Audio CD, Geschwindigkeit verändern

[mlspider]

Ich bekomme es einfach nicht gebacken das Wiedergabetempo (nicht Pitch!!!) zu verändern.

Hier die relevanten Codestellen:

Delphi-Quellcode:

procedure TForm1.PlayTrack(drive, track: DWORD);
begin
  if (stream[drive]) then
    BASS_CD_StreamSetTrack(stream[drive],track) // already have a stream, so just set the track
  else
  begin
    stream[drive] := BASS_CD_StreamCreate(drive, track, BASS_CD_FREEOLD); // create stream
    BASS_ChannelSetSync(stream[drive], BASS_SYNC_END, 0, @EndSync, 0); // set end syc
  end;
  if (drive = DWORD(curdrive)) then
    trkPos.Max := BASS_ChannelGetLength(stream[drive]) div 176400; // set pos scroller range
  BASS_ChannelPlay(stream[drive], False); // start playing
end;

procedure TForm1.UpdateTrackList;
var
  vol, spd: DWORD;
  cdtext, t: PChar;
  a, tc, l: Integer;
  text, tag: String;
begin
  tc := BASS_CD_GetTracks(curdrive);
  lstTracks.Items.Clear;
  if (tc = -1) then // no CD
    Exit;

  cdtext := BASS_CD_GetID(curdrive, BASS_CDID_TEXT); // get CD-TEXT
  for a := 0 to tc - 1 do
  begin
    l := BASS_CD_GetTrackLength(curdrive, a);
    text := Format('Track %.2d', [a + 1]);
    if (cdtext <> nil) then
    begin
      t := cdtext;
      tag := Format('TITLE%d=', [a + 1]); // the CD-TEXT tag to look for
      while (t <> nil) do
      begin
         if (Copy(t, 1, Length(tag)) = tag) then // found the track title...
         begin
           text := Copy(t, Length(tag)+1, Length(t) - Length(tag)); // replace "track x" with title
           Break;
         end;        t := t + Length(t) + 1;
      end;
    end;
    if (l = -1) then
      text := text + ' (data)'
    else
    begin
      l := l div 176400;
      text := text + Format(' (%d:%.2d)', [l div 60, l mod 60]);
    end;
    lstTracks.Items.Add(text)
  end;
  a := BASS_CD_StreamGetTrack(stream[curdrive]);
  if (a <> -1) then // this drive has a stream
  begin
    lstTracks.ItemIndex := LOWORD(a); // select current track
    trkPos.Max := BASS_ChannelGetLength(stream[curdrive]) div 176400; // set pos scroller range
  end
  vol := 100;
  spd := 44100;
  BASS_ChannelGetAttributes(stream[curdrive], spd, vol, l); // get speed & volume
  trkVol.Position := 100 - vol; // set volume slider pos
  trkSpeed.Position := spd div 441; // set speed slider pos
  GroupBox2.Caption := Format('Speed - %d%%', [trkVol.Position]);
end;

//ab hier scheitert es

procedure TCDPlayer.Button2Click(Sender: TObject);
begin
 chan2:=stream[curdrive];
 BASS_FX_TempoCreate(chan2, BASS_STREAM_DECODE);
 BASS_FX_TempoGetSource(chan2);
 BASS_FX_TempoSet(chan2, LMDTrackBar10.Position,  44100, +100);
 Label50.Caption := Format('%d %%', [LMDTrackBar10.Position]);
end;

chan2 ist vom Typ HSTREAM