Mounten Lion and Airplay Mirroring...

Hi guys!

I am having problems with the Airplay Mirroring... as long as I am streaming via iTunes... sound and video quality is perfect... but as soon as I switch to Mirroring the video quality is horrible.. also the frame rate is like 5-10 fps only the sound seams to work... at least most of the time...

I know it is a beta (or two betas^^)... but are you experiencing the same problems?

Greetings
Julian

 

I believe airplay mirror records the screen contents in real time, compresses them, and sends the video feed across the network.

iTunes streaming just sends the pre-encoded file over the network.

There is a classic trade off between encode time, file size, and quality. You can't have all three, and there is a bandwidth limitation on the wireless network, so you can't send uncompressed video over the network, and your encode time is essentially zero, since it's streaming the contents live. That's very likely to have a serious impact on quality.

The difference with iTunes streaming is that the video stream was encoded in advance. It might have taken 10x realtime to encode that stream, so you get much better results with the same bandwidth limitation.

 

Thank you! So this is why I may have problems... but du you have them as well? I saw videos of test with nearly no problems^^

My i5 Pro shouldn't be that bad

 

Isn't apple rushing with a new release?

 

Not really. OS X 10.8 isn't going to be a radical new release but rather more of a collection of smaller updates similar to the upgrade from Leopard to Snow Leopard. 10.8 isn't going to come out for quite a bit of time, approximately one year after 10.7 came out. It will likely be another $30 download package from the App Store since someone at Apple (I think it was Tim Cook but maybe someone else) said that they won't be releasing 10.8 on any USB thumb drives.

I don't have 10.8 on my system and won't install it until the final retail release comes out. However, AirPlay mirroring for general OS use seems to have mixed performance across the board. You can't really get it to work smoothly and Engadget couldn't get it to work at all. I read through some other articles on different websites and they too couldn't even get it to work.

One thing to think about is your router. AirPlay goes through your wireless network and the service will only be as fast (or slow) as your wi-fi router. 802.11g models are going to provide pretty crappy AirPlay video mirroring while 802.11n (150-300Mbps) will be a lot better. Even on my 300Mbps 802.11n wi-fi connection, AirPlay mirroring from my iPad 2 is not 100% smooth. It is OK for general use but it isn't a full 30fps, let alone 24fps.

 

I just made a little video but now I realize that the typewriter video I chose wasn't the best idea to show the lag... (I am nearly 24h awake so that is my excuse )

Have fun with it

OS X Mountain Lion Airplay Mirroring - YouTube

PS: this is wifi only... I'll give ethernet a try soon! (thanks for that hint!)

 

You have the idiom backwards.