PetaLinux
PetaLinux can be built for these reference designs by using the Makefile in the PetaLinux directory
of the repository.
Requirements
To build the PetaLinux projects, you will need a physical or virtual machine running one of the supported Linux distributions as well as the Vitis Core Development Kit installed.
Attention
You cannot build the PetaLinux projects in the Windows operating system. Windows users are advised to use a Linux virtual machine to build the PetaLinux projects.
How to build
From a command terminal, clone the Git repository and
cdinto it.git clone --recursive https://github.com/fpgadeveloper/rpi-camera-fmc.git cd rpi-camera-fmc
Launch PetaLinux by sourcing the
settings.shbash script, eg:source <path-to-installed-petalinux>/settings.sh
Launch Vivado by sourcing the
settings64.shbash script, eg:source <vivado-install-dir>/settings64.sh
Build the Vivado and PetaLinux project for your specific target platform by running the following commands and replacing
<target>with one of the following:zcu104,zcu102_hpc0,zcu102_hpc1,zcu106_hpc0,pynqzu,uzevcd PetaLinux make petalinux TARGET=<target>
The last command will launch the build process for the corresponding Vivado project if that project has not already been built and it’s hardware exported.
Note that there currently is no PetaLinux project for the Genesys-ZU board, because there is currently no PetaLinux BSP available for that board.
Prepare the SD card
Once the build process is complete, you must prepare the SD card for booting PetaLinux.
The SD card must first be prepared with two partitions: one for the boot files and another for the root file system.
Plug the SD card into your computer and find it’s device name using the
dmesgcommand. The SD card should be found at the end of the log, and it’s device name should be something like/dev/sdX, whereXis a letter such as a,b,c,d, etc. Note that you should replace theXin the following instructions.
Warning
Do not continue these steps until you are certain that you have found the correct device name for the SD card. If you use the wrong device name in the following steps, you risk losing data on one of your hard drives.
Run
fdiskby typing the commandsudo fdisk /dev/sdXMake the
bootpartition: typingnto create a new partition, then typepto make it primary, then use the default partition number and first sector. For the last sector, type+1Gto allocate 1GB to this partition.Make the
bootpartition bootable by typingaMake the
rootpartition: typingnto create a new partition, then typepto make it primary, then use the default partition number, first sector and last sector.Save the partition table by typing
wFormat the
bootpartition (FAT32) by typingsudo mkfs.vfat -F 32 -n boot /dev/sdX1Format the
rootpartition (ext4) by typingsudo mkfs.ext4 -L root /dev/sdX2
Copy the following files to the
bootpartition of the SD card: Assuming thebootpartition was mounted to/media/user/boot, follow these instructions:$ cd /media/user/boot/ $ sudo cp /<petalinux-project>/images/linux/BOOT.BIN . $ sudo cp /<petalinux-project>/images/linux/boot.scr . $ sudo cp /<petalinux-project>/images/linux/image.ub .
Create the root file system by extracting the
rootfs.tar.gzfile to therootpartition. Assuming therootpartition was mounted to/media/user/root, follow these instructions:$ cd /media/user/root/ $ sudo cp /<petalinux-project>/images/linux/rootfs.tar.gz . $ sudo tar xvf rootfs.tar.gz -C . $ sync
Once the
synccommand returns, you will be able to eject the SD card from the machine.
Boot from SD card
Plug the SD card into your target board.
Ensure that the target board is configured to boot from SD card:
ZCU10x: DIP switch SW6 must be set to 1000 (1=ON,2=OFF,3=OFF,4=OFF)
PYNQ-ZU: Switch labelled “JTAG SD” must be flipped to the right (towards “SD”)
UltraZed-EV: DIP switch SW2 (on the SoM) is set to 1000 (1=ON,2=OFF,3=OFF,4=OFF)
Connect the RPi Camera FMC to the FMC connector of the target board. Connect one or more Raspberry Pi camera module v2 to the RPi Camera FMC.
Connect the USB-UART to your PC and then open a UART terminal set to 115200 baud and the comport that corresponds to your target board.
Connect and power your hardware.
Test the cameras
Log into PetaLinux using the username
petalinux. The first time you boot, you will be forced to set the password for this user. On subsequent boots, you will be required to use the chosen password.Check that the cameras have been enumerated correctly by running the
v4l2-ctl --list-devicescommand. The output should be similar to the following:zcu104-rpi-cam-fmc-2022-1:~$ v4l2-ctl --list-devices vcap_mipi_0_v_proc output 0 (platform:vcap_mipi_0_v_proc:0): /dev/video0 vcap_mipi_1_v_proc output 0 (platform:vcap_mipi_1_v_proc:0): /dev/video1 vcap_mipi_2_v_proc output 0 (platform:vcap_mipi_2_v_proc:0): /dev/video2 vcap_mipi_3_v_proc output 0 (platform:vcap_mipi_3_v_proc:0): /dev/video3 Xilinx Video Composite Device (platform:xilinx-video): /dev/media0 /dev/media1 /dev/media2 /dev/media3Note that there will only be video and media devices for the cameras that you have physically connected, so if you have only connected 2 cameras for example, then you should only see 2 video devices and 2 media devices listed.
Run the init script with the command
init_cams.sh.zcu104-rpi-cam-fmc-2022-1:~$ init_cams.sh ------------------------------------------------- Capture pipeline init: RPi cam -> Scaler -> DDR ------------------------------------------------- Configuring all video capture pipelines to: - RPi Camera output : 1920 x 1080 - Scaler (VPSS) output : 1920 x 1080 YUY2 - Frame rate : fps Video Mixer found here: - a0100000.v_mix Detected and configured the following cameras on RPi Camera FMC: - CAM0: /dev/media0 = /dev/video0 - CAM1: /dev/media1 = /dev/video1 - CAM2: /dev/media2 = /dev/video2 - CAM3: /dev/media3 = /dev/video3
The init script is located in
/usr/binand it serves as an example for setting the video pipe parameters using media-ctl. It configures all of the capture pipelines to a resolution, format and frame rate that is specified by a set of variables at the top of the script. It also lists the video mixer bus_id, as well as all of the connected RPi cameras and the media and video devices to which they are associated. The init script makes it easy to find all of the connected media and video devices, and to configure them so that they can be used with GStreamer or other applications.Before we can use the display pipeline, we need to set it up with the following command:
modetest -M xlnx -D a0100000.v_mix -s 52@40:1920x1080@NV16
Note that the
-Doption must specify the correctbus_idof the video mixer. This can be found in the output of theinit_cams.shscript (see above), or you can find it with the following command:find /sys/bus/platform/devices/ -name "*.v_mix". Here we are setting it up for 1080p resolution and NV16 pixel format, which is the expected format for this hardware.Use Gstreamer to display the video from a single camera on the DisplayPort monitor:
gst-launch-1.0 v4l2src device=/dev/video0 io-mode=mmap ! \ video/x-raw, width=1920, height=1080, format=YUY2, framerate=30/1 ! \ kmssink bus-id=a0100000.v_mix plane-id=34 render-rectangle="<0,0,1920,1080>" \ show-preroll-frame=false sync=false can-scale=false
Note that in this command, as in the previous step, you must use the correct
bus_idfor the video mixer. To test a different camera, change the targeted video device from/dev/video0to another, such as/dev/video1. To stop streaming the video, press Ctrl-C.Run the display cams script to display all cameras on the monitor at the same time.
sudo displaycams.sh
The display cams script is in the
/usr/bindirectory and it serves as an example for setting up the video pipelines and configuring the display pipeline to show all video streams. Here is the output of that script:zcu104-rpi-cam-fmc-2022-1:~$ sudo ./displaycams.sh ------------------------------------------------- Capture pipeline init: RPi cam -> Scaler -> DDR ------------------------------------------------- Configuring all video capture pipelines to: - RPi Camera output : 1920 x 1080 - Scaler (VPSS) output : 960 x 540 YUY2 - Frame rate : 30 fps Video Mixer found here: - a0100000.v_mix Detected and configured the following cameras on RPi Camera FMC: - CAM0: /dev/media0 = /dev/video0 - CAM1: /dev/media1 = /dev/video1 - CAM2: /dev/media2 = /dev/video2 - CAM3: /dev/media3 = /dev/video3 setting mode 1920x1080-60.00Hz on connectors 52, crtc 40 GStreamer command: -------------------------- gst-launch-1.0 v4l2src device=/dev/video0 io-mode=mmap ! video/x-raw, width=960, height=540, format=YUY2, framerate=30/1 ! kmssink bus-id=a0100000.v_mix plane-id=34 render-rectangle="<0,0,960,540>" show-preroll-frame=false sync=false can-scale=false v4l2src device=/dev/video1 io-mode=mmap ! video/x-raw, width=960, height=540, format=YUY2, framerate=30/1 ! kmssink bus-id=a0100000.v_mix plane-id=35 render-rectangle="<960,0,960,540>" show-preroll-frame=false sync=false can-scale=false v4l2src device=/dev/video2 io-mode=mmap ! video/x-raw, width=960, height=540, format=YUY2, framerate=30/1 ! kmssink bus-id=a0100000.v_mix plane-id=36 render-rectangle="<0,540,960,540>" show-preroll-frame=false sync=false can-scale=false v4l2src device=/dev/video3 io-mode=mmap ! video/x-raw, width=960, height=540, format=YUY2, framerate=30/1 ! kmssink bus-id=a0100000.v_mix plane-id=37 render-rectangle="<960,540,960,540>" show-preroll-frame=false sync=false can-scale=false -------------------------- Setting pipeline to PAUSED ... Pipeline is live and does not need PREROLL ... Pipeline is PREROLLED ... Setting pipeline to PLAYING ... New clock: GstSystemClock ^Chandling interrupt. Interrupt: Stopping pipeline ... Execution ended after 0:00:02.340043242 Setting pipeline to NULL ... Freeing pipeline ... zcu104-rpi-cam-fmc-2022-1:~$
Debugging tips
Video pipe settings
The media-ctl command can be useful in debugging issues with your video pipe design. Below we show an
example of the media-ctl -d /dev/media0 -p output, which shows each of the elements in the video pipe as well
as how they are connected and configured.
zcu104-rpi-cam-fmc-2022-1:~$ media-ctl -d /dev/media0 -p
Media controller API version 5.15.19
Media device information
------------------------
driver xilinx-video
model Xilinx Video Composite Device
serial
bus info
hw revision 0x0
driver version 5.15.19
Device topology
- entity 1: vcap_mipi_0_v_proc output 0 (1 pad, 1 link)
type Node subtype V4L flags 0
device node name /dev/video0
pad0: Sink
<- "a0000000.v_proc_ss":1 [ENABLED]
- entity 5: 80000000.mipi_csi2_rx_subsystem (2 pads, 2 links)
type V4L2 subdev subtype Unknown flags 0
device node name /dev/v4l-subdev0
pad0: Sink
[fmt:SRGGB10_1X10/1920x1080 field:none colorspace:srgb]
<- "imx219 1-0010":0 [ENABLED]
pad1: Source
[fmt:SRGGB10_1X10/1920x1080 field:none colorspace:srgb]
-> "a0110000.ISPPipeline_accel":0 [ENABLED]
- entity 8: imx219 1-0010 (1 pad, 1 link)
type V4L2 subdev subtype Sensor flags 0
device node name /dev/v4l-subdev1
pad0: Source
[fmt:SRGGB10_1X10/1920x1080 field:none colorspace:srgb xfer:srgb ycbcr:601 quantization:full-range
crop.bounds:(8,8)/3280x2464
crop:(688,700)/1920x1080]
-> "80000000.mipi_csi2_rx_subsystem":0 [ENABLED]
- entity 10: a0000000.v_proc_ss (2 pads, 2 links)
type V4L2 subdev subtype Unknown flags 0
device node name /dev/v4l-subdev2
pad0: Sink
[fmt:RBG888_1X24/1920x1080 field:none colorspace:srgb]
<- "a0110000.ISPPipeline_accel":1 [ENABLED]
pad1: Source
[fmt:UYVY8_1X16/960x540 field:none colorspace:srgb]
-> "vcap_mipi_0_v_proc output 0":0 [ENABLED]
- entity 13: a0110000.ISPPipeline_accel (2 pads, 2 links)
type V4L2 subdev subtype Unknown flags 0
device node name /dev/v4l-subdev3
pad0: Sink
[fmt:SRGGB10_1X10/1920x1080 field:none colorspace:srgb]
<- "80000000.mipi_csi2_rx_subsystem":1 [ENABLED]
pad1: Source
[fmt:RBG888_1X24/1920x1080 field:none colorspace:srgb]
-> "a0000000.v_proc_ss":0 [ENABLED]
Individual interfaces can be configured using media-ctl -V with commands similar to the following:
media-ctl -V '"80000000.mipi_csi2_rx_subsystem":0 [fmt:SRGGB10_1X10/1920x1080 field:none colorspace:srgb]' -d /dev/media0
media-ctl -V '"80000000.mipi_csi2_rx_subsystem":1 [fmt:SRGGB10_1X10/1920x1080 field:none colorspace:srgb]' -d /dev/media0
media-ctl -V '"a0110000.ISPPipeline_accel":0 [fmt:SRGGB10_1X10/1920x1080 field:none colorspace:srgb]' -d /dev/media0
media-ctl -V '"a0110000.ISPPipeline_accel":1 [fmt:RBG888_1X24/1920x1080 field:none colorspace:srgb]' -d /dev/media0
media-ctl -V '"a0040000.v_proc_ss":0 [fmt:RBG888_1X24/1920x1080 field:none colorspace:srgb]' -d /dev/media0
media-ctl -V '"a0040000.v_proc_ss":1 [fmt:UYVY8_1X16/1920x1080 field:none colorspace:srgb]' -d /dev/media0
Video and media devices
In PetaLinux, each connected RPi camera will be associated with a video device and a media device.
When using tools such as GStreamer, we need to specify the video or media device to use, so
it is important to know which cameras (which ports) are associated with which video devices and
which media devices. Note that they are not necessarily aligned by index (ie. /dev/video0 and
/dev/media0 are not necessarily associated with the same camera). So in the case that we have not
connected a camera to every port that is supported by our hardware design, we need to determine the
video and media device associations.
When you list the video devices using v4l2-ctl --list-devices, you will find a video device
(eg. /dev/video0) for every video pipe in the hardware (Vivado) design. In other words, you will
find a video device for every camera that the hardware is capable of connecting with. However,
it is important to know that you will only find a media device (eg. /dev/media0) for every camera
that has actually been physically connected to the hardware and successfully enumerated.
To make this clear, let’s consider a typical example. Most of the designs in this project are built to handle 4 cameras, but let’s say that we only connect 2x RPi cameras, one on port CAM1 and another on port CAM2. This would result in the following list of devices:
zcu104-rpi-cam-fmc-2022-1:~$ v4l2-ctl --list-devices
vcap_mipi_0_v_proc output 0 (platform:vcap_mipi_0_v_proc:0):
/dev/video0
vcap_mipi_1_v_proc output 0 (platform:vcap_mipi_1_v_proc:0):
/dev/video1
vcap_mipi_2_v_proc output 0 (platform:vcap_mipi_2_v_proc:0):
/dev/video2
vcap_mipi_3_v_proc output 0 (platform:vcap_mipi_3_v_proc:0):
/dev/video3
Xilinx Video Composite Device (platform:xilinx-video):
/dev/media0
/dev/media1
Notice that we have 4 video devices, but only 2 media devices. That is because the hardware can support 4 cameras, but only 2 have been connected and enumerated. From the above, we can determine these associations:
CAM1 is associated with
/dev/video1(sinceplatform:vcap_mipi_1_v_procis CAM1)CAM2 is associated with
/dev/video2(sinceplatform:vcap_mipi_2_v_procis CAM2)
To determine the associations with the media devices, we need to use a different tool: media-ctl.
As shown in the previous section, we can use the command media-ctl -p /dev/media0 to inspect
the video pipe elements of a particular media device. One of those elements, usually the first one,
is the video device. We can use grep to filter out the specific line indicating the associated
video device:
zcu104-rpi-cam-fmc-2022-1:~$ media-ctl -d /dev/media0 -p | grep "dev/video"
device node name /dev/video1
zcu104-rpi-cam-fmc-2022-1:~$ media-ctl -d /dev/media1 -p | grep "dev/video"
device node name /dev/video2
From the above, we determined these associations:
/dev/video1(which we know is CAM1) is associated with/dev/media0/dev/video2(which we know is CAM2) is associated with/dev/media1
Below are a few examples of camera connections and the resulting video and media device associations.
Only CAM1 and CAM2 connected
Port |
Video device |
Media device |
|---|---|---|
CAM0 |
|
N/C |
CAM1 |
|
|
CAM2 |
|
|
CAM3 |
|
N/C |
Only CAM0 and CAM1 connected
Port |
Video device |
Media device |
|---|---|---|
CAM0 |
|
|
CAM1 |
|
|
CAM2 |
|
N/C |
CAM3 |
|
N/C |
Only CAM2 and CAM3 connected
Port |
Video device |
Media device |
|---|---|---|
CAM0 |
|
N/C |
CAM1 |
|
N/C |
CAM2 |
|
|
CAM3 |
|
|
Init script
To make it easier for the user to identify and configure the connected cameras, and their associated video and media devices, a bash script is included in the root file system. When executed, the script lists the detected cameras, their physical ports, and their video and media devices. It also configures all of the video pipes according to the variables defined at the top of the script, or passed in as command line arguments.
The script is located in /usr/bin and can be called from the command line by typing init_cams.sh.
An example output of the script is shown below:
zcu104-rpi-cam-fmc-2022-1:~$ init_cams.sh
-------------------------------------------------
Capture pipeline init: RPi cam -> Scaler -> DDR
-------------------------------------------------
Configuring all video capture pipelines to:
- RPi Camera output : 1920 x 1080
- Scaler (VPSS) output : 1920 x 1080 YUY2
- Frame rate : fps
Video Mixer found here:
- a0100000.v_mix
Detected and configured the following cameras on RPi Camera FMC:
- CAM1: /dev/media0 = /dev/video1
- CAM2: /dev/media1 = /dev/video2
- CAM3: /dev/media2 = /dev/video3
In the example above, only cameras CAM1, CAM2 and CAM3 are physically connected. Notice that the video and media device indices don’t align, which can occur when less than 4 cameras are connected.
Usage
There are two main ways to use the init script: edit/customize it according to your needs; or run it with command line arguments to specify the desired configuration. If you edit the file, you will find five variables at the top of the script that can be modified to your needs. In below example, the RPi cameras are configured for 1080p resolution and the Video Processing Subsystem is configured to output 720p. The video format is set to YUY2:
# Resolution of RPi cameras (must be a resolution supported by the IMX219 Linux driver 640x480, 1640x1232, 1920x1080)
SRC_RES_W="${1:-1920}"
SRC_RES_H="${2:-1080}"
# Resolution of RPi camera pipelines (after Video Processing Subsystem IP)
OUT_RES_W="${3:-1280}"
OUT_RES_H="${4:-720}"
# Output format of the RPi camera pipelines (use a GStreamer pixel format from the dict above)
OUT_FORMAT="${5:-YUY2}"
The init script can take command line arguments to fill the configuration variables. The usage is shown below. Note that if you specify the configuration values in the command line, you must specify ALL variables and use the same order as shown below.
./init_cams.sh <SRC_RES_W> <SRC_RES_H> <OUT_RES_W> <OUT_RES_H> <OUT_FORMAT>
An example for configuring the RPi cameras to output 1080p which is then downscaled to 720p is shown below:
./init_cams.sh 1920 1080 1280 720 YUY2
The easy way to modify the script in PetaLinux is to copy the file from /usr/bin/init_cams.sh to the home
directory and modify the copy from there.
If you want to modify the init script that gets integrated into your build, you can find it in the BSP files
for your target board in this location of the repository:
PetaLinux/bsp/<target>/project-spec/meta-user/recipes-apps/init_cams/files/init_cams.sh
Yavta
An alternative way to get images from the cameras is to use the yavta tool, for example:
yavta -n 3 -c1 -f NV12 -s 1920x1080 --skip 9 -F /dev/video0
Changing camera settings
It is possible to change certain camera settings to improve the quality of the images from the cameras,
to change the colors or to flip the images. The settings that can be changed will depend on the camera
that is being used. To get a list of the settings, use the v4l2-ctl -d /dev/video0 --list-ctrls command.
In the case of the Raspberry Pi camera v2, this is the output from running that command:
uzevrpicamfmc20221:~$ v4l2-ctl -d /dev/video0 --list-ctrls
User Controls
exposure 0x00980911 (int) : min=4 max=1759 step=1 default=1600 value=1600
horizontal_flip 0x00980914 (bool) : default=0 value=0 flags=modify-layout
vertical_flip 0x00980915 (bool) : default=0 value=0 flags=modify-layout
red_gamma_correction_1_0_1_10 0x0098c9c1 (int) : min=1 max=40 step=1 default=10 value=10 flags=slider
blue_gamma_correction_1_0_1_10 0x0098c9c2 (int) : min=1 max=40 step=1 default=10 value=10 flags=slider
green_gamma_correction_1_0_1_1 0x0098c9c3 (int) : min=1 max=40 step=1 default=10 value=10 flags=slider
low_latency_controls 0x0098ca21 (int) : min=2 max=8 step=1 default=4 value=4
Image Source Controls
vertical_blanking 0x009e0901 (int) : min=4 max=64455 step=1 default=683 value=683
horizontal_blanking 0x009e0902 (int) : min=1528 max=1528 step=1 default=1528 value=1528 flags=read-only
analogue_gain 0x009e0903 (int) : min=0 max=232 step=1 default=0 value=0
red_pixel_value 0x009e0904 (int) : min=0 max=1023 step=1 default=1023 value=1023
green_red_pixel_value 0x009e0905 (int) : min=0 max=1023 step=1 default=1023 value=1023
blue_pixel_value 0x009e0906 (int) : min=0 max=1023 step=1 default=1023 value=1023
green_blue_pixel_value 0x009e0907 (int) : min=0 max=1023 step=1 default=1023 value=1023
Image Processing Controls
link_frequency 0x009f0901 (intmenu): min=0 max=0 default=0 value=0 flags=read-only
pixel_rate 0x009f0902 (int64) : min=182400000 max=182400000 step=1 default=182400000 value=182400000 flags=read-only
test_pattern 0x009f0903 (menu) : min=0 max=4 default=0 value=0
digital_gain 0x009f0905 (int) : min=256 max=4095 step=1 default=256 value=256
To change the exposure setting, we can run this command:
v4l2-ctl -d /dev/video0 --set-ctrl=exposure=1000
To change the analogue gain setting, we can run this command:
v4l2-ctl -d /dev/video0 --set-ctrl=analogue_gain=200
To change the digital gain setting, we can run this command:
v4l2-ctl -d /dev/video0 --set-ctrl=digital_gain=1000
Tip
If you find that you cannot change one of the settings above, or that some of them are missing, you might be targetting the wrong video device. If you target a video device that has no camera physically connected to it (thus also does not have an associated media device), you will find that not all of the settings are listed and available to modify. Read section Video and media devices for more information on determining the correct video device for the camera you intend to target.
If you wish to change certain settings on all of the connected cameras, one easy way to do that is to copy
the init script located at /usr/bin/init_cams.sh and add the desired configuration commands
in the appropriate section of the script. Then you can run your modified version of the script from the
command line and the configurations will be made to all of the connected cameras.
Display pipeline
This section will provide an example of using the Video Mixer based display pipeline with GStreamer. We will first configure the capture/video pipelines as follows:
RPi cameras will output 1080p resolution
Video Processing Subsystem will downscale to 960x540 (one quarter of the 1080p monitor)
Video Processing Subsystem will output YUY2 format
We can make the above configuration on ALL video pipes by using the init cams script:
init_cams.sh 1920 1080 960 540 YUY2
The display pipeline uses the Video Mixer IP to combine up to four video streams and send them to the DisplayPort live interface of the ZynqMP. In order to use the display pipeline in GStreamer, you first need to enable it with the following command:
modetest -M xlnx -D a0100000.v_mix -s 52@40:1920x1080@NV16
After running that command, the monitor should show a blue screen. At this point you are ready to use GStreamer to drive the Video Mixer. Note the following important points:
the
widthandheightparameters are set to output resolution of the video pipes.the
formatparameter is set toYUY2which is required by the Video Mixer as it is configured for that format in the Vivado design.the
render-rectangleparameter is set to<x,y,width,height>where x and y indicate where to position the top left corner of the video on the monitor. Width and height are set to the resolution of the video pipes.the
plane-idis set to 34, 35, 36 or 37, which correspond to the layer inputs of the Video Mixer IP.
sudo gst-launch-1.0 v4l2src device=/dev/video0 io-mode=mmap \
! video/x-raw, width=960, height=540, format=YUY2, framerate=30/1 \
! kmssink bus-id=a0100000.v_mix plane-id=34 render-rectangle="<0,0,960,540>" show-preroll-frame=false sync=false can-scale=false \
v4l2src device=/dev/video1 io-mode=mmap \
! video/x-raw, width=960, height=540, format=YUY2, framerate=30/1 \
! kmssink bus-id=a0100000.v_mix plane-id=35 render-rectangle="<960,0,960,540>" show-preroll-frame=false sync=false can-scale=false \
v4l2src device=/dev/video2 io-mode=mmap \
! video/x-raw, width=960, height=540, format=YUY2, framerate=30/1 \
! kmssink bus-id=a0100000.v_mix plane-id=36 render-rectangle="<0,540,960,540>" show-preroll-frame=false sync=false can-scale=false \
v4l2src device=/dev/video3 io-mode=mmap \
! video/x-raw, width=960, height=540, format=YUY2, framerate=30/1 \
! kmssink bus-id=a0100000.v_mix plane-id=37 render-rectangle="<960,540,960,540>" show-preroll-frame=false sync=false can-scale=false
Known issues and limitations
PYNQ-ZU and Genesys-ZU limits
The ZynqMP devices on the PYNQ-ZU and Genesys-ZU boards are relatively small devices in terms of FPGA resources. Fitting the necessary logic to handle four video streams simultaneously can be a challenge on these boards. For this reason, in our Vivado designs for these boards we have included the video pipes for only two cameras: CAM1 and CAM2.