TDA4VM: When camera collects image data, it needs to reserve buffer 10ms, but it will cause the queue not to be scheduled

Hi yang,

Sorry for the late reply. Yes, once we call dequeue in the application, that buffer will not be used untill it is enqueued back. Once dequeued, you could call map buffer to access this buffer in the application and modify the content of it in the application.

Regards,

Brijesh

Hi   Brijesh Jadav，

Hi   Brijesh Jadav，

      If I don't call the  enqueue function "vxGraphParameterEnqueueReadyRef" after calling the dequeue function "vxGraphParameterDequeueDoneRef", what method do we have to get the next buffer in the queue?

Regards,

Yang

Hi Yang,

There is no other method, we need to use dequeue function to get a completed frame in the application and once application is done using this frame, we can submit it back to the framework by calling enqueue function.. 

I am still not getting where you see the issue here. What's this 10ms wait?

Regards,

Brijesh

Hi   Brijesh Jadav，

      Because the application needs 10ms to process the data in the buffer, but within 10ms, we want to get to the data in the next buffer.

Thanks

Hi Yang,

If the camera is running at 30fps, the frame will come at every 33ms. Once buffer is fully captured you could use it in the application for the processing. If this processing takes 10ms, it should be ok, because, typically, there would be queue of buffer for the capture and you are using it for less than 33ms. 

So it should be fine to use the frame for 10ms, after it has been dequeued. 

Regards,

Brijesh

Hi   Brijesh Jadav，

   10 ms is the ideal time, occasionally longer. Our application scenario is to get the next buffer without releasing one of the buffers. After processing the buffer, we can join the queue. We need to cache 6 buffers

Hi Yang,

Keeping 6 buffer as a cache is ok, but you need to make sure that algorithm is running in real time, ie if you are dequeuing buffer every 33ms, you could enqueue buffer at every 33ms. 

Otherwise graph cannot run in real time. 

You could have cached buffer by increasing number of output buffers for the capture node. 

Regards,

Brijesh 

For example, one thread does not finish processing the buffer within 33 ms, and the other thread needs to be queued for the next buffer. Memcopy cannot be called to save data due to performance requirements

Hi Yang,

Once in a while, if a thread takes more than 33ms, it should be ok, because there is a queue frames. 

But this should not happen on every frame.

Regards,

Brijesh 

 Hi，Brijesh Jadav ,

  If a frame is processed for more than 33 ms and there are four frames in a buffer, then the processing time of a buffer is 132 Ms. Therefore, we want to get the data of the next buffer in the queue synchronously.

Thanks.

Hi Yang,

Could not understand your statement "processing time of a buffer is 132 Ms"? If you mean that same frame would be returned after 132ms, it is not because of async mode. It is just that there are three frame before this frame to finish. 

Also could you help me understand "next buffer synchronously"?

Regards,

Brijesh 

Hi，Brijesh Jadav ,

     Sorry to reply now，  "Next buffer synchronously" is to get the buffer in the next queue without enqueue。Now the problem has a solution, but there may be a bug, later need your help, thank you very much。

Hi Yang,

I am sorry i could not get it. How can we enqueue the buffer to next queue, without enqueue? 

What's the solution that we are talking?

Regards,

Brijesh