Parent Object are read.
 *                      # If Object Handle is not 0, only the record of this 
 *                      # Object is read.
 *
 * Return values: Some PTP_RC_* code.
 *      PTPCANONFolderEntry** entries - the pointer to the folder entry array
 *      uint32_t* entnum - the number of elements of the array
 *
 **/
uint16_t
ptp_canon_getfolderentries (PTPParams* params, uint32_t store, uint32_t p2, 
			    uint32_t parent, uint32_t handle, 
			    PTPCANONFolderEntry** entries, uint32_t* entnum)
{
	uint16_t ret;
	PTPContainer ptp;
	char *data = NULL;
	
	PTP_CNT_INIT(ptp);
	ptp.Code=PTP_OC_CANON_GetFolderEntries;
	ptp.Param1=store;
	ptp.Param2=p2;
	ptp.Param3=parent;
	ptp.Param4=handle;
	ptp.Nparam=4;
	ret=ptp_transaction(params, &ptp, PTP_DP_GETDATA, 0, &data);
	if (ret == PTP_RC_OK) {
		int i;
		*entnum=ptp.Param1;
		*entries=calloc(*entnum, sizeof(PTPCANONFolderEntry));
		if (*entries!=NULL) {
			for(i=0; i<(*entnum); i++)
				ptp_unpack_Canon_FE(params,
					data+i*PTP_CANON_FolderEntryLen,
					&((*entries)[i]) );
		} else {
			ret=PTP_ERROR_IO; /* Cannot allocate memory */
		}
	}
	free(data);
	return ret;
}


/* Non PTP protocol functions */
/* devinfo testing functions */

int
ptp_operation_issupported(PTPParams* params, uint16_t operation)
{
	int i=0;

	for (;i<params->deviceinfo.OperationsSupported_len;i++) {
		if (params->deviceinfo.OperationsSupported[i]==operation)
			return 1;
	}
	return 0;
}


int
ptp_property_issupported(PTPParams* params, uint16_t property)
{
	int i=0;

	for (;i<params->deviceinfo.DevicePropertiesSupported_len;i++) {
		if (params->deviceinfo.DevicePropertiesSupported[i]==property)
			return 1;
	}
	return 0;
}

/* ptp structures feeing functions */

void
ptp_free_devicepropdesc(PTPDevicePropDesc* dpd)
{
	uint16_t i;

	free(dpd->FactoryDefaultValue);