ARM single board CHDKPTP driver support and video quality under linux ?

jhenry5

1

« on: 24 / February / 2014, 02:37:19 »

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Hi,
I just discovered CHDK 2 days ago and I'm seeing conflicting and sometimes unreliable information.
I am interested in connecting a canon point & shoot camera to a ODroid, or UDOO or Radxa Rock single board computer. The selected single board computer will run linux on a ARM architecture. I read beaglebone (a ARM linux platform) has CHDK support. Is there any support for linux ARM boards in general or for the 3 specific boards I mentioned ? Where can i find the drivers for the ARM linux pc? CHDKPTP "streams video from the camera screen via usb, to a PC". Is this video HD (my hypothetical camera shoots at 1080p, 30fps)? What quality is streamed? I want HD video streamed to my linux ARM pc for image processing. From a linux pc, under an ARM architecture : What are some other options for a) streaming video to a pc from a camera and b) controlling a camera from a pc (i.e. a backup plan, if CHDK doesn't work) ?

Thanks kindly,
Sorry for the newbie questions,
Hopefully the answers help, not just me, but other beginners.

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zeno

891

Re: ARM single board CHDKPTP driver support and video quality under linux ?

« Reply #1 on: 24 / February / 2014, 04:55:41 »

When controlling a CHDK-enabled camera via PTP over a usb link, the only thing that matters at the computer end is having libusb support. The architecture/cpu of the computer is irrelevant.

There's libusb support for various linux flavours - see this thread for example http://chdk.setepontos.com/index.php?topic=8246.0

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lyzby

52

Re: ARM single board CHDKPTP driver support and video quality under linux ?

« Reply #2 on: 24 / February / 2014, 14:17:58 »

Not quite what you want, since it's single shot at a time, but you might look here for how to get chdkptp compiled on a headless dockstar running debian. Fairly straightforward.

http://chdk.wikia.com/wiki/Chdkptp_in_headless_linux_Dockstar_-_remote_control

I'd be happy to see what you come up with for processing any kind of stream.

« Last Edit: 24 / February / 2014, 14:19:43 by lyzby »

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reyalp

14034

Re: ARM single board CHDKPTP driver support and video quality under linux ?

« Reply #3 on: 24 / February / 2014, 23:45:25 »

Quote from: jhenry5 on 24 / February / 2014, 02:37:19

Is this video HD (my hypothetical camera shoots at 1080p, 30fps)?

No. It's raw data from from the camera display frame buffers, polled at whatever rate your client can manage (generally less than 30 FPS, not synced with the camera frame rate).

The exact resolution depends on the camera, and the camera settings. In general, it's something like 720x240 or 720x480, YUV 411 (described in http://chdk.wikia.com/wiki/Frame_buffers#Viewport)

Quote

I want HD video streamed to my linux ARM pc for image processing. From a linux pc, under an ARM architecture : What are some other options for a) streaming video to a pc from a camera

Some cameras (mostly older ones) allow you to use the video out port in shooting mode, so on those you could theoretically use a video capture device. However, I'm not aware that any of the HDMI equipped cameras support this.

It's possible that with enough reverse engineering you could hack the HDMI out to be on in record mode. OTOH, it's also possible that the hardware is incapable of doing that.

Quote

and b) controlling a camera from a pc (i.e. a backup plan, if CHDK doesn't work) ?

I'm not sure what you mean here. On most (maybe all?) recent canon cameras, CHDK is your only option for controlling the camera from a PC. Some older ones support Canon's SDK, and can be controlled using their software or third party applications like gphoto.

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