I am trying to insert an AVURLAsset of a AVPlayerItem that states AVPlayerItemStatusReadyToPlay
into an AVMutableComposition
like this:
composition_ = [[AVMutableComposition alloc] init];
insertionPoint_ = kCMTimeZero;
item_ = [[AVPlayerItem playerItemWithURL:[NSURL URLWithString:@"http://devimages.apple.com/iphone/samples/bipbop/bipbopall.m3u8"]] retain];
[item_ addObserver:self forKeyPath:@"status" options:0 context:nil];
player_ = [[AVPlayer playerWithPlayerItem:item_] retain];
[player_ addObserver:self forKeyPath:@"currentItem.duration" options:0 context:nil];
/**
* append a player-item to our composition
*/
- (void)addItemToComposition:(AVPlayerItem *)item
{
NSError *error = nil;
VTRACE(@"item duration: %g", CMTimeGetSeconds(item.duration));
if (![composition_ insertTimeRange:CMTimeRangeMake(kCMTimeZero, item.duration)
ofAsset:item.asset
atTime:insertionPoint_
error:&error])
{
VTRACE(@"error: %@", error);
}
}
/**
* simplified value observer callback
*/
- (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary *)change context:(void *)context
{
if ([object isKindOfClass:[AVPlayerItem class]])
{
AVPlayerItem *item = (AVPlayerItem *)object;
//playerItem status value changed?
if ([keyPath isEqualToString:@"status"])
{ //yes->
switch(item.status)
{
case AVPlayerItemStatusFailed:
VTRACE(@"player item status failed");
break;
case AVPlayerItemStatusReadyToPlay:
VTRACE(@"player item status is ready to play");
[self addItemToComposition:player_.currentItem];
break;
case AVPlayerItemStatusUnknown:
VTRACE(@"player item status is unknown");
break;
}
}
}
else if([object isKindOfClass:[AVPlayer class]])
{
if ([keyPath isEqualToString:@"currentItem.duration"])
{ //yes->
VTRACE(@"player item duration available");
}
}
}
Unfortunately, all I get is this lousy error message from the attempt to invoke AVMutableComposition insertTimeRange:ofAsset:atTime:error:
2011-11-29 22:24:59.446 XXX[13626:10703] -[XXX addItemToComposition:] -- error: Error Domain=AVFoundationErrorDomain Code=-11800 "The operation could not be completed" UserInfo=0x7699f30 {NSLocalizedFailureReason=An unknown error occurred (-12780), NSUnderlyingError=0xd124dd0 "The operation couldn’t be completed. (OSStatus error -12780.)", NSLocalizedDescription=The operation could not be completed}
What am I missing?
Why is it not possible to insert the item into the composition?
When inspecting the AVURLAsset
of that AVPlayerItem
I also noticed that the tracks array is allocated but empty. Could that be the reason, and if so, how do I get the AVURLAsset
to properly hold valid tracks?
Well, I got an answer from another source and I do not like it ...
It is apparently only possible to insert local items (assets) into an AVMutableComposition
, remote items (like HTTP video streams) will not work.
The fact that the documentation does not say so and the fact that the error-message I am receiving is useless seems to be an omission by Apple. I did file a bug-report to improve that situation.
Apple Radar Bug Id: 10517711
Open Radar bug report.
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