NSURL*videoUrl = mediaURL;

/**

*  mov格式转mp4格式

*/

AVURLAsset*avAsset = [AVURLAssetURLAssetWithURL:[NSURLfileURLWithPath:videoUrl.absoluteString]options:nil];

AVAssetExportSession *exportSession = [[AVAssetExportSession alloc] initWithAsset:avAsset presetName:AVAssetExportPresetMediumQuality];

NSArray*compatiblePresets = [AVAssetExportSessionexportPresetsCompatibleWithAsset:avAsset];

/**

AVAssetExportPresetMediumQuality 表示视频的转换质量，

*/

if([compatiblePresetscontainsObject:AVAssetExportPresetMediumQuality]) {

NSURL*newVideoUrl ;//一般.mp4

NSDateFormatter *formater = [[NSDateFormatter alloc] init];//用时间给文件全名，以免重复，在测试的时候其实可以判断文件是否存在若存在，则删除，重新生成文件即可

[formatersetDateFormat:@"yyyy-MM-dd-HH:mm:ss"];

newVideoUrl = [NSURL fileURLWithPath:[NSHomeDirectory() stringByAppendingFormat:@"/Documents/output-%@.mp4", [formater stringFromDate:[NSDate date]]]] ;

exportSession.outputURL= newVideoUrl;

//要转换的格式，这里使用 MP4

exportSession.outputFileType=AVFileTypeMPEG4;

//转换的数据是否对网络使用优化

exportSession.shouldOptimizeForNetworkUse=YES;

//异步处理开始转换

[exportSessionexportAsynchronouslyWithCompletionHandler:^(void)

{

//转换状态监控

switch(exportSession.status) {

case AVAssetExportSessionStatusUnknown:

NSLog(@"AVAssetExportSessionStatusUnknown");

break;

case AVAssetExportSessionStatusWaiting:

NSLog(@"AVAssetExportSessionStatusWaiting");

break;

case AVAssetExportSessionStatusExporting:

NSLog(@"AVAssetExportSessionStatusExporting");

break;

case AVAssetExportSessionStatusFailed:

NSLog(@"AVAssetExportSessionStatusFailed");

break;

case AVAssetExportSessionStatusCancelled:

NSLog(@"AVAssetExportSessionStatusCancelled");

break;

case AVAssetExportSessionStatusCompleted:

{

//转换完成

NSLog(@"AVAssetExportSessionStatusCompleted");

break;

}

}

}];

}