Question

我的程序将MP4文件上传到blob然后将其修剪为10秒并重新上传到blob。我现在通过VS中的azure模拟器运行它时工作，但是当我将它部署到云时，输出文件有0个字节。

微调：

public static void Trimmer(string localStoragePath, Stream output )
{
    string path2= localStoragePath.Remove(localStoragePath.Length-4 )+ "_trimmed.mp4";
    string ffmpeg = "ffmpeg.exe";
    bool success = false;
    string ExeArguments;

    try
    {

        Process proc;
        proc = new Process();
        proc.StartInfo.FileName = ffmpeg;
        ExeArguments = @" -t 10 -i " + localStoragePath + " -map_metadata 0 -acodec copy " 
                                     + path2 + " -y";
        //ExeArguments = @"–t 10 -i -acodec" + localStoragePath + path2 ;
        Trace.TraceInformation(ExeArguments);
        proc.StartInfo.Arguments = ExeArguments;
        proc.StartInfo.CreateNoWindow = true;
        proc.StartInfo.UseShellExecute = false;
        proc.StartInfo.ErrorDialog = false;
        proc.Start();
        proc.WaitForExit();
        success = true;
    }

    catch { }

    Trace.TraceInformation(string.Format("Video has been trimmed") );

    using (Stream file = File.OpenRead(path2))
    {
        Trace.TraceInformation(string.Format("Video moving to CopyStream"));
        copyStream(file, output);
    }
}

复制流：

public static void copyStream(Stream input, Stream output)
{
    Trace.TraceInformation(string.Format("Video has been trimmed and now sent to be copied to stream"));
    byte[] buffer = new byte[8 * 1024];
    int len;
    while ((len = input.Read(buffer, 0, buffer.Length)) > 0)
    {
        output.Write(buffer, 0, len);
    }
}

Blob mover：

public static void fileMover (CloudBlob mover, string filePath, Stream input, Stream output)
        {


            string localStoragePath;
            //start string from 7th letter, eg, images
            string link = filePath.Substring(7);


                LocalResource locRes;
                locRes = RoleEnvironment.GetLocalResource("WorkerRoleLocalStorage");

                //To determine the path to the local storage resource's directory

                localStoragePath = string.Format(locRes.RootPath);

            //Moving file to local storage
            try
            {
                mover.DownloadToFile(localStoragePath + link, FileMode.OpenOrCreate);
                Trace.TraceInformation("file mover has been called " + localStoragePath + link);
                //add meta data
            }
            catch(Exception e) { }

            try
            {
                Trimmer(localStoragePath + link, output);
            }
            catch(Exception e) {}
        }

谢谢。

Answer 1

根据您的描述，我创建了我的项目来测试此问题。我可以使用存储模拟器在我身边按预期工作，并使用真实存储帐户部署到Azure。

我注意到您已使用try-catch包裹了代码，以下是您找到并解决此问题的一些建议：

您可以为云服务项目启用诊断程序，以便在部署到Azure之前记录应用程序日志。捕获异常时，可以利用System.Diagnostics.Trace记录详细错误。有关详细信息，请参阅此tutorial。
对于Trimmer方法，您需要检查path2文件是否存在。我测试过，如果没有生成文件，那么输出blob文件的大小为0。我修改了Trimmer方法，你可以参考它。

public static void Trimmer(string localStoragePath, CloudBlockBlob outPutBlob)
{
    string path2 = localStoragePath.Remove(localStoragePath.Length - 4) + "_trimmed.mp4";
    string ffmpeg = "ffmpeg.exe";
    bool success = false;
    string ExeArguments;
    try
    {
        Process proc;
        proc = new Process();
        proc.StartInfo.FileName = ffmpeg;
        ExeArguments = @" -t 10 -i " + localStoragePath + " -map_metadata 0 -acodec copy "
                                        + path2 + " -y";
        Trace.TraceInformation(ExeArguments);
        proc.StartInfo.Arguments = ExeArguments;
        proc.StartInfo.CreateNoWindow = true;
        proc.StartInfo.UseShellExecute = false;
        proc.StartInfo.ErrorDialog = false;
        proc.Start();
        proc.WaitForExit();
    }
    catch(Exception ex)
    {
        Trace.TraceError($"Trimmer exception:{ex.Message}\r\nStackTrace:{ex.StackTrace}");
    }

    var fi = new FileInfo(path2);
    if (fi.Exists)
    {
        success = true;
        Trace.TraceInformation(string.Format("Video has been trimmed"));
        using (Stream file = File.OpenRead(path2))
        {
            Trace.TraceInformation(string.Format("Video moving to CopyStream"));
            Trace.TraceInformation(string.Format("Video has been trimmed and now sent to be copied to stream"));
            byte[] buffer = new byte[8 * 1024];
            int len;
            using (Stream outpuStream = outPutBlob.OpenWrite())
            {
                while ((len = file.Read(buffer, 0, buffer.Length)) > 0)
                {
                    outpuStream.Write(buffer, 0, len);
                }
            }    
        }
    }
    else
    {
        Trace.TraceWarning(string.Format("Video has not been trimmed"));
    }
}

此外，您可以按照此tutorial查看诊断数据，也可以利用Microsoft Azure Storage Explorer检查相关存储帐户的WADLogsTable以检查应用程序日志。

在Azure中部署时，文件未复制到流，但通过VS模拟器

1 个答案: