Innerhalb einer Universal Windows App sollen Media-Files transcodiert werden. Die üblichen Formate werden ordnungsgemäß transcodiert,
Ausnahmen werden durch entsprechende Fehlermeldungen behandelt. Was überhaupt nicht funktioniert, sind das TranscodeProgress-Handling sowie das ProgressComplete-Handling. In den im Folgenden aufgelisteten Routinen Convert_SOURCE_To_DEST, TranscodeProgress
sowie TranscodeComplete ist der m. E. dafür verantwortliche Code gelb hervorgehoben.
Als Vorbild für das Programm wurde
https://msdn.microsoft.com/windows/uwp/audio-video-camera/transcode-media-files
herangezogen. Hat jemand eine Idee?
Private
Async
Function Convert_SOURCE_To_DEST(ta
As
Double,
te As
Double) _
As
Task
Dim pro
As
MediaEncodingProfile
Dim res
As Windows.Media.Transcoding.PrepareTranscodeResult
Dim ope
As
IAsyncActionWithProgress(Of
Double)
Dim fol
As Windows.Storage.StorageFolder
Dim cod =
New
MediaTranscoder()
Dim fop
As
New Windows.Storage.Pickers.FolderPicker
Dim mus
As FileProperties.MusicProperties
Dim dur
As
Long
Dim msg
As
String
Try
pro = MediaEncodingProfile.CreateWav(AUDIO_Qual)
' avoid warning
Select
Case DEST_Type
Case
"WAV" : pro =
MediaEncodingProfile.CreateWav(AUDIO_Qual)
Case
"WMA" : pro =
MediaEncodingProfile.CreateWma(AUDIO_Qual)
Case
"MP3" : pro =
MediaEncodingProfile.CreateMp3(AUDIO_Qual)
Case
"M4a" : pro =
MediaEncodingProfile.CreateM4a(AUDIO_Qual)
Case
"AVI" : pro =
MediaEncodingProfile.CreateAvi(VIDEO_Qual)
Case
"MP4" : pro =
MediaEncodingProfile.CreateMp4(VIDEO_Qual)
Case
"WMV" : pro =
MediaEncodingProfile.CreateWmv(VIDEO_Qual)
End
Select
fop.ViewMode = PickerViewMode.List
fop.SuggestedStartLocation = PickerLocationId.ComputerFolder
fop.CommitButtonText = "Ziel-Ordner auswählen"
fop.FileTypeFilter.Clear()
fop.FileTypeFilter.Add(".WAV")
fop.FileTypeFilter.Add(".WMA")
fop.FileTypeFilter.Add(".MP3")
fop.FileTypeFilter.Add(".M4a")
fop.FileTypeFilter.Add(".AVI")
fop.FileTypeFilter.Add(".MP4")
fop.FileTypeFilter.Add(".WMV")
fop.FileTypeFilter.Add(".MOV")
fol = Await fop.PickSingleFolderAsync()
mus = Await PICK_StorFil.Properties.GetMusicPropertiesAsync()
dur = mus.Duration.Ticks
If fol
Is
Nothing
Then
MyMessage("")
cmd_Choice.Visibility = Visibility.Visible
Exit
Function
End
If
DEST_StorFil = Await _
fol.CreateFileAsync(PICK_StorFil.Name +
"." +
DEST_Type,
CreationCollisionOption.ReplaceExisting)
cod.TrimStartTime =
New
TimeSpan(CLng(10000000
* ta))
cod.TrimStopTime = New
TimeSpan(dur -
CLng(10000000 * te))
cod.AlwaysReencode = True
res =
Await cod.PrepareFileTranscodeAsync(PICK_StorFil,
DEST_StorFil,
pro)
If res.CanTranscode
Then
ope = res.TranscodeAsync()
ope.Progress = New _
AsyncActionProgressHandler(Of
Double) _
(AddressOf TranscodeProgress)
'--------------------------------------------------------------
ope.Completed = New _
AsyncActionWithProgressCompletedHandler(Of
Double) _
(AddressOf TranscodeComplete)
Else
msg = ""
msg = msg + "Fehler beim Transcodieren der Datei """
msg = msg + PICK_StorFil.Name
msg = msg + """: "
Select
Case res.FailureReason
Case
TranscodeFailureReason.CodecNotFound
ErrorCases(msg + "Codec nicht gefunden")
Case
TranscodeFailureReason.InvalidProfile
ErrorCases(msg + "Ungültiges Profil")
Case
TranscodeFailureReason.Unknown
ErrorCases(msg + "Unbekannte Ursache")
Case
TranscodeFailureReason.None
ErrorCases(msg + "Keine Ursache")
End
Select
End
If
cmd_Choice.Visibility = Visibility.Visible
Catch ex
As
Exception
ErrorCases("Convert_SOURCE_To_DEST(" +
SRC__Type +
" ---> " +
DEST_Type +
"): " +
ex.Message)
cmd_Choice.Visibility = Visibility.Visible
End
Try
End
Function
Private
Sub TranscodeProgress(AsyncInfo
As _
IAsyncActionWithProgress(Of
Double),
prc As
Double)
MyMessage(CStr(prc))
End
Sub
Private
Sub TranscodeComplete(AsyncInfo
As _
IAsyncActionWithProgress(Of
Double),
sta As
AsyncStatus)
AsyncInfo.GetResults()
Select
Case AsyncInfo.Status
Case
AsyncStatus.Completed : MyMessage("Transcodierung
erfolgt")
Case
AsyncStatus.Canceled : MyMessage("Transcodierung
abgebrochen")
Case
AsyncStatus.Error : MyMessage("Transcodierung
fehlerhaft")
Case
AsyncStatus.Started : MyMessage("Transcodierung
gestartet")
End
Select
End
Sub
