Tuesday, 26 August 2014

Ospreys with Chromecast

Watching the Dyfi ospreys on a computer screen is as good a way as any to while away five months that could usefully be spent doing something else - but it's not always convenient. Like many other DOP fans, I have always wished that I could display the live pictures on my big TV screen, and observe from the comfort of my lazy armchair – or even (heath and welfare permitting) in my bedroom. And now there is a way to do this...

Google's CHROMECAST device is a “streaming dongle” - which sounds like something you'd pay extra for in certain establishments on the seamier side of Greek Street, but in fact describes a gadget that can fetch video files from internet sites such as YouTube, and output them in a format that can display on any compatible TV. (It can do other things, too, but more of this later.)

The Chromecast connected to a Toshiba 22L702 TV
That word “compatible” is the first thing to consider. To use Chromecast – or any other of the growing selection of similar devices, we need a TV that has an HDMI input port. In the case of Chromecast, there is no other option than HDMI. It does have a USB socket but this is solely for the supply of external power, via an adapter. (Supplied.) The TV should also have a minimum resolution of 720p HD, otherwise there is not much point in the whole exercise.[1] (I'm assuming here that our friends at the Dyfi Osprey Project will have been supplied with enough bandwidth next year for their streaming to be in high resolution.) Chromecast outputs a native resolution of 1080p, but it recognises other screen formats from HDMI signalling and adapts itself accordingly.

The Chromecast dongle itself is a small black (or white in some versions) device with a male HDMI connector, an indicator LED, and a small (almost invisible) reset button along one of its chamfered edges. This button is the only external control on the gizmo, and turns out to be quite an important one as lock-ups and hangs are not unusual. This is still emergent technology, and it shows.

The unit plugs into the HDMI slot and, when powered up, searches for a local wireless network and waits to be told what to do next. This can be done via a downloadable app on your PC, but I chose to configure using my smartphone - also running the app - so that I could watch what was going on. Once given the password for a local router, it is time for a nice refreshing cup of tea because Chromecast will immediately connect to the net and start updating it's own firmware – a process that can take up to twelve minutes to complete.

That delay apart, I found the whole set-up to be painless and mostly automatic. However, if you are one of those nerdy types whose home network has several diverse routers, proxy servers, and internal firewalls, you will have to explain all this to Chromecast before it will work – and it probably serves you right.

With everything operating as it should, we can now return to our PC and explore the less well-advertised abilities of Chromecast. In a sentence, it can cast Chrome...

Chrome tab casting to TV via Chromecast, showing
the location of the extra menu icon at top right

 You will need to have the latest version of Google Chrome (36.0.1 at the time of writing) for Windows 7 or 8, Mac OS, or Linux installed. Run this up and log onto the MWT Live Streaming site in the normal way. Now, find the new icon which is at the top-right corner of the browser window. Clicking on this brings up a menu where the “name” of your newly-installed Chromecast device will appear. Select it, and the browser page will be showing on the remote TV set! Chrome and Chromecast recognise what the “Full-screen” control on the LS pane does, and will automatically use the whole screen on the TV to display it.

Running the full LS streaming window on the TV
At this point, I got some very useful cardio exercise while running from one room to another to look at different screens. Once I was convinced that this thing actually did what it was supposed to be doing, I went on to the next stage...

Live desktop mirroring on the TV. Note the high
processor useage (50%) shown on the gauge app
at top right - this is on a 2.7 Ghz quad-core machine.
Now Google's Chrome is a decent-enough browser, but as a personal preference I don't like using it. I prefer good old Firefox with all its extensions and extra facilities. Given that Chromecast's underlying functionality depends on Chrome itself, is there any way round this? Turns out, there is. On the same menu shown earlier, there is a sub-menu – all undocumented - which contains the option “Cast entire screen (Experimental)” I duly experimented with this and it works, sending the entire live PC desktop to a connected TV. With my wireless mouse and keyboard taken into the adjacent room, I can now control the PC from there as well. (Your own mileage may vary with this, as most generic wireless keyboards have fairly short range.)

This mode of operation needs a fairly stout PC to run it, as all the mirror-and-encode work on the live desktop involves some heavy lifting on the part of the CPU. A low-end laptop or netbook device will probably not cut it.

So... there you are: full-screen ospreys on your living room television – and all for £30 quid. (UK pricing.) Chromecast is available from the usual outlets, or Amazon, or Google itself. The price does not seem to vary but, as always, watch out for carriage charges if ordering online.

[1] For older widescreen TV receivers that have composite or RGB video input, it is possible to obtain an HDMI converter. 

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