int USBGrabber::open(const char* aDevPath, size_t *aWidth, size_t *aHeight, uint32_t *aFormat) {
if (mFd != 0) {
error("Device already opened");
return 0;
}
// Open capture device
mFd = v4l2_open(aDevPath, O_RDWR | O_NONBLOCK, 0);
if (mFd < 0)
{
error("Cannot open capturer device\n");
return 0;
}
if (!validateCaptureDevice()) return 0;
if (!initCaptureFormat()) return 0;
if (!setCaptureFormat(aWidth, aHeight, aFormat)) return 0;
if (!getCaptureInfo()) return 0;
if (!initBuffers()) return 0;
if (!startStreaming()) return 0;
return 1;
}
/*!
* Start saving data.
*
* This first checks whether it needsNewCaptureInfo() and calls
* getCaptureInfo() if necessary.
*
* \return whether any necessary capture info was successfully retrieved
* and saving was successfully started.
*/
bool DataSink::start()
{
if (!needsNewCaptureInfo() || getCaptureInfo())
return startSaving();
return false;
}
