项目中之前使用的是AVPlayer直接播放URL地址，但是不知道是相机的wifi不够稳定还是代码的问题，app总是出现缓冲卡顿，就考虑改写成边下边播的模式，查过了许多资料，发现大部分都是用的同一种方法
AVAssetResourceLoaderDelegate 代理方法，来看看如何实现
首先要实现两个必须的代理方法
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AVAssetResourceLoaderDelegateObjective-C#pragma mark - AVAssetResourceLoaderDelegate//开始加载- (BOOL)resourceLoader:(AVAssetResourceLoader *)resourceLoader shouldWaitForLoadingOfRequestedResource:(AVAssetResourceLoadingRequest *)loadingRequest { [self addLoadingRequest:loadingRequest]; return YES;}//取消加载- (void)resourceLoader:(AVAssetResourceLoader *)resourceLoader didCancelLoadingRequest:(AVAssetResourceLoadingRequest *)loadingRequest { [self removeLoadingRequest:loadingRequest];}#pragma mark - AVAssetResourceLoaderDelegate//开始加载- (BOOL)resourceLoader:(AVAssetResourceLoader *)resourceLoader shouldWaitForLoadingOfRequestedResource:(AVAssetResourceLoadingRequest *)loadingRequest { [self addLoadingRequest:loadingRequest]; return YES;}//取消加载- (void)resourceLoader:(AVAssetResourceLoader *)resourceLoader didCancelLoadingRequest:(AVAssetResourceLoadingRequest *)loadingRequest { [self removeLoadingRequest:loadingRequest];} |
然后要定义一个下载类，其实就是分段下载数据的下载器
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AVAssetResourceLoaderDelegateObjective-C- (void)start { NSMutableURLRequest * request = [NSMutableURLRequest requestWithURL:[self.requestURL originalSchemeURL] cachePolicy:NSURLRequestReloadIgnoringCacheData timeoutInterval:RequestTimeout]; if (self.requestOffset > 0) { [request addValue:[NSString stringWithFormat:@"bytes=%ld-%ld", self.requestOffset, self.fileLength - 1] forHTTPHeaderField:@"Range"]; } self.session = [NSURLSession sessionWithConfiguration:[NSURLSessionConfiguration defaultSessionConfiguration] delegate:self delegateQueue:[NSOperationQueue mainQueue]]; self.task = [self.session dataTaskWithRequest:request]; [self.task resume];}#pragma mark - NSURLSessionDataDelegate//服务器响应- (void)URLSession:(NSURLSession *)session dataTask:(NSURLSessionDataTask *)dataTask didReceiveResponse:(NSURLResponse *)response completionHandler:(void (^)(NSURLSessionResponseDisposition))completionHandler { if (self.cancel) return; SRQLog(@"response: %@",response); completionHandler(NSURLSessionResponseAllow); NSHTTPURLResponse * httpResponse = (NSHTTPURLResponse *)response; NSString * contentRange = [[httpResponse allHeaderFields] objectForKey:@"Content-Range"]; NSString * fileLength = [[contentRange componentsSeparatedByString:@"/"] lastObject]; self.fileLength = fileLength.integerValue > 0 ? fileLength.integerValue : response.expectedContentLength; if (self.delegate && [self.delegate respondsToSelector:@selector(requestTaskDidReceiveResponse)]) { [self.delegate requestTaskDidReceiveResponse]; }}//服务器返回数据 可能会调用多次- (void)URLSession:(NSURLSession *)session dataTask:(NSURLSessionDataTask *)dataTask didReceiveData:(NSData *)data { if (self.cancel) return; //SRQLog(@"收到响应了: %@",data); self.cacheLength += data.length; if (self.delegate && [self.delegate respondsToSelector:@selector(requestTaskDidUpdateCache)]) { [self.delegate requestTaskDidUpdateCache]; }}//请求完成会调用该方法，请求失败则error有值- (void)URLSession:(NSURLSession *)session task:(NSURLSessionTask *)task didCompleteWithError:(NSError *)error { if (self.cancel) { SRQLog(@"下载取消"); }else { if (error) { if (self.delegate && [self.delegate respondsToSelector:@selector(requestTaskDidFailWithError:)]) { [self.delegate requestTaskDidFailWithError:error]; } }else { //可以缓存则保存文件 if (self.cache) { [FileHandle cacheTempFileWithFileName:[NSString fileNameWithURL:self.requestURL]]; } if (self.delegate && [self.delegate respondsToSelector:@selector(requestTaskDidFinishLoadingWithCache:)]) { [self.delegate requestTaskDidFinishLoadingWithCache:self.cache]; } } }}- (void)start { NSMutableURLRequest * request = [NSMutableURLRequest requestWithURL:[self.requestURL originalSchemeURL] cachePolicy:NSURLRequestReloadIgnoringCacheData timeoutInterval:RequestTimeout]; if (self.requestOffset > 0) { [request addValue:[NSString stringWithFormat:@"bytes=%ld-%ld", self.requestOffset, self.fileLength - 1] forHTTPHeaderField:@"Range"]; } self.session = [NSURLSession sessionWithConfiguration:[NSURLSessionConfiguration defaultSessionConfiguration] delegate:self delegateQueue:[NSOperationQueue mainQueue]]; self.task = [self.session dataTaskWithRequest:request]; [self.task resume];}#pragma mark - NSURLSessionDataDelegate//服务器响应- (void)URLSession:(NSURLSession *)session dataTask:(NSURLSessionDataTask *)dataTask didReceiveResponse:(NSURLResponse *)response completionHandler:(void (^)(NSURLSessionResponseDisposition))completionHandler { if (self.cancel) return; SRQLog(@"response: %@",response); completionHandler(NSURLSessionResponseAllow); NSHTTPURLResponse * httpResponse = (NSHTTPURLResponse *)response; NSString * contentRange = [[httpResponse allHeaderFields] objectForKey:@"Content-Range"]; NSString * fileLength = [[contentRange componentsSeparatedByString:@"/"] lastObject]; self.fileLength = fileLength.integerValue > 0 ? fileLength.integerValue : response.expectedContentLength; if (self.delegate && [self.delegate respondsToSelector:@selector(requestTaskDidReceiveResponse)]) { [self.delegate requestTaskDidReceiveResponse]; }}//服务器返回数据 可能会调用多次- (void)URLSession:(NSURLSession *)session dataTask:(NSURLSessionDataTask *)dataTask didReceiveData:(NSData *)data { if (self.cancel) return; //SRQLog(@"收到响应了: %@",data); self.cacheLength += data.length; if (self.delegate && [self.delegate respondsToSelector:@selector(requestTaskDidUpdateCache)]) { [self.delegate requestTaskDidUpdateCache]; }}//请求完成会调用该方法，请求失败则error有值- (void)URLSession:(NSURLSession *)session task:(NSURLSessionTask *)task didCompleteWithError:(NSError *)error { if (self.cancel) { SRQLog(@"下载取消"); }else { if (error) { if (self.delegate && [self.delegate respondsToSelector:@selector(requestTaskDidFailWithError:)]) { [self.delegate requestTaskDidFailWithError:error]; } }else { //可以缓存则保存文件 if (self.cache) { [FileHandle cacheTempFileWithFileName:[NSString fileNameWithURL:self.requestURL]]; } if (self.delegate && [self.delegate respondsToSelector:@selector(requestTaskDidFinishLoadingWithCache:)]) { [self.delegate requestTaskDidFinishLoadingWithCache:self.cache]; } } }} |
最后将拿到的数据塞进AVAssetResourceLoaderDelegate代理中，交还给AVPlayer，就可以播放了
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AVAssetResourceLoaderDelegateObjective-C- (BOOL)finishLoadingWithLoadingRequest:(AVAssetResourceLoadingRequest *)loadingRequest { //填充信息 CFStringRef contentType = UTTypeCreatePreferredIdentifierForTag(kUTTagClassMIMEType, (__bridge CFStringRef)(MimeType), NULL); loadingRequest.contentInformationRequest.contentType = CFBridgingRelease(contentType); loadingRequest.contentInformationRequest.byteRangeAccessSupported = YES; loadingRequest.contentInformationRequest.contentLength = self.requestTask.fileLength; //读文件，填充数据 NSUInteger cacheLength = self.requestTask.cacheLength; NSUInteger requestedOffset = loadingRequest.dataRequest.requestedOffset; if (loadingRequest.dataRequest.currentOffset != 0) { requestedOffset = loadingRequest.dataRequest.currentOffset; } NSUInteger canReadLength = cacheLength - (requestedOffset - self.requestTask.requestOffset); NSUInteger respondLength = MIN(canReadLength, loadingRequest.dataRequest.requestedLength); //SRQLog(@"好不容易填充一次"); [loadingRequest.dataRequest respondWithData:[FileHandle readTempFileDataWithOffset:requestedOffset - self.requestTask.requestOffset length:respondLength]]; //如果完全响应了所需要的数据，则完成 NSUInteger nowendOffset = requestedOffset + canReadLength; NSUInteger reqEndOffset = loadingRequest.dataRequest.requestedOffset + loadingRequest.dataRequest.requestedLength; if (nowendOffset >= reqEndOffset) { [loadingRequest finishLoading]; return YES; } return NO;}- (void)player{ self.resouerLoader = [[ResourceLoader alloc] init]; self.asset = [AVURLAsset URLAssetWithURL:[self.videoUrl customSchemeURL] options:nil]; [self.asset.resourceLoader setDelegate:self.resouerLoader queue:dispatch_get_main_queue()]; _playerItem = [AVPlayerItem playerItemWithAsset:self.asset]; _players = [AVPlayer playerWithPlayerItem:_playerItem];}- (BOOL)finishLoadingWithLoadingRequest:(AVAssetResourceLoadingRequest *)loadingRequest { //填充信息 CFStringRef contentType = UTTypeCreatePreferredIdentifierForTag(kUTTagClassMIMEType, (__bridge CFStringRef)(MimeType), NULL); loadingRequest.contentInformationRequest.contentType = CFBridgingRelease(contentType); loadingRequest.contentInformationRequest.byteRangeAccessSupported = YES; loadingRequest.contentInformationRequest.contentLength = self.requestTask.fileLength; //读文件，填充数据 NSUInteger cacheLength = self.requestTask.cacheLength; NSUInteger requestedOffset = loadingRequest.dataRequest.requestedOffset; if (loadingRequest.dataRequest.currentOffset != 0) { requestedOffset = loadingRequest.dataRequest.currentOffset; } NSUInteger canReadLength = cacheLength - (requestedOffset - self.requestTask.requestOffset); NSUInteger respondLength = MIN(canReadLength, loadingRequest.dataRequest.requestedLength); //SRQLog(@"好不容易填充一次"); [loadingRequest.dataRequest respondWithData:[FileHandle readTempFileDataWithOffset:requestedOffset - self.requestTask.requestOffset length:respondLength]]; //如果完全响应了所需要的数据，则完成 NSUInteger nowendOffset = requestedOffset + canReadLength; NSUInteger reqEndOffset = loadingRequest.dataRequest.requestedOffset + loadingRequest.dataRequest.requestedLength; if (nowendOffset >= reqEndOffset) { [loadingRequest finishLoading]; return YES; } return NO;}- (void)player{ self.resouerLoader = [[ResourceLoader alloc] init]; self.asset = [AVURLAsset URLAssetWithURL:[self.videoUrl customSchemeURL] options:nil]; [self.asset.resourceLoader setDelegate:self.resouerLoader queue:dispatch_get_main_queue()]; _playerItem = [AVPlayerItem playerItemWithAsset:self.asset]; _players = [AVPlayer playerWithPlayerItem:_playerItem];} |
注意：此方法服务器端最好支持Range头，这样才是分段下载。
总结
以上所述是小编给大家介绍的iOS 边下边播的实现代码，希望对大家有所帮助，如果大家有任何疑问请给我留言，小编会及时回复大家的。在此也非常感谢大家对服务器之家网站的支持！
原文链接：https://blog.duicode.com/2526.html
