I want to play liveStream on iPhoneDevice with AVPlayer. Also i want to get CVPixelBufferRef from this stream for next usage.
I use Apple guide for creating player. Currently with locally stored videoFiles this player works just fine, also when i try to play this AppleSampleStremURL - http://devimages.apple.com/iphone/samples/bipbop/bipbopall.m3u8 - its work sine too. 
Problems appear when i want to play stream with rtsp:// like this one: rtsp://192.192.168.1:8227/TTLS/Streaming/channels/2?videoCodecType=H.264
An code - almost all done using guid provided by Apple, but anyway:
Prepare asset for playing
- (void)initialSetupWithURL:(NSURL *)url
{
    NSDictionary *assetOptions = @{ AVURLAssetPreferPreciseDurationAndTimingKey : @YES,
                                    AVURLAssetReferenceRestrictionsKey : @(AVAssetReferenceRestrictionForbidNone)};
    self.urlAsset = [AVURLAsset URLAssetWithURL:url options:assetOptions];
}
Prepare player
- (void)prepareToPlay
{
    NSArray *keys = @[@"tracks"];
    __weak SPHVideoPlayer *weakSelf = self;
    [weakSelf.urlAsset loadValuesAsynchronouslyForKeys:keys completionHandler:^{
        dispatch_async(dispatch_get_main_queue(), ^{
            [weakSelf startLoading];
        });
    }];
}
- (void)startLoading
{
    NSError *error;
    AVKeyValueStatus status = [self.urlAsset statusOfValueForKey:@"tracks" error:&error];
    if (status == AVKeyValueStatusLoaded) {
        self.assetDuration = CMTimeGetSeconds(self.urlAsset.duration);
        NSDictionary* videoOutputOptions = @{ (id)kCVPixelBufferPixelFormatTypeKey : @(kCVPixelFormatType_420YpCbCr8BiPlanarVideoRange)};
        self.videoOutput = [[AVPlayerItemVideoOutput alloc] initWithPixelBufferAttributes:videoOutputOptions];
        self.playerItem = [AVPlayerItem playerItemWithAsset: self.urlAsset];
        [self.playerItem addObserver:self
                          forKeyPath:@"status"
                             options:NSKeyValueObservingOptionInitial
                             context:&ItemStatusContext];
        [self.playerItem addObserver:self
                          forKeyPath:@"loadedTimeRanges"
                             options:NSKeyValueObservingOptionNew|NSKeyValueObservingOptionOld
                             context:&ItemStatusContext];
        [[NSNotificationCenter defaultCenter] addObserver:self
                                                 selector:@selector(playerItemDidReachEnd:)
                                                     name:AVPlayerItemDidPlayToEndTimeNotification
                                                   object:self.playerItem];
        [[NSNotificationCenter defaultCenter] addObserver:self
                                                 selector:@selector(didFailedToPlayToEnd)
                                                     name:AVPlayerItemFailedToPlayToEndTimeNotification
                                                   object:nil];
        [self.playerItem addOutput:self.videoOutput];
        self.assetPlayer = [AVPlayer playerWithPlayerItem:self.playerItem];
        [self addPeriodicalObserver];
        NSLog(@"Player created");
    } else {
        NSLog(@"The asset's tracks were not loaded:\n%@", error.localizedDescription);
    }
}
Problems appear here - AVKeyValueStatus status = [self.urlAsset statusOfValueForKey:@"tracks" error:&error]; - this line with rtsp:// URL return AVKeyValueStatusFailed 
with Error:
Printing description of error:
Error Domain=AVFoundationErrorDomain Code=-11800 
"The operation could not be completed" 
UserInfo=0x7fd1ea5a8a10 {NSLocalizedFailureReason=An unknown error occurred (-12936), 
NSLocalizedDescription=The operation could not be completed,
NSURL=rtsp://192.168.1.168:8556/PSIA/Streaming/channels/2?videoCodecType=H.264,
NSUnderlyingError=0x7fd1ea53f830 "The operation couldn’t be completed.
(OSStatus error -12936.)"}
I also looked for questions:
- FirstOne - try to use for this stream sample app from Apple - StitchedStreamPlayer - but get few different error for streams that i want to play there
 - SecondOne - try to use both suggestion - 
fileURLWithPathreturn incorrect URL like :rtsp://192.168.1.168:8556/PSIA/Streaming/channels/2?videoCodecType=H.264 --file:///- so it's i guess incorrect - According to AppleDev try to create AvPlayer with diff approaches: like 
[AVPlayer playerWithPlayerItem:playerItem]and like[AVPlayer playerWithURL:url]- nothing changed. Also try to setup different setting for AVAsset - ininitialSetupWithURL(see method implementation above). 
So, question is AVPlayer support playing rtsp:// stream? If yes, can someone provide sample of correct usage? Nad what i'm doing wrong in code? If AvPlayer not support rtsp:// maybe exist some alternative solution?