any progress made in stitching video since the last answer by Luke Yeager ?
I plan to develop 360 surround view for my car
Since --- StitcHD Project --- by Luke is already 5 years old
I expect some progress to be announced in technology, faster GPU live video processing and better depth maps matching.
https://github.com/lukeyeager/StitcHD
I would prefer WebRTC video tools but didn't get any answer on how to connect 4 usb webcams and get 4 live video streams for stitching.
If you want to enumerate all devices using WebRTC,
https://webrtc.github.io/samples/src/content/devices/input-output/
shows how to do that and then open a specific device. You can open multiple devices at the same time but mind you that this is going to be taxing for the USB bus.
The canvas sample which shows how to grab a frame from the video stream and convert it into an image might be useful too.
Related
I am using the AR Parrot drone 2.0, and I want to somehow "trick" the PC into thinking that the video stream coming from it is a second webcam.
The reason is that I want to use some existing computer vision libraries, and it would much more straight forward to just specify which webcam is the source of the video stream, on which the algorithms will run.
I came across an iOS app that streams video from the AR drone, but it seems to stream it on iPhones/iPads and not on computer devices.
Are you looking for a full app or do you want to create one by yourself?
I'm working with an AR.Drone 2.0 for a research project and although it is an old device which makes it complicated to find resources, there are... and lots of them.
If you want to create your own app, you don't say which language / platform you want to use it. If you want to use Java, you can use YADrone. It has a good API and it also has examples, including a full application that can be used.
https://vsis-www.informatik.uni-hamburg.de/oldServer/teaching//projects/yadrone/
I'm new to Roku development (in R&D phase actually). I read that we can't test Roku app on simulator and need real device. If we develop an application, how will we test it?
I checked Roku developer site and different links on internet, but could not find anything that answers my questions
As per my info, Roku sells 5 devices so:
Can we do one app that supports all 5 devices?
Do we need assets in multiple resolutions?
Do I need to buy all devices?
Can we do one app that supports all 5 devices?
Yes. Roku is trying hard to keep their platform coherent, though there are performance issues between the OpenGL and non-OpenGL devices. The "legacy" models (<2222) are no more supported, the firmware is kept current for the others.
Do we need assets in multiple resolutions?
Theoretically yes, practically - not really. You can make-do with assets in only one resolution, if you RTFM and pre-plan carefully. You'll need 3 sizes of app icon, no sweat. For the real UI though, you can either do HD (720) or FHD (1080) and leave it scale accordingly - the thing is TV is very forgiving to scaling graphics because of 10ft watching distance (60" 1080p screen is "Retina" beyond 8ft). Can largely snub SD.
Do I need to buy all devices?
No. And there are much more than 5 devices that are in use - see https://forums.roku.com/viewtopic.php?f=34&t=86471&start=15#p536994 for some statistics (RokuCo does not publish statistics, so that's about the best info available). If you buy only 2 devices, i'll say get
a #42xx (Roku 3 or current Roku 2) as reference model with OpenGL
a #27xx (Roku 1 or SE) or #5xxx RokuTV as reference for "slower", non-OGLES
As 3rd model i'll say the "new HDMI stick" #3600. You can get that one as the only device, its performance is somewhere between (1) and (2) above... but i don't think developing with only 1 device is a good idea.
One thing you may not have noticed is that there are also these "Roku TV" things under Hisense/TCL/Sharp/Insignia brands, models #5xxx. These are proper TVs with proper Roku smarts - meaning can run your Roku app. And one can be had for as little as... (skimming BestBuy web) $130-150 for 24-32" screen.
And i haven't even mentioned the 4k/HDR craze here, nor the new 37xx/46xx models that will be out for the holiday season (i only expect minor, evolutionary changes there).
Disclosure: I am a Roku employee.
That's correct, you'll need an actual Roku device to test your application. You can buy them used on eBay for very cheap ($20-35), or you can buy a brand new unit from our website for $50. The latest Roku Streaming Stick (Model #3600X) is my personal favorite option, and a great value.
You don't need to buy all devices, although we do recommend having many models so that you can QA test across devices. However, one popular development approach is to build your channel on a lower-end model, which theoretically will assure it works on higher-end models as well. This will also mean you have to spend less on your purchase.
Download our Precertification Checklist and open the third sheet, which includes a list of all our model numbers and corresponding code names. I'd recommend building on a "Giga" or a "Paolo."
Think of this cost as an R&D expense. Plus you'll get to enjoy the device on your free time as well!
As for your other questions:
Yes, you will only build one app that will work on all different devices. We do recommend taking the time to make sure your app is optimized across all devices, including older devices with less processing power. Our Performance Guide is a great starting point for this.
The other option is to check if the first number of the device model is less than “3” (which indicates it's a lower-end device) and add conditionals off that, such as removing animations.
You can find two examples of this on our RokuDev GitHub page:
Hero-Grid-Channel —> Components —> LoadingIndicator —> LoadingIndicator.brs —> Line 244
Multi-Live-Channel —> Source —> Main.brs —> Line 21
Yes, you do need different assets based on resolutions. Take a look at this document: https://github.com/rokudev/docs/blob/master/design/channel-artwork.md
I want to embed a video stream into my web page, which is part of our own cloud based software. The video should be low-latency (like video conferencing), and it would be preferable, but not required, for it to include audio. I am comfortable serving streaming binary data from the server-side, and embedding it into the page using HTML5 video.
What I am not comfortable with is the ability to capture the video data to begin with. The client does not already have a solution in place, and is looking to us for assistance. The video would be routed through our server equipment, and not be an embedded peice that connects directly to the video source.
It is a known quantity for us to use a USB or built-in camera from the computer. What I would like more information is about stand-alone cameras.
Some models of cameras have their own API documentation (example). It would seem from what I am reading that a manufacturer would typically have their own API which they repeat on many or all of their models, and that each manufacturer would be different in their API. However, I have only done surface reading and hope to gain more knowledge from someone who has already researched this, or perhaps even had first hand experience.
Do stand-alone cameras generally include an API? (Wouldn't this is a common requirement, so that security software can use multiple lines of cameras?) Or if not an API, how is the data retrieved from the on-board webserver? Is it usually flash based? Perhaps there is a re-useable video stream I could capture from there? Or is the stream formatting usually diverse?
What would I run into when trying to get the server-side to capture that data?
How does latency on a stand-alone device compare with a USB camera solution?
Do you have tips on picking out a stand-alone camera that would be a good fit for streaming through a server?
I am experienced at using JavaScript (both HTML5 and Node.JS), Perl and Java.
Each camera manufacturer has their own take on this from the point of access points; generally you should be able to ask for a snapshot or a MJPEG stream, but it can vary. Take a look at this entry on CodeProject; it tackles two common methodologies. Here's another one targeted at Foscam specifically.
Get a good NAS, I suggest Synology, check out their long list of supported IP Web Cams. You can connect them with a hub or with a router or whatever you wish. It's not a "computer" as-in "tower", but it does many computer jobs, and it can stay on while your computer is off or away, and do thing like like video feeds, torrents, backups, etc.
I'm not an expert on all the features, so I don't know how to get it to broadcast without recording, but even if it does then at least it's separate. Synology is a popular brand and there are lot of authorized and un-authorized plugins for it. Check them out and see if one suits you.
I got a question of image capture with a PC camera(integrated note book camera or web cam). While I am developing a computer vision system in which high quality image capture is the key issue, most of the current method is use VFW or directShow to capture video stream and snap one frame as an image.
However, this method could not get high quality image ( or using up the full capacity of the camera). For example, I got a 5 mega pixel web cam. but the video stream is maximum 720P(USB bandwidth problem?). Video streaming is wasting some of the camera sensors.
Could I video streaming and taking picture independently? like inputing video with a 640*480 video stream and render on the stream. then take a picture of 1280*720 from the same cam? I guess this would be a hardware problem? the new HTC one X camera?
In short, it's there a way for a PC system to take a picture ,full use of the sensor capacity, without video streaming and capture one frame. Is this a hardware related problem? Does common web cam support this? Or a Software problem, I should learn DirectShow things?
Thanks a lot.
I vaguely remember (some) video sources offer both a capture and still pin, the latter I assume would offer you higher quality. You can easily test this in GraphEdit. If it works then yes, you'll have to learn DirectShow. Or pay someone to code this for you.
Could we get two live video streams at the same time? Or should I switch cameras to get two streams?
According to Apple, accessing both cameras at once is not supported. If you have access to the Apple Developer Forums, see this post.
Also, BTW, switching streams is quite slow in my experience and would be no substitute for accessing both cameras at once.