我正在使用此代码开始播放参考形成播放列表的本地视频块。
完全相同的代码适用于一个项目，但不适用于另一个项目。
在我正在进行的项目中，我可以看到第一个块是如何加载的，第一个框架也会显示出来。但AVPlayer永远不会开始播放，因为它永远不会收到AVPlayerStatusReadyToPlay通知：
- (void)loadAssetAsync
{
NSLog(@"loadAssetAsync for URL: %@", videoURL);
/**
* Create an asset for inspection of a resource referenced by a given URL.
* Load the values for the asset keys "tracks", "playable".
*/
AVURLAsset *asset = [AVURLAsset URLAssetWithURL:videoURL options:nil];
NSArray *requestedKeys = [NSArray arrayWithObjects:kTracksKey, kPlayableKey, nil];
// Tells the asset to load the values of any of the specified keys that are not already loaded.
[asset loadValuesAsynchronouslyForKeys:requestedKeys completionHandler:
^{
dispatch_async( dispatch_get_main_queue(),
^{
// IMPORTANT: Must dispatch to main queue in order to operate on the AVPlayer and AVPlayerItem.
[self prepareToPlayAsset:asset withKeys:requestedKeys];
});
}];
}
/**
* Invoked at the completion of the loading of the values for all keys on the asset that required.
*/
- (void)prepareToPlayAsset:(AVURLAsset *)asset withKeys:(NSArray *)requestedKeys
{
//assert([NSThread isMainThread]);
// Make sure that the value of each key has loaded successfully.
for (NSString *thisKey in requestedKeys)
{
NSError *error = nil;
AVKeyValueStatus keyStatus = [asset statusOfValueForKey:thisKey error:&error];
if (keyStatus == AVKeyValueStatusFailed)
{
BVLogWarn(@"%@: %@", THIS_FILE, error.localizedDescription);
[self handleErrorForProxy:error];
[self assetFailedToPrepareForPlayback];
return;
}
}
if (!asset.playable)
{
BVLogWarn(@"%@: Item cannot be played", THIS_FILE);
[self handleErrorForProxy:nil];
[self assetFailedToPrepareForPlayback];
return;
}
// Create a new instance of AVPlayerItem from the now successfully loaded AVAsset.
playerItem = [[AVPlayerItem alloc] initWithAsset:asset];
// Observe the player item "status" key to determine when it is ready to play.
[playerItem addObserver:self
forKeyPath:kStatusKey
options:NSKeyValueObservingOptionInitial | NSKeyValueObservingOptionNew
context:BVPlayerItemStatusObserverContext];
[playerItem addObserver:self
forKeyPath:kBufferEmpty
options:NSKeyValueObservingOptionNew
context:BVPLayerBufferEmptyObserverContext];
[playerItem addObserver:self
forKeyPath:kLikelyToKeepUp
options:NSKeyValueObservingOptionNew
context:BVPlayerLikelyToKeepUpObserverContext];
[[NSNotificationCenter defaultCenter] addObserver:self
selector:@selector(playerItemDidReachEnd:)
name:AVPlayerItemDidPlayToEndTimeNotification
object:playerItem];
// Get a new AVPlayer initialized to play the specified player item.
player = [[AVPlayer alloc] initWithPlayerItem:playerItem];
// Do nothing if the item has finished playing
[player setActionAtItemEnd:AVPlayerActionAtItemEndNone];
/* Observe the AVPlayer "currentItem" property to find out when any
AVPlayer replaceCurrentItemWithPlayerItem: replacement will/did
occur.*/
[player addObserver:self
forKeyPath:kCurrentItemKey
options:NSKeyValueObservingOptionInitial | NSKeyValueObservingOptionNew
context:BVCurrentItemObserverContext];
// Observe the AVPlayer "rate" property to update the scrubber control.
[player addObserver:self
forKeyPath:kRateKey
options:NSKeyValueObservingOptionInitial | NSKeyValueObservingOptionNew
context:BVRateObserverContext];
[player replaceCurrentItemWithPlayerItem:playerItem];
}
- (void)observeValueForKeyPath:(NSString*) keyPath
ofObject:(id)object
change:(NSDictionary*)change
context:(void*)context
{
// AVPlayerItem "status" property value observer.
if (context == BVPlayerItemStatusObserverContext)
{
AVPlayerStatus status = [[change objectForKey:NSKeyValueChangeNewKey] integerValue];
switch (status)
{
case AVPlayerStatusUnknown:
{
[self removeTimeObserver];
[self syncTimeScrubber];
[timeControl setEnabled:NO];
[playButton setEnabled:NO];
[fullscreenButton setEnabled:NO];
[loadingIndicator startAnimating];
}
break;
case AVPlayerStatusReadyToPlay:
{
if (firstPlayback|becomeActive)
{
[timeControl setEnabled:YES];
[playButton setEnabled:YES];
[fullscreenButton setEnabled:YES];
[upperControls setHidden:NO];
[lowerControls setHidden:NO];
[loadingIndicator stopAnimating];
if (firstPlayback) {
[playbackView setNeedsDisplay];
}
if (self.shouldAutoplay)
[player play];
if (firstPlayback) {
timeRemaining.text = [NSString stringWithFormat:@"-%@", timeStringForSeconds(CMTimeGetSeconds(playerItem.duration) )];
}
firstPlayback = NO;
controlsHidden = NO;
if (!isSeeking)
[self startHideControlsTimer];
}
if (becomeActive) {
dispatch_async(dispatch_get_main_queue(), ^{
[player seekToTime:CMTimeMakeWithSeconds(lastTimeStop, NSEC_PER_SEC)
toleranceBefore:kCMTimeZero
toleranceAfter:kCMTimeZero
completionHandler:^(BOOL finished) {
if (finished && rateToRestoreAfterScrubbing)
{
[player setRate:rateToRestoreAfterScrubbing];
rateToRestoreAfterScrubbing = 0.f;
}
[self addTimeObserver];
[playbackView setPlayer:player];
becomeActive = NO;
}];
});
}else{
[self addTimeObserver];
}
}
break;
case AVPlayerStatusFailed:
{
AVPlayerItem *thePlayerItem = (AVPlayerItem *)object;
BVLogWarn(@"%@: %@", THIS_FILE, thePlayerItem.error.localizedDescription);
[self handleErrorForProxy:thePlayerItem.error];
[self assetFailedToPrepareForPlayback];
}
break;
}
}
// AVPlayer "rate" property value observer.
else if (context == BVRateObserverContext)
{
[self updatePlayPauseButton];
}
// AVPlayer "currentItem" buffer is empty observer
else if (context == BVPLayerBufferEmptyObserverContext)
{
[loadingIndicator startAnimating];
}
// AVPlayer "currentItem" is likely to keep up observer
else if (context == BVPlayerLikelyToKeepUpObserverContext)
{
[loadingIndicator stopAnimating];
}
// AVPlayer "currentItem" property observer.
else if (context == BVCurrentItemObserverContext)
{
AVPlayerItem *newPlayerItem = [change objectForKey:NSKeyValueChangeNewKey];
// New player item null?
if (newPlayerItem == (id)[NSNull null])
{
[playButton setEnabled:NO];
[timeControl setEnabled:NO];
} else // Replacement of player currentItem has occurred
{
if (!becomeActive) {
[playbackView setPlayer:player];
}else{
}
[playbackView setVideoFillMode:[self scalingMode]];
[self updatePlayPauseButton];
}
}
else
{
[super observeValueForKeyPath:keyPath ofObject:object change:change context:context];
}
return;
}
答案 0 :(得分：0)
您是否尝试在if之前添加一些日志？也许通知工作正常，但因为你的if？
而被停止了case AVPlayerStatusReadyToPlay:
{
NSLog(@"NOTIFICATION TEST PASSED");
if (firstPlayback|becomeActive) {}
}