aboutsummaryrefslogtreecommitdiffstats
path: root/Game/Code/Classes/URecord.pas
blob: 8a537dc9f6afa5b6e5204e78a99fc72a114d6dc3 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
unit URecord;

interface

{$IFDEF FPC}
  {$MODE Delphi}
{$ENDIF}

{$I switches.inc}

uses Classes,
     Math,
     SysUtils,
     sdl,
     UCommon,
     UMusic,
     UIni;

const
  BaseToneFreq = 65.4064; // lowest (half-)tone to analyze (C2 = 65.4064 Hz)
  NumHalftones = 36; // C2-B4 (for Whitney and my high voice)

type
  TCaptureBuffer = class
    private
      VoiceStream:  TAudioVoiceStream; // stream for voice passthrough
      AnalysisBufferLock: PSDL_Mutex;

      function GetToneString: string; // converts a tone to its string represenatation;

      procedure BoostBuffer(Buffer: PChar; Size: Cardinal);
      procedure ProcessNewBuffer(Buffer: PChar; BufferSize: integer);

      // we call it to analyze sound by checking Autocorrelation
      procedure AnalyzeByAutocorrelation;
      // use this to check one frequency by Autocorrelation
      function AnalyzeAutocorrelationFreq(Freq: real): real;
    public
      AnalysisBuffer:  array[0..4095] of smallint; // newest 4096 samples
      AnalysisBufferSize: integer; // number of samples of BufferArray to analyze

      LogBuffer:   TMemoryStream;              // full buffer

      AudioFormat: TAudioFormatInfo;

      // pitch detection
      // TODO: remove ToneValid, set Tone/ToneAbs=-1 if invalid instead
      ToneValid:    boolean;    // true if Tone contains a valid value (otherwise it contains noise)
      Tone:         integer;    // tone relative to one octave (e.g. C2=C3=C4). Range: 0-11
      ToneAbs:      integer;    // absolute (full range) tone (e.g. C2<>C3). Range: 0..NumHalftones-1

      // methods
      constructor Create;
      destructor Destroy; override;

      procedure Clear;

      // use to analyze sound from buffers to get new pitch
      procedure AnalyzeBuffer;
      procedure LockAnalysisBuffer();   {$IFDEF HasInline}inline;{$ENDIF}
      procedure UnlockAnalysisBuffer(); {$IFDEF HasInline}inline;{$ENDIF}

      function MaxSampleVolume: Single;
      property ToneString: string READ GetToneString;
  end;

const
  DEFAULT_SOURCE_NAME = '[Default]';

type
  TAudioInputSource = record
    Name:   string;
  end;

  // soundcard input-devices information
  TAudioInputDevice = class
    public
      CfgIndex:        integer;   // index of this device in Ini.InputDeviceConfig
      Name:            string;    // soundcard name
      Source:          array of TAudioInputSource; // soundcard input-sources
      SourceRestore:   integer;  // source-index that will be selected after capturing (-1: not detected)
      MicSource:       integer;  // source-index of mic (-1: none detected)

      AudioFormat:     TAudioFormatInfo; // capture format info (e.g. 44.1kHz SInt16 stereo)
      CaptureChannel:  array of TCaptureBuffer; // sound-buffer references used for mono or stereo channel's capture data

      destructor Destroy; override;

      procedure LinkCaptureBuffer(ChannelIndex: integer; Sound: TCaptureBuffer);

      // TODO: add Open/Close functions so Start/Stop becomes faster
      //function Open(): boolean;  virtual; abstract;
      //function Close(): boolean; virtual; abstract;
      function Start(): boolean; virtual; abstract;
      function Stop(): boolean;  virtual; abstract;

      function GetVolume(): single;        virtual; abstract;
      procedure SetVolume(Volume: single); virtual; abstract;
  end;

  TAudioInputProcessor = class
    public
      Sound:  array of TCaptureBuffer; // sound-buffers for every player
      DeviceList: array of TAudioInputDevice;

      constructor Create;
      destructor Destroy; override;

      procedure UpdateInputDeviceConfig;

      // handle microphone input
      procedure HandleMicrophoneData(Buffer: PChar; Size: Cardinal;
                                     InputDevice: TAudioInputDevice);
  end;

  TAudioInputBase = class( TInterfacedObject, IAudioInput )
    private
      Started: boolean;
    protected
      function UnifyDeviceName(const name: string; deviceIndex: integer): string;
    public
      function GetName: String;           virtual; abstract;
      function InitializeRecord: boolean; virtual; abstract;
      function FinalizeRecord: boolean;   virtual;

      procedure CaptureStart;
      procedure CaptureStop;
  end;


  TSmallIntArray = array [0..(MaxInt div SizeOf(SmallInt))-1] of SmallInt;
  PSmallIntArray = ^TSmallIntArray;

  function AudioInputProcessor(): TAudioInputProcessor;

implementation

uses
  ULog,
  UMain;

var
  singleton_AudioInputProcessor : TAudioInputProcessor = nil;


{ Global }

function AudioInputProcessor(): TAudioInputProcessor;
begin
  if singleton_AudioInputProcessor = nil then
    singleton_AudioInputProcessor := TAudioInputProcessor.create();

  result := singleton_AudioInputProcessor;
end;


{ TAudioInputDevice }

destructor TAudioInputDevice.Destroy;
begin
  Stop();
  Source := nil;
  CaptureChannel := nil;
  FreeAndNil(AudioFormat);
  inherited Destroy;
end;

procedure TAudioInputDevice.LinkCaptureBuffer(ChannelIndex: integer; Sound: TCaptureBuffer);
var
  DeviceCfg: PInputDeviceConfig;
  OldSound: TCaptureBuffer;
begin
  // check bounds
  if ((ChannelIndex < 0) or (ChannelIndex > High(CaptureChannel))) then
    Exit;

  // reset previously assigned (old) capture-buffer
  OldSound := CaptureChannel[ChannelIndex];
  if (OldSound <> nil) then
  begin
    // close voice stream
    FreeAndNil(OldSound.VoiceStream);
    // free old audio-format info
    FreeAndNil(OldSound.AudioFormat);
  end;

  // set audio-format of new capture-buffer
  if (Sound <> nil) then
  begin
    // copy the input-device audio-format ...
    Sound.AudioFormat := AudioFormat.Copy;
    // and adjust it because capture buffers are always mono
    Sound.AudioFormat.Channels := 1;
    DeviceCfg := @Ini.InputDeviceConfig[CfgIndex];

    if (Ini.VoicePassthrough = 1) then
    begin
      // TODO: map odd players to the left and even players to the right speaker
      Sound.VoiceStream := AudioPlayback.CreateVoiceStream(CHANNELMAP_FRONT, AudioFormat);
    end;
  end;

  // replace old with new buffer (Note: Sound might be nil)
  CaptureChannel[ChannelIndex] := Sound;
end;

{ TSound }

constructor TCaptureBuffer.Create;
begin
  inherited;
  LogBuffer := TMemoryStream.Create;
  AnalysisBufferLock := SDL_CreateMutex();
  AnalysisBufferSize := Length(AnalysisBuffer);
end;

destructor TCaptureBuffer.Destroy;
begin
  FreeAndNil(LogBuffer);
  FreeAndNil(VoiceStream);
  FreeAndNil(AudioFormat);
  SDL_DestroyMutex(AnalysisBufferLock);
  inherited;
end;

procedure TCaptureBuffer.LockAnalysisBuffer();
begin
  SDL_mutexP(AnalysisBufferLock);
end;

procedure TCaptureBuffer.UnlockAnalysisBuffer();
begin
  SDL_mutexV(AnalysisBufferLock);
end;

procedure TCaptureBuffer.Clear;
begin
  if assigned(LogBuffer) then
    LogBuffer.Clear;
  LockAnalysisBuffer();
  FillChar(AnalysisBuffer[0], Length(AnalysisBuffer) * SizeOf(SmallInt), 0);
  UnlockAnalysisBuffer();
end;

procedure TCaptureBuffer.ProcessNewBuffer(Buffer: PChar; BufferSize: integer);
var
  BufferOffset: integer;
  SampleCount: integer;
  i: integer;
begin
  // apply software boost
  //BoostBuffer(Buffer, Size);

  // voice passthrough (send data to playback-device)
  if (assigned(VoiceStream)) then
    VoiceStream.WriteData(Buffer, BufferSize);

  // we assume that samples are in S16Int format
  // TODO: support float too
  if (AudioFormat.Format <> asfS16) then
    Exit;

  // process BufferArray
  BufferOffset := 0;

  SampleCount := BufferSize div SizeOf(SmallInt);

  // check if we have more new samples than we can store
  if (SampleCount > Length(AnalysisBuffer)) then
  begin
    // discard the oldest of the new samples
    BufferOffset := (SampleCount - Length(AnalysisBuffer)) * SizeOf(SmallInt);
    SampleCount := Length(AnalysisBuffer);
  end;


  LockAnalysisBuffer();
  try

    // move old samples to the beginning of the array (if necessary)
    for i := 0 to High(AnalysisBuffer)-SampleCount do
      AnalysisBuffer[i] := AnalysisBuffer[i+SampleCount];

    // copy new samples to analysis buffer
    Move(Buffer[BufferOffset], AnalysisBuffer[Length(AnalysisBuffer)-SampleCount],
         SampleCount * SizeOf(SmallInt));

  finally
    UnlockAnalysisBuffer();
  end;


  // save capture-data to BufferLong if enabled
  if (Ini.SavePlayback = 1) then
  begin
    // this is just for debugging (approx 15MB per player for a 3min song!!!)
    // For an in-game replay-mode we need to compress data so we do not
    // waste that much memory. Maybe ogg-vorbis with voice-preset in fast-mode?
    // Or we could use a faster but not that efficient lossless compression.
    LogBuffer.WriteBuffer(Buffer, BufferSize);
  end;
end;

procedure TCaptureBuffer.AnalyzeBuffer;
var
  Volume:    single;
  MaxVolume: single;
  SampleIndex: integer;
  Threshold: single;
begin
  ToneValid := false;
  ToneAbs := -1;
  Tone    := -1;

  LockAnalysisBuffer();
  try

    // find maximum volume of first 1024 samples
    MaxVolume := 0;
    for SampleIndex := 0 to 1023 do
    begin
      Volume := Abs(AnalysisBuffer[SampleIndex]) / -Low(Smallint);
      if Volume > MaxVolume then
         MaxVolume := Volume;
    end;

    Threshold := IThresholdVals[Ini.ThresholdIndex];

    // check if signal has an acceptable volume (ignore background-noise)
    if MaxVolume >= Threshold then
    begin
      // analyse the current voice pitch
      AnalyzeByAutocorrelation;
      ToneValid := true;
    end;

  finally
    UnlockAnalysisBuffer();
  end;
end;

procedure TCaptureBuffer.AnalyzeByAutocorrelation;
var
  ToneIndex: integer;
  CurFreq:   real;
  CurWeight: real;
  MaxWeight: real;
  MaxTone:   integer;
const
  HalftoneBase = 1.05946309436; // 2^(1/12) -> HalftoneBase^12 = 2 (one octave)
begin
  // prepare to analyze
  MaxWeight := -1;
  MaxTone := 0; // this is not needed, but it satifies the compiler

  // analyze halftones
  // Note: at the lowest tone (~65Hz) and a buffer-size of 4096
  // at 44.1 (or 48kHz) only 6 (or 5) samples are compared, this might be
  // too few samples -> use a bigger buffer-size
  for ToneIndex := 0 to NumHalftones-1 do
  begin
    CurFreq := BaseToneFreq * Power(HalftoneBase, ToneIndex);
    CurWeight := AnalyzeAutocorrelationFreq(CurFreq);

    // TODO: prefer higher frequencies (use >= or use downto)
    if (CurWeight > MaxWeight) then
    begin
      // this frequency has a higher weight
      MaxWeight := CurWeight;
      MaxTone   := ToneIndex;
    end;
  end;

  ToneAbs := MaxTone;
  Tone    := MaxTone mod 12;
end;

// result medium difference
function TCaptureBuffer.AnalyzeAutocorrelationFreq(Freq: real): real;
var
  Dist:                   real;    // distance (0=equal .. 1=totally different) between correlated samples
  AccumDist:              real;    // accumulated distances
  SampleIndex:            integer; // index of sample to analyze
  CorrelatingSampleIndex: integer; // index of sample one period ahead
  SamplesPerPeriod:       integer; // samples in one period
begin
  SampleIndex := 0;
  SamplesPerPeriod := Round(AudioFormat.SampleRate/Freq);
  CorrelatingSampleIndex := SampleIndex + SamplesPerPeriod;

  AccumDist := 0;

  // compare correlating samples
  while (CorrelatingSampleIndex < AnalysisBufferSize) do
  begin
    // calc distance (correlation: 1-dist) to corresponding sample in next period
    Dist := Abs(AnalysisBuffer[SampleIndex] - AnalysisBuffer[CorrelatingSampleIndex]) /
            High(Word);
    AccumDist := AccumDist + Dist;
    Inc(SampleIndex);
    Inc(CorrelatingSampleIndex);
  end;

  // return "inverse" average distance (=correlation)
  Result := 1 - AccumDist / AnalysisBufferSize;
end;

function TCaptureBuffer.MaxSampleVolume: Single;
var
  lSampleIndex: Integer;
  lMaxVol : Longint;
begin;
  LockAnalysisBuffer();
  try
    lMaxVol := 0;
    for lSampleIndex := 0 to High(AnalysisBuffer) do
    begin
      if Abs(AnalysisBuffer[lSampleIndex]) > lMaxVol then
        lMaxVol := Abs(AnalysisBuffer[lSampleIndex]);
    end;
  finally
    UnlockAnalysisBuffer();
  end;

  result := lMaxVol / -Low(Smallint);
end;

const
  ToneStrings: array[0..11] of string = (
    'C', 'C#', 'D', 'D#', 'E', 'F', 'F#', 'G', 'G#', 'A', 'A#', 'B'
  );

function TCaptureBuffer.GetToneString: string;
begin
  if (ToneValid) then
    Result := ToneStrings[Tone] + IntToStr(ToneAbs div 12 + 2)
  else
    Result := '-';
end;

procedure TCaptureBuffer.BoostBuffer(Buffer: PChar; Size: Cardinal);
var
  i: integer;
  Value: Longint;
  SampleCount: integer;
  SampleBuffer: PSmallIntArray; // buffer handled as array of samples
  Boost:  byte;
begin
  // TODO: set boost per device
  {
  case Ini.MicBoost of
    0:   Boost := 1;
    1:   Boost := 2;
    2:   Boost := 4;
    3:   Boost := 8;
    else Boost := 1;
  end;
  }
  Boost := 1;

  // at the moment we will boost SInt16 data only
  if (AudioFormat.Format = asfS16) then
  begin
    // interpret buffer as buffer of bytes
    SampleBuffer := PSmallIntArray(Buffer);
    SampleCount := Size div AudioFormat.FrameSize;

    // boost buffer
    for i := 0 to SampleCount-1 do
    begin
      Value := SampleBuffer^[i] * Boost;

      // TODO :  JB -  This will clip the audio... cant we reduce the "Boost" if the data clips ??
      if Value > High(Smallint) then
        Value := High(Smallint);

      if Value < Low(Smallint) then
        Value := Low(Smallint);

      SampleBuffer^[i] := Value;
    end;
  end;
end;


{ TAudioInputProcessor }

constructor TAudioInputProcessor.Create;
var
  i: integer;
begin
  inherited;
  SetLength(Sound, 6 {max players});//Ini.Players+1);
  for i := 0 to High(Sound) do
    Sound[i] := TCaptureBuffer.Create;
end;

destructor TAudioInputProcessor.Destroy;
var
  i: integer;
begin
  for i := 0 to High(Sound) do
    Sound[i].Free;
  SetLength(Sound, 0);
  inherited;
end;

// updates InputDeviceConfig with current input-device information
// See: TIni.LoadInputDeviceCfg()
procedure TAudioInputProcessor.UpdateInputDeviceConfig;
var
  deviceIndex: integer;
  newDevice: boolean;
  deviceIniIndex: integer;
  deviceCfg: PInputDeviceConfig;
  device: TAudioInputDevice;
  channelCount: integer;
  channelIndex: integer;
  i: integer;
begin
  // Input devices - append detected soundcards
  for deviceIndex := 0 to High(DeviceList) do
  begin
    newDevice := true;
    //Search for Card in List
    for deviceIniIndex := 0 to High(Ini.InputDeviceConfig) do
    begin
      deviceCfg := @Ini.InputDeviceConfig[deviceIniIndex];
      device := DeviceList[deviceIndex];

      if (deviceCfg.Name = Trim(device.Name)) then
      begin
        newDevice := false;

        // store highest channel index as an offset for the new channels
        channelIndex := High(deviceCfg.ChannelToPlayerMap);
        // add missing channels or remove non-existing ones
        SetLength(deviceCfg.ChannelToPlayerMap, device.AudioFormat.Channels);
        // initialize added channels to 0
        for i := channelIndex+1 to High(deviceCfg.ChannelToPlayerMap) do
        begin
          deviceCfg.ChannelToPlayerMap[i] := 0;
        end;

        // associate ini-index with device
        device.CfgIndex := deviceIniIndex;
        break;
      end;
    end;

    //If not in List -> Add
    if newDevice then
    begin
      // resize list
      SetLength(Ini.InputDeviceConfig, Length(Ini.InputDeviceConfig)+1);
      deviceCfg := @Ini.InputDeviceConfig[High(Ini.InputDeviceConfig)];
      device := DeviceList[deviceIndex];

      // associate ini-index with device
      device.CfgIndex := High(Ini.InputDeviceConfig);

      deviceCfg.Name := Trim(device.Name);
      deviceCfg.Input := 0;

      channelCount := device.AudioFormat.Channels;
      SetLength(deviceCfg.ChannelToPlayerMap, channelCount);

      for channelIndex := 0 to channelCount-1 do
      begin
        // set default at first start of USDX (1st device, 1st channel -> player1)
        if ((channelIndex = 0) and (device.CfgIndex = 0)) then
          deviceCfg.ChannelToPlayerMap[0] := 1
        else
          deviceCfg.ChannelToPlayerMap[channelIndex] := 0;
      end;
    end;
  end;
end;

{*
 * Handles captured microphone input data.
 * Params:
 *   Buffer - buffer of signed 16bit interleaved stereo PCM-samples.
 *     Interleaved means that a right-channel sample follows a left-
 *     channel sample and vice versa (0:left[0],1:right[0],2:left[1],...).
 *   Length - number of bytes in Buffer
 *   Input - Soundcard-Input used for capture
 *}
procedure TAudioInputProcessor.HandleMicrophoneData(Buffer: PChar; Size: Cardinal; InputDevice: TAudioInputDevice);
var
  MultiChannelBuffer: PChar;  // buffer handled as array of bytes (offset relative to channel)
  SingleChannelBuffer: PChar; // temporary buffer for new samples per channel
  SingleChannelBufferSize: integer;
  ChannelIndex: integer;
  CaptureChannel: TCaptureBuffer;
  AudioFormat: TAudioFormatInfo;
  SampleSize: integer;
  SampleCount: integer;
  SamplesPerChannel: integer;
  i: integer;
begin
  AudioFormat := InputDevice.AudioFormat;
  SampleSize := AudioSampleSize[AudioFormat.Format];
  SampleCount := Size div SampleSize;
  SamplesPerChannel := Size div AudioFormat.FrameSize;

  SingleChannelBufferSize := SamplesPerChannel * SampleSize;
  GetMem(SingleChannelBuffer, SingleChannelBufferSize);

  // process channels
  for ChannelIndex := 0 to High(InputDevice.CaptureChannel) do
  begin
    CaptureChannel := InputDevice.CaptureChannel[ChannelIndex];
    // check if a capture buffer was assigned, otherwise there is nothing to do
    if (CaptureChannel <> nil) then
    begin
      // set offset according to channel index
      MultiChannelBuffer := @Buffer[ChannelIndex * SampleSize];
      // seperate channel-data from interleaved multi-channel (e.g. stereo) data
      for i := 0 to SamplesPerChannel-1 do
      begin
        Move(MultiChannelBuffer[i*AudioFormat.FrameSize],
             SingleChannelBuffer[i*SampleSize],
             SampleSize);
      end;
      CaptureChannel.ProcessNewBuffer(SingleChannelBuffer, SingleChannelBufferSize);
    end;
  end;

  FreeMem(SingleChannelBuffer);
end;


{ TAudioInputBase }

function TAudioInputBase.FinalizeRecord: boolean;
var
  i: integer;
begin
  for i := 0 to High(AudioInputProcessor.DeviceList) do
    AudioInputProcessor.DeviceList[i].Free();
  AudioInputProcessor.DeviceList := nil;
  Result := true;
end;

{*
 * Start capturing on all used input-device.
 *}
procedure TAudioInputBase.CaptureStart;
var
  S:  integer;
  DeviceIndex: integer;
  ChannelIndex: integer;
  Device: TAudioInputDevice;
  DeviceCfg: PInputDeviceConfig;
  DeviceUsed: boolean;
  Player: integer;
begin
  if (Started) then
    CaptureStop();

  // reset buffers
  for S := 0 to High(AudioInputProcessor.Sound) do
    AudioInputProcessor.Sound[S].Clear;

  // start capturing on each used device
  for DeviceIndex := 0 to High(AudioInputProcessor.DeviceList) do
  begin
    Device := AudioInputProcessor.DeviceList[DeviceIndex];
    if not assigned(Device) then
      continue;
    DeviceCfg := @Ini.InputDeviceConfig[Device.CfgIndex];

    DeviceUsed := false;

    // check if device is used
    for ChannelIndex := 0 to High(DeviceCfg.ChannelToPlayerMap) do
    begin
      Player := DeviceCfg.ChannelToPlayerMap[ChannelIndex]-1;
      if (Player < 0) or (Player >= PlayersPlay) then
      begin
        Device.LinkCaptureBuffer(ChannelIndex, nil);
      end
      else
      begin
        Device.LinkCaptureBuffer(ChannelIndex, AudioInputProcessor.Sound[Player]);
        DeviceUsed := true;
      end;
    end;

    // start device if used
    if (DeviceUsed) then
    begin
      //Log.BenchmarkStart(2);
      Device.Start();
      //Log.BenchmarkEnd(2);
      //Log.LogBenchmark('Device.Start', 2) ;
    end;
  end;

  Started := true;
end;

{*
 * Stop input-capturing on all soundcards.
 *}
procedure TAudioInputBase.CaptureStop;
var
  DeviceIndex: integer;
  ChannelIndex: integer;
  Device: TAudioInputDevice;
  DeviceCfg: PInputDeviceConfig;
begin
  for DeviceIndex := 0 to High(AudioInputProcessor.DeviceList) do
  begin
    Device := AudioInputProcessor.DeviceList[DeviceIndex];
    if not assigned(Device) then
      continue;

    Device.Stop();

    // disconnect capture buffers
    DeviceCfg := @Ini.InputDeviceConfig[Device.CfgIndex];
    for ChannelIndex := 0 to High(DeviceCfg.ChannelToPlayerMap) do
      Device.LinkCaptureBuffer(ChannelIndex, nil);
  end;

  Started := false;
end;

function TAudioInputBase.UnifyDeviceName(const name: string; deviceIndex: integer): string;
var
  count: integer; // count of devices with this name

  function IsDuplicate(const name: string): boolean;
  var
    i: integer;
  begin
    Result := False;
    // search devices with same description
    For i := 0 to deviceIndex-1 do
    begin
      if (AudioInputProcessor.DeviceList[i].Name = name) then
      begin
        Result := True;
        Break;
      end;
    end;
  end;
begin
  count := 1;
  result := name;

  // if there is another device with the same ID, search for an available name
  while (IsDuplicate(result)) do
  begin
    Inc(count);
    // set description
    result := name + ' ('+IntToStr(count)+')';
  end;
end;

end.