what is the different between writePartial function and write function in V4l2Output ?
class V4l2Output : public V4l2Access
{
protected:
V4l2Output(V4l2Device* device);
public:
static V4l2Output* create(const V4L2DeviceParameters & param, IoType iotype = V4l2Access::IOTYPE_MMAP);
virtual ~V4l2Output();
size_t write(char* buffer, size_t bufferSize);
int isWritable(timeval* tv);
bool startPartialWrite(void);
size_t writePartial(char* buffer, size_t bufferSize);
bool endPartialWrite(void);
};