直接显示相机旋转 90 度 [英] Direct Show camera rotation 90 degree
问题描述
我已经成功地使用 directshow 从网络摄像头预览和录制图像,但问题是当我在平板电脑上使用该应用程序时,方向与我在 PC 上看到的不一样.是否可以旋转此预览图像?我可以在保存之前旋转从预览中获取的位图图像",但是如果我可以在预览中显示正确的方向,那将对我非常有帮助.
I have successfully use directshow to preview and record an image from webcam, but the problem is when I used the application in the tablet, the orientation is not the same as what I saw in PC. Is there a possibility to rotate this preview image? I can rotate the bitmap 'image' taken from the preview before it is saved, but if I can show the correct orientation in the preview , that would be very helpful for me.
我已经阅读了一些喜欢使用 igraphbuilder、渲染文件等的建议......但由于我不是一个非常有经验的 VB.net 开发人员,我很难理解所有这些概念.我花了很多天只是为了找出不同的代码来使相机捕捉工作.但是现在遇到了方向问题.
I have read through some of the suggestion liked using igraphbuilder, render file and etc.... but since I am not an very experienced VB.net developer, I have a very hard time to understand all these concept. I spend many many days just to find out different code to make the camera capture works. But now came across the orientation problem.
此应用程序将前往第三世界国家以帮助协助医院工作,但我现在被困住了....如果有人可以帮助我弄清楚我该怎么做.我真的很感激....
This application is going to the third world countries to help assist hospital work but I am stuck now.... If anyone can help me to figure out how I can do it. I would be really appreciate....
这是代码的样子,如果有人可以帮助添加一些过滤器,以便我可以在 90 度视图中预览图像.
This is what the code looks like and if anyone can help to add some filter so that I can preview the image in a 90 degree view.
非常感谢!!!!
Imports DirectShowLib
Imports System
Imports System.Diagnostics
Imports System.Drawing
Imports System.Drawing.Imaging
Imports System.Runtime.InteropServices
Imports System.Windows.Forms
Imports System.Runtime.InteropServices.ComTypes
Public Class Form2
Dim MyPicturesFolder As String = Environment.GetFolderPath(Environment.SpecialFolder.MyPictures)
Dim D As Integer = &H8000
'Dim D As Integer = Convert.ToInt32("0X8000", 16)
Public WM_GRAPHNOTIFY As Integer = D + 1
Dim VideoWindow As IVideoWindow = Nothing
Dim MediaControl As IMediaControl = Nothing
Dim MediaEventEx As IMediaEventEx = Nothing
Dim GraphBuilder As IGraphBuilder = Nothing
Dim CaptureGraphBuilder As ICaptureGraphBuilder2 = Nothing
Enum PlayState
Stopped
Paused
Running
Init
End Enum
Dim CurrentState As PlayState = PlayState.Stopped
Dim rot As DsROTEntry = Nothing
Private Sub Form1_FormClosing(ByVal sender As Object, ByVal e As System.Windows.Forms.FormClosingEventArgs)
closeinterfaces()
End Sub
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
CaptureVideo()
PictureBox1.Visible = True
End Sub
Private Sub CaptureVideo()
Dim hr As Integer = 0
Dim sourceFilter As IBaseFilter = Nothing
Try
GetInterfaces()
hr = CaptureGraphBuilder.SetFiltergraph(GraphBuilder) 'Specifies filter graph "graphbuilder" for the capture graph builder "captureGraphBuilder" to use.
sourceFilter = FindCaptureDevice()
hr = GraphBuilder.AddFilter(sourceFilter, "Video Capture")
hr = CaptureGraphBuilder.RenderStream(PinCategory.Preview, MediaType.Video, sourceFilter, Nothing, Nothing)
Marshal.ReleaseComObject(sourceFilter)
SetupVideoWindow()
rot = New DsROTEntry(GraphBuilder)
hr = MediaControl.Run()
CurrentState = PlayState.Running
Catch ex As Exception
MessageBox.Show("An unrecoverable error has occurred.With error : " & ex.ToString)
End Try
End Sub
Private Sub GetInterfaces()
Dim hr As Integer = 0
GraphBuilder = CType(New FilterGraph, IGraphBuilder)
CaptureGraphBuilder = CType(New CaptureGraphBuilder2, ICaptureGraphBuilder2)
MediaControl = CType(GraphBuilder, IMediaControl)
VideoWindow = CType(GraphBuilder, IVideoWindow)
MediaEventEx = CType(GraphBuilder, IMediaEventEx)
hr = MediaEventEx.SetNotifyWindow(Me.Handle, WM_GRAPHNOTIFY, IntPtr.Zero) 'This method designates a window as the recipient of messages generated by or sent to the current DirectShow object
End Sub
Public Function FindCaptureDevice() As IBaseFilter
Dim hr As Integer = 0
Dim classEnum As IEnumMoniker = Nothing
Dim moniker As IMoniker() = New IMoniker(0) {}
Dim source As Object = Nothing
Dim devEnum As ICreateDevEnum = CType(New CreateDevEnum, ICreateDevEnum)
hr = devEnum.CreateClassEnumerator(FilterCategory.VideoInputDevice, classEnum, 0)
Marshal.ReleaseComObject(devEnum)
If classEnum Is Nothing Then
Throw New ApplicationException("No video capture device was detected.\r\n\r\n" & _
"This sample requires a video capture device, such as a USB WebCam,\r\n" & _
"to be installed and working properly. The sample will now close.")
End If
If classEnum.Next(moniker.Length, moniker, IntPtr.Zero) = 0 Then
Dim iid As Guid = GetType(IBaseFilter).GUID
moniker(0).BindToObject(Nothing, Nothing, iid, source)
Else
Throw New ApplicationException("Unable to access video capture device!")
End If
Marshal.ReleaseComObject(moniker(0))
Marshal.ReleaseComObject(classEnum)
Return CType(source, IBaseFilter)
End Function
Public Sub SetupVideoWindow()
Dim hr As Integer = 0
'set the video window to be a child of the main window
'putowner : Sets the owning parent window for the video playback window.
hr = VideoWindow.put_Owner(PictureBox1.Handle) 'Me.Handle)
PictureBox1.Visible = False
hr = VideoWindow.put_WindowStyle(WindowStyle.Child Or WindowStyle.ClipChildren)
'Use helper function to position video window in client rect of main application window
ResizeVideoWindow()
'Make the video window visible, now that it is properly positioned
'put_visible : This method changes the visibility of the video window.
hr = VideoWindow.put_Visible(OABool.True)
End Sub
Public Sub ResizeVideoWindow()
'Resize the video preview window to match owner window size
'left , top , width , height
If Not (VideoWindow Is Nothing) Then 'if the videopreview is not nothing
VideoWindow.SetWindowPosition(0, 0, Me.Width, Me.ClientSize.Height)
End If
End Sub
Public Sub closeinterfaces()
'//stop previewing data
If Not (Me.MediaControl Is Nothing) Then
Me.MediaControl.StopWhenReady()
End If
Me.CurrentState = PlayState.Stopped
'//stop recieving events
If Not (Me.MediaEventEx Is Nothing) Then
Me.MediaEventEx.SetNotifyWindow(IntPtr.Zero, WM_GRAPHNOTIFY, IntPtr.Zero)
End If
'// Relinquish ownership (IMPORTANT!) of the video window.
'// Failing to call put_Owner can lead to assert failures within
'// the video renderer, as it still assumes that it has a valid
'// parent window.
If Not (Me.VideoWindow Is Nothing) Then
Me.VideoWindow.put_Visible(OABool.False)
Me.VideoWindow.put_Owner(IntPtr.Zero)
End If
' // Remove filter graph from the running object table
If Not (rot Is Nothing) Then
rot.Dispose()
rot = Nothing
End If
'// Release DirectShow interfaces
Marshal.ReleaseComObject(Me.MediaControl) : Me.MediaControl = Nothing
Marshal.ReleaseComObject(Me.MediaEventEx) : Me.MediaEventEx = Nothing
Marshal.ReleaseComObject(Me.VideoWindow) : Me.VideoWindow = Nothing
Marshal.ReleaseComObject(Me.GraphBuilder) : Me.GraphBuilder = Nothing
Marshal.ReleaseComObject(Me.CaptureGraphBuilder) : Me.CaptureGraphBuilder = Nothing
End Sub
Private Sub btnGrab_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnGrab.Click
GrabImage()
End Sub
Public Sub GrabImage()
'
'' Get image from clipboard and convert it to a bitmap
'Try
' MediaControl.Pause()
' Clipboard.SetImage(PictureBox1.Image)
' '
' If Clipboard.ContainsImage Then
' PictureBox2.Image = Clipboard.GetImage()
' End If
'Catch
'End Try
Try
MediaControl.Pause()
Dim bmp As New Bitmap(PictureBox1.Width, PictureBox1.Height)
Using g As Graphics = Graphics.FromImage(bmp)
Dim pt As Point = PictureBox1.PointToScreen(New Point(0, 0))
g.CopyFromScreen(pt.X, pt.Y, 0, 0, bmp.Size)
End Using
PictureBox2.Image = bmp
PictureBox2.Visible = True
'PictureBox1.Visible = False
Catch
MsgBox("error")
End Try
End Sub
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click, btnGrab.Click
MediaControl.Run()
End Sub
Private Sub btnSave_Click(sender As System.Object, e As System.EventArgs) Handles BtnSave.Click
Dim newimage As Image = PictureBox2.Image
Dim gr As Graphics = Graphics.FromImage(newimage)
Dim myFontLabels As New Font("Arial", 40)
Dim myBrushLabels As New SolidBrush(Color.Black)
Dim FolderBrowser As New FolderBrowserDialog
If FolderBrowser.ShowDialog = Windows.Forms.DialogResult.OK Then
Me.lblPath.Text = FolderBrowser.SelectedPath & "\Amytest.bmp"
MsgBox("msg" & Me.lblPath.Text)
End If
'newimage.Save(Me.lblPath.Text, ImageFormat.Jpeg)
'MsgBox("The picture has been successfully copied and saved")
End Sub
Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
Dim newimage As Image = PictureBox2.Image
Dim gr As Graphics = Graphics.FromImage(newimage)
Dim myFontLabels As New Font("Arial", 40)
Dim myBrushLabels As New SolidBrush(Color.Black)
Dim _sourcefilename$ = Me.lblPath.Text
Dim _destinationfilename$ = "C:\test.jpg"
JpegSaveClass.SaveImage(_sourcefilename, _destinationfilename)
End Sub
推荐答案
DirectShow API 没有内置的视频旋转功能.假设您需要旋转,然后将外部(第三方)转换过滤器插入管道并执行转换.
DirectShow API does not have built in capabilities to rotate video. It is assumed that if you need rotation then an external (third party) transformation filter is inserted into pipeline and perform a transform.
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