url为相册中视频对应的路径
// 将原始视频的URL转化为NSData数据,写入沙盒
- (void)videoWithUrl:(NSURL *)url withFileName:(NSString *)fileName andVideoUrlPath:(NSString *)KVideoUrlPath{
NSFileManager * fileManager = [NSFileManager defaultManager];
if (![fileManager fileExistsAtPath:KVideoUrlPath]) {
[fileManager createDirectoryAtPath:KVideoUrlPath withIntermediateDirectories:YES attributes:nil error:nil];
}
ALAssetsLibrary *assetLibrary = [[ALAssetsLibrary alloc] init];
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
if (url) {
[assetLibrary assetForURL:url resultBlock:^(ALAsset *asset) {
ALAssetRepresentation *rep = [asset defaultRepresentation];
NSString * videoPath = [KVideoUrlPath stringByAppendingPathComponent:fileName];
const char *cvideoPath = [videoPath UTF8String];
FILE *file = fopen(cvideoPath, "a+");
if (file) {
const int bufferSize = 111024 * 1024;
// 初始化一个1M的buffer
Byte *buffer = (Byte*)malloc(bufferSize);
NSUInteger read = 0, offset = 0, written = 0;
NSError* err = nil;
if (rep.size != 0)
{
do {
read = [rep getBytes:buffer fromOffset:offset length:bufferSize error:&err];
written = fwrite(buffer, sizeof(char), read, file);
offset += read;
} while (read != 0 && !err);
}
// 释放缓冲区，关闭文件
free(buffer);
buffer = NULL;
fclose(file);
file = NULL;
}
} failureBlock:nil];
}
});
}
http://www.jianshu.com/p/1eeaec2ae0fa
http://blog.csdn.net/wsyx768/article/details/50771993
http://www.jianshu.com/p/29585a416af2