Capturing single image

2024-02-25 21:53

Is there an example of a program that will capture just a single image with the camera? I don't need to capture video, but I do want just a single image taken at regular intervals.

Would this require using opencv-mobile or is there a different utility that can be used?

2024-02-26 1:39

For capturing a single image using the libraries mentioned:

1 Using OpenCV-Mobile:
When using OpenCV-Mobile to capture an image, you should skip the initial frames captured because the YUV format may not be correctly set up initially. After initializing the camera, you can discard a few initial frames before capturing the image to ensure that the camera setup is stabilized.

2 Using V4L2:
V4L2 (Video for Linux 2) can be used to capture images directly in NV12 format (YUV420SP).
You can refer to the link viewtopic.php?t=106

3 Using RKMPI:
For capturing and encoding an image using RKMPI, you can refer to the sample codes provided in <luckfox-pico sdk>/media/samples/simple_test/. Translate and refine the code according to your requirements.

2024-02-27 18:20

Perfect, thank you very much! I will give these a try.

2024-03-09 3:43

Coming back to this after a while. I did manage to get the "v4l2_test" utility to work and I could convert the YUV file using a tool on my desktop computer.

However, I have been trying to follow the instructions here for installing the v4l2 tools https://wiki.luckfox.com/Luckfox-Pico/C ... ls-toolkit.

I have run through the Buildroot menuconfig process a couple of times, but the v4l2-ctrl command & ffplay never seem to be installed. Is there some extra step to getting these working?

Thanks!

2024-03-09 6:23

torchris4 wrote: ↑2024-03-09 3:43 Coming back to this after a while. I did manage to get the "v4l2_test" utility to work and I could convert the YUV file using a tool on my desktop computer.

However, I have been trying to follow the instructions here for installing the v4l2 tools https://wiki.luckfox.com/Luckfox-Pico/C ... ls-toolkit.

I have run through the Buildroot menuconfig process a couple of times, but the v4l2-ctrl command & ffplay never seem to be installed. Is there some extra step to getting these working?

Thanks!

Hello, this is a task that is prone to errors, so you need to ensure that no steps are missing in your execution. Here are the steps you need to follow:

1Delete the old rootfs.img by executing the command in the SDK root directory.

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./build.sh clean rootfs

2Enter the directory <Luckfox-pico-sdk>/sysdrv/source/buildroot/buildroot-2023.02.6.

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cd sysdrv/source/buildroot/buildroot-2023.02.6
make luckfox_pico_defconfig

3Execute the command to add tools such as v4l2-ctl.

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make menuconfig

4Save the settings and compile.

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make savedefconfig
make -j

5Return to the SDK root directory and execute the command to generate and package the rootfs.img.

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./build.sh rootfs
./build.sh firmware

Note: ffplay is designed for PC use, primarily for viewing images in YUV format.In buildroot, there is no need to add ffplay.

2024-03-09 17:25

Thanks! I will try this. I think I was probably missing the "clean" step. I will post the results.

2024-03-10 22:57

Trying this out, it seems to get stuck on this "library intl found: NO" error:

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Run-time dependency libffi found: YES 3.4.4
Run-time dependency zlib found: YES 1.2.13
Checking for function "ngettext" : NO 
Library intl found: NO

output/build/libglib2-2.72.3/meson.build:2102:4: ERROR: Automatic wrap-based subproject downloading is disabled

A full log can be found at /root/sdk/luckfox-pico/sysdrv/source/buildroot/buildroot-2023.02.6/output/build/libglib2-2.72.3/build/meson-logs/meson-log.txt
make: *** [package/pkg-generic.mk:283: /root/sdk/luckfox-pico/sysdrv/source/buildroot/buildroot-2023.02.6/output/build/libglib2-2.72.3/.stamp_configured] Error 1

Not sure what that library is. Even after I deselected all the V4L2 packages it still gives me that.

2024-03-10 23:00

And from the log file for the compile:

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Checking for function "ngettext" : NO
Running compile:
Working directory:  /root/sdk/luckfox-pico/sysdrv/source/buildroot/buildroot-2023.02.6/output/build/libglib2-2.72.3/build/meson->
Command line:  /root/sdk/luckfox-pico/sysdrv/source/buildroot/buildroot-2023.02.6/output/host/bin/arm-rockchip830-linux-uclibcgn>

Code:
 int main(void) { return 0; }

Compiler stdout:

Compiler stderr:
 /root/sdk/luckfox-pico/tools/linux/toolchain/arm-rockchip830-linux-uclibcgnueabihf/bin/../lib/gcc/arm-rockchip830-linux-uclibcg>
collect2: error: ld returned 1 exit status

Library intl found: NO

output/build/libglib2-2.72.3/meson.build:2102:4: ERROR: Automatic wrap-based subproject downloading is disabled

2024-03-11 1:49

torchris4 wrote: ↑2024-03-10 23:00 And from the log file for the compile:

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Checking for function "ngettext" : NO
Running compile:
Working directory:  /root/sdk/luckfox-pico/sysdrv/source/buildroot/buildroot-2023.02.6/output/build/libglib2-2.72.3/build/meson->
Command line:  /root/sdk/luckfox-pico/sysdrv/source/buildroot/buildroot-2023.02.6/output/host/bin/arm-rockchip830-linux-uclibcgn>

Code:
 int main(void) { return 0; }

Compiler stdout:

Compiler stderr:
 /root/sdk/luckfox-pico/tools/linux/toolchain/arm-rockchip830-linux-uclibcgnueabihf/bin/../lib/gcc/arm-rockchip830-linux-uclibcg>
collect2: error: ld returned 1 exit status

Library intl found: NO

output/build/libglib2-2.72.3/meson.build:2102:4: ERROR: Automatic wrap-based subproject downloading is disabled

Unfortunately, I haven't encountered this problem before, so I'm not sure what issues you've encountered during the buildroot setup.
You can try the following steps to restore everything to its original state:

1.elete <SDK Path>/sysdrv/source/buildroot/buildroot-2023.02.6/output.
2.Retrieve the luckfox_pico_defconfig from GitHub and overwrite it in <SDK Path>/sysdrv/source/buildroot/buildroot-2023.02.6/configs/luckfox_pico_defconfig (the original luckfox_pico_defconfig may have been modified when executing savedefconfig).
3.Re-execute the rootfs to add libv4l.

I hope this helps.

2024-03-11 2:16

Thanks!

What I did was go back up to the sdk root and do a "make clean" which deleted everything. Then I did the ./make -lunch & ./make to rebuild everything.

Then I went back through the menuconfig process and everything compiled. I will test the new image tomorrow.

I also have no idea why it got stuck on the "ngettext" issue. I can't see what would be using it.

V4l2 is finally installed!!