标签: avassetexportsession

我正在使用AVEditDemoApple的WWDC 2010样本包中的项目,我正在尝试更改导出视频的帧速率.使用AVMutableCompositionframeDuration设置的视频导出视频:

videoComposition.frameDuration = CMTimeMake(1, 30); // 30 fps

出于某种原因,将30更改为25并不会更改使用framerate该视频导出的视频AVAssetExportSession.有谁知道为什么？

我不得不将大文件大小的歌曲从iTunes库转换为较小的8K歌曲文件.

当我执行转换异步时,即使写入doc文件夹未完成,bool也总是返回true.目前我正在使用10秒的延迟再次调用该功能,它在iPhone 5s的临时工作正常,但我想迎合较慢的设备.

请在我的代码上给我一些指针/推荐.

-(void)startUploadSongAnalysis
{
     [self updateProgressYForID3NForUpload:NO];

    if ([self.uploadWorkingAray count]>=1)
    {
        Song *songVar = [self.uploadWorkingAray objectAtIndex:0];//core data var
        NSLog(@"songVar %@",songVar.songName);
        NSLog(@"songVar %@",songVar.songURL);
        NSURL *songU = [NSURL URLWithString:songVar.songURL]; //URL of iTunes Lib
       // self.asset = [AVAsset assetWithURL:songU];
       // NSLog(@"asset %@",self.asset);
        NSError *error;
        NSString *subString = [[songVar.songURL componentsSeparatedByString:@"id="] lastObject];
        NSString *savedPath = [self.documentsDir stringByAppendingPathComponent:[NSString stringWithFormat:@"audio%@.m4a",subString]];//save file name of converted 8kb song
        NSString *subStringPath = [NSString stringWithFormat:@"audio%@.m4a",subString];

        if ([self.fileManager fileExistsAtPath:savedPath] == YES)
            [self.fileManager removeItemAtPath:savedPath error:&error];
        NSLog(@"cacheDir %@",savedPath);

        //export low bitrate song to …

我正在开发App,我正在编写视频并导出到目录.它在iOS 7中运行良好,但在iOS 8中失败.

以下是我的代码:

AVAsset *pVideoTrack = [AVAsset assetWithURL:[NSURL fileURLWithPath:assetPath]];
AVVideoComposition *origionalComposition = [AVVideoComposition videoCompositionWithPropertiesOfAsset:pVideoTrack];

AVAssetTrack *clipVideoTrack = [[pVideoTrack tracksWithMediaType:AVMediaTypeVideo] objectAtIndex:0];

AVMutableComposition* mixComposition = [AVMutableComposition composition];
AVMutableCompositionTrack *compositionVideoTrack = [mixComposition addMutableTrackWithMediaType:AVMediaTypeVideo  preferredTrackID:kCMPersistentTrackID_Invalid];
[compositionVideoTrack insertTimeRange:CMTimeRangeMake(kCMTimeZero, pVideoTrack.duration)
                               ofTrack:clipVideoTrack
                                atTime:kCMTimeZero error:nil];
[compositionVideoTrack setPreferredTransform:[[[pVideoTrack tracksWithMediaType:AVMediaTypeVideo] objectAtIndex:0] preferredTransform]];

BOOL bIsPotrait = [self checkVideoOrientationProperty:[[pVideoTrack tracksWithMediaType:AVMediaTypeVideo] objectAtIndex:0]];

CGSize videoSize = CGSizeMake(0, 0);
if(bIsPotrait)
   videoSize = CGSizeMake([[[pVideoTrack tracksWithMediaType:AVMediaTypeVideo] objectAtIndex:0] naturalSize].height, [[[pVideoTrack tracksWithMediaType:AVMediaTypeVideo] objectAtIndex:0] naturalSize].width);

else
   videoSize = [[[pVideoTrack tracksWithMediaType:AVMediaTypeVideo] objectAtIndex:0] naturalSize];

AVMutableVideoComposition* videoComp = [AVMutableVideoComposition videoComposition];
videoComp.renderSize = …

出于某种原因,我总是收到此错误:

错误域= NSURLErrorDomain代码= -3000"无法创建文件"UserInfo = {NSLocalizedDescription =无法创建文件,NSUnderlyingError = 0x1321dd730 {错误域= NSOSStatusErrorDomain代码= -12115"(null)"}}

尝试将AVSession导出到m4a时.这在我的同事设备上运行良好,但每次在我的iPad Air 2(iOS 9.1)以及我们的QA iPad Mini 3上都会失败.

- (void)processSourceVideoFile:(NSURL *)mediaURL completion:(void (^)(BOOL success))completion {
    [self showProgressOverlay];

    NSString *outputFileType = AVFileTypeMPEG4;

    __block NSString *videoID = nil;
    if (self.videoAttachment == nil) {
        [MagicalRecord saveUsingEditContextWithBlockAndWait:^(NSManagedObjectContext *localContext) {
            self.videoAttachment = [SPXAttachment MR_createEntityInContext:localContext];
            self.videoAttachment.uuid = [NSString uuid];
            self.videoAttachment.clientCreatedAt = [NSDate date];
            videoID = self.videoAttachment.uuid;
        }];
    } else {
        videoID = self.videoAttachment.uuid;
    }

    self.videoAttachment = [SPXAttachment MR_findFirstByAttribute:@"uuid" withValue:videoID];

    NSString *targetPath = self.videoAttachment.filePath;
    DDLogVerbose(@"Exporting Video …

我在前置Camera中遇到使用AVAssetExportSession导出的视频方向错误.我按照这个教程/sf/answers/2475805461/但我得到了这个场景.我认为将图像切成两半并没有错.我尝试更改视频图层,渲染图层但没有运气.我的代码看起来像这样.

let composition = AVMutableComposition()
        let vidAsset = AVURLAsset(url: path)

        // get video track
        let vtrack =  vidAsset.tracks(withMediaType: AVMediaTypeVideo)
        // get audi trac

        let videoTrack:AVAssetTrack = vtrack[0]
        _ = videoTrack.timeRange.duration
        let vid_timerange = CMTimeRangeMake(kCMTimeZero, vidAsset.duration)

        var _: NSError?
        let compositionvideoTrack:AVMutableCompositionTrack = composition.addMutableTrack(withMediaType: AVMediaTypeVideo, preferredTrackID: CMPersistentTrackID())

        do {
            try compositionvideoTrack.insertTimeRange(vid_timerange, of: videoTrack, at: kCMTimeZero)

        } catch let error {
            print(error.localizedDescription)
        }

        let compositionVideoTrack = composition.addMutableTrack(withMediaType: AVMediaTypeAudio, preferredTrackID: kCMPersistentTrackID_Invalid)

        let audioTrack = vidAsset.tracks(withMediaType: AVMediaTypeAudio)[0]

        do {
            try compositionVideoTrack.insertTimeRange(CMTimeRangeMake(kCMTimeZero, vidAsset.duration), of: …

我正在尝试从UIImagePickerController创建的源视频中导出.mov文件.问题是输出文件AVAssetExportSession创建的只有668个字节.它为什么失败？我的代码:

- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info
{
    NSURL *imagePickerVideoURL = [info objectForKey:UIImagePickerControllerMediaURL];
    NSString *filename = @"vid1.mov";

    AVAsset *video = [AVAsset assetWithURL:imagePickerVideoURL];
    AVAssetExportSession *exportSession
      = [AVAssetExportSession exportSessionWithAsset:video presetName:AVAssetExportPresetMediumQuality];
    exportSession.shouldOptimizeForNetworkUse = YES;
    exportSession.outputFileType = AVFileTypeQuickTimeMovie;
    exportSession.outputURL = [pathToSavedVideosDirectory URLByAppendingPathComponent:filename];
    NSLog(@"processing video...: %@", exportSession);
    [exportSession exportAsynchronouslyWithCompletionHandler:^{
                       NSLog(@"done processing video!");
                   }];
}

我正在尝试在 Xamarin / Monotouch 中进行一些基本的视频合成，并取得了一些成功，但我陷入了看似相当简单的任务。

我以纵向方式录制相机中的视频，因此我使用 AVAssetExportSession 来旋转视频。我创建了一个图层指令来旋转视频，效果很好。我能够以正确的方向成功导出视频。

问题：

当我将音轨添加到导出中时，我总是收到失败响应并显示以下错误：

Domain=AVFoundationErrorDomain Code=-11841“操作已停止”UserInfo=0x1912c320 {NSLocalizedDescription=操作已停止，NSLocalizedFailureReason=无法合成视频。}

如果我没有在 exportSession 上设置 videoComposition 属性，则音频和视频导出完全正常，只是方向错误。如果有人能给我一些建议，我将不胜感激。下面是我的代码：

var composition = new AVMutableComposition();
                var compositionTrackAudio = composition.AddMutableTrack(AVMediaType.Audio, 0);
                var compositionTrackVideo = composition.AddMutableTrack(AVMediaType.Video, 0);
                var videoCompositionInstructions = new AVVideoCompositionInstruction[files.Count];
            var index = 0;
            var renderSize = new SizeF(480, 480);
            var _startTime = CMTime.Zero;
            //AVUrlAsset asset;



            var asset = new AVUrlAsset(new NSUrl(file, false), new AVUrlAssetOptions());
            //var asset = AVAsset.FromUrl(new NSUrl(file, false));


            //create an avassetrack with our asset
            var videoTrack = asset.TracksWithMediaType(AVMediaType.Video)[0];
            var …

有人知道如何使用具有 2 个以上通道的 AVAssetWriterInput init 吗？

我正在尝试初始化一个音频输入，以这种方式在 AVAssetWriter 之后添加它：

let audioInput = AVAssetWriterInput(mediaType: AVMediaTypeAudio, outputSettings: audioOutputSettings)

assetWriter.add(audioInput)

assetWriter.startWriting()

但是当我使用包含大于 2 的通道键数的 audioOutputSettings 字典初始化 audioInput 时它会崩溃。错误是：

Terminating app due to uncaught exception ‘NSInvalidArgumentException’, reason: ’*** -[AVAssetWriterInput initWithMediaType:outputSettings:sourceFormatHint:] 6 is not a valid channel count for Format ID ‘aac ’. Use kAudioFormatProperty_AvailableEncodeNumberChannels (<AudioToolbox/AudioFormat.h>) to enumerate available channel counts for a given format.

我正在使用 PryntTrimmerView 来修剪视频文件。有我的代码用于导出修剪视频文件并生成视频缩略图：

func prepareAssetComposition() throws {

    guard let asset = trimmerView.asset, let videoTrack = asset.tracks(withMediaType: AVMediaTypeVideo).last else {
      return
    }
    let size = videoTrack.naturalSize.applying(videoTrack.preferredTransform)
    print(CGSize(width: fabs(size.width), height: fabs(size.height)))

    let assetComposition = AVMutableComposition()
    let start = trimmerView.startTime?.seconds
    let end = trimmerView.endTime?.seconds
    let startTime = CMTime(seconds: Double(start ?? 0), preferredTimescale: 1000)
    let endTime = CMTime(seconds: Double(end ?? 0), preferredTimescale: 1000)
    let trackTimeRange = CMTimeRange(start: startTime, end: endTime)


    let compositionTrack = assetComposition.addMutableTrack(withMediaType: AVMediaTypeVideo, preferredTrackID: kCMPersistentTrackID_Invalid)
    try compositionTrack.insertTimeRange(trackTimeRange, of: videoTrack, at: kCMTimeZero)

    var …

我正在使用AVAssetExportSession在 iOS 应用程序中导出视频。为了以正确的方向呈现视频，我使用AVAssetTrack的是preferredTransform. 对于一些源视频，这个属性似乎有一个错误的值，结果视频出现偏移或全黑。我怎样才能解决这个问题？