ios - 将 AVAsset 读入帧并编译回视频

Question

各位!我项目中的想法是收集视频，将其分成帧，然后逐帧应用特定效果(不是主题)，然后将所有内容编译回来。

使用以下代码，我能够将视频读入帧并将它们传递到数组中:

//initialize avassetreader
AVAsset *avAsset = [AVAsset assetWithURL:url];
NSError *error = nil;
AVAssetReader *reader = [[AVAssetReader alloc] initWithAsset:avAsset error:&error];

//get video track
NSArray *videoTracks = [avAsset tracksWithMediaType:AVMediaTypeVideo];
AVAssetTrack *videoTrack = [videoTracks objectAtIndex:0];

NSDictionary *options = [NSDictionary dictionaryWithObject:[NSNumber numberWithInt:kCVPixelFormatType_32BGRA] forKey:(id)kCVPixelBufferPixelFormatTypeKey];

AVAssetReaderTrackOutput *asset_reader_output = [[AVAssetReaderTrackOutput alloc] initWithTrack:videoTrack outputSettings:options];

[reader addOutput:asset_reader_output];
[reader startReading];

接下来，正如我上面所说，我逐帧阅读轨道

//while there is something to read
while ( [reader status]==AVAssetReaderStatusReading ) { 


    CMSampleBufferRef sampleBuffer = [asset_reader_output copyNextSampleBuffer];
    CVImageBufferRef imageBuffer = CMSampleBufferGetImageBuffer(sampleBuffer);

    // Lock the base address of the pixel buffer
    CVPixelBufferLockBaseAddress(imageBuffer, 0);

    // Get the number of bytes per row for the pixel buffer
    size_t bytesPerRow = CVPixelBufferGetBytesPerRow(imageBuffer);

    // Get the pixel buffer width and height
    size_t width = CVPixelBufferGetWidth(imageBuffer);
    size_t height = CVPixelBufferGetHeight(imageBuffer);

    //Generate image to edit
    unsigned char* pixel = (unsigned char *)CVPixelBufferGetBaseAddress(imageBuffer);
    CGColorSpaceRef colorSpace=CGColorSpaceCreateDeviceRGB();
    CGContextRef context=CGBitmapContextCreate(pixel, width, height, 8, bytesPerRow, colorSpace, kCGBitmapByteOrder32Little|kCGImageAlphaPremultipliedFirst);

    CGImageRef image = CGBitmapContextCreateImage(context);
    UIImage* myImage = [[UIImage alloc] initWithCGImage:image];
    [photos addObject:myImage];

}

我可以将所有内容放入数组中，但我需要将所有内容编译回视频轨道，使用原始轨道的音频进行编译，然后保存。但是，我在网上找不到任何有用的信息。请帮忙!

提前致谢!

Answer 1

一旦你有了图像数组，AVAssetWriter 就是你的 friend 。