Question

问题在于：

有一个视频文件;
管理员在播放时运行它（视频广播开始）;
用户已连接到服务器 - 必须提供给当前正在播放的视频流。实时网络直播。

为了实现这项任务，我作为文章的基础： http://www.strathweb.com/2013/01/asynchronously-streaming-video-with-asp-net-web-api/
有效。独立地并行地为流提供视频文件。我正在寻找。

接下来有必要解决向多个客户广播的问题（工作中的第3段）。我读了这篇文章： http://gigi.nullneuron.net/gigilabs/streaming-data-with-asp-net-web-api-and-pushcontentstream/

由于我必须在视频字节中提供证据 - 我将StreamWriter类替换为Stream 它适用于第一个客户端之一。

我创建了一个网站Asp.Net WebForms + WebApi + HTML5。网页 - 运行视频管理器并由用户查看。 WebApi为播放器提供<video>（HTML5）视频流。

HTML5：

<video>
    <source src="http://localhost:8080/SiteVideoStreaming/api/live/?filename=nameFile" />
</video>

WebApi控制器：

//Controllers
public class LiveController : ApiController
{
    private static ConcurrentBag<Stream> clients; // List of clients who need to simultaneously deliver video data
    static string fileName = "";

    static LiveController()
    {
        clients = new ConcurrentBag<Stream>();
        WriteToStream(); // The first call - start to play a video file
    }

    [HttpGet]
    public HttpResponseMessage Subscribe(string filename)
    {
        fileName = HostingEnvironment.MapPath("~/Videos/") + filename;

        var response = Request.CreateResponse();
        response.Content = new PushStreamContent((a, b, c) => { OnStreamAvailable(a, b, c); }, "video/mp4");
        return response;
    }


    private void OnStreamAvailable(Stream stream, HttpContent content, TransportContext context)
    {
        clients.Add(stream); // Add new client
    }

    //Class record a video file into a streams
    public async static void WriteToStream()
    {
        var buffer = new byte[65536];

        using (var video = File.Open(fileName, FileMode.Open, FileAccess.Read, FileShare.Read))
        {
            var length = (int)video.Length;
            var bytesRead = 1;

            while (length > 0 && bytesRead > 0)
            {
                bytesRead = video.Read(buffer, 0, Math.Min(length, buffer.Length));

                foreach (var client in clients)// Each client in turn we return video data
                {
                    try
                    {
                        await client.WriteAsync(buffer, 0, bytesRead); // ERROR - here !!! when you connect a second client
                        await client.FlushAsync();
                    }
                    catch (Exception ex)
                    {
                        Stream ignore;
                        clients.TryTake(out ignore);
                    }
                }

                length -= bytesRead;
            }
        }
    }
}

如果请求首先来自一个客户端 - 则是视频。工作。如果来自第二个客户端的请求 - 当你尝试开始给他一个流错误时会发生。在这个连接drop和第一个客户端。

错误如下：

[System.Web.HttpException] = {“远程主机关闭了连接。错误代码是0x800704CD。“}

据我所知，在互联网上搜索后：

0x800704CD“在不存在的网络上尝试了一项操作连接“。

告诉我，我做得不对？谢谢。

Answer 1

我这样做了。我用这个控制器：

public class VideoController : ApiController
{

    // GET api/<controller>
    public HttpResponseMessage Get(string filename)
    {
        if (filename == null)
            return new HttpResponseMessage(HttpStatusCode.BadRequest);

        string filePath = HostingEnvironment.MapPath("~/Videos/") + filename;

        if (Request.Headers.Range != null)
        {
            //Range Specifc request: Stream video on wanted range.
            try
            {
                //NOTE: ETag calculation only with file name is one approach (Not the best one though - GUIDs or DateTime is may required in live applications.).
                Encoder stringEncoder = Encoding.UTF8.GetEncoder();
                byte[] stringBytes = new byte[stringEncoder.GetByteCount(filePath.ToCharArray(), 0, filePath.Length, true)];
                stringEncoder.GetBytes(filePath.ToCharArray(), 0, filePath.Length, stringBytes, 0, true);
                MD5CryptoServiceProvider MD5Enc = new MD5CryptoServiceProvider();
                string hash = BitConverter.ToString(MD5Enc.ComputeHash(stringBytes)).Replace("-", string.Empty);

                HttpResponseMessage partialResponse = Request.CreateResponse(HttpStatusCode.PartialContent);
                partialResponse.Headers.AcceptRanges.Add("bytes");
                partialResponse.Headers.ETag = new EntityTagHeaderValue("\"" + hash + "\"");

                var stream = new FileStream(filePath, FileMode.Open, FileAccess.Read);
                partialResponse.Content = new ByteRangeStreamContent(stream, Request.Headers.Range, new MediaTypeHeaderValue("video/mp4"));
                return partialResponse;
            }
            catch (Exception ex)
            {
                return new HttpResponseMessage(HttpStatusCode.InternalServerError);
            }
        }
        else
        {
            return new HttpResponseMessage(HttpStatusCode.RequestedRangeNotSatisfiable);
        }
    }
}

在客户端 - 我通过SignalR技术运行<video>视频播放器。

使用Asp.Net WebForms + WebApi + HTML5

1 个答案: