C# Directshow.net未在视频上显示覆盖图像
在我的Directshow.net应用程序中,我使用BufferCB在每个帧上绘制时间戳。时间戳显示在屏幕上和快照中,但在写入AVI文件时不会显示。 我错过了什么C# Directshow.net未在视频上显示覆盖图像,c#,overlay,video-capture,directshow,directshow.net,C#,Overlay,Video Capture,Directshow,Directshow.net,在我的Directshow.net应用程序中,我使用BufferCB在每个帧上绘制时间戳。时间戳显示在屏幕上和快照中,但在写入AVI文件时不会显示。 我错过了什么 int ISampleGrabberCB.BufferCB(double SampleTime, IntPtr pBuffer, int BufferLen) { int stride = 0; int scan0 = 0; Bitmap FrameShot = null; GCHandle handl
int ISampleGrabberCB.BufferCB(double SampleTime, IntPtr pBuffer, int BufferLen) {
int stride = 0;
int scan0 = 0;
Bitmap FrameShot = null;
GCHandle handle;
// Draw Time Stamp
if (overlayBitmap != null & overlayEnabled) {
// Create image to draw on camera frame shot
Graphics g = Graphics.FromImage(overlayBitmap);
g.Clear(Color.Transparent);
g.SmoothingMode = SmoothingMode.AntiAlias;
g.TextRenderingHint = TextRenderingHint.AntiAlias;
DateTime now = DateTime.Now;
string format = "M/d/yyy HH:mm:ss.fff";
g.DrawString(now.ToString(format), fontOverlay, textYellow, 4, SnapShotHeight - FontSize * 2);
// Draw image on camera frame shot
stride = SnapShotWidth * 3;
FrameShot = new Bitmap(SnapShotWidth, SnapShotHeight, stride, PixelFormat.Format24bppRgb, pBuffer);
Graphics g2 = Graphics.FromImage(FrameShot);
g2.SmoothingMode = SmoothingMode.AntiAlias;
overlayBitmap.RotateFlip(RotateFlipType.RotateNoneFlipY);
g2.DrawImage(overlayBitmap, 0, 0, overlayBitmap.Width, overlayBitmap.Height);
g.Dispose();
g2.Dispose();
FrameShot.Dispose();
}
//Has a snapshot been requested?
if (frameCaptured) {
return 0;
}
frameCaptured = true;
bufferedSize = BufferLen;
stride = SnapShotWidth * 3;
Marshal.Copy(pBuffer, savedArray, 0, BufferLen);
handle = GCHandle.Alloc(savedArray, GCHandleType.Pinned);
scan0 = (int)handle.AddrOfPinnedObject();
scan0 += (SnapShotHeight - 1) * stride;
FrameShot = new Bitmap(SnapShotWidth, SnapShotHeight, -stride, PixelFormat.Format24bppRgb, (IntPtr)scan0);
handle.Free();
// Return bitmap by an event
FrameEvent2(FrameShot);
return 0;
}
使用
BufferCB
您拥有一份数据副本,您所做的更改会对进一步的数据流产生影响SampleCB
相反,它会公开实际数据,并允许您在进一步发送之前更改有效负载。感谢您的快速响应,我不知道BufferCB和SampleCB之间的区别。不幸的是,这并没有解决问题。在进一步检查后,我注意到文本显示在几个框架上,但太少了,似乎没有框架显示它。如有任何进一步建议,将不胜感激。