从图像数组创建视频的问题答案

【问题标题】：Issue in creating video from array of image从图像数组创建视频的问题
【发布时间】：2013-10-04 02:44:59
【问题描述】：

我使用以下代码从图像和音频数组（预先录制）生成视频..

- (void)viewDidLoad
{
    imagearray=[[NSMutableArray alloc]initWithObjects:@"Quiz pic1.jpg",@"Quiz pic2.jpg",@"Quiz pic3.jpg",@"Quiz pic6.jpg",@"Quiz pic7.jpg",nil];
    image1array=[[NSMutableArray alloc]init];
    for (int i=0; i<[imagearray count]; i++)
    {
        UIImage *aimage=[UIImage imageNamed:[imagearray objectAtIndex:i]];
        [image1array addObject:aimage];
    }
    NSLog(@"%@",image1array);
    ImageVideoPath=@"/Users/image/Library/Application Support/iPhone Simulator/4.3/Applications/6CC91208-5819-4BFF-B868-6605887861EB/Output";
    FinalVideoPath=@"/Users/image/Library/Application Support/iPhone Simulator/4.3/Applications/6CC91208-5819-4BFF-B868-6605887861EB/VideoOutput";
    CGSize size;
    UIImage *image=[UIImage imageNamed:[imagearray objectAtIndex:0]];
    size=image.size;
    NSString *audioFilePath;
    int duration=10;
    //[self pixelBufferFromCGImage:[[image1array objectAtIndex:0] CGImage]];
    [self writeImageAndAudioAsMovie:image andAudio:audioFilePath duration:duration];

    //[self pixelBufferFromCGImage:[image CGImage] andSize:size];
    [super viewDidLoad];
}

- (void)writeImageAndAudioAsMovie:(UIImage*)image andAudio:(NSString *)audioFilePath duration:(int)duration {
    NSLog(@"start make movie: length:%d",duration);
    NSError *error = nil;
    AVAssetWriter *videoWriter = [[AVAssetWriter alloc] initWithURL:[NSURL fileURLWithPath:ImageVideoPath] fileType:AVFileTypeQuickTimeMovie
                                                              error:&error];
    NSParameterAssert(videoWriter);
    if ([[NSFileManager defaultManager] fileExistsAtPath:ImageVideoPath]) 
        [[NSFileManager defaultManager] removeItemAtPath:ImageVideoPath error:nil];

    NSDictionary *videoSettings = [NSDictionary dictionaryWithObjectsAndKeys:AVVideoCodecH264, AVVideoCodecKey,
                                   [NSNumber numberWithInt:image.size.width],AVVideoWidthKey,[NSNumber numberWithInt:image.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]);
    writerInput.expectsMediaDataInRealTime = YES;
    [videoWriter setShouldOptimizeForNetworkUse:YES];
    [videoWriter addInput:writerInput];

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

    //Write samples:
    CVPixelBufferRef buffer = [self pixelBufferFromCGImage:image.CGImage];
    [adaptor appendPixelBuffer:buffer withPresentationTime:kCMTimeZero];

    //Finish the session:
    [videoWriter endSessionAtSourceTime:CMTimeMake(duration, 1)];
    [writerInput markAsFinished];
    [videoWriter finishWriting];

    CVPixelBufferPoolRelease(adaptor.pixelBufferPool);
    [videoWriter release];
    [writerInput release];
    audioFilePath=[[NSBundle mainBundle]pathForResource:@"Video" ofType:@"mp3"];
    NSLog(@"%@",audioFilePath);
    [self addAudioToFileAtPath:ImageVideoPath andAudioPath:audioFilePath];
}

-(CVPixelBufferRef)pixelBufferFromCGImage: (CGImageRef) image{
    float width = CGImageGetWidth(image);
    float height = CGImageGetHeight(image);

    NSDictionary *options = [NSDictionary dictionaryWithObjectsAndKeys:
                             [NSNumber numberWithBool:YES], kCVPixelBufferCGImageCompatibilityKey,
                             [NSNumber numberWithBool:YES], kCVPixelBufferCGBitmapContextCompatibilityKey,
                             nil];
    CVPixelBufferRef pxbuffer = NULL;
    CVReturn status = CVPixelBufferCreate(kCFAllocatorDefault, width,height, kCVPixelFormatType_32ARGB,(CFDictionaryRef)options,&pxbuffer);

    NSParameterAssert(status == kCVReturnSuccess && pxbuffer != NULL);

    CVPixelBufferLockBaseAddress(pxbuffer, 0);
    void *pxdata = CVPixelBufferGetBaseAddress(pxbuffer);

    NSParameterAssert(pxdata != NULL);

    CGColorSpaceRef rgbColorSpace = CGColorSpaceCreateDeviceRGB();
    CGContextRef context = CGBitmapContextCreate(pxdata,width,height,8,4*width,rgbColorSpace,kCGImageAlphaNoneSkipFirst);

    NSParameterAssert(context);
    CGContextDrawImage(context, CGRectMake(0, 0,width, height), image);

    CGColorSpaceRelease(rgbColorSpace);
    CGContextRelease(context);

    CVPixelBufferUnlockBaseAddress(pxbuffer, 0);

    return pxbuffer;
}

-(void) addAudioToFileAtPath:(NSString *)vidoPath andAudioPath:(NSString *)audioFilePath{
    AVMutableComposition* mixComposition = [AVMutableComposition composition];
    NSLog(@"%@ %@",ImageVideoPath,audioFilePath);
    NSURL* audio_inputFileUrl = [NSURL fileURLWithPath:audioFilePath];
    NSURL* video_inputFileUrl = [NSURL fileURLWithPath:ImageVideoPath];
    NSLog(@"%@",video_inputFileUrl);
    NSString *outputFilePath = FinalVideoPath;
    NSURL* outputFileUrl = [NSURL fileURLWithPath:outputFilePath];

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

   AVURLAsset* audioAsset = [[AVURLAsset alloc]initWithURL:audio_inputFileUrl options:nil];
AVURLAsset* videoAsset = [[AVURLAsset alloc]initWithURL:video_inputFileUrl options:nil];
NSLog(@"asset:%@",videoAsset);
NSArray *tracks1=[videoAsset tracksWithMediaType:AVMediaTypeVideo];
if ([tracks1 count]>0)
{
    //CMTimeRange video_timeRange = CMTimeRangeMake(kCMTimeZero,videoAsset.duration);
    AVAssetTrack *videoAssetTrack=[tracks1 objectAtIndex:0];
    AVMutableCompositionTrack *a_compositionVideoTrack = [mixComposition addMutableTrackWithMediaType:AVMediaTypeVideo preferredTrackID:kCMPersistentTrackID_Invalid];

    [a_compositionVideoTrack insertTimeRange:CMTimeRangeMake(kCMTimeZero,videoAsset.duration) ofTrack:videoAssetTrack atTime:kCMTimeZero error:nil];  

}

NSArray *tracks = [audioAsset tracksWithMediaType:AVMediaTypeAudio];
if([tracks count]>0)
{
    AVAssetTrack * audioAssetTrack = [tracks objectAtIndex:0];
    AVMutableCompositionTrack *compositionAudioTrack = [mixComposition addMutableTrackWithMediaType:AVMediaTypeAudio 
                                                                                   preferredTrackID: kCMPersistentTrackID_Invalid];

    [compositionAudioTrack insertTimeRange:CMTimeRangeMake(kCMTimeZero,audioAsset.duration) ofTrack:audioAssetTrack atTime:kCMTimeZero error:nil];  


    //nextClipStartTime = CMTimeAdd(nextClipStartTime, a_timeRange.duration);
    [audioAsset release];audioAsset = nil;
}


    AVAssetExportSession* _assetExport = [[AVAssetExportSession alloc] initWithAsset:mixComposition presetName:AVAssetExportPresetHighestQuality];   
    _assetExport.outputFileType = AVFileTypeMPEG4;
    _assetExport.outputURL = outputFileUrl;

    [_assetExport exportAsynchronouslyWithCompletionHandler:
     ^(void ) {
         switch (_assetExport.status) 
         {
             case AVAssetExportSessionStatusCompleted:
                 //export complete 
                 NSLog(@"Export Complete");
                 break;
             case AVAssetExportSessionStatusFailed:
                 NSLog(@"Export Failed");
                 NSLog(@"ExportSessionError: %@", [_assetExport.error localizedDescription]);
                 //export error (see exportSession.error)  
                 break;
             case AVAssetExportSessionStatusCancelled:
                 NSLog(@"Export Failed");
                 NSLog(@"ExportSessionError: %@", [_assetExport.error localizedDescription]);
                 //export cancelled  
                 break;
         }
     }];    
}

我发现其中一个视频文件是通过writeImageAndAudioAsMovie 方法创建的，但它不支持我机器中的任何播放器... 我不知道我错过了什么？有什么建议请...

【问题讨论】：

标签： iphone video avassetwriter

【解决方案1】：

问题出在两个地方：

1.您提供的路径应该是允许您编写的文件目录。它必须有一些特定的扩展名。因为您正在创建 HighestQualityVideo，所以它应该是 .mov。

2.您应该提供正确的 outputFileType 应该根据扩展名和预设类型。所以在你的情况下应该是_assetExport.outputFileType = AVFileTypeQuickTimeMovie;。

尝试这些更改。

更新： 要消除崩溃，您需要将 AVAssetTrack 的代码替换为 addAudioToFileAtPath 方法中的以下代码：

NSArray *tracks = [videoAsset tracksWithMediaType:AVMediaTypeAudio];
if([tracks count]>0)
{
AVAssetTrack * audioAssetTrack = [tracks objectAtIndex:0];
    AVMutableCompositionTrack *compositionAudioTrack = [mixComposition addMutableTrackWithMediaType:AVMediaTypeAudio 
                                                                                preferredTrackID: kCMPersistentTrackID_Invalid];

    [compositionAudioTrack insertTimeRange:CMTimeRangeMake(kCMTimeZero,videoAsset.duration) ofTrack:audioAssetTrack atTime:kCMTimeZero error:nil];  


    //nextClipStartTime = CMTimeAdd(nextClipStartTime, a_timeRange.duration);
    [audioAsset release];audioAsset = nil;
}

关于视频类型：

Facebook 支持 QuickTimeVideo(mov/qt) 见http://www.facebook.com/help/?faq=218673814818907

要支持其他类型的视频，您需要在创建 AVAssetExportSession 对象时更改 presetName 并为此输出文件的扩展名，请阅读此文档。

http://www.google.co.in/url?sa=t&rct=j&q=AVAssetExportSession++class&source=web&cd=1&ved=0CCYQFjAA&url=http%3A%2F%2Fdeveloper.apple.com%2Flibrary%2Fios%2FDOCUMENTATION%2FAVFoundation%2FReference%2FAVAssetExportSession_Class%2FReference%2FReference.html&ei=xXxPT5akDsG8rAeck5XUDQ&usg=AFQjCNH1HqxIiT1kYJom6kZ82NS-qjVSyQ&cad=rja

更新 1：

这里我们访问每个图像并在显示一段时间后将其附加到缓冲区（我已经划分了持续时间。

for (int i=0; i<[image1array count]; i++)
    {
        int time = (int)i*(duration/[image1array count]);
        CVPixelBufferRef buffer = [self pixelBufferFromCGImage:[[image1array objectAtIndex:i] CGImage]];
        [adaptor appendPixelBuffer:buffer withPresentationTime:CMTimeMake(time, 1)];
    }

更新 2：

这是我在其中进行了一些更改以构成混合资产的代码。

-(void) addAudioToFileAtPath:(NSString *)vidoPath andAudioPath:(NSString *)audioFilePath{

    NSURL* audio_inputFileUrl = [NSURL fileURLWithPath:audioFilePath];
    NSURL* video_inputFileUrl = [NSURL fileURLWithPath:ImageVideoPath];
     NSURL* outputFileUrl = [NSURL fileURLWithPath:FinalVideoPath];
    AVMutableComposition *composition = [AVMutableComposition composition];
    AVAsset * audioAsset = [AVURLAsset URLAssetWithURL:audio_inputFileUrl options:nil];;
    AVAsset * videoAsset = [AVURLAsset URLAssetWithURL:video_inputFileUrl options:nil];

    AVMutableCompositionTrack *compositionVideoTrack = [composition addMutableTrackWithMediaType:AVMediaTypeVideo
                                                                                preferredTrackID:kCMPersistentTrackID_Invalid];
    AVMutableCompositionTrack *compositionAudioTrack = [composition addMutableTrackWithMediaType:AVMediaTypeAudio
                                                                                preferredTrackID:kCMPersistentTrackID_Invalid];

    NSError *error = nil;
    BOOL ok = NO;

    CMTimeRange video_timeRange = CMTimeRangeMake(kCMTimeZero,videoAsset.duration);
    AVAssetTrack *sourceVideoTrack = [[videoAsset tracksWithMediaType:AVMediaTypeVideo] objectAtIndex:0];
    ok = [compositionVideoTrack insertTimeRange:video_timeRange ofTrack:sourceVideoTrack atTime:kCMTimeZero error:&error];
    if (!ok) {
        // Deal with the error.
        NSLog(@"Error : %@ : %d",error,videoAsset.duration.value);
    }
    CMTimeRange audio_timeRange = CMTimeRangeMake(kCMTimeZero, audioAsset.duration);
    AVAssetTrack *sourceAudioTrack = [[audioAsset tracksWithMediaType:AVMediaTypeAudio] objectAtIndex:0];
    ok = [compositionAudioTrack insertTimeRange:audio_timeRange ofTrack:sourceAudioTrack atTime:kCMTimeZero error:&error];
    if (!ok) {
        // Deal with the error.
        NSLog(@"Error : %@ : %d",error,audioAsset.duration.value);
    }

    AVAssetExportSession* _assetExport = [[AVAssetExportSession alloc] initWithAsset:composition presetName:AVAssetExportPresetHighestQuality];   
    _assetExport.outputFileType = AVFileTypeQuickTimeMovie;
    _assetExport.outputURL = outputFileUrl;

    [_assetExport exportAsynchronouslyWithCompletionHandler:
     ^(void ) {
         switch (_assetExport.status) 
         {
             case AVAssetExportSessionStatusCompleted:
                 //export complete 
                 NSLog(@"Export Complete");
                 break;
             case AVAssetExportSessionStatusFailed:
                 NSLog(@"Export Failed");
                 NSLog(@"ExportSessionError: %@", [_assetExport.error localizedDescription]);
                 //export error (see exportSession.error)  
                 break;
             case AVAssetExportSessionStatusCancelled:
                 NSLog(@"Export Failed");
                 NSLog(@"ExportSessionError: %@", [_assetExport.error localizedDescription]);
                 //export cancelled  
                 break;
         }
         NSLog(@"Error : %@",_assetExport.error);
     }];    
}

谢谢，

【讨论】：

感谢您的 rply .....Bt 如果视频在 AVFileTypeQuickTimeMovie 中，我教过我会在 facebook 中播放 tat 视频时使用 pblm ....
我也在AVAssetTrack 中的addAudioToFileAtPath 中获得SIGABRT
请查看更新后的答案。我已经更新了有关崩溃以及视频支持的信息。
感谢您的建议，bt 我仍然生成了 pblm tat 视频文件 bt 我看不到任何视频 bt 我可以听到音频...我不知道我是不见了……
而且即使是快速播放器也无法读取 tat 格式，bt vlc 播放器正在读取 tat...

【解决方案2】：

引起我注意的一件事是，您在 writeImageAndAudioAsMovie:andAudio:duration: 方法中调用了 CVPixelBufferPoolRelease(adaptor.pixelBufferPool);，但由于您没有创建 adaptor.pixelBufferPool，因此您不拥有它，因此不应该发布它，正确的？对我来说似乎很可疑。

【讨论】：