服务器之家

服务器之家 > 正文

iOS 边下边播的实现代码

时间：2021-04-05 16:00     来源/作者：duicode

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

?
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
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

?
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
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

?
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
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

标签：
iOS 边下边播 

相关文章

热门资讯

2020微信伤感网名听哭了 让对方看到心疼的伤感网名大全
2020微信伤感网名听哭了 让对方看到心疼的伤感网名大全 2019-12-26
yue是什么意思 网络流行语yue了是什么梗
yue是什么意思 网络流行语yue了是什么梗 2020-10-11
背刺什么意思 网络词语背刺是什么梗
背刺什么意思 网络词语背刺是什么梗 2020-05-22
Intellij idea2020永久破解，亲测可用！！！
Intellij idea2020永久破解，亲测可用！！！ 2020-07-29
苹果12mini价格表官网报价 iPhone12mini全版本价格汇总
苹果12mini价格表官网报价 iPhone12mini全版本价格汇总 2020-11-13
返回顶部