Trenz Electronic GmbH Support Forum

Trenz Electronic Products => UltraScale => Topic started by: aforizma on August 23, 2020, 03:24:19 PM

Title: Real Time Capture and Record Video
Post by: aforizma on August 23, 2020, 03:24:19 PM
I will start a project and I wonder your opinion. The scenario is as follows. I use (ultrazed it have PL (FPGA) and PS (Linux)) It takes PL of the video video(raw video 640x480 30fps) over ethernet, performs pixel manipulation, then writes this video to memory. After that, PS comes in and takes the raw video data from the memory and transfers it to SATA.Video What is the best and no problem way? I dont want any loss. Our hardware is ultrascale(xilinx). This app will work on petalinux(linux). Raw video will be saved to SATA.

I want to use V42L library and driver. But I don't understand. I have no device as /dev/video0. How can ı capture video stream(from memory ) using V4L2.
Is there a way to read memory with V4L2?
Title: Re: Real Time Capture and Record Video
Post by: Oleksandr Kiyenko on August 24, 2020, 07:59:16 AM
Hello,

as I understand your task, you don't need video step if you are not going to display this video. The simplest way I see to implement it:
- Create own or program standard DMA or VDMA core
- Allocate or reserve some DMA buffer in memory
- Write simple driver to manage the buffer and pass the data to app
- Write app which will write data to SATA
- Optional you can define the framebuffer to control video stream (this way if your buffer is frame size*N you will see every N frame)
I you really want to use V4L you will need to write your own DRM driver which will provide /dev/video device for you. Implementation of this
driver is depend on how you are transfer your data to memory.
Your frame size and rate is low, so I see no problems with any of this colutions.

Best regards
Oleksandr Kiyenko