当前播放位置不会改变HTML视频

current playback position doesn't change on html video

本文关键字：改变 HTML 视频 播放 位置      更新时间：2023-09-26

我有一个html5视频播放器驻留在mvc3剃刀视图。我的视频播放得很好，但奇怪的是，我似乎无法用video元素的滑块控制来改变播放位置(时间)。我用鼠标改变播放位置，但它只是从它离开的地方继续。

我想我应该有正确的一些额外的javascript来处理视频搜索，但这只是无稽之谈，不是吗?我遗漏了什么?

下面是我的html。

<video id="presentedFile" width="780" height="510" controls>
    <source src="/Folder/GetVideoStream?videoId=3" type="video/mp4">
</video>

编辑:我已经想到，当我有一个源作为一个actionlink到我的mvc控制器这个问题发生。如果我直接从文件中获取文件，它会像我预期的那样工作。所以我的控制器一定有问题。

public FileResult GetVideoStream( string videoId )
{
    /// create my stream
    return File(myStream, MimeMapping.GetMimeMapping(myVideo));
}

从这个答案开始，我设法克服了这个问题。估计是响应上缺少http头accept-ranges和content-range，导致视频不可压缩。

只是为了简化上面链接中提到的解决方案，他们使用了http处理程序来解决问题。但我想说的是，使用实现http处理程序不是所需解决方案的一部分。解决方案是，您必须在响应中添加必要的头，如下所示:

public FileResult GetVideoStream( string videoId )
{
    /// create the stream
    /// if request contains range details
    if ( !String.IsNullOrEmpty(HttpContext.Request.ServerVariables["HTTP_RANGE"]) )
        SetHeadersForRangedRequests(stream, HttpContext);
    return File(myStream, MimeMapping.GetMimeMapping(myVideo));
}

下面的方法是从上面的链接中引用的，我只是删除了StreamReader周围的using，因为我需要在操作完成后保持流打开。

void SetHeadersForRangedRequests ( Stream stream, HttpContextBase context )
{
    long size, start, end, length, fp = 0;
    StreamReader reader = new StreamReader(stream);
    size = reader.BaseStream.Length;
    start = 0;
    end = size - 1;
    length = size;
    context.Response.AddHeader("Accept-Ranges", "0-" + size);
    if ( !String.IsNullOrEmpty(context.Request.ServerVariables["HTTP_RANGE"]) )
    {
        long anotherStart = start;
        long anotherEnd = end;
        string[] arr_split = context.Request.ServerVariables["HTTP_RANGE"].Split(new char[] { Convert.ToChar("=") });
        string range = arr_split[1];
        // Make sure the client hasn't sent us a multibyte range
        if ( range.IndexOf(",") > -1 )
        {
            // (?) Shoud this be issued here, or should the first
            // range be used? Or should the header be ignored and
            // we output the whole content?
            context.Response.AddHeader("Content-Range", "bytes " + start + "-" + end + "/" + size);
            throw new HttpException(416, "Requested Range Not Satisfiable");
        }
        // If the range starts with an '-' we start from the beginning
        // If not, we forward the file pointer
        // And make sure to get the end byte if spesified
        if ( range.StartsWith("-") )
        {
            // The n-number of the last bytes is requested
            anotherStart = size - Convert.ToInt64(range.Substring(1));
        }
        else
        {
            arr_split = range.Split(new char[] { Convert.ToChar("-") });
            anotherStart = Convert.ToInt64(arr_split[0]);
            long temp = 0;
            anotherEnd = ( arr_split.Length > 1 && Int64.TryParse(arr_split[1].ToString(), out temp) ) ? Convert.ToInt64(arr_split[1]) : size;
        }
        /* Check the range and make sure it's treated according to the specs.
            * http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html
            */
        // End bytes can not be larger than $end.
        anotherEnd = ( anotherEnd > end ) ? end : anotherEnd;
        // Validate the requested range and return an error if it's not correct.
        if ( anotherStart > anotherEnd || anotherStart > size - 1 || anotherEnd >= size )
        {
            context.Response.AddHeader("Content-Range", "bytes " + start + "-" + end + "/" + size);
            throw new HttpException(416, "Requested Range Not Satisfiable");
        }
        start = anotherStart;
        end = anotherEnd;
        length = end - start + 1; // Calculate new content length
        fp = reader.BaseStream.Seek(start, SeekOrigin.Begin);
        context.Response.StatusCode = 206;
    }
    // Notify the client the byte range we'll be outputting
    context.Response.AddHeader("Content-Range", "bytes " + start + "-" + end + "/" + size);
    context.Response.AddHeader("Content-Length", length.ToString());
}
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