TDA4AL-Q1: TDA4AL: How to setup DSS(display subsystem) from camera preview video frame direct to display frame ?

Part Number: TDA4AL-Q1

Tool/software:

Hi TI expert

TDA4AL: How to setup DSS(display subsystem) from camera preview video frame direct to display frame ? 

we need to set up DSS and output to FPD display ( display resolution is 3840x2160x12bit ) with minimum memory allocation.

how to setup DSS  dtsi/kernel config/kernel driver and related test tool ?

we need to examine the memory map first because our final DDR size is very small( only 1GB)

  • Hi,

    Looking at the diagram above, it seems you are using CSITX to transmit the data over MIPI interface to the display device, can you please confirm the same?

    In this case, CSITX is not available on Linux, so is it possible to use RTOS driver and using vision apps, can you connect CSIRX to CSITX? 

    Regards,

    Brijesh

  • Hi Brijesh,

    Not really sure what you meant about "is it possible  to use RTOS driver and using vision apps, can you connect CSIRX to CSITX?" Can you explain more about it?

     In our case, it looks like CSIRX is connected to another CSI bus's TX. Does packages/ti/drv/csirx/examples/csirxtx_loopback_test/src/main_rtos.c cover this case?

    Thank you.

  • Hi Eddie,

    I mean, RTOS drivers support both CSIRX and CSITX modules independently and They can be connected via memory using OpenVX framework. CSIRX can write the output in memory, which can be read back by CSITX and OpenVX can help in connecting them/synchronizing them.. 

    The one demo in PDK CSIRXTX_Loopback connects CSIRX to CSITX bypassing memory.. 

    Regards,

    Brijesh

  • Hi Brijesh,

    Thanks for your reply. Another question is where is the position of ISP along the data path? Is it like the below if we do CSIRXTX_Loopback ?

     Camera sensor -> CSIRX -> CSITX -> ISP -> MIPI -> Display

    Thanks

    Eddie

     

  • Hi Eddie,

    Well if your input format from CSIRX is RAW data, yes, then ISP is required and in that case, the data path would be

    sensor -> CSIRX -> memory -> ISP -> memory -> CSITX -> 

    Regards,

    Brijesh

  • Hi Rrijesh,

    Thanks for your reply. You are wonderful. Need your input for the following question:

    If ISP is required, in addition to CSIRX-TX loopback, software-wise what else work should we do? Is there any sample code for that?

    Thanks,

    Eddie

     

  • based on my early understanding, the camera video stream is from CSI RX-> VPAC -> DSS -> CSI TX -> FPD

    please give us guide about memory map, dtsi setting

  • Hi Eddie,

    Well, not exact usecase, but there is a similar usecase available in the RTOS SDK. Single camera usecase in the RTOS SDK captures data from CSIRX, processes them in ISP/VPAC and sends it out via DSS. We need to here just replace DSS with CSITX.

    Regards,

    Brijesh

  • Hi Brijesh,

    Thanks. I am wondering for camera 3a (auto white balance/auto exposure/auto focus), where are they processed along the data path?

    Is it processed by ISP? or C7x (DSP)? Or can be processed by either of them by configuration? 

    How does it work for TDA4AL and is there any reference code or document? Appreciate your help.

    Eddie   

  • Hi Eddie,

    well, there is a 2A algorithm which runs based on the statistics (H3A) output from ISP. The output of this algorithm is again applied in the ISP. This algorithm currently runs on R5F core and yes there is a reference algorithm available in the SDK.  

    Regards,

    Brijesh