Creating flac file or flac stream using BASS dll with Delphi - delphi

Question

I am playing with BASS from http://www.un4seen.com/.
I need to create a flac file(16bits) or flac stream from user speaking on Microphone.
I have seen this demo in BASS source code.
There is a bassenc_flac.dll as well with these functions:
function BASS_Encode_FLAC_Start(handle:DWORD; options:PChar; flags:DWORD; proc:ENCODEPROCEX; user:Pointer): HENCODE; {$IFDEF MSWINDOWS}stdcall{$ELSE}cdecl{$ENDIF}; external bassencflacdll;
function BASS_Encode_FLAC_StartFile(handle:DWORD; options:PChar; flags:DWORD; filename:PChar): HENCODE; {$IFDEF MSWINDOWS}stdcall{$ELSE}cdecl{$ENDIF}; external bassencflacdll;
How could I change the next code to encode the audio to flac file or stream?
From RecordTest BASS demo
(* This is called while recording audio *)
function RecordingCallback(Handle: HRECORD; buffer: Pointer; length: DWORD; user: Pointer): boolean; stdcall;
var level:dword;
begin
level:=BASS_ChannelGetLevel(Handle);
// Copy new buffer contents to the memory buffer
Form1.WaveStream.Write(buffer^, length);
// Allow recording to continue
Result := True;
end;
(* Start recording to memory *)
procedure TForm1.StartRecording;
begin
if ComboBox1.ItemIndex < 0 then Exit;
if WaveStream.Size > 0 then
begin // free old recording
BASS_StreamFree(chan);
WaveStream.Clear;
end;
// generate header for WAV file
with WaveHdr do
begin
riff := 'RIFF';
len := 36;
cWavFmt := 'WAVEfmt ';
dwHdrLen := 16;
wFormat := 1;
wNumChannels := 2;
dwSampleRate := 44100;
wBlockAlign := 4;
dwBytesPerSec := 176400;
wBitsPerSample := 16;
cData := 'data';
dwDataLen := 0;
end;
WaveStream.Write(WaveHdr, SizeOf(WAVHDR));
// start recording # 44100hz 16-bit stereo
rchan := BASS_RecordStart(44100, 2, 0, #RecordingCallback, nil);
if rchan = 0 then
begin
MessageDlg('Couldn''t start recording!', mtError, [mbOk], 0);
WaveStream.Clear;
end
else
begin
bRecord.Caption := 'Stop';
bPlay.Enabled := False;
bSave.Enabled := False;
end;
end;
(* Stop recording *)
procedure TForm1.StopRecording;
var
i: integer;
he:BassEnc.HENCODE;
begin
BASS_ChannelStop(rchan);
bRecord.Caption := 'Record';
// complete the WAV header
WaveStream.Position := 4;
i := WaveStream.Size - 8;
WaveStream.Write(i, 4);
i := i - $24;
WaveStream.Position := 40;
WaveStream.Write(i, 4);
WaveStream.Position := 0;
// create a stream from the recorded data
chan := BASS_StreamCreateFile(True, WaveStream.Memory, 0, WaveStream.Size, 0);
if chan <> 0 then
begin
// enable "Play" & "Save" buttons
bPlay.Enabled := True;
bSave.Enabled := True;
end
else
MessageDlg('Error creating stream from recorded data!', mtError, [mbOk], 0);
if SaveDialog.Execute then
WaveStream.SaveToFile(SaveDialog.FileName);
end;

Answer 1

I have updated code because of comments that show incorrect work of previous encoder version. And I am totally agree with these comments.
In order to create an encoder to FLAC we should go to un4seen web-site and download the next files:
BASS audio library 2.4
BASSFLAC 2.4.4
BASSenc 2.4.14
BASSenc_FLAC 2.4.1.1
Go through these folders and look for the next files:
bass.pas
bassenc.pas
bassenc_flac.pas
Now place these pas-files into one folder and add it to Library via Delphi's options.
After this step create new project, save it in separate folder.
Then go through BASS_XXX folders and look for *.dll files.
Combine them together in the folder where you have saved your project!
Now let's write some code.
Add to the uses clause bass.pas, bassenc.pas and bassenc_flac.pas. Then copy the code shown below.
uses ..., BASS, BASSEnc, BASSEnc_FLAC;
...
TForm1 = class(TForm)
ProgressBar1: TProgressBar;
public
{ Public declarations }
procedure StartEncode(SourceFileName, OutputFileName: String);
procedure StopEncode;
end;
...
procedure TForm1.StartEncode(SourceFileName, OutputFileName: String);
var
PercentDone: Cardinal;
Buffer: array [0..1024] of Byte;
begin
Channel := BASS_StreamCreateFile(false, PChar(SourceFileName), 0, 0, BASS_MUSIC_DECODE or BASS_UNICODE);
BASSEnc_FLAC.BASS_Encode_FLAC_StartFile(Channel, 0, BASS_ENCODE_FP_AUTO or BASS_UNICODE, PChar(OutputFileName));
while BASS_ChannelIsActive(Channel) > 0 do
begin
BASS_ChannelGetData(Channel, #Buffer, 1024);
PercentDone := Trunc(100 * (BASS_ChannelGetPosition(Channel, BASS_POS_BYTE) / BASS_ChannelGetLength(Channel, BASS_POS_BYTE)));
ProgressBar1.Position := PercentDone;
end;
StopEncode;
end;
procedure TForm1.StopEncode;
begin
BASS_Encode_Stop(Channel);
BASS_StreamFree(Channel);
end;
procedure TForm1.Button1Click(Sender: TObject);
begin
BASS_Init(-1, 44100, 0, Application.Handle, nil);
try
// Set name of file to convert it to FLAC and save it with output name
StartEncode('SourceFileName', 'OutputFileName');
finally
BASS.BASS_Free;
end;
end;
One notice:
Indeed, file encoded with previous version of the code had incorrect header (I could see it when opened file in Notepad.exe). After code has been updated I can see valid header (in Notepad, of course, because I have no professional instruments for work with audio-files).
Now you even have no need to add plugin to BASS as I did earlier.
Since this I think that the encoder works as it was expected.