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在我的一个应用程序中,我需要在视频中添加一些图像。所以我将中断视频分成两部分,并从该图像制作一个视频。现在我想合并这三个视频文件并制作一个视频文件。但我不知道将这三个视频结合起来。我在这里看到了一些代码。但这对我没有帮助。对于中断视频和从图像制作视频,我现在使用下面的代码,我希望代码合并所有视频。

将当前视图屏幕放在视频文件之间的任何其他想法。

用于中断视频文件

NSURL *url = [NSURL fileURLWithPath:[[NSBundle mainBundle] pathForResource:@"Affagogato" ofType:@"mp4"]];
 AVURLAsset *anAsset = [[AVURLAsset alloc] initWithURL:url options:nil];




for(int i = 0; i < 2; i++) {
    AVAssetExportSession *exportSession = [[AVAssetExportSession alloc]
                                           initWithAsset:anAsset presetName:AVAssetExportPresetLowQuality];
    NSString *filePath = nil;
    NSUInteger count = 0;
    do {
        filePath = NSTemporaryDirectory();

        NSString *numberString = count > 0 ? [NSString stringWithFormat:@"-%i", count] : @"";
        filePath = [filePath stringByAppendingPathComponent:[NSString stringWithFormat:@"Output-%@.mov", numberString]];
        count++;
    } while([[NSFileManager defaultManager] fileExistsAtPath:filePath]);      

    exportSession.outputURL = [NSURL fileURLWithPath:filePath];
    exportSession.outputFileType = AVFileTypeQuickTimeMovie;
    CMTimeRange range;
    if(i == 0){
        CMTime start = CMTimeMakeWithSeconds(0.0, 600);
        CMTime duration = CMTimeMakeWithSeconds(10.0, 600);
        range = CMTimeRangeMake(start, duration);
    }else{
        CMTime start = CMTimeMakeWithSeconds(10.0, 600);
        range = CMTimeRangeMake(start, anAsset.duration);
    }
    exportSession.timeRange = range;   

    [exportSession exportAsynchronouslyWithCompletionHandler:^
     {
         dispatch_async(dispatch_get_main_queue(), ^{
             [self exportDidFinish:exportSession Tag:i];
         });
     }]; 
}

从图像中获取视频

CGRect rect=CGRectMake(0, 0, 320, 480);
view = [[UIView alloc]initWithFrame:rect];

NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = ([paths count] > 0) ? [paths objectAtIndex:0] : nil;
NSString *path = [documentsDirectory stringByAppendingPathComponent:[@"video2"  stringByAppendingString:@".mov"]];

CGSize size = self.view.frame.size;


NSMutableDictionary *attributes = [[NSMutableDictionary alloc]init];
[attributes setObject:[NSNumber numberWithUnsignedInt:kCVPixelFormatType_32ARGB] forKey:(NSString*)kCVPixelBufferPixelFormatTypeKey];
[attributes setObject:[NSNumber numberWithUnsignedInt:320] forKey:(NSString*)kCVPixelBufferWidthKey];
[attributes setObject:[NSNumber numberWithUnsignedInt:480] forKey:(NSString*)kCVPixelBufferHeightKey];


NSError *error = nil;
AVAssetWriter *videoWriter = [[AVAssetWriter alloc] initWithURL:
                              [NSURL fileURLWithPath:path] fileType:AVFileTypeQuickTimeMovie
                                                          error:&error];


NSParameterAssert(videoWriter);
NSDictionary *videoSettings = [NSDictionary dictionaryWithObjectsAndKeys:
                               AVVideoCodecH264, AVVideoCodecKey,
                               [NSNumber numberWithInt:size.width], AVVideoWidthKey,
                               [NSNumber numberWithInt:size.height], AVVideoHeightKey,
                               nil];

AVAssetWriterInput* writerInput = [[AVAssetWriterInput
                                    assetWriterInputWithMediaType:AVMediaTypeVideo
                                    outputSettings:videoSettings] retain];


AVAssetWriterInputPixelBufferAdaptor *adaptor = [AVAssetWriterInputPixelBufferAdaptor
                                                 assetWriterInputPixelBufferAdaptorWithAssetWriterInput:writerInput
                                                 sourcePixelBufferAttributes:nil];


NSParameterAssert(writerInput);
NSParameterAssert([videoWriter canAddInput:writerInput]);
[videoWriter addInput:writerInput];


//Start a session:
[videoWriter startWriting];
[videoWriter startSessionAtSourceTime:kCMTimeZero];

CVPixelBufferRef buffer = NULL;

//convert uiimage to CGImage.

xPixel=0;
yPixel=250;

buffer = [self pixelBufferFromCGImage:[[UIImage imageNamed:@"1.jpeg"] CGImage]];



CVPixelBufferPoolCreatePixelBuffer (NULL, adaptor.pixelBufferPool, &buffer);
[adaptor appendPixelBuffer:buffer withPresentationTime:kCMTimeZero];

for (int i = 0;i<2; i++)
{
    if([writerInput isReadyForMoreMediaData])
    {
        //NSLog(@"inside for loop %d",i);

        for(int pframetime=1;pframetime<=2;pframetime++)
        {  

            CMTime frameTime = CMTimeMake(pframetime,25);
            CMTime lastTime=CMTimeMake(i,1); //i is from 0 to 19 of the loop above
            CMTime presentTime=CMTimeAdd(lastTime, frameTime);

            if(i==0)
                buffer = [self pixelBufferFromCGImage:[[UIImage imageNamed:@"1.jpeg"] CGImage]];
            else
                buffer = [self pixelBufferFromCGImage:[[UIImage imageNamed:@"2.jpeg"] CGImage]];
            while ( ![writerInput isReadyForMoreMediaData] )
            {
                [NSThread sleepForTimeInterval:0.05];
            }

            [adaptor appendPixelBuffer:buffer withPresentationTime:presentTime];
            i++;
        }
        if(buffer)
            CVBufferRelease(buffer);
        //[NSThread sleepForTimeInterval:0.1];
    }
}
[writerInput markAsFinished];
[videoWriter finishWriting];
[videoPathArray addObject:path];

//Finish the session:

[videoWriter release];
[writerInput release];
CVPixelBufferPoolRelease(adaptor.pixelBufferPool);

对于合并视频文件,我尝试使用此代码,但这里没有用,视频之间有一些空白屏幕

   AVMutableComposition* mixComposition = [AVMutableComposition composition];

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

    NSString* video_inputFilePath1 = [videoPathArray objectAtIndex:1];
    NSURL*    video_inputFileUrl1 = [NSURL fileURLWithPath:video_inputFilePath1];

    NSString* video_inputFilePath2 = [videoPathArray objectAtIndex:0];
    NSURL*    video_inputFileUrl2 = [NSURL fileURLWithPath:video_inputFilePath2];

    NSString* video_inputFilePath3 = [videoPathArray objectAtIndex:2];
    NSURL*    video_inputFileUrl3 = [NSURL fileURLWithPath:video_inputFilePath3];

    NSString* outputFileName = @"outputFile.mov";
    NSString* outputFilePath = [NSString stringWithFormat:@"%@/%@",documentsDirectoryPath,outputFileName];

    NSURL*    outputFileUrl = [NSURL fileURLWithPath:outputFilePath];

    if ([[NSFileManager defaultManager] fileExistsAtPath:outputFilePath]) 
        [[NSFileManager defaultManager] removeItemAtPath:outputFilePath error:nil];

    CMTime nextClipStartTime = kCMTimeZero;


    AVURLAsset* videoAsset1 = [[AVURLAsset alloc]initWithURL:video_inputFileUrl1 options:nil];
    AVURLAsset* videoAsset2 = [[AVURLAsset alloc]initWithURL:video_inputFileUrl2 options:nil];
    AVURLAsset* videoAsset3 = [[AVURLAsset alloc]initWithURL:video_inputFileUrl3 options:nil];


    CMTimeRange video_timeRange1 = CMTimeRangeMake(kCMTimeZero,videoAsset1.duration);
    AVMutableCompositionTrack *a_compositionVideoTrack1 = [mixComposition addMutableTrackWithMediaType:AVMediaTypeVideo preferredTrackID:kCMPersistentTrackID_Invalid];
    [a_compositionVideoTrack1 insertTimeRange:video_timeRange1 ofTrack:[[videoAsset1 tracksWithMediaType:AVMediaTypeVideo] objectAtIndex:0] atTime:nextClipStartTime error:nil];

    CMTimeRange video_timeRange3 = CMTimeRangeMake(nextClipStartTime,videoAsset3.duration);

    [a_compositionVideoTrack1 insertTimeRange:video_timeRange3 ofTrack:[[videoAsset3 tracksWithMediaType:AVMediaTypeVideo] objectAtIndex:0] atTime:videoAsset1.duration error:nil];

    CMTimeRange video_timeRange2 = CMTimeRangeMake(nextClipStartTime,videoAsset1.duration);
    [a_compositionVideoTrack1 insertTimeRange:video_timeRange2 ofTrack:[[videoAsset2 tracksWithMediaType:AVMediaTypeVideo] objectAtIndex:0] atTime:videoAsset1.duration error:nil];



    AVAssetExportSession* _assetExport = [[AVAssetExportSession alloc] initWithAsset:mixComposition presetName:AVAssetExportPresetLowQuality];   
    _assetExport.shouldOptimizeForNetworkUse = YES;
    _assetExport.outputFileType = @"com.apple.quicktime-movie";
    _assetExport.outputURL = outputFileUrl;
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1 回答 1

2

Try watching the video called "Working with Media in AV Foundation" in the apple developers portal. It tells you how to do what you are describing.

https://developer.apple.com/videos/wwdc/2011/

于 2012-04-09T09:07:56.617 回答