AvassetExportSessionStatus在IOS 9中合并音频文件时失败

我已经使用了这段代码，它在以前版本的iOS9上运行得非常好。但在IOS 9版本上，它总是运行AvassetExportSessionStatus失败

AVAsset *avAsset1 = [AVURLAsset URLAssetWithURL:[NSURL fileURLWithPath:[NSString stringWithFormat:@"%@/firstPart.caf",docsDir]] options:nil];
AVAsset *avAsset2 = [AVURLAsset URLAssetWithURL:[NSURL fileURLWithPath:[NSString stringWithFormat:@"%@/New-Recording.caf",docsDir]] options:nil];

AVMutableComposition *composition = [[AVMutableComposition alloc] init];
[composition addMutableTrackWithMediaType:AVMediaTypeAudio preferredTrackID:kCMPersistentTrackID_Invalid];

AVMutableCompositionTrack *track = [composition addMutableTrackWithMediaType:AVMediaTypeAudio preferredTrackID:kCMPersistentTrackID_Invalid];

AVAssetTrack *assetTrack1;
AVAssetTrack *assetTrack2;

if ([avAsset1 tracksWithMediaType:AVMediaTypeAudio].count > 0) {
    assetTrack1 = [[avAsset1 tracksWithMediaType:AVMediaTypeAudio] objectAtIndex:0];
    assetTrack2 = [[avAsset2 tracksWithMediaType:AVMediaTypeAudio] objectAtIndex:0];
}

CMTime insertionPoint = kCMTimeZero;
[track insertTimeRange:CMTimeRangeMake(kCMTimeZero, avAsset1.duration) ofTrack:assetTrack1 atTime:insertionPoint error:nil];
insertionPoint = CMTimeAdd(insertionPoint, avAsset1.duration);
[track insertTimeRange:CMTimeRangeMake(kCMTimeZero, avAsset2.duration) ofTrack:assetTrack2 atTime:insertionPoint error:nil];

AVAssetExportSession *exportSession = [AVAssetExportSession exportSessionWithAsset:composition presetName:AVAssetExportPresetAppleM4A];
exportSession.outputURL = [NSURL fileURLWithPath:[NSString stringWithFormat:@"%@/mergedFilePart1.caf",documentsDirectory]];
exportSession.outputFileType = AVFileTypeAppleM4A;

[exportSession exportAsynchronouslyWithCompletionHandler:^{
    if (AVAssetExportSessionStatusCompleted == exportSession.status) {

        NSLog(@"AVAssetExportSessionStatusCompleted");

        [self mergeAudioPart2];

    } else if (AVAssetExportSessionStatusFailed == exportSession.status) {
        NSLog(@"AVAssetExportSessionStatusFailed");
    } else {
        NSLog(@"Export Session Status: %ld", (long)exportSession.status);
    }
}];

我搜索了整个互联网，但没有找到任何解决方案。我们将感谢您的帮助。

您的代码应该可以工作，但如果没有看到您的输入文件，就很难判断。然而，它仍然可以改进

由于某种原因，您有一个未使用的可变轨迹。您可以删除它：

AVMutableComposition *composition = [[AVMutableComposition alloc] init];
// This track is unused. Delete it!
// [composition addMutableTrackWithMediaType:AVMediaTypeAudio preferredTrackID:kCMPersistentTrackID_Invalid];

AVMutableCompositionTrack *track = [composition addMutableTrackWithMediaType:AVMediaTypeAudio preferredTrackID:kCMPersistentTrackID_Invalid];

导出失败时（

AVAssetExportSessionStatusFailed==exportSession.status

）请检查

exportSession.error

，了解更多信息

AVFoundation

错误消息通常会留下很多不尽如人意的地方，但您可能很幸运

您正在导出m4a文件，但文件后缀为

.caf

。将其更改为

.m4a

（

AVAssetExportSession

似乎不支持导出为

AVFileTypeCoreAudioFormat

）。 请确保在导出之前始终删除输出URL，因为您忘记了执行以下操作：

NSURL *ouputURL = [NSURL fileURLWithPath:[NSString stringWithFormat:@"%@/mergedFilePart1.m4a",documentsDirectory]];
[[NSFileManager defaultManager] removeItemAtURL:ouputURL error:nil];

AVAssetExportSession *exportSession = [AVAssetExportSession exportSessionWithAsset:composition presetName:AVAssetExportPresetAppleM4A];
exportSession.outputURL = ouputURL;
exportSession.outputFileType = AVFileTypeAppleM4A;

insertTimeRange:ofTrack:error:

返回成功标志和错误！咨询他们！他们可能会指出您的代码有问题

NSError *error;
if (![track insertTimeRange:CMTimeRangeMake(kCMTimeZero, avAsset1.duration) ofTrack:assetTrack1 atTime:insertionPoint error:&error]) {
    NSLog(@"ERROR 1: %@", error);
}

这种情况很奇怪。检查一个资源中是否存在音频曲目，然后再使用另一个资源：

if ([avAsset1 tracksWithMediaType:AVMediaTypeAudio].count > 0) {
    assetTrack1 = [[avAsset1 tracksWithMediaType:AVMediaTypeAudio] objectAtIndex:0];
    assetTrack2 = [[avAsset2 tracksWithMediaType:AVMediaTypeAudio] objectAtIndex:0];
}

问题是： //[composition addMutableTrackWithMediaType:AVMediaTypeAudio preferredTrackID:kCMPersistentTrackID_无效]；这条线增加了额外的轨道。现在，这段代码在IOS 9上也运行得很好

NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];

NSString *path1 = [NSString stringWithFormat:@"%@/firstPart.caf",documentsDirectory];
NSString *path2 = [NSString stringWithFormat:@"%@/New-Recording.caf",documentsDirectory];

AVAsset *avAsset1 = [AVURLAsset URLAssetWithURL:[NSURL fileURLWithPath:path1] options:nil];
AVAsset *avAsset2 = [AVURLAsset URLAssetWithURL:[NSURL fileURLWithPath:path2] options:nil];

AVMutableComposition *composition = [[AVMutableComposition alloc] init];
//    [composition addMutableTrackWithMediaType:AVMediaTypeAudio preferredTrackID:kCMPersistentTrackID_Invalid];

AVMutableCompositionTrack *track = [composition addMutableTrackWithMediaType:AVMediaTypeAudio preferredTrackID:kCMPersistentTrackID_Invalid];

AVAssetTrack *assetTrack1;
AVAssetTrack *assetTrack2;

if ([avAsset1 tracksWithMediaType:AVMediaTypeAudio].count > 0) {
    assetTrack1 = [[avAsset1 tracksWithMediaType:AVMediaTypeAudio] objectAtIndex:0];
    assetTrack2 = [[avAsset2 tracksWithMediaType:AVMediaTypeAudio] objectAtIndex:0];
}

NSError *error;

CMTime insertionPoint = kCMTimeZero;

[track insertTimeRange:CMTimeRangeMake(kCMTimeZero, avAsset1.duration) ofTrack:assetTrack1 atTime:insertionPoint error:nil];
insertionPoint = CMTimeAdd(insertionPoint, avAsset1.duration);
[track insertTimeRange:CMTimeRangeMake(kCMTimeZero, avAsset2.duration) ofTrack:assetTrack2 atTime:insertionPoint error:nil];

NSURL *outPutUrl = [NSURL fileURLWithPath:[NSString stringWithFormat:@"%@/mergedFilePart1.caf",documentsDirectory]];


AVAssetExportSession *exportSession = [AVAssetExportSession exportSessionWithAsset:composition presetName:AVAssetExportPresetAppleM4A];

exportSession.outputURL = outPutUrl;

exportSession.outputFileType = AVFileTypeAppleM4A;

[exportSession exportAsynchronouslyWithCompletionHandler:^{
    if (AVAssetExportSessionStatusCompleted == exportSession.status) {

        NSLog(@"AVAssetExportSessionStatusCompleted");
        [self mergeAudioPart2];

    } else if (AVAssetExportSessionStatusFailed == exportSession.status) {

        NSLog(@"%ld",(long)exportSession.status);
        NSLog(@"AVAssetExportSessionStatusFailed");
    } else {
        NSLog(@"Export Session Status: %ld", (long)exportSession.status);
    }
}];

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我还遇到一个问题，请对此进行调查并提出建议：