Question

insertTimeRange：ofTrack：atTime：error：类AVMutableCompositionTrack返回NO并且错误＆＃34;操作无法完成＆＃34;在iPhone上（但不是模拟器）。错误消息是无益的，我很难找到错误的原因，更不用说解决方法了。任何帮助将不胜感激。

在下面的示例代码中，我正在尝试将音频剪辑添加到AVMutableCompositionTrack。以下是代码中的内容：

AVMutableComposition和AVMutableCompositionTrack对象在init中创建。
调用类方法addPhrase：atTime：将音频剪辑添加到合成轨道。
实际插入的函数是addAudioClip：atTime：。
辅助函数audioClipWithName：ofType将请求的音频文件加载到AVAssetTrack中。

- ＆GT; NSLOG输出：

insertTimeRange atTime = 0.0 range =（0.0,2.1）compositionTrack = - - - - - 错误！错误域= AVFoundationErrorDomain代码= -11800＆＃34;操作无法完成＆＃34; UserInfo = {NSLocalizedDescription =操作无法完成，NSUnderlyingError = 0x16fc1c90 {错误域= NSOSStatusErrorDomain代码= -12780＆＃34;（null）＆＃34;}，NSLocalizedFailureReason =发生未知错误（-12780）}

- ＆GT;样本代码：

@interface MyAudioPlayer()

@property (strong, nonatomic) AVMutableComposition *composition;
@property (strong, nonatomic) AVMutableCompositionTrack *compositionTrack;

@end


@implementation MyAudioPlayer

- (id) init
{
    self = [super init];
    if (self != nil) {
        self.composition = [AVMutableComposition composition];
        self.compositionTrack = [self.composition addMutableTrackWithMediaType:AVMediaTypeAudio preferredTrackID:kCMPersistentTrackID_Invalid];
    }
    return self;
}

// Add the phrase into compositionAudioTrack at the given time.
- (void) addPhrase:(NSString *)phrase atTime:(CMTime)atTime
{
    // Add the phrase to the audio.
    AVAssetTrack *audioClip = [self audioClipWithName:phrase ofType:@"mp3"];
    // Add the phrase to the audio track.
    [self addAudioClip:audioClip atTime];
}

// Add the given audio clip to the composed audio at the given time.
- (void) addAudioClip:(AVAssetTrack *)audioClip atTime:(CMTime)atTime
{
    NSError *error = [[NSError alloc] init];
    CMTimeRange audioClipRange = CMTimeRangeMake(kCMTimeZero, audioClip.timeRange.duration);
    BOOL success = [self.compositionTrack insertTimeRange:audioClipRange ofTrack:audioClip atTime:atTime error:&error];
    NSLog(@"insertTimeRange atTime=%.1f range=(%.1f, %.1f) compositionTrack=%@\n", CMTimeGetSeconds(atTime), CMTimeGetSeconds(audioClipRange.start), CMTimeGetSeconds(audioClipRange.duration), self.compositionTrack);
    if (!success) {
        NSLog(@"----------ERROR! %@", error);
    }
}

// Return an audio clip with the given name and type.
- (AVAssetTrack *) audioClipWithName:(NSString *)name ofType:(NSString *)type
{
    NSString *soundFilePath = [[NSBundle mainBundle] pathForResource:name ofType:type];
    NSURL *fileURL = [[NSURL alloc] initFileURLWithPath:soundFilePath];
    AVAsset *avAsset = [AVURLAsset URLAssetWithURL:fileURL options:nil];
    AVAssetTrack *audioClip = [[avAsset tracksWithMediaType:AVMediaTypeAudio] objectAtIndex:0];
    return audioClip;
}

@end

Answer 1

你的问题在于

- (AVAssetTrack *) audioClipWithName:(NSString *)name ofType:(NSString *)type;

它允许轨道拥有AVAsset超出范围并被取消分配，使轨道处于不良状态。

确保AVAsset被引用（至少），直到您致电insertTimeRange。实际上，这意味着您应该将AVAsset及其AVAssetTrack一起传递。

insertTimeRange：ofTrack：atTime：error :(类AVMutableCompositionTrack）在iPhone上失败

1 个答案: