我正在使用Mplayer通过命令行从视频中提取音频。这是我使用的命令:
mplayer -ao pcm:fast:file=aaa.wav aaa.avi
我将Mplayer.exe和aaa.avi复制到Windows驱动器(C :)和外部硬盘驱动器的根目录(在我的情况下为X)上。
当我从C执行时，转储以正常速度开始(我实时查看视频)，而Mplayer不会创建aaa.wav。
当我执行X表格时，转储以快速启动(如-ao pcm:fast音频驱动程序所要求)，并且正确创建了aaa.wav。
我的应用程式中有相同的问题，这是我用来执行的程式码:
public static string DumpWav_ConsoleOutput = "";
public static int DumpWav_ProcessID = 0;
Process DumpWav_Process = null;
private void DumpWav(string SourceFileName, string DestinationFileName, bool NeedToCut, TimeSpan Start, TimeSpan End)
{
//cancelliamo le variabili
DumpWav_ConsoleOutput = "";
//Handle della finestra di Media Player
Variables.MediaPlayerHandle = 0;
Variables.MediaPlayerHandle = (int)MediaPlayer.Handle;
Thread thread = new Thread(() => _DumpWav(SourceFileName, DestinationFileName, NeedToCut,Start, End)); //il thread principale di Dump Wav
thread.Start();
while (thread.IsAlive) //aspettiamo il suo completamento
{
Application.DoEvents();
}
var myForm = new Output();
myForm.SetOutputText = Variables.ConsoleOutputMP;
myForm.Show();
Variables.MediaPlayerExit = true;
// ok il processo è terminato
}
private void _DumpWav(string SourceFileName, string DestinationFileName, bool NeedToCut, TimeSpan Start, TimeSpan End)
{
string Output;
Output = RunDumpWav((output) => { }, SourceFileName, DestinationFileName, NeedToCut, Start, End);
}
// Media Player avviato da questa funzione
public string RunDumpWav(Action<string> output, string SourceFileName, string DestinationFileName, bool NeedToCut, TimeSpan Start, TimeSpan End)
{
if (output == null)
throw new ArgumentNullException("output");
string args;
ProcessStartInfo ps = new ProcessStartInfo();
ps.FileName = FindMediaPlayerPath("mplayer.exe");
ps.UseShellExecute = false;
ps.RedirectStandardInput = true;
ps.RedirectStandardError = true;
ps.RedirectStandardOutput = true;
ps.CreateNoWindow = true;
ps.WorkingDirectory = @"x:\";
args = "-wid ";
args += Variables.MediaPlayerHandle;
args += " -ao pcm:fast:file=";
args += DestinationFileName;
if (NeedToCut == true)
{
args += " -ss " + Start + " -endpos " + End;
}
//args += " -vo null -vc null -quiet ";
//-wid will tell MPlayer to show output inisde our panel
args += " " + SourceFileName;
ps.Arguments = args;
using (DumpWav_Process = Process.Start(ps))
using (ManualResetEvent mreOut = new ManualResetEvent(false),
mreErr = new ManualResetEvent(false))
{
DumpWav_Process.OutputDataReceived += (o, e) => { if (e.Data == null) mreOut.Set(); else output(e.Data); };
DumpWav_Process.BeginOutputReadLine();
DumpWav_Process.ErrorDataReceived += (o, e) => { if (e.Data == null) mreErr.Set(); else output(e.Data); }; ;
DumpWav_Process.BeginErrorReadLine();
output = s => DumpWav_ElaborateOutput(s);
DumpWav_ProcessID = DumpWav_Process.Id;
//processMP.StandardInput.Close();
DumpWav_Process.WaitForExit();
mreOut.WaitOne();
mreErr.WaitOne();
//stringa di ritorno (tutto il contenuto della console)
return DumpWav_ConsoleOutput;
}
}
//controlliamo l'output della console
private void DumpWav_ElaborateOutput(string output)
{
Variables.ConsoleOutputMP = Variables.ConsoleOutputMP + output + Environment.NewLine;
if (output.IndexOf("A:") != -1)
{
//some check here
}
}我最近添加了这个:
ps.WorkingDirectory = @"x:\";
但是结果不会改变，视频速度也不快，Mplayer不会创建wav文件。
在我的应用中，像C测试一样，我收到一些错误:
[AO PCM] Failed to open aaa.wav for writing!
Failed to initialize audio driver 'pcm:fast:file=aaa.wav'
还有一个问题，当我使用mPlayer将视频封装在我的应用程序中时，该过程大约在我启动它后一分钟开始……也许与转储问题有关？
拜托，有什么建议吗？
编辑:
我刚刚发现:如果我以管理员权限启动命令提示符，那么也在C Drive Mplayer中以正确的方式进行工作...
不幸的是我的应用程序没有。我编辑了 list 以授予管理员权限，但这是相同的。在stackoverflow的某个地方，我读到一些有关将shellexecute设置为true的信息，但不幸的是，这种方式(无论如何我都需要测试)我失去了重定向输入/输出/错误的能力。
我需要找到一种方法来从我的应用程序中以管理员权限启动该过程(然后是mplayer.exe)，而无需使用shellexecute ...
编辑2°
我用以下代码创建了一个简单的按钮:
string args;
//Handle della finestra di Media Player
Variables.MediaPlayerHandle = 0;
Variables.MediaPlayerHandle = (int)MediaPlayer.Handle;
ProcessStartInfo psi = new ProcessStartInfo();
psi.FileName = FindMediaPlayerPath("mplayer.exe");
//psi.FileName = @"x:\mplayer.exe";
psi.UseShellExecute = true;
psi.CreateNoWindow = true;
psi.WindowStyle = ProcessWindowStyle.Hidden;
psi.WorkingDirectory = Environment.CurrentDirectory; ;
psi.Verb = "runas";
args = "-wid ";
args += Variables.MediaPlayerHandle;
args += " -ao pcm:fast:file=";
args += @"x:\aaa.wav";
args += @" x:\aaa.avi";
psi.Arguments = args;
Process.Start(psi);:-(同样的结果，Mplayer无法打开音频驱动程序并保存文件。
再次失败。.3°编辑:
我尝试使用CMD:
private void button2_Click(object sender, EventArgs e)
{
ProcessStartInfo processInfo;
Process process;
Variables.MediaPlayerHandle = 0;
Variables.MediaPlayerHandle = (int)MediaPlayer.Handle;
string args = "";
args = @"x:\mplayer.exe -wid " + Variables.MediaPlayerHandle + @" -ao pcm:fast:file=x:\aaa.wav x:\aaa.avi";
MessageBox.Show(args);
processInfo = new ProcessStartInfo("cmd.exe", "/c " + args);
processInfo.CreateNoWindow = true;
processInfo.UseShellExecute = true;
processInfo.Verb = "runas";
process = Process.Start(processInfo);
process.WaitForExit();
MessageBox.Show("terminato");
process.Close();
}现在我看到视频的第一帧和Mplayer冻结了...
我失去了使用mplayer的希望:-(
最佳答案
终于我解决了...
这是代码:
if (output == null)
throw new ArgumentNullException("output");
string args;
ProcessStartInfo psi = new ProcessStartInfo();
psi.FileName = FindMediaPlayerPath("mplayer.exe");
//psi.FileName = @"x:\mplayer.exe";
psi.UseShellExecute = false;
psi.RedirectStandardInput = true;
psi.RedirectStandardError = true;
psi.RedirectStandardOutput = true;
psi.CreateNoWindow = true;
psi.WorkingDirectory = Path.GetDirectoryName(DestinationFileName);
psi.Verb = "runas";
args = "-wid ";
args += Variables.MediaPlayerHandle;
args += " -ao pcm:fast:file=";
args += Path.GetFileName(DestinationFileName);
if (NeedToCut == true)
{
args += " -ss " + Start + " -endpos " + End;
}
//args += " -vo null -vc null -quiet ";
//-wid will tell MPlayer to show output inisde our panel
args += " " + SourceFileName;
psi.Arguments = args;
据我了解，我需要将Process.WorkingDirectory移动到与目标文件相同的文件夹(在我的情况下是wav)。
现在它摇晃了:-)
无需UAC
无需useshellexecute = true
感谢史丹利的帮助!
关于c# - Mplayer转储视频音频，仅在非C硬盘上工作良好，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/38134590/