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DM8148 RDK video shaking

Expert 1840 points

Dear experts,

I am working with dm8148 RDK v3.5, during testing I realized that the video stream from our Board got the shaking problem. in normally, It looks ok but when you test by using the camera looking a highway video, you can be easy to figure out this issues. Let see the video at link below for detail:

https://app.box.com/s/3wyw6jei7ycc9f7jg4xm

Please focus on the moving of car, you can see sometime it stop and continue to run ... the moving is not smooth.

Because this one doesnt happen with direct output HDMI, I guess the problem stay in somewhere at ring buffer or lock, unlock mechanism of software.

PLease give me a hand if you have experiences about that.

P/s: this issue also happen with dm368 camera and appro software. 

  • Hongfeng, did you get any idea for that?

  • Bioz,

    What is the bitrate you are trying this on? Can you try increasing the streaming buffer size and check?

    Can you try with lower bitrate and check if issue persists?

    Also, it could be that the I frames are large that write operation are getting locked and some issue there with frame skips 

    Are you observing the stutter in the video or is it a frame loss?

    Also, was the ARM load too high at that instant? whats is the usecase you are running, is it 5MP?

    Regards,

    Raghu

  • Hi,

    I am using:

    - Tri stream full features usecase with full HD resolution for main capture. 

    - the ARM load is no problem. 

    - I have checked VLC information and didn't see frame loss issues during streaming.

    - "Also, it could be that the I frames are large that write operation are getting locked and some issue there with frame skips" can you explain more about this? 

    - I have already tried to adjust the bitrate from 1000 to 10000 but the problem still appear.

    - What do you mean about stream buffer size? If you are talking about VLC buffer so I have already tried but It couldnot solve the problem completly. If you mentioned about some others buffer on code please show me how to exactly increase the stream buffer size? I also tried some places but I am not sure that correct way.

     Thanks

  • I also try to use I frame for all video stream instead of include P frames. The video look smooth and problem may be solved. So I think the issues relate to P frame buffers, do you  have any suggestion to fix this?

    thanks

  • To get all I frames, you might this fix in enclink_h264_set_params_stream_preset

    staticParams->rateControlParams.maxPicSizeRatioI = 0;
    dynamicParams->rateControlParams.maxPicSizeRatioI = 0;

    Anyways, issue can be due the repeat of frames or data in input or ouput buffer, can you check by increasing output buffers.

    Also, you can check by checking the count of buffers getting skipped or getting repeated, by having some logs in Encoder link. 

    The issue from log looks like due to repeat of some frames which is causing this

    Regards,

    Raghu

  • Dear Raghu Kudva,

    Thanks for your response, I still sink in that issues. And now I have another one. I really need your quick advice in this case. I modified the third stream from using MJPEG to H254 with resolution is 320x240. I did it by just modify the use case to add 1 more scaler and change everything which relate to third stream to similar config as second stream and system are now running. The problem is the third stream was really not smooth and strong shrinking. I think I make some thing wrong in configuration during modification. From VLC media information I have the report to second and third stream as below:

    THIRD STREAM

    SECOND STREAM


    From above information, I guess the shrink problem which happen in third stream may come from packet lost, large DEmuxed data size and  content bitrate.

    Can you help to figure out the way to make the Demuxed data size and Content bitrate of third stream have similar value as second stream? I am sorry if this is a stupid question but I have not much experience in this.


    Thank you so much