TDA4VM: Fvid2 timestamp

Hi yunhao li,

Which exactly timestamp you are using to find the difference? Are you using TIVX_REFERENCE_TIMESTAMP reference attribute to get/query the timestamp? 

As such memory copy or DMA copy should not affect CSIRX capture timestamp, but lets first check method you are using to get the timestamp..

Regards,

Brijesh

Thanks for reply.

And yes we query timestamp by vxQueryReference() and TIVX_REFERENCE_TIMESTAMP, after vxGraphParameterDequeueDonRef() on A72.

Regards,

                                Yunhao Li

We log here：

and get log like:

Normally, diff%40ms should be near 0. But sometimes it was quite small. At this time, all 4 images were teared.

Hi,

Which SDK release are you using? Also are you using SPL bootflow? 

Typically in the PSDKRA releases, we have given highest priority to the CSIRX, so memcpy on A72 should not have affect on the CSIRX. But lets see if you are using PSDKRA release and priorities are setup correctly.

When usecase is running, can you also print the capture statistics and share the numbers? In multi-cam example, you can get statistics by pressing 'p' on the console. I want to see if there is any error reported by the CSIRX. 

Regards,

Brijesh

Hi,

We got sdk release here: https://www.ti.com/tool/download/PROCESSOR-SDK-RTOS-J721E/07.03.00.07 
and we are using SPL bootflow.

We add log in capture target process function, like this

Normal frame interval is 40000us. And sometimes a72 app dequeued slowly, which caused frame drop. So N*40000us is also normal.

We got logs like

or

56600 plus 63400 is 120000, and 120000 is 40000*3, which means one frame was too fast and the next frame resumed to its proper phase.

Similarly， 9000 plus 71100 is about 80000 which is 40000*2. 

Is there anything wrong we can find in Capture status log?

Regards,

Li

Hi Li,

But what exactly are you running on A72? Can you please share this code? Are you doing memcpy between dequeue and enqueue operation on A72 or running memcpy on a separate low priority task on A72? Also are you doing this memcpy operation continuously or just once?

Regards,

Brijesh

Hi Brijesh，

We are doing frame memcpy between dequeue and enqueue on A72(QNX), 20 frames per second.  The memcpy task's priority is 10, which is the highest among apps on A72

Regards,

Li

Hi Li,

But it is not recommended to do memcpy between dequeue and enqueue operation on A72. Because it can potentially take more than 33ms and can affect operation of CSIRX, because CSIRX can potentially run out of the buffer and can drop the buffers in this case. 

Do you see this issue if you remove this memcpy? or if you can do smaller memcpy, which can taken always less 33ms, then CSIRX will run fine.. 

Regards,

Brijesh

Thanks Xu Liu.