BorlandTalk.com

Markus · Guest

Is it possible to detect keyframes with DSPack
(http://www.progdigy.com/modules.php?name=DSPack) or does anybody know
another way to detect the keyframes?
I want to display the movie with the option to jump to the next/last
keyframe (like in VirtualDub).

Does anybody knows a way how can I do this?
--> The movie is displayed with DSPack.

Thx for all answers.

Markus

Tsviatko Jognov · Guest

Hi,
IMediaSample has a method "IsSyncPoint" which determines if the beginning of this sample is a synchronization point (start of a key frame).

You can also search the stream for your self, but this will involve writing your own reader, parser and knowing the stream format.

Regards,
Tsviatko Jongov
http://tsviatko.jongov.com

"Markus" <TheRealHawk (AT) Freenet (DOT) de> wrote:

Markus · Guest

I tried to modify a procedure in the DSPack-Demo
DSVideoWinDowEx\PlayWin to detect KeyFrames but I had no luck:

This was my try:
procedure TForm1.DSTrackBar1Timer(sender: TObject; CurrentPos,
StopPos: Cardinal);
var
CurrPos : Int64;
Value, H, M, S : Integer;
MediaSeeking: IMediaSeeking;
MediaSample: IMediaSample;
begin
//FilterGraph1.QueryInterface(IMediaSeeking, MediaSeeking);
//with MediaSeeking do
//Begin
// GetCurrentPosition(CurrPos);
// Value := Trunc(CurrPos / 10000000);
// H := value div 3600;
// M := (value mod 3600) div 60;
// S := (value mod 3600) mod 60;
// Panel2.Caption := Format('%d:%2.2d:%2.2d', [H, M, S]);
//End;
FilterGraph1.QueryInterface(IMediaSample, MediaSample);
if MediaSample <> nil then Panel2.Caption := MediaSample.IsSyncPoint;
// At this point I don't know how to convert HResult to string or
boolean (I only want to display a true or false in the label). :-/
else Panel2.Caption := 'nil';
If OsdChanged then
Begin
DSVideoWindowEx1.ClearBack;
OsdChanged := False;
End;
end;

but it doesn't work, because MediaSample is everytime nil. :-/

Can anybody help me?

Thanks

Markus

Tsviatko Jognov schrieb: