我有AVAsset AVAssetTrack，其大小（例如 - （width = 1920，height = 1080））。我需要的东西 - 将这个资产适合给定的屏幕尺寸（例如（宽度= 320，高度= 568）），如果是横向资产 - 旋转它（90度），如果是正方形 - 在顶部和底部添加黑色条纹。我试过这个：
- (void)changeAsset:(AVAsset*)asset savetoURL:(NSURL*)toURL withSize:(CGSize)toSize offsetRatioPoint:(CGPoint*)offsetRatioPoint completion:(void (^)(NSURL* in_url, NSError* error))handler
{
AVAssetTrack *videoTrack = [[asset tracksWithMediaType:AVMediaTypeVideo] firstObject];
if (!videoTrack)
{
if (handler)
handler(nil, [NSError errorWithDomain:@"com.myapp.error" code:-1 userInfo:@{@"message" : @"there are no video tracks in asset"}]);
return;
}
CGFloat newHeight = [videoTrack naturalSize].height/3*4;
CGFloat newWidth = [videoTrack naturalSize].width/3*4;
const CGFloat videoAspectRatio = newWidth / newHeight;
const CGFloat toSizeAspectRatio = toSize.width / toSize.height;
CGFloat scale = 1.f;
if (videoAspectRatio > toSizeAspectRatio)
{
scale = toSize.height / newHeight;
}
else
{
scale = toSize.width /newWidth;
}
CGAffineTransform scaleTrans = CGAffineTransformMakeScale(scale, scale);
CGAffineTransform translateTrans = CGAffineTransformIdentity;
if (videoAspectRatio > toSizeAspectRatio)
{
if (offsetRatioPoint)
{
const CGFloat dx = offsetRatioPoint->x * newWidth * scale;
translateTrans = CGAffineTransformMakeTranslation(-dx, 0.f);
}
else
{
const CGFloat dx = 0.5f * (newWidth * scale - toSize.width);
translateTrans = CGAffineTransformMakeTranslation(-dx, 0.f);
}
}
else
{
if (offsetRatioPoint)
{
const CGFloat dy = offsetRatioPoint->y * newHeight * scale;
translateTrans = CGAffineTransformMakeTranslation(0.f, -dy);
}
else
{
const CGFloat dy = 0.5f * (newHeight * scale - toSize.height);
translateTrans = CGAffineTransformMakeTranslation(0.f, -dy);
}
}
CGAffineTransform t1 = CGAffineTransformTranslate(translateTrans, toSize.height, -scale*toSize.width);
// Rotate transformation
CGAffineTransform t2 = CGAffineTransformRotate(t1, M_PI_2);
CGAffineTransform finalTrans = CGAffineTransformConcat(scaleTrans, t2);
AVMutableVideoComposition *videoComposition = [[AVMutableVideoComposition alloc] init];
videoComposition.renderSize = toSize;
int32_t frameRate = 30;
videoComposition.frameDuration = CMTimeMake(1, frameRate);
AVMutableVideoCompositionInstruction *instruction = [AVMutableVideoCompositionInstruction videoCompositionInstruction];
instruction.timeRange = CMTimeRangeMake(kCMTimeZero, asset.duration);
AVMutableVideoCompositionLayerInstruction* layerInstruction = [AVMutableVideoCompositionLayerInstruction videoCompositionLayerInstructionWithAssetTrack:videoTrack];
[layerInstruction setTransform:finalTrans atTime:kCMTimeZero];
instruction.layerInstructions = @[layerInstruction];
videoComposition.instructions = @[instruction];
AVAssetExportSession *exporter = [[AVAssetExportSession alloc] initWithAsset:asset presetName:AVAssetExportPreset640x480];
exporter.videoComposition = videoComposition;
exporter.shouldOptimizeForNetworkUse = YES;
NSString *exportPath = [NSTemporaryDirectory() stringByAppendingPathComponent:kCroppedFileName];
if (toURL)
exportPath = toURL.path;
if ([[NSFileManager defaultManager] fileExistsAtPath:exportPath] == YES)
[[NSFileManager defaultManager] removeItemAtPath:exportPath error:nil];
__block NSURL* outURL = [NSURL fileURLWithPath: exportPath];
exporter.outputURL = outURL;
exporter.outputFileType = AVFileTypeMPEG4;
exporter.timeRange = instruction.timeRange;
NSLog(@"%@", exportPath);
[exporter exportAsynchronouslyWithCompletionHandler:^(void) {
if (!toURL)
{
if ([[NSFileManager defaultManager] fileExistsAtPath:[GlobalConst fullMoviePath]] == YES)
[[NSFileManager defaultManager] removeItemAtPath:[GlobalConst fullMoviePath] error:nil];
NSError *error;
if (![[NSFileManager defaultManager] moveItemAtPath: exportPath toPath:[GlobalConst fullMoviePath] error:&error]) {
NSLog(@"Error %@", error);
}
outURL = [NSURL fileURLWithPath: [GlobalConst fullMoviePath] ];
}
NSLog(@"%@", outURL);
handler(outURL, nil);
}];
}
这几乎是第一步 - 旋转横向资产，但结果资产有点缩放。提前感谢所有建议。
答案 0 :(得分：0)
我解决了这个prblm usrin这段代码。在此代码中我将横向旋转为视频肖像。使其正方形也添加图像作为水印。
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_HIGH, 0), ^(){
// input clip
AVAssetTrack *clipVideoTrack = [[asset tracksWithMediaType:AVMediaTypeVideo] objectAtIndex:0];
int videoDimention;
// make it square
UIInterfaceOrientation orientation = [self orientationForTrack:asset];
BOOL isPortrait = (orientation == UIInterfaceOrientationPortrait || orientation == UIInterfaceOrientationPortraitUpsideDown) ? YES: NO;
CGSize videoSize;
NSUserDefaults *userDefault=[NSUserDefaults standardUserDefaults];
if(isPortrait) {
//videoSize = CGSizeMake(complimentSize*.7,clipVideoTrack.naturalSize.height );
videoSize = CGSizeMake(clipVideoTrack.naturalSize.height,clipVideoTrack.naturalSize.width*.7 );
[userDefault setDouble:videoSize.width forKey:VIDEO_WIDTH_OUTPUT];
[userDefault setDouble:videoSize.height forKey:VIDEO_HEIGHT_OUTPUT];
videoDimention=0;// for Portrait
} else {
videoSize = CGSizeMake(clipVideoTrack.naturalSize.width, clipVideoTrack.naturalSize.height);
videoDimention=1;// for Landscape
[userDefault setDouble:videoSize.width forKey:VIDEO_WIDTH_OUTPUT];
[userDefault setDouble:videoSize.height forKey:VIDEO_HEIGHT_OUTPUT];
}
AVMutableVideoComposition* videoComposition = [AVMutableVideoComposition videoComposition];
if([[NSUserDefaults standardUserDefaults] integerForKey:SIZE]==0){
videoComposition.renderSize = CGSizeMake(clipVideoTrack.naturalSize.height , clipVideoTrack.naturalSize.height);
videoDimention=2; // for squre
double height=clipVideoTrack.naturalSize.height;
[userDefault setDouble:height forKey:VIDEO_WIDTH_OUTPUT];
[userDefault setDouble:height forKey:VIDEO_HEIGHT_OUTPUT];
}
else{
videoComposition.renderSize =videoSize;
}
// videoComposition.renderScale=.5;
if([[NSUserDefaults standardUserDefaults] integerForKey:FPS]==0){
videoComposition.frameDuration = CMTimeMake(1, 15);
}
else if ([[NSUserDefaults standardUserDefaults] integerForKey:FPS]==1){
videoComposition.frameDuration = CMTimeMake(1, 20);
}
else if ([[NSUserDefaults standardUserDefaults] integerForKey:FPS]==2){
videoComposition.frameDuration = CMTimeMake(1, 25);
}
else{
videoComposition.frameDuration = CMTimeMake(1, 30);
}
AVMutableVideoCompositionInstruction *instruction = [AVMutableVideoCompositionInstruction videoCompositionInstruction];
instruction.timeRange = CMTimeRangeMake(kCMTimeZero, [asset duration] );;
AVMutableVideoCompositionLayerInstruction* transformer = [AVMutableVideoCompositionLayerInstruction videoCompositionLayerInstructionWithAssetTrack:clipVideoTrack];
// rotate to portrait
if([self orientationForTrack:asset]==UIInterfaceOrientationPortrait){
CGAffineTransform t1 = CGAffineTransformMakeTranslation(clipVideoTrack.naturalSize.height, -(clipVideoTrack.naturalSize.width - clipVideoTrack.naturalSize.height) /2 );
CGAffineTransform t2 = CGAffineTransformRotate(t1, M_PI_2);
CGAffineTransform finalTransform = t2;
[transformer setTransform:finalTransform atTime:kCMTimeZero];
}
//for water mark
CGSize sizeOfVideo=[asset naturalSize];
//Image of watermark
UIImage *myImage=[UIImage imageNamed:@"watermark"];
CALayer *layerCa = [CALayer layer];
layerCa.contents = (id)myImage.CGImage;
if([[NSUserDefaults standardUserDefaults] integerForKey:SIZE]==0){
layerCa.frame = CGRectMake(videoSize.height-(videoSize.height/6), 0, videoSize.height/6, (videoSize.height/6)/4);
}
else{
layerCa.frame = CGRectMake(videoSize.width-(videoSize.width/6), 0, videoSize.width/6, (videoSize.width/6)/4);
}
// layerCa.frame = CGRectMake(videoSize.width-200, 0, 200, 60);
layerCa.opacity = 1.0;
CALayer *parentLayer=[CALayer layer];
CALayer *videoLayer=[CALayer layer];
parentLayer.frame=CGRectMake(0, 0, videoSize.width, videoSize.height);
videoLayer.frame=CGRectMake(0, 0, videoSize.width, videoSize.height);
[parentLayer addSublayer:videoLayer];
[parentLayer addSublayer:layerCa];
instruction.layerInstructions = [NSArray arrayWithObject:transformer];
videoComposition.instructions = [NSArray arrayWithObject: instruction];
if([[NSUserDefaults standardUserDefaults] boolForKey:UP_PID]==NO){
videoComposition.animationTool=[AVVideoCompositionCoreAnimationTool videoCompositionCoreAnimationToolWithPostProcessingAsVideoLayer:videoLayer inLayer:parentLayer];
}
AVAssetExportSession *exportSession = [[AVAssetExportSession alloc] initWithAsset:asset presetName:AVAssetExportPresetHighestQuality];
// AVMutableComposition *composition = [AVMutableComposition composition];
// [composition addMutableTrackWithMediaType:AVMediaTypeVideo preferredTrackID:kCMPersistentTrackID_Invalid];
// e.g .mov type
exportSession.outputURL = fileURL;
exportSession.videoComposition = videoComposition;
// [exportSession addObserver: forKeyPath:@"progress" options:NSKeyValueObservingOptionNew context:NULL];
exportSession.outputFileType = AVFileTypeQuickTimeMovie;
AVAssetExportSessionStatus status = [exportSession status];
[exportSession exportAsynchronouslyWithCompletionHandler:^{
dispatch_async(dispatch_get_main_queue(), ^{
VideoEditVC *controller=[[VideoEditVC alloc] init];
controller.isFirst=YES;
controller.videoSize=videoDimention;
[self.navigationController pushViewController:controller animated:YES];
self.delegate=controller;
});
}];
});
你还需要实现这个：
- (UIInterfaceOrientation)orientationForTrack:(AVAsset *)asset
{
AVAssetTrack *videoTrack = [[asset tracksWithMediaType:AVMediaTypeVideo] objectAtIndex:0];
CGSize size = [videoTrack naturalSize];
CGAffineTransform txf = [videoTrack preferredTransform];
if (size.width == txf.tx && size.height == txf.ty)
return UIInterfaceOrientationLandscapeRight;
else if (txf.tx == 0 && txf.ty == 0)
return UIInterfaceOrientationLandscapeLeft;
else if (txf.tx == 0 && txf.ty == size.width)
return UIInterfaceOrientationPortraitUpsideDown;
else
return UIInterfaceOrientationPortrait;
}