Archives for : airplay

AV WWDC, part 2: Fair Is Pretty Foul

Next up on our tour of WWDC 2015 media sessions is the innocently-titled Content Protection for HTTP Live Streaming. Sounds harmless, but I think there’s reason for worry.

For content protections, HLS has always had a story: transport segments get a one-time AES encryption, and can be served from a dumb http server (at CocoaConf a few years back, I demo’ed serving HLS from Dropbox, before it was https:-always). You’re responsible for guarding the keys and delivering them only to authenticated users. AV Foundation can get the keys, decrypt the segments, and play them with no client-side effort beyond handling the authentication. It’s a neat system, because it’s easy to deploy on content delivery networks, as you’re largely just dropping off a bunch of flat files, and the part you protect on your own server is tiny.

So what’s “FairPlay Streaming”, then?

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Reflecting and streaming

I’m testing the viability of a project I’d like to launch soon, one element of which involves doing an internet livestream of iPhone and iPad apps. Not from the simulator, but real production apps running on real devices. And I’m going to need some advice from you people who know your networking.

The various streaming services make it possible to stream your desktop easily enough — so far I’m really impressed with UStream producer and I wonder why the kids I see livestreaming are all doing or Twitch instead of UStream or LiveStream (is it the cost? Streaming Media had a nice comparison by Jan Ozer of the different streaming platforms an issue or two ago). So that means you just have to get the iPhone output to the screen, and there you go.

So how do you do that? Amit Agarwal has a nice roundup of the options, saving the best for last: AirPlay. Using Reflection or AirServer, you can mirror the screen from a suitably new iPhone or iPad to a window on your Mac.

I evaluated the two and eventually bought Reflection, based on what seemed like much superior audio performance. But still, it seemed glitchy, and tended to freeze frame frequently. Reflection has a handy recording feature, so here’s what that looks like when playing the action game Deathsmiles:

Note that this video is somewhat deceiving in that the audio gets at least 10 seconds out of sync in the recorded version (you can hear the boss battle long before you can see it), which didn’t happen while I was playing it. Nevertheless, point being that this kind of freeze-up glitch would totally unacceptable to livestream viewers.

But AirPlay works great on my AppleTV, so what’s the deal? Before hanging the problem entirely on Reflection, I played another round much closer to the wifi access point. Flawless. The video I mean… my gameplay leaves much to be desired:

The size and compression on this mp4 is a little different… the point is that the video doesn’t freeze as long as I’m close enough to the wifi access point.

So, the problem is that when I play down in my office, the wifi signal gets weak (I sometimes see 2 or even 1 bar), and that presumably drops below a threshold that’s practical for AirPlay. How do I fix this? This is where I need help. Here’s a simplified look at my home network:

The DSL (U-Verse now, I guess) comes in on the first floor on the left, behind a TV, where it then connects to a D-Link router and wifi AP (shown as an AirPort base station in this picture, uses network 192.168.2.x). I don’t use the U-Verse built-in wifi because the D-Link has such better range, which is important for getting a strong signal to the Mini on the top floor, which was not pre-wired for ethernet. We have ethernet (cat 5e) on the first floor and the basement, so one of the ethernet cables coming out of the D-Link goes down to a switch in the basement, and one of those connections goes to a switch in my office (shown with the Power Mac… hey, old stencils on Graffletopia, OK?)

So… how do I get a better wifi signal in the office? I have ethernet down here, so I’ve generally not really cared about wifi being any better than adequate. I have old wifi routers lying around, so I could easily set up another wifi network in place of the switch in the office, but then I’d be on a different network (192.168.3.x, I guess), and so I’d be cut off from the rest of the house, which hoses me out of my Subversion repository (on the Mini) and everyone else out of the color laser printer (in my office).

Another option would be a wifi repeater, I guess, but where to put it? On this floor, but directly under the wifi AP? Or just in the office itself? Is it going to make enough of a difference to be worth it?

Or is there some other kind of device I don’t know about, one that extends an existing wifi network via ethernet (so that the new AP, presumably down in my office, isn’t in the business of handing out DHCP addresses, but instead can relay it over ethernet to the AP on the first floor)?

Bounds on this problem: there’s no point spending more than $200 on a solution, because at that price-point, I could hard-wire the connection from the iPhone/iPad with VGA or HDMI output and either a VGA2USB or a BlackMagic Intensity Pro.

Comment section below, or @invalidname on Twitter and Thank in advance for any suggestions you guys and girls care to offer.