How to avoid copying frame bitmap and use pointer to data instead

RVMedia support and discussion (components for displaying and controlling IP cameras, webcams, video conferencing, video chats, recording audio and video files)
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ya_vanka
Posts: 64
Joined: Tue Oct 22, 2019 6:24 pm

How to avoid copying frame bitmap and use pointer to data instead

Post by ya_vanka »

Got one more question.

At some moment this update was done: https://www.trichview.com/forums/viewto ... 950#p36950

This should have made possible not to copy frame bitmap.


I have a working code:

Code: Select all

FLastFrame: TRVMBitmap;

procedure TVideoDlgForm2.RVCamera1GetImage(Sender: TObject; img: TRVMBitmap);
begin
  LastGotVideoData := MyNowEx;

  FVideoWidth := img.Width;
  FVideoHeight := img.Height;

  FLastFrame.AssignRVMBitmap(img);
end;

function TVideoDlgForm2.VideoData : PByte;
begin
  Result := Pointer(FLastFrame.Data);
end;



procedure TGLVideoToolWin.DoPaint;
if (VideoDlgForm2.VideoData <> nil) then
begin
  glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, VideoDlgForm2.FVideoWidth, VideoDlgForm2.FVideoHeight, GL_BGRA, GL_UNSIGNED_BYTE, VideoDlgForm2.VideoData);
  DrawTexture2DAtPos(0, 0, FVideoTexPart.TexPart, true);
end;

But want to remove FLastFrame.AssignRVMBitmap(img).
Tried to use pointer variable:

Code: Select all

PImgBuffer : Pointer;

procedure TVideoDlgForm2.RVCamera1GetImage(Sender: TObject; img: TRVMBitmap);
begin
  LastGotVideoData := MyNowEx;

  FVideoWidth := img.Width;
  FVideoHeight := img.Height;

  PImgBuffer := Pointer(img.Data);
end;

function TVideoDlgForm2.VideoData : PByte;
begin
  Result := PImgBuffer;
end;



procedure TGLVideoToolWin.DoPaint;
if (VideoDlgForm2.VideoData <> nil) then
begin
  glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, VideoDlgForm2.FVideoWidth, VideoDlgForm2.FVideoHeight, GL_BGRA, GL_UNSIGNED_BYTE, VideoDlgForm2.VideoData);
  DrawTexture2DAtPos(0, 0, FVideoTexPart.TexPart, true);
end;
But that didn't work.

Procedure TGLVideoToolWin.DoPaint; is called not from RVCamera1GetImage, but on getting user message signalizing that a window should be repainted.

How can I avoid FLastFrame.AssignRVMBitmap(img) correctly?

And is it worth removing (I mean will it increase performance significantly in case of HD ready or Full HD video)?
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