AVPlayer from AVMutableComposition with audio and video won't play - ios

Question

I'm trying to show a video from a composition of both video and audio. However, I seem to have a problem, once the video status never reaches AVPlayerStatusReadyToPlay.
If I include the video asset or the audio asset directly to the player item it will work. Thus, I know there is no problem with the assets.
This is my code:
- (void) loadPlayer {
NSURL *videoURL = **;
AVURLAsset *videoAsset = [AVURLAsset URLAssetWithURL:videoURL options:nil];
NSURL *audioURL = **;
AVURLAsset *audioAsset = [AVURLAsset URLAssetWithURL:audioURL options:nil];
NSArray *keys = [NSArray arrayWithObject:#"duration"];
[videoAsset loadValuesAsynchronouslyForKeys:keys completionHandler:^() {
NSError *error = nil;
AVKeyValueStatus durationStatus = [videoAsset statusOfValueForKey:#"duration" error:&error];
switch (durationStatus) {
case AVKeyValueStatusLoaded:;
_videoDuration = videoAsset.duration;
if (_audioDuration.flags == kCMTimeFlags_Valid) {
[self loadPlayWithVideoAsset:videoAsset withDuration:_videoDuration andAudioAsset:audioAsset withDuration:_audioDuration];
}
break;
}
}];
[audioAsset loadValuesAsynchronouslyForKeys:keys completionHandler:^() {
NSError *error = nil;
AVKeyValueStatus durationStatus = [audioAsset statusOfValueForKey:#"duration" error:&error];
switch (durationStatus) {
case AVKeyValueStatusLoaded:;
_audioDuration = audioAsset.duration;
if (_videoDuration.flags == kCMTimeFlags_Valid) {
[self loadPlayWithVideoAsset:videoAsset withDuration:_videoDuration andAudioAsset:audioAsset withDuration:_audioDuration];
}
break;
}
}];
}
- (void) loadPlayWithVideoAsset:(AVURLAsset *)videoAsset withDuration:(CMTime)videoDuration andAudioAsset:(AVURLAsset *)audioAsset withDuration:(CMTime)audioDuration {
AVMutableComposition *composition = [AVMutableComposition composition];
//Video
AVMutableCompositionTrack *compositionVideoTrack = [composition addMutableTrackWithMediaType:AVMediaTypeVideo preferredTrackID:kCMPersistentTrackID_Invalid];
AVAssetTrack *videoTrack = [[videoAsset tracksWithMediaType:AVMediaTypeVideo] lastObject];
NSError *videoError = nil;
if (![compositionVideoTrack insertTimeRange:CMTimeRangeMake(kCMTimeZero,videoDuration)
ofTrack:videoTrack
atTime:kCMTimeZero
error:&videoError]) {
NSLog(#"videoError: %#",videoError);
}
//Audio
AVMutableCompositionTrack *compositionAudioTrack = [composition addMutableTrackWithMediaType:AVMediaTypeAudio preferredTrackID:kCMPersistentTrackID_Invalid];
AVAssetTrack *audioTrack = [[audioAsset tracksWithMediaType:AVMediaTypeAudio] lastObject];
NSError *audioError = nil;
if (![compositionAudioTrack insertTimeRange:CMTimeRangeMake(kCMTimeZero,audioDuration)
ofTrack:audioTrack
atTime:kCMTimeZero
error:&audioError]) {
NSLog(#"audioError: %#",audioError);
}
NSInteger compare = CMTimeCompare(videoDuration, audioDuration);
if (compare == 1) {
//The video is larger
CMTime timeDiff = CMTimeSubtract(videoDuration, audioDuration);
[compositionAudioTrack insertEmptyTimeRange:CMTimeRangeMake(audioDuration, timeDiff)];
}
else {
CMTime timeDiff = CMTimeSubtract(audioDuration, videoDuration);
[compositionVideoTrack insertEmptyTimeRange:CMTimeRangeMake(videoDuration, timeDiff)];
}
AVPlayerItem * playerItem = [AVPlayerItem playerItemWithAsset:composition];
self.mPlayer = [AVPlayer playerWithPlayerItem:playerItem];
self.mPlaybackView = [[AVPlayerPlaybackView alloc] initWithFrame:CGRectZero];
[self.view addSubview:self.mPlaybackView];
[self.mPlayer addObserver:self forKeyPath:#"status" options:0 context:AVPlayerPlaybackViewControllerStatusObservationContext];
}
- (void)observeValueForKeyPath:(NSString*) path ofObject:(id)object change:(NSDictionary*)change context:(void*)context
{
if (self.mPlayer.status == AVPlayerStatusReadyToPlay) {
[self.mPlaybackView setPlayer:self.mPlayer];
isReadyToPlay = YES;
_playVideoBtn.hidden = NO;
}
}
- (void) playVideo {
if (YES || isReadyToPlay) {
[self.mPlayer play];
}
}

Answer 1

From my experience, AVPlayer works with AVMutableComposition only if resource/video is bundled with app. If video resource is on network, then AVPlayer won't play with AVMUtableComposition, despite status reported by AVPlayerItem and AVPlayer as "Ready to Play".