We have a dashboard system (Dashing) that we can view through a browser (Chrome). We have two TVs up displaying this dashboard now. Each TV has a $350 PC connected to it. I am wondering if we could use a Chromecast plugged into each TV and have only one PC "displaying" the dashboard. This is relevant because 1) we are looking at adding monitors after we expand our office and 2) the PCs tend to be a pain in the ..., with things like updates pushed from IT, password chances, etc. One PC would definitely be better. Bonus points if I can get rid of all the PCs and just use Chromecast pointed at a URL.
Thanks,
Although not supported officially, I was successfully able to cast my entire screen to two devices by using both the Google cast and the Google cast (Beta) extensions simultaneously. I could only get it to work using one extension in an incognito window and the other in a normal window.
You can cast to multiple Cast devices if you create an additional "people" in Chrome settings for each of your Cast devices, then open a new window(not tab) for each "people".
Each "people"/user can attach to a different Cast device. It helps to match the user name to the device or location to keep it all straight.
Ex: Cast a movie from NAS to 3 TVs.
Use VLC to stream movie.
Open 3 Chrome/chromium windows(not tabs), changing each window to a unique user/person.
Start streaming.
Point each window at stream, play and cast to a different device.
Performance will depend on ability of PC and router/wifi. We use the Ethernet power supply for Chromecast to reduce load on wifi AP. (We had Cat5 Ethernet already installed)
Since all browser windows are pointed at same stream, the sync is pretty good. Although we usually stream to living room, patio, and game room which a difference hard to detect.
Hope this helps someone.
Currently, you can only be connected to a single device at a time, hence can only mirror to one Cast device. You mentioned you are mirroring your browser. Is the content that you are mirroring a simple page, a video, ...? You may be able to come up with a simple app that would eliminate the need for having PC's completely. Tell us more about the content you are mirroring (hopefully it is not flash :-) )
The Chrome browser extension can only cast to one device. A workaround is to install the Chrome browser extension Beta version alongside the non-beta version, and you'll have a second browser extension that can cast to a second device.
My colleague suggests that if you install Chrome Canary, the Beta version of Chrome, you can run two Chromes, with two extensions each, and support four devices.
Hopefully, this limitation will be removed, and the browser extension will support multiple devices.
Our use case is driving information kiosk displays from a single computer. Chromecast is nice in that the display's physical security does not expose the PC driving the display.
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I want to use an USB HID from a website. The website will only be accessed by Chrome browsers. The solution should require a minimum amount of extra software and setup for the website user to work.
The USB device presents itself as USB HID to the OS and I need to write and read byte arrays to and from it in order to implement the manufacturers specification for some of the device's features.
My current solution consists of two parts:
A Chrome App that uses the chrome.hid API to talk to the device. This App exposes a Chrome Cross-Extension messaging port to provide and interface for "service calls".
JavaScript code on the website that sends requests to the Chrome App, which then talks to the USB device to process the request.
In order to make it easier for the user I want to get rid of the App, so the user can just surf to the website, grant access to the device if necessary and then be able to use the device.
To be clear, I want the user to be able to use the website without installing any dependency first.
I already tried using the WebUSB navigator.usb API but Chrome blocks access to USB HID devices. Is there another way to accomplish this?
WebHID is being developed for this use case. It has been available behind a feature flag since Chrome 78, with an original trial expected in Chrome 84 (probably later due to current Covid-19 situation), estimated stable August 2020 .
For more details: https://github.com/robatwilliams/awesome-webhid
My WP8 app has some audio or videos, I'd like to share them with other plateform devices, such as iPhone or android devices. The first thing that comes to mind is Bluetooth. Can I realize this feature in my app? And how to do it? Thank you!
Sure you can do that, its the same like all file sharing apps do (whatsapp for Example) but your are about to do this using bluetooth connection, you just need to build a connection and transfer the file to the target device which should be able to open the file according to its format and the installed apps on the device.
I've worked with iOS Bluetooth extensively and the different ways you can share data over Bluetooth is by:
Using one of the Bluetooth profiles already supported by iOS: http://support.apple.com/kb/ht3647
Bluetooth LE (Core Bluetooth). I haven't used this, but the bandwidth and data structure of data being transmitted is limited, so it may not suit your purpose of sending audio and video.
Game Kit. This is for iPhone-to-iPhone data transmission though.
External Accessory Framework. This framework allows you to transmit raw data, but is only available to BT-enabled devices with special Apple authentication hardware (you have to join the MFi program and go all these hoops to get your device qualified). This doesn't work for you too, since you'd want to send data from WP8 or Android, which are definitely not MFi qualified.
So, bottom line, you CAN NOT send raw audio or video data from WP8 and Android to your iPhone unless you jailbreak the iPhone and put a new stack. iOS's BT stack is really limiting in that way, as I've learned the hard way.
On the bright side, you can definitely send raw data between Android and WP8 over Bluetooth. You have to create an RFCOMM socket on both ends (one sending; one listening). The Bluetooth profile used for this sort of data transfer is called a Serial Port Profile.
I want to make an HTML5 game that can be controlled with mobile. So how to communicate between mobile and browser on PC?
I think of the following ways:
Bluetooth This may be the most easy way to use. But I searched and found that Chrome made bluetooth API proposal last year but is now available only on Chrome dev, which means I cannot make the game popular for everyone.
WiFi I don't know how to set up a host on browser using WiFi information. If so, I can then connect my mobile to WiFi. This is considered to be faster than web socket since it's local network.
Web Socket There're a lot of information about how to use this. But as this use WAN, it is considered to be slower and is my last choice.
So, does anyone know how to achieve this with the former 2 ways?
I'm looking for a way to securely deliver video to mobile devices. There are two options:
HLS in tag. This works very nicely for iOS and supports adaptive bitrate, perfect for mobile. However, is seems to only work well on iOS. There seems to be only fragmented support for it on Android. I've read that Android has officially supported it since 3.0, but on all the android devices I've tested (>3.0), HLS hasn't played back on the browser.
Progressive download in tag. This will work on iOS and Android devices fine, but the concern is that since it's just a progressive download of the video, that the user find a way to just grab that video once the browser has finished downloading it. This may be more difficult on iOS, but I'm sure it's not that hard to figure out where the browser stored the video download in a tmp folder somewhere.
Either method I'd say can be protected from deeplinking by using an expiring token approach, where the token is generated serverside with a secret key that only the content server knows about. The video request would only be valid for 5 or 10 minutes, would would kill of deeplinking.
Is anyone aware of any way around these issues? Even if I was able to prevent deeplinking, the user could still get the video itself and re-distribute. Perhaps it's just not possible?
Thanks
Rule #1 of the internet:
If you don't want someone stealing it, don't put it online.
Welcome to the circumvention arms race. Brought to you by DownloadHelper.
There's nothing you can do to stop someone who really wants to pirate your video. There are various measures, like those you mention, that make it more difficult, but someone who really wants to copy it could find a way to capture it from memory, or even just point a camera at the screen and record the playback of the video.
It's the same way you protect your car. You install a steering lock, an alarm and an engine immobiliser, and then someone comes alongs and pulls the car onto a flat-bed truck and drives away with it.
Bottom line - you can't stop a determined thief, but you can make theft more difficult so that you're not the most attractive target.
As I was reading the above I could easily get pass all these techniques pretty quickly.
For a project I can't describe too much because of nda, we created our own protocol based on a well known encryption method can't mention that either , military grade) , encoded packets on the server to the protocol, and decoded on the device.
unfortunately this isn't perfect either because a lot of mobile apps can be re-versed engineered and once you get the key game over, very easy on android, of course you could periodically recycle the key, in which case even if they decompiled the android app and got the key it wouldn't work very long.
This is a lot of work and can't be implemented with html5 or hLS or event rtsp.
It also requires a custom server application that takes the video stream re-transmits it with the custom protocol.
On the other hand the protocol was transport agnostic, which meant we could use a variety of transports, tcp, IAP and bluetooth. Also would work on all mobile / desktop platforms.
The other little requirement, is couldn't use a browser, have to be a custom app.
Any ideas on how to get memory usage, Javascript errors, etc. from Chrome running on Google TV?
I have a page that is getting the "Aw, snap!" error when viewed in the Chrome browser on Google TV (Logitech). The page is fairly simple, but it does load a bunch of photos, though only up to 7 at a time (the photos are loaded using JavaScript). The photos are 640x480 and ~500KB each. They are stacked and the top one fades out (using jQuery) until all are gone then a new batch is loaded.
It only crashes on Google TV (it runs fine on Windows 7) and it takes a while before it crashes (I can get it down to about 10-20 minutes before it crashes by turning on a "fast mode" on our page).
Unfortunately I can't figure out how to get any information that might help me debug it. It would be cool to be able to get Chrome's developer tools on the Google TV device.
Currently there is no way to pull debug information from Chrome on Google TV. The Logitech Review is rather limited in it's RAM and you may be encountering an issue there (I don't know how big these images are). It is also possible that you have a memory leak in your javascript code. This might be hidden on other systems running a browser as there would be more memory to buffer you from seeing the error.
My advice would be to create a virtual machine (VirtualBox is free and runs on Windows) - create a VM with limited memory (256Mb Ram for instance) and install Ubuntu or some other flavor of linux that can run Chrome. Then run your app in the VM and see what happens.
Failing that you could always try loading the imaged with static image tags and see if it is the images that are causing the crash. If it's not the images then I would say look at your JS code closely and perhaps run it through JSLint (http://www.jslint.com/)