iOS视频压缩

//
//  ViewController.m
//  iOS视频测试
//
//  Created by apple on 15/8/19.
//  Copyright (c) 2015年 tqh. All rights reserved.
//

#import "ViewController.h"
#import <AVFoundation/AVFoundation.h>
@interface ViewController ()

@end

@implementation ViewController

//下载视频
- (void)viewDidLoad {
[super viewDidLoad];
NSString *path = NSHomeDirectory();//主目录
NSLog(@"NSHomeDirectory:%@",path);
//获取沙盒中的路径

NSArray *storeFilePath = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,NSUserDomainMask, YES);

NSString *doucumentsDirectiory = [storeFilePath objectAtIndex:0];

NSString *plistPath =[doucumentsDirectiory stringByAppendingPathComponent:@"mp4Test.mp4"];

NSFileManager *file = [NSFileManager defaultManager];

if ([file fileExistsAtPath:plistPath])

{
NSLog(@"沙盒中有视频");
}
else //若沙盒中没有

{
NSError *error;
NSFileManager *fileManager = [NSFileManager defaultManager];
NSString *bundle = [[NSBundle mainBundle] pathForResource:@"mp4Test" ofType:@"mp4"];
[fileManager copyItemAtPath:bundle toPath:plistPath error:&error];
NSLog(@"写入没有%d",[fileManager copyItemAtPath:bundle toPath:plistPath error:&error]);

}

NSString *newPlistPath =[doucumentsDirectiory stringByAppendingPathComponent:@"mp4Test5.mp4"];
[self lowQuailtyWithInputURL:[NSURL fileURLWithPath:plistPath] outputURL:[NSURL fileURLWithPath:newPlistPath] blockHandler:^(AVAssetExportSession *session) {
if (session.status == AVAssetExportSessionStatusCompleted)
{
NSLog(@"压缩完成");
}else if (session.status == AVAssetExportSessionStatusFailed) {
NSLog(@"压缩失败");
}
}];
}

#pragma mark - 视频压缩

- (void) lowQuailtyWithInputURL:(NSURL*)inputURL
outputURL:(NSURL*)outputURL
blockHandler:(void (^)(AVAssetExportSession*))handler
{
AVURLAsset *asset = [AVURLAsset URLAssetWithURL:inputURL options:nil];
AVAssetExportSession *session = [[AVAssetExportSession alloc] initWithAsset:asset     presetName:AVAssetExportPresetLowQuality];
session.outputURL = outputURL;
session.outputFileType = AVFileTypeQuickTimeMovie;
[session exportAsynchronouslyWithCompletionHandler:^(void)
{
handler(session);
}];
}

@end

AVAssetExportPresetLowQuality：低质量压缩

AVF_EXPORT NSString *const AVAssetExportPresetLowQuality NS_AVAILABLE_IOS(4_0);
AVF_EXPORT NSString *const AVAssetExportPresetMediumQuality NS_AVAILABLE_IOS(4_0);
AVF_EXPORT NSString *const AVAssetExportPresetHighestQuality NS_AVAILABLE_IOS(4_0);