Hardware power and transfering data

StereoPi hardware discussion
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Secondary
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Hardware power and transfering data

Post by Secondary » Sun Jul 28, 2019 11:31 am

Hello. I have few questions about StereoPi.

First: is it powerfull enough to capture video-stream from two cameras with enough quality and frames frequency for being comfortable for human eye and transfer mixed video-stream to more powerfull device? I know that it has it's own OS and is computer by itself, but I need capture video-stream for showing it in fullscreen mode, so captured images must have big size and FPS is important too. Or maybe it will be even big overkill for such task?

Another question: is it possible to transfer video-stream from it to another computer in real time through USB for example? I know that there is way to transfer stream through network, but it can be not the best way for me.

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Realizator
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Re: Hardware power and transfering data

Post by Realizator » Sun Jul 28, 2019 12:25 pm

Hi Secondary,
Video livestream is working out-of-the-box, and this is optimized solution now, as it uses Pi's GPU. So you can capture this stream and either record it, or foward to your Big Brother for processing.
As for high-quality - it depends on your needs. You can set 10 or 20 MBit bitrate (H264) for HD video, or even FullHD video. For HD you may obtain up to 42 FPS (some tuning needed), and 30 FPS for FullHD.

For USB transfer there are two ways. First one is a stream to Android phone by USB. This feature is supported in our S.L.P. image, and StereoPi is detected as "Android acessory" by phone.

Another way is to use USB Gadget mode (advanced feature), when you connect StereoPi to another device through StereoPi's microUSB. In this case StereoPi is detected as RNDIS device (of course, you need to do some coding to enable this feature).

If it is not a secret, what task you are trying to solve with this approach?
Eugene a.k.a. Realizator

Secondary
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Re: Hardware power and transfering data

Post by Secondary » Sun Jul 28, 2019 12:47 pm

Realizator wrote:
Sun Jul 28, 2019 12:25 pm
If it is not a secret, what task you are trying to solve with this approach?
Thanks for the answer.
I want to do some kind of AR device. So, postprocessing of video-stream will require enough computing to make little computer being laggy if do such suff just on it. If it realy can do HD in 35+ FPS and transfer it - I think, it is enough for me. Not very cool that using it as peripheral device needs doing some tricks but I will try to understand how to do it :)

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Re: Hardware power and transfering data

Post by Realizator » Sun Jul 28, 2019 4:52 pm

Secondary, this is a working approach with video livestream and post-processing on receiving part. AR.js is a great example of such approach. We have a plans to do an experiment with livestream to the phone and add AR with AR.js as a proof-of-concept.
Eugene a.k.a. Realizator

Secondary
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Re: Hardware power and transfering data

Post by Secondary » Sun Jul 28, 2019 6:46 pm

That's nice. But streaming video through wi-fi network between two devices is physically hard in some cases because you need to keep enough good router somewhere near.

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Re: Hardware power and transfering data

Post by stereomaton » Tue Jul 30, 2019 6:40 am

There is no builtin wifi, but you can add a dongle.
Also, most phones nowadays include a simple wifi hotspot that can be useful with stereopi.

Network can also be used via Ethernet, but it still requires infrastructure.

The third way highlighted by Realizator is to use USB gadget which makes the stereopi appear as a network USB device. With a bit of configuration, you have a network buddy without WiFi nor Ethernet.
Due to hardware limitations on raspberry-pi module, this solution disables Ethernet and USB ports.
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StereoPi Standard Edition + CM3Lite module

Secondary
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Re: Hardware power and transfering data

Post by Secondary » Thu Aug 01, 2019 1:56 pm

Realizator wrote:
Sun Jul 28, 2019 4:52 pm
I'm sorry for asking again, but are the answers for this post on vir2real compatible with StereoPi or not? I'm not so good with linux and raspberry wizardry, so searched for some other posts about this and found it.
http://forum.virt2real.ru/viewtopic.php?f=38&t=14736

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Re: Hardware power and transfering data

Post by Realizator » Fri Aug 02, 2019 7:46 pm

Secondary wrote:
Thu Aug 01, 2019 1:56 pm
Realizator wrote:
Sun Jul 28, 2019 4:52 pm
I'm sorry for asking again, but are the answers for this post on vir2real compatible with StereoPi or not? I'm not so good with linux and raspberry wizardry, so searched for some other posts about this and found it.
http://forum.virt2real.ru/viewtopic.php?f=38&t=14736
Nope, as our board virt2real (developed in 2010-2011,EOL now) was built on another SoC (TI DaVinchi DM365/368), and used special Linux edition. You may consider StereoPi as a virt2real 2.0 board, with the Raspberry Pi CM as a heart, and with all Raspberry Pi ecosystem.
If you'll find any Pi-related receipts, say, on https://www.raspberrypi.org/forums/, all of them will work with the StereoPi.
Eugene a.k.a. Realizator

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Re: Hardware power and transfering data

Post by Secondary » Sat Aug 03, 2019 9:53 am

Realizator wrote:
Fri Aug 02, 2019 7:46 pm
Big thanks.

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