我有一个 vb6 应用程序，它将调用 mencoder.exe，它是 mplayer 的一部分，用于将一些文件转换为 flv 格式。每当我尝试转换这个 opendivx 文件时，我都会从 mencoder 收到这个奇怪的未处理异常问题。
目前，我不清楚这个编解码器是否是这背后的罪魁祸首。无论哪种方式，我都尝试修改命令行，甚至下载了 mencoder 的最新可用版本。
所以转换工作正常，唯一的问题是 mencoder 最终会崩溃，因为视频文件不知何故超过了 100% 到 102%。因此我的问题是我如何路由此异常以由我的 vb6 应用程序处理，以便不会显示丑陋的错误弹出窗口？
我什至在代码中包含了异常捕获，但它没有捕获该异常。
' Function GetCommandOutput
'
' sCommandLine: [in] Command line to launch
' blnStdOut [in,opt] True (defualt) to capture output to STDOUT
' blnStdErr [in,opt] True to capture output to STDERR. False is default.
' blnOEMConvert: [in,opt] True (default) to convert DOS characters to Windows, False to skip conversion
'
' Returns: String with STDOUT and/or STDERR output
'
Public Function GetCommandOutput(sCommandLine As String, _
Optional blnStdOut As Boolean = True, _
Optional blnStdErr As Boolean = False, _
Optional blnOEMConvert As Boolean = True, _
Optional encoderType As String) As String
Dim hPipeRead As Long, hPipeWrite1 As Long, hPipeWrite2 As Long
Dim hCurProcess As Long
Dim sa As SECURITY_ATTRIBUTES
Dim si As STARTUPINFO
Dim pi As PROCESS_INFORMATION
Dim baOutput() As Byte
Dim sNewOutPut As String
Dim lBytesRead As Long
Dim fTwoHandles As Boolean
Dim lRet As Long
Const BUFSIZE = 1024 ' pipe buffer size
On Error GoTo ErrorHandler
' At least one of them should be True, otherwise there's no point in calling the function
If (Not blnStdOut) And (Not blnStdErr) Then
Err.Raise 5 ' Invalid Procedure call or Argument
End If
' If both are true, we need two write handles. If not, one is enough.
fTwoHandles = blnStdOut And blnStdErr
ReDim baOutput(BUFSIZE - 1) As Byte
With sa
.nLength = Len(sa)
.bInheritHandle = 1 ' get inheritable pipe handles
End With
If CreatePipe(hPipeRead, hPipeWrite1, sa, BUFSIZE) = 0 Then
Exit Function
End If
hCurProcess = GetCurrentProcess()
' Replace our inheritable read handle with an non-inheritable. Not that it
' seems to be necessary in this case, but the docs say we should.
Call DuplicateHandle(hCurProcess, hPipeRead, hCurProcess, hPipeRead, 0&, 0&, DUPLICATE_SAME_ACCESS Or DUPLICATE_CLOSE_SOURCE)
' If both STDOUT and STDERR should be redirected, get an extra handle.
If fTwoHandles Then
Call DuplicateHandle(hCurProcess, hPipeWrite1, hCurProcess, hPipeWrite2, 0&, 1&, DUPLICATE_SAME_ACCESS)
End If
With si
.cb = Len(si)
.dwFlags = STARTF_USESHOWWINDOW Or STARTF_USESTDHANDLES
.wShowWindow = SW_HIDE ' hide the window
If fTwoHandles Then
.hStdOutput = hPipeWrite1
.hStdError = hPipeWrite2
ElseIf blnStdOut Then
.hStdOutput = hPipeWrite1
Else
.hStdError = hPipeWrite1
End If
End With
Dim totalSeconds As Double
If CreateProcess(vbNullString, sCommandLine, ByVal 0&, ByVal 0&, 1, 0&, ByVal 0&, vbNullString, si, pi) Then
' Close thread handle - we don't need it
Call CloseHandle(pi.hThread)
' Also close our handle(s) to the write end of the pipe. This is important, since
' ReadFile will *not* return until all write handles are closed or the buffer is full.
Call CloseHandle(hPipeWrite1)
hPipeWrite1 = 0
If hPipeWrite2 Then
Call CloseHandle(hPipeWrite2)
hPipeWrite2 = 0
End If
Do
' Add a DoEvents to allow more data to be written to the buffer for each call.
' This results in fewer, larger chunks to be read.
'DoEvents
If ReadFile(hPipeRead, baOutput(0), BUFSIZE, lBytesRead, ByVal 0&) = 0 Then
Exit Do
End If
If blnOEMConvert Then
' convert from "DOS" to "Windows" characters
sNewOutPut = String$(lBytesRead, 0)
Call OemToCharBuff(baOutput(0), sNewOutPut, lBytesRead)
Else
' perform no conversion (except to Unicode)
sNewOutPut = Left$(StrConv(baOutput(), vbUnicode), lBytesRead)
End If
GetCommandOutput = GetCommandOutput & sNewOutPut
' If you are executing an application that outputs data during a long time,
' and don't want to lock up your application, it might be a better idea to
' wrap this code in a class module in an ActiveX EXE and execute it asynchronously.
' Then you can raise an event here each time more data is available.
'Debug.Print sNewOutPut + vbNewLine
If encoderType = "ffmpeg" Then
If totalSeconds < 1 Then
totalSeconds = GetFFmpegFileTotalSeconds(sNewOutPut)
End If
Call CalculateFFMpegProgress(sNewOutPut, totalSeconds)
Else
Call CalculateMencoderProgress(sNewOutPut)
End If
'RaiseEvent OutputAvailable(sNewOutput)
Loop
' When the process terminates successfully, Err.LastDllError will be
' ERROR_BROKEN_PIPE (109). Other values indicates an error.
Call CloseHandle(pi.hProcess)
Else
GetCommandOutput = "Failed to create process, check the path of the command line."
End If
' clean up
Call CloseHandle(hPipeRead)
If hPipeWrite1 Then
Call CloseHandle(hPipeWrite1)
End If
If hPipeWrite2 Then
Call CloseHandle(hPipeWrite2)
End If
Exit Function
ErrorHandler:
Call WriteErrorLog(Err, "Class clsThread : Sub GetCommandOutput")
End Function
更新：
如果你们好奇应用程序在崩溃时输出了什么，这里是：
1 个重复帧！
Pos: 83.2s 2504f (99%) 112.65fps Trem: 0min 6mb AV:0.008 [571:79]] 1 个重复帧！
Pos: 83.4s 2510f (102%) 112.74fps Trem: 0min 6mb AV:0.006 [571:79] 1 个重复帧！
Pos: 83.6s 2516f (102%) 112.84fps Trem: 0min 6mb AV:0.004 [571:79] 1 个重复帧！
[mpeg4 @ 0x1ac53a0]隐藏 40 DC、40 AC、40 MV 错误 AV:0.003 [571:79]
替代文字 http://img21.imageshack.us/img21/4539/exception.png
谢谢 ：）