/**
* \brief Get a list of interface association Descriptors from the device
*/
std::list<USBDescriptorPtr> Device::interfaceAssociationDescriptors(
bool videoonly) throw(USBError) {
std::list<USBDescriptorPtr> iadescriptors;
// see whether there is any additional data that could contain
// an interface association descriptor
ConfigurationPtr config = activeConfig();
if (config->extra().size() == 0) {
debug(LOG_DEBUG, DEBUG_LOG, 0, "no data for descriptors");
return iadescriptors;
}
// try to parse additional descriptors
DescriptorFactory f(*this);
std::vector<USBDescriptorPtr> list = f.descriptors(config->extra());
debug(LOG_DEBUG, DEBUG_LOG, 0, "found %d additional descriptors",
list.size());
// no check whether they are InterfaceAssociationDescriptors
std::vector<USBDescriptorPtr>::const_iterator i;
for (i = list.begin(); i != list.end(); i++) {
USBDescriptorPtr dp = *i;
if (isPtr<InterfaceAssociationDescriptor>(dp)) {
InterfaceAssociationDescriptor *iad
= getPtr<InterfaceAssociationDescriptor>(dp);
bool isvideo = iad->isVideoInterfaceCollection();
debug(LOG_DEBUG, DEBUG_LOG, 0, "isvideo = %s",
(isvideo) ? "YES" : "NO");
if ((!videoonly) || (isvideo)) {
iadescriptors.push_back(dp);
}
}
}
// return all the interface association descriptors we have found
return iadescriptors;
}
/**
* \brief Construct a camera from a USB Device
*
* The constructor undertakes an extensive analysis of the descriptors
* to find the video control and video streaming interfaces of the video
* function of the device. It also makes sure no kernel driver is attached
* to the device. It does not, however, claim any of the interfaces, this
* is done when the device is really used.
* \param _device an USB device to open as a UVC camera
* \param force force opening as camera even if the
* interface associaten descriptor does not
* declare itself as a video interface association
* descriptor (handles the TIS camera)
* XXX apparently the force parameter is never used, so the question should be
* asked whether we can remove it.
*/
UVCCamera::UVCCamera(Device& _device, bool /* force */) throw(USBError)
: device(_device) {
debug(LOG_DEBUG, DEBUG_LOG, 0, "create a UVC camera object");
// make sure the camera is open, this most probably will not have
// any effect
device.open();
// scan the active configuration for one that has an Interface
// association descriptor
ConfigurationPtr config = device.activeConfig();
if (config->extra().size() == 0) {
debug(LOG_ERR, DEBUG_LOG, 0, "no extra descriptors");
throw USBError("no InterfaceAssociationDescriptor");
}
// get the list of interface association descriptors
std::list<USBDescriptorPtr> iadlist
= device.interfaceAssociationDescriptors(true);
if (0 == iadlist.size()) {
throw USBError("no Video Interface Association found");
}
iadptr = *iadlist.begin();
debug(LOG_DEBUG, DEBUG_LOG, 0, "Video Interface Association found");
// get the control interface, and the list of interface descriptors
// for the control interface, and claim it
uint8_t ci = controlInterfaceNumber();
videocontrol = (*config)[ci];
debug(LOG_DEBUG, DEBUG_LOG, 0, "Control interface number: %d", ci);
videocontrol->detachKernelDriver();
// we also need to know all the video control descriptors appended
// to this InterfaceDescriptor. The VideoControlDescriptorFactory
// does that.
debug(LOG_DEBUG, DEBUG_LOG, 0, "parse the video control descriptors");
InterfaceDescriptorPtr controlinterface = (*videocontrol)[0];
VideoControlDescriptorFactory vcdf(device);
videocontroldescriptors = vcdf.descriptors(controlinterface->extra());
std::cout << videocontroldescriptors[0];
// now claim get the various interface descriptors, i.e. the
// alternate settings for an interface
int interfacecount = iad().bInterfaceCount();
debug(LOG_DEBUG, DEBUG_LOG, 0, "interfaces in association: %d",
interfacecount);
// now parse the video streaming interfaces
debug(LOG_DEBUG, DEBUG_LOG, 0, "parse streaming interface descriptors");
VideoStreamingDescriptorFactory vsf(device);
for (int vsif = controlInterfaceNumber() + 1;
vsif < controlInterfaceNumber() + iad().bInterfaceCount();
vsif++) {
debug(LOG_DEBUG, DEBUG_LOG, 0,
"analyzing video streaming interface %d", vsif);
InterfacePtr interface = (*config)[vsif];
// only alternate setting 0 contains the formats
InterfaceDescriptorPtr id = (*interface)[0];
std::string extra = id->extra();
debug(LOG_DEBUG, DEBUG_LOG, 0, "extra descriptors: %d bytes",
extra.size());
USBDescriptorPtr vsd = vsf.descriptor(extra);
debug(LOG_DEBUG, DEBUG_LOG, 0, "parse complete");
videostreaming.push_back(vsd);
}
debug(LOG_DEBUG, DEBUG_LOG, 0, "UVCCamera constructed");
}