ios根据视频地址获取某一帧的图像

http://blog.fuckbugs.me/category/ios/

//CatchImage.h

#import <Foundation/Foundation.h>

@interface CatchImage : NSObject

/*

*videoURL:视频地址(本地/网络)

*time :第N帧

*/

+ (UIImage*) thumbnailImageForVideo:(NSURL *)videoURL atTime:(NSTimeInterval)time;

@end

//CatchImage.m

#import "CatchImage.h"

#import <AVFoundation/AVFoundation.h>

#import <AVFoundation/AVAssetImageGenerator.h>

#import <AVFoundation/AVAsset.h>

@implementation CatchImage

+ (UIImage*) thumbnailImageForVideo:(NSURL *)videoURL atTime:(NSTimeInterval)time {

AVURLAsset *asset = [[[AVURLAsset alloc] initWithURL:videoURL options:nil]autorelease];

NSParameterAssert(asset);

AVAssetImageGenerator *assetImageGenerator =[[[AVAssetImageGenerator alloc] initWithAsset:asset]autorelease];

assetImageGenerator.appliesPreferredTrackTransform = YES;

assetImageGenerator.apertureMode =AVAssetImageGeneratorApertureModeEncodedPixels;

CGImageRef thumbnailImageRef = NULL;

CFTimeInterval thumbnailImageTime = time;

NSError *thumbnailImageGenerationError = nil;

thumbnailImageRef = [assetImageGenerator copyCGImageAtTime:CMTimeMake(thumbnailImageTime, 60)actualTime:NULL error:&thumbnailImageGenerationError];

if(!thumbnailImageRef)

NSLog(@"thumbnailImageGenerationError %@",thumbnailImageGenerationError);

UIImage*thumbnailImage = thumbnailImageRef ? [[[UIImage alloc]initWithCGImage:thumbnailImageRef] autorelease] : nil;

return thumbnailImage;

}

@end