How you can ditch your Displaylink adapter using a Apple TV [Archive]

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Ren

10-23-2013, 01:34 AM

Youtube video demo:

http://www.youtube.com/watch?v=31LEoqvYeMM

kingsapo

10-23-2013, 03:49 AM

Ren

10-23-2013, 04:13 AM

Nice video! I've been pretty unhappy with DisplayLink in general, and Mavericks isn't helping, so I'm seriously considering this.

Do you notice a large CPU spike when you play video on the Apple TV screen? Also, you mentioned you had the Apple TV and your computer hooked up together, did you do this directly with an ethernet cable or through some type of router or switch?

Thanks, I used a gigabit switch. Unfortunately I didn't check the CPU usage, but the mac mini's fan never ramped up. I can check it again tomorrow for the CPU usage.

gilesmartin

10-23-2013, 04:38 AM

kinda embarrassing that you can get that from an apple TV over ethernet with all the overhead involved (even with gigabit) but somehow they can't get this thing working over a 5gbps USB 3.0 connection. And they claim they don't know how to "get the pixels" obviously airplay works. Seems like us mac users (probably one of the primary demographics for this type of product) just aren't important enough. Especially considering how long mavericks GM was available to test with.

edit: it also should be noted that the Apple TV has only a 10/100 ethernet port so… yeah… not even usb 2.0 bandwidth.

Ren

10-23-2013, 04:42 AM

kinda embarrassing that you can get that from an apple TV over ethernet with all the overhead involved (even with gigabit) but somehow they can't get this thing working over a 5gbps USB 3.0 connection. And they claim they don't know how to "get the pixels" obviously airplay works. Seems like us mac users (probably one of the primary demographics for this type of product) just aren't important enough. Especially considering how long mavericks GM was available to test with.

Yah, I wasn't really impressed with their release notes blaming all the problems on mavericks and none on their driver.

Wim

10-23-2013, 10:28 AM

The Apple TV and AirPlay uses private APIs in OS X to get it's screen updates. These APIs are not public. We would LOVE to have access to this API as we could make an improved USB display solution without the issues that are seen today.

This has been discussed with Apple but they have been unwilling to give access to this private API. As you might understand this is very frustrating for us, as it makes our solution doesn't perform as well as it could because we're locked out of a private API.

Wim

gilesmartin

10-23-2013, 12:42 PM

Really? Then how come third parties are able to create devices that work with airplay mirroring. Just look at rplay for the raspberry pi or air server. And why does air display work perfectly on mavericks while your product does not? Apple changed the APIs, stop blaming them and stop waiting on them to change them. Find a way to make this work as is. If the eventually update the APIs... Great. You can release the current driver again. But in the mean time get off your ass and find a way to make things work. Figure out what air display and others are doing and publish a working beta. Or find a way to mimic an airplay device on localhost. You shouldn't have expected the GM to change before release and you shouldn't expect Apple to swoop in and fix your product for you.

ehendrix

10-23-2013, 03:49 PM

Would agree here; at least now with Mavericks being able to use Airplay as another monitor. Would seem to me that making a small Airplay Server and then sending what it gets out to the USB should work.
There are some available here, some even open source: http://code.google.com/p/open-airplay/

Ren

10-23-2013, 05:39 PM

CPU usage is around 1% additional at 720P on static screens like outlook. Video takes a larger hit at around 3% using mplayerX playing a full 1080P bluray rip around 30 gigs.

In my experience, this actually seems like less thank the displaylink process. I think airplay uses GPU acceleration to encode the video it sends so it doesn't need to use much CPU. One quirk I did notice was quickly switching displays with mplayerX several times fast causes it to stutter and requires a restart of the movie. This is all on a i7 2.3Ghz mini.

So far so good! Tempted to buy 2 1080P IPS displays and a apple TV 3.

kingsapo

10-23-2013, 07:16 PM

Awesome, thanks for posting that info! That CPU usage isn't nearly as bad as I thought it would be - definitely less than what DisplayLink would use in similar situations.

Ren

10-23-2013, 10:30 PM

Just ordered a refurb apple tv 3rd gen from the apple store for $75. The displaylink adapter is going on craigslist....

emmgee

10-24-2013, 12:24 AM

Ren

10-24-2013, 01:58 AM

Can you share the details of the networking? I use my MacBook Pro at home and at work. I have gigabit at home and could easily put an Apple TV on my home switch but at work I would think I'd have to have a dedicated switch that was on its own network. My company wouldn't allow the ATV on the corporate LAN.

Everything is wired on my home gigabit network, but the Apple TV is only 100mb ethernet. I monitored the bandwidth usage on my Mac when airplaying and believe it or not it's only around one megabyte a second at 720p.

I think the reason wired is better isn't because of bandwidth but less latency and no dropped frames. If the computer is wired and the Apple TV is wireless the experience is better, but not amazing. I can't wait try full 1080p.

One quirk I noticed is that when I was watching a full screen YouTube video on my main display the Apple TV would stop mirroring after 10 or so minutes. I'm guessing it's som kind of activity timer. Hopefully I can get around it.