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DVR RDK question on DEI output frame rate

Thomas Lo
Expert 1560 points

The platform I am using is DVR RDK 3.00 on DM816x, and I am testing my algorithm using the DVR

By calling the print system info status API, I found that when I am just using DEI_LINK_OUT_QUE_DEI_SC and DEI_LINK_OUT_QUE_VIP_SC outpu of a DEI link, the output frame rate is same as my expectation.

but if I also use DEI_LINK_OUT_QUE_VIP_SC_SECONDARY_OUT, it seems  the output frame rate of DEI_LINK_OUT_QUE_VIP_SC is now dropped by half, and same to DEI_LINK_OUT_QUE_VIP_SC_SECONDARY_OUT

Is it supposed to happen?

Thanks

  • 0
    TI__Guru**** 477195 points

    Hi,

     

    VIP_SC and VIP_SECONDARY_OUT are coming from the same hardware pipe, so fps will become half when both will be used.

     

    Regards,

    Brijesh Jadav

  • 0 in reply to Brijesh Jadav
    Expert 1560 points

    so if I want 2 output resolution and don't want frame rate decrease, I have to change it to

    ---> DEI --------|                                                   |-------------------------->
                           |------->  Merge  ------> Dup -------|
    ---> DEI-H -----|                                                   |-------->  Scaler  ----->

    is that right?

    and can the number of DupLink and MergeLink be increased? or is it fixed because of memory allocation?
    because after this change, I would be using all the 4 Dup and 5 Merge in VPSS in my system, which is the max number defined in  SYSTEM_VPSS_LINK_ID_MERGE and SYSTEM_VPSS_LINK_ID_DUP already,
    I think it is sufficient at the moment, but no further path can be created for further system development.

    Thanks.

  • 0 in reply to Thomas Lo
    TI__Guru 59700 points

    What is the fps you require ?

    For NTSC input DEI will convert 60 fields to 60 frames. You can then have 30 fps output on VIP_SC and 30 fps output VIP_SC_SECONDARY ?

    So pls mention whether your DEI input is field or frame, what is the input fps and what is the expected output fps on VIP and VIP_SECONDARY queues

  • 0 in reply to Badri Narayanan
    Expert 1560 points

    we would have a system with 4 channels frame multiplex 1080p video input at 30 fps on each capture port, so a total of 16 channels each with 6 to 7 fps.

    if DEI would devide frame rate by half, it would be down to about 3 fps only ,right?

    Does the scalar must output YUV422 format? can it output YUV420 format?
    If not, what component can I use to convert to 420 formate after scaling?

     

  • 0 in reply to Thomas Lo
    TI__Guru 59700 points

    If you are using DEI in dual output mode then only SC_5 scaler is available for use.SC5 can output only 422I format. You need NSF link to convert 422I to 420SP.

  • 0 in reply to Badri Narayanan
    Expert 1560 points

    for dual ouput mode, do you mean using DEI_LINK_OUT_QUE_VIP_SC_SECONDARY_OUT?

    if it is the case, does it mean if I do not enable this DEI output, there are more choices instead of just SC5?

    How many NSF link can I create in DM816x?

  • 0 in reply to Thomas Lo
    TI__Guru 59700 points

    Dual output means enabling DEI_SC and DEI_VIP_SC output queues. If you require 5 resolutions then you should use SC5 along with both the DEIs. You can dup the capture output and feed it to both DEIs and Scalar link. You need to connect NSF after Scaler link if you want to encode the stream