Previous 1 2 Next 15 Replies Latest reply: Mar 21, 2012 8:41 AM by ziwy
ziwy Level 1 Level 1

I just got new iPad and new AppleTV, I played streaming video on my iPad, (which is an app using wi-fi bandwith), I also turn on AirPlay on iPad and mirror to TV through AppleTV2. The router is AirPort, I believe the mirroring also use wi fi bandwith, the result is that the video is lagged so much and can't even watch.

 

However, if I use AV cable connect directly from iPad to TV, the streaming video is normal, play perfect, so is it case normal? I don't know if streaming and mirroring use the double bandwith to cause the problem, any advice??

 

Thanks

ziwy


AppleTV 2, iOS 5.1
Reply by Alley_Cat on Mar 20, 2012 11:43 AM Helpful

Airplay is over hyped in my view even with good wifi connections.

 

Mirroring over wifi will entail compromises compared to a direct video connection to the TV.

 

AC

Reply by Winston Churchill on Mar 20, 2012 11:46 AM Helpful

Mirroring always works fine for me, your network may have a problem such as interference.

 

Interference can be caused by other networks in the neighbourhood or from household electrical items.

 

You can download and install iStumbler (NetStumbler for windows users) to help you see which channels are used by neighbouring networks so that you can avoid them, but iStumbler will not see household items.

 

Refer to your router manual for instructions on changing your wifi channel or adjusting your multicast rate.

 

There are other types of problems that can affect networks, but this is by far the most common, hence worth mentioning first.

All replies

  • Alley_Cat Level 6 Level 6

    Airplay is over hyped in my view even with good wifi connections.

     

    Mirroring over wifi will entail compromises compared to a direct video connection to the TV.

     

    AC

  • Winston Churchill Level 10 Level 10
    expertise.macosx
    Mac OS X

    Mirroring always works fine for me, your network may have a problem such as interference.

     

    Interference can be caused by other networks in the neighbourhood or from household electrical items.

     

    You can download and install iStumbler (NetStumbler for windows users) to help you see which channels are used by neighbouring networks so that you can avoid them, but iStumbler will not see household items.

     

    Refer to your router manual for instructions on changing your wifi channel or adjusting your multicast rate.

     

    There are other types of problems that can affect networks, but this is by far the most common, hence worth mentioning first.

  • ziwy Level 1 Level 1

    so my assumption is correct, it seems didn't optimize AppleTV's mirroring function... any solution? If it over hypes the wi fi, so what's the point to use airplay mirroring?

  • Winston Churchill Level 10 Level 10
    expertise.macosx
    Mac OS X

    ziwy wrote:

     

    .........so what's the point to use airplay mirroring?

    As, I say it works fine here, I use it regularly.

  • ziwy Level 1 Level 1

    I use Airport, I didn't realize household electrical may cause the problems, but we onlt use router to connect two laptop at home, and none of them using bandwith at that time. I also switch channel to 9, which most of neighbors use channel 1. I don't know how to adjust multicast rate, and good rate to recommend?

     

    thanks

  • Winston Churchill Level 10 Level 10
    expertise.macosx
    Mac OS X

    The higher the multicast rate, the higher the rate a device needs to capable of in order to work on the network, this can remove fringe devices, but if the rate is too high, the device you want to use may not be able to connect. it's more a matter of trial and error than any one rate being the best.

  • Alley_Cat Level 6 Level 6

    ziwy wrote:

     

    so my assumption is correct, it seems didn't optimize AppleTV's mirroring function... any solution? If it over hypes the wi fi, so what's the point to use airplay mirroring?

    I'm sure they have optimised it, it's just that mirroring video over wifi is not a trivial task, and for many Airplay tasks video has to be converted or buffered first.  It's getting a lot of hype because of the iOS devices, but I don't think personally it's mature enough to work perfectly all of the time.

     

    For Airplay of streams that AppleTV can decode (existing video, music etc) all the iOS device has to do is feed the data to the AppleTV but if it can't feed it quickly enough there'll be a lag or buffering issue.

     

    With live mirroring compression of the video frames will be required on the fly like a VNC screen sharing app,  if the connection is slow the video quality will compromise by getting more compressed or frame rate will drop.

     

    I don't think it's so much that Airplay is rubbish, just that unless all variables are perfect it's easy to get less than optimal performance.

     

    I'm just a bit cynical about it.

     

    AC

  • ziwy Level 1 Level 1

    I believe the streaming vdieo is decoded to fit apply format, QT or MP4, I don't know, but I don't realize streaming through Airplay has also decoding from apple device to apple TV?

  • ziwy Level 1 Level 1

    Thank about mulitrate, I will try to adjust to see if it may improve, I guess wifi bandwith maybe the issue.

  • Alley_Cat Level 6 Level 6

    If you Airplay rather than mirror a file from an app in a compatible format eg movie from iTunes on an iPad, then it makes no sense for the iPAd to decompress, recompress and send to AppleTV if AppleTv can handle the native (usually h264) video.  If the video or page is in another format it may require encoding to send which may cause a lag.

     

    Mirroring should work real time but has to compress the data and the only way to get 'better performance' on a limited connection is by heavier compression or lowering frame rate.

     

    AC

  • ziwy Level 1 Level 1

    unfortunately the video streaming app and apple TV has no option to increase compression and adjust frame rate.

  • Alley_Cat Level 6 Level 6

    I wouldn't expect it to - I meant the OS should be doing this transparently for you if needed, but if it can't you may get issues.

     

    I may be wrong, and some other views would help, but AFAIK Airplay mirroring and Airplay from an app are not quite the same thing.

     

    Bear in mind if your app is using wifi to get stuff from the internet or the newtork to the iPad and then has to send it to AppleTV (with or without processing) the bandwidth needed on wifi is higher than transmitting something already stored on the iPad to the AppleTV.

     

    AC

  • ziwy Level 1 Level 1

    http://support.apple.com/kb/TS4215

     

    here is I would like to try to optimize the wifi connection, will try at home... thanks AC and Wiston!!

  • ziwy Level 1 Level 1

    I believe Apple should be thinking of this issue of overwhilem the wifi network. Or they develop a new function, but the current capacity couldn't take it... then...what we can do, right?

Previous 1 2 Next