feat(dmr): decode and route AMBE voice

BUILD.MD

@@ -13,4 +13,4 @@ cmake --build build/dmr
 fpc -Fu. -FE/tmp tests/dmr_protocol_test.pas
 /tmp/dmr_protocol_test
 fpc -Fu. -FE/tmp tests/dmr_frontend_test.pas
-/tmp/dmr_frontend_test
+LD_LIBRARY_PATH=build/dmr /tmp/dmr_frontend_test

DMRDecoder.pas

@@ -27,8 +27,11 @@ const
   DMR_RING_SIZE        = 65536; // >1.3 s at 48 kHz, power of two
   DMR_BURST_DIBITS     = 144;
   DMR_SYNC_END_DIBIT   = 89;    // sync occupies burst dibits 66..89
+  DMR_VOICE_FRAME_SAMPLES = DMR_PCM_SAMPLES; // 20 ms at 8 kHz
 
 type
+  TDMRAudioEvent = procedure(const PCM: array of Single; Count: Integer) of object;
+
   TDMRSyncKind = (
     dskNone,
     dskBSData, dskBSVoice,
@@ -62,6 +65,9 @@ type
     ServiceOptions: Integer;
     TargetID: LongWord;
     SourceID: LongWord;
+    SelectedSlot: Integer;
+    VoiceFrameCount: QWord;
+    VoiceErrorCount: QWord;
   end;
 
   TDMRDecoder = class;
@@ -111,6 +117,9 @@ type
     FLastLCSlot: Integer;
     FColorCodeValid: Boolean;
     FColorCode, FLastDataType, FSlotTypeCorrectedBits: Integer;
+    FSelectedSlot: Integer;
+    FVoiceFrameCount, FVoiceErrorCount: QWord;
+    FOnAudio: TDMRAudioEvent;
     FBurstCount: QWord;
     FRMSSq: Double;
 
@@ -127,6 +136,7 @@ type
     function Digitize(Phase: Integer; Symbol: Double): Byte;
     procedure StartBurstTracking(Phase: Integer);
     procedure CompleteBurst;
+    procedure DecodeVoiceBurst;
     procedure ResetDSP;
   public
     constructor Create;
@@ -140,6 +150,7 @@ type
 
     class function SyncKindName(Kind: TDMRSyncKind): string; static;
     property Enabled: Boolean read FEnabled;
+    property OnAudio: TDMRAudioEvent read FOnAudio write FOnAudio;
   end;
 
 implementation
@@ -275,6 +286,10 @@ begin
     FColorCode := 0;
     FLastDataType := 0;
     FSlotTypeCorrectedBits := 0;
+    FSelectedSlot := -1;
+    FVoiceFrameCount := 0;
+    FVoiceErrorCount := 0;
+    DMRMbeReset(FMbe);
     FTrackPhase := -1;
     FCurrentBurstPos := 0;
     FBurstCount := 0;
@@ -480,11 +495,51 @@ begin
       FLastLCSlot := 1
     else
       FLastLCSlot := 0;
+    if FSelectedSlot < 0 then FSelectedSlot := FLastLCSlot;
   end;
+  DecodeVoiceBurst;
   Inc(FBurstCount);
   FCurrentBurstPos := 0;
 end;
 
+procedure TDMRDecoder.DecodeVoiceBurst;
+var
+  Frames: TDMRAMBEFrames;
+  PCM: array[0..DMR_PCM_SAMPLES - 1] of Single;
+  MbeResult: TDMRMbeResult;
+  Slot, FrameIndex, RC: Integer;
+begin
+  if (FMbe = nil) or (FLastSyncTick = 0) or
+     (GetTickCount64 - FLastSyncTick > DMR_SYNC_HOLD_MS) then Exit;
+  if not (FSyncKind in [dskBSVoice, dskMSVoice, dskDirectTS1Voice,
+          dskDirectTS2Voice]) then Exit;
+
+  if FSyncKind in [dskBSVoice] then
+  begin
+    if not FLastBurstInfo.CACH.Valid then Exit;
+    Slot := FLastBurstInfo.CACH.Slot;
+  end
+  else if FSyncKind = dskDirectTS2Voice then Slot := 1
+  else Slot := 0;
+  if FSelectedSlot < 0 then FSelectedSlot := Slot;
+  if Slot <> FSelectedSlot then Exit;
+
+  DMRExtractAMBEFrames(FLastBurst, Frames);
+  for FrameIndex := 0 to 2 do
+  begin
+    FillChar(MbeResult, SizeOf(MbeResult), 0);
+    RC := DMRMbeDecode(FMbe, @Frames[FrameIndex][0], @PCM[0], @MbeResult);
+    if RC <> 0 then
+    begin
+      Inc(FVoiceErrorCount);
+      Continue;
+    end;
+    Inc(FVoiceFrameCount);
+    if MbeResult.ErrorsTotal > 0 then Inc(FVoiceErrorCount, MbeResult.ErrorsTotal);
+    if Assigned(FOnAudio) then FOnAudio(PCM, Length(PCM));
+  end;
+end;
+
 procedure TDMRDecoder.NoteSync(Phase: Integer; Kind: TDMRSyncKind;
   Inverted: Boolean);
 var
@@ -559,6 +614,9 @@ begin
       S.ServiceOptions := FLastLinkControl.ServiceOptions;
       S.TargetID := FLastLinkControl.TargetID;
       S.SourceID := FLastLinkControl.SourceID;
+      S.SelectedSlot := FSelectedSlot;
+      S.VoiceFrameCount := FVoiceFrameCount;
+      S.VoiceErrorCount := FVoiceErrorCount;
     finally
       FStatusLock.Leave;
     end;

DMRProtocol.pas

@@ -3,9 +3,21 @@ unit DMRProtocol;
 {
   Small, allocation-free DMR burst protocol layer.
 
-  The CACH interleave and Hamming/Golay generator matrices are derived from
-  dsd-fme (src/dmr_bs.c and src/fec.c). The original code is distributed
-  under the ISC licence; see the dsd-fme source tree for its full notice.
+  The CACH/AMBE interleavers and Hamming/Golay matrices are derived from
+  dsd-fme (src/dmr_bs.c, src/fec.c and include/dmr_const.h).
+
+  Copyright (C) 2010 DSD Author
+  Permission to use, copy, modify, and/or distribute this software for any
+  purpose with or without fee is hereby granted, provided that the above
+  copyright notice and this permission notice appear in all copies.
+
+  THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
+  REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+  AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
+  INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+  LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
+  OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+  PERFORMANCE OF THIS SOFTWARE.
 }
 
 {$IFDEF FPC}
@@ -25,6 +37,8 @@ type
   TDMRBit7 = array[0..6] of Byte;
   TDMRBit20 = array[0..19] of Byte;
   TDMRBit96 = array[0..95] of Byte;
+  TDMRAMBEFrame = array[0..95] of Byte;
+  TDMRAMBEFrames = array[0..2] of TDMRAMBEFrame;
 
   TDMRCACH = record
     Valid: Boolean;
@@ -68,6 +82,10 @@ function DMRGolay208Encode(Value: Byte): TDMRBit20;
 procedure DMRBPTC19696Encode(const Payload: TDMRBit96;
   out Burst: TDMRDibitBurst);
 procedure DMRFullLCSetParity(var Payload: TDMRBit96; DataType: Integer);
+procedure DMRExtractAMBEFrames(const Burst: TDMRDibitBurst;
+  out Frames: TDMRAMBEFrames);
+procedure DMRInsertAMBEFrames(const Frames: TDMRAMBEFrames;
+  var Burst: TDMRDibitBurst);
 function DMRDecodeCACH(const Burst: TDMRDibitBurst; out CACH: TDMRCACH): Boolean;
 function DMRDecodeSlotType(const Burst: TDMRDibitBurst;
   out SlotType: TDMRSlotType): Boolean;
@@ -110,6 +128,19 @@ const
   HAMMING_15_11_SYNDROME: array[0..14] of Byte =
     (9,13,15,14,7,10,5,11,12,6,3, 8,4,2,1);
 
+  AMBE_W: array[0..35] of Byte = (
+    0,1,0,1,0,1, 0,1,0,1,0,1, 0,1,0,1,0,1,
+    0,1,0,1,0,2, 0,2,0,2,0,2, 0,2,0,2,0,2);
+  AMBE_X: array[0..35] of Byte = (
+    23,10,22,9,21,8, 20,7,19,6,18,5, 17,4,16,3,15,2,
+    14,1,13,0,12,10, 11,9,10,8,9,7, 8,6,7,5,6,4);
+  AMBE_Y: array[0..35] of Byte = (
+    0,2,0,2,0,2, 0,2,0,3,0,3, 1,3,1,3,1,3,
+    1,3,1,3,1,3, 1,3,1,3,1,3, 1,3,1,3,1,3);
+  AMBE_Z: array[0..35] of Byte = (
+    5,3,4,2,3,1, 2,0,1,13,0,12, 22,11,21,10,20,9,
+    19,8,18,7,17,6, 16,5,15,4,14,3, 13,2,12,1,11,0);
+
 function DMRHamming74Encode(Value: Byte): TDMRBit7;
 var
   i, j: Integer;
@@ -203,6 +234,49 @@ begin
   end;
 end;
 
+function AMBEDibitIndex(FrameIndex, DibitIndex: Integer): Integer;
+begin
+  case FrameIndex of
+    0: Result := 12 + DibitIndex;
+    1: if DibitIndex < 18 then Result := 48 + DibitIndex
+       else Result := 90 + DibitIndex - 18;
+  else
+    Result := 108 + DibitIndex;
+  end;
+end;
+
+procedure DMRExtractAMBEFrames(const Burst: TDMRDibitBurst;
+  out Frames: TDMRAMBEFrames);
+var
+  FrameIndex, i, DibitIndex: Integer;
+  Dibit: Byte;
+begin
+  FillChar(Frames, SizeOf(Frames), 0);
+  for FrameIndex := 0 to 2 do
+    for i := 0 to 35 do
+    begin
+      DibitIndex := AMBEDibitIndex(FrameIndex, i);
+      Dibit := Burst[DibitIndex];
+      Frames[FrameIndex][AMBE_W[i] * 24 + AMBE_X[i]] := (Dibit shr 1) and 1;
+      Frames[FrameIndex][AMBE_Y[i] * 24 + AMBE_Z[i]] := Dibit and 1;
+    end;
+end;
+
+procedure DMRInsertAMBEFrames(const Frames: TDMRAMBEFrames;
+  var Burst: TDMRDibitBurst);
+var
+  FrameIndex, i, DibitIndex: Integer;
+begin
+  for FrameIndex := 0 to 2 do
+    for i := 0 to 35 do
+    begin
+      DibitIndex := AMBEDibitIndex(FrameIndex, i);
+      Burst[DibitIndex] :=
+        ((Frames[FrameIndex][AMBE_W[i] * 24 + AMBE_X[i]] and 1) shl 1) or
+        (Frames[FrameIndex][AMBE_Y[i] * 24 + AMBE_Z[i]] and 1);
+    end;
+end;
+
 function DecodeHamming74(const Received: TDMRBit7; out Value: Byte;
   out Corrected: Integer): Boolean;
 var

RadioController.pas

@@ -405,6 +405,7 @@ type
     // вызывающим (GUI или демон) после CreateEngines.
     procedure OnAudioReady(const Left, Right: array of Single; Count: Integer);
     procedure OnDemodAudioReady(const Left, Right: array of Single; Count: Integer);
+    procedure OnDMRAudioReady(const PCM: array of Single; Count: Integer);
     procedure OnSpectrumReady(const Pixels: array of Single; Count: Integer);
     procedure OnWaterfallReady(const Pixels: array of Single; Count: Integer);
     procedure OnMicPacket(const Data: TMicDataPacket);
@@ -851,6 +852,7 @@ begin
 
   // DMR front-end owns a worker thread. It stays idle until MODE_DMR is active.
   FDMRDec := TDMRDecoder.Create;
+  FDMRDec.OnAudio := OnDMRAudioReady;
 
   // Audio out/in — объекты создаём сейчас, Open вызывается позже (после показа
   // формы / при подключении устройства).
@@ -862,6 +864,13 @@ end;
 procedure TRadioController.FreeEngines;
 var i: Integer;
 begin
+  // Stop the DMR worker before destroying any of its audio destinations.
+  if Assigned(FDMRDec) then
+  begin
+    FDMRDec.SetEnabled(False);
+    FDMRDec.OnAudio := nil;
+    FreeAndNil(FDMRDec);
+  end;
   if Assigned(FNetwork) then
   begin
     if FNetwork.Connected then FNetwork.Disconnect;
@@ -883,7 +892,6 @@ begin
     FDSPEngine.Close;
     FreeAndNil(FDSPEngine);
   end;
-  if Assigned(FDMRDec) then FreeAndNil(FDMRDec);
   if Assigned(FBeaconDec) then FreeAndNil(FBeaconDec);
 end;
 
@@ -1186,6 +1194,39 @@ begin
     FDMRDec.SetEnabled(False);
 end;
 
+procedure TRadioController.OnDMRAudioReady(const PCM: array of Single;
+  Count: Integer);
+// DMR worker thread, 8 kHz mono from mbelib. Linear 6x interpolation brings
+// it to the common 48 kHz output route used by local, web and radio speakers.
+var
+  Left, Right: array of Single;
+  i, Phase, OutPos, N: Integer;
+  A, B, V, Gain: Single;
+begin
+  if (FMode <> MODE_DMR) or FMuted or (Count <= 0) then Exit;
+  N := Min(Count, Length(PCM));
+  SetLength(Left, N * 6);
+  SetLength(Right, N * 6);
+  Gain := FVolume / 100.0;
+  OutPos := 0;
+  for i := 0 to N - 1 do
+  begin
+    A := PCM[i];
+    if i + 1 < N then B := PCM[i + 1] else B := A;
+    for Phase := 0 to 5 do
+    begin
+      V := (A + (B - A) * (Phase / 6.0)) * Gain;
+      Left[OutPos] := V;
+      Right[OutPos] := V;
+      Inc(OutPos);
+    end;
+  end;
+  if FSendAudioToRadio and Assigned(FNetwork) then
+    FNetwork.SendSpeakerAudio(Left, Right, OutPos);
+  if Assigned(FOnAudioConsume) and FOnAudioConsume(Left, Right, OutPos) then Exit;
+  if FLocalAudio and Assigned(FAudioOut) then FAudioOut.Write(Left, Right, OutPos);
+end;
+
 // ---------------------------------------------------------------------------
 // Мультислайсы (софт-fan-out)
 // ---------------------------------------------------------------------------

native/dmr/README.md

@@ -11,7 +11,11 @@ cmake -S native/dmr -B build/dmr -DCMAKE_BUILD_TYPE=Release
 cmake --build build/dmr
 ```
 
-The current ABI implements the stateful AMBE+2 vocoder boundary. The burst/FEC
-layer will feed its row-major `char[4][24]` output to this library. Keep the ABI
-versioned: the GUI and daemon must remain usable when the optional library is
-not installed.
+The Pascal burst/FEC layer extracts three row-major `char[4][24]` AMBE+2
+frames from each selected voice-slot burst and feeds them through this ABI.
+Decoded 8 kHz mono PCM is resampled to EWSDR's 48 kHz speaker/web route.
+
+For a build-tree run, either copy `libewsdr_dmr.so` beside the EWSDR executable
+or add `build/dmr` to `LD_LIBRARY_PATH`. `cmake --install build/dmr` installs the
+adapter system-wide. The GUI and daemon remain usable (with metadata but no
+voice) when this optional library is absent.

tests/dmr_frontend_test.pas

@@ -9,6 +9,20 @@ uses
 const
   BS_VOICE_SYNC = '131111333113313313113313';
 
+type
+  TAudioSink = class
+  public
+    CallCount: Integer;
+    SampleCount: Integer;
+    procedure AudioReady(const PCM: array of Single; Count: Integer);
+  end;
+
+procedure TAudioSink.AudioReady(const PCM: array of Single; Count: Integer);
+begin
+  Inc(CallCount);
+  Inc(SampleCount, Count);
+end;
+
 procedure FeedSync(D: TDMRDecoder; const Pattern: string; Invert: Boolean);
 var
   L, R: array of Single;
@@ -95,9 +109,12 @@ end;
 var
   D: TDMRDecoder;
   S: TDMRStatus;
+  Sink: TAudioSink;
 begin
+  Sink := TAudioSink.Create;
   D := TDMRDecoder.Create;
   try
+    D.OnAudio := Sink.AudioReady;
     D.SetEnabled(True);
     FeedSync(D, BS_VOICE_SYNC, False);
     Sleep(50);
@@ -124,8 +141,18 @@ begin
     D.SetInverted(False);
     D.SetEnabled(True);
     TestBurst(D);
+    D.GetStatus(S);
+    if S.VocoderAvailable and
+       ((Sink.CallCount <> 3) or
+        (Sink.SampleCount <> 3 * DMR_VOICE_FRAME_SAMPLES)) then
+    begin
+      WriteLn('AMBE callback failed: calls=', Sink.CallCount,
+              ' samples=', Sink.SampleCount);
+      Halt(5);
+    end;
     WriteLn('DMR front-end sync tests passed');
   finally
     D.Free;
+    Sink.Free;
   end;
 end.

tests/dmr_protocol_test.pas

@@ -76,6 +76,8 @@ var
   Burst: TDMRDibitBurst;
   Info: TDMRBurstInfo;
   Payload: TDMRBit96;
+  Frames: TDMRAMBEFrames;
+  VoiceDibits: array[0..107] of Byte;
   i: Integer;
 begin
   FillChar(Burst, SizeOf(Burst), 0);
@@ -155,5 +157,20 @@ begin
   DMRParseBurst(Burst, Info);
   Check(not Info.LinkControl.Decoded, 'invalid Full LC RS checksum accepted');
 
-  WriteLn('DMR CACH, Slot Type, BPTC and Full LC tests passed');
+  // Three AMBE frames occupy 36 + 18/18 + 36 dibits around the centre sync.
+  FillChar(Burst, SizeOf(Burst), 0);
+  for i := 12 to 65 do Burst[i] := (i * 3 + 1) and 3;
+  for i := 90 to 143 do Burst[i] := (i * 3 + 2) and 3;
+  for i := 0 to 53 do VoiceDibits[i] := Burst[12 + i];
+  for i := 0 to 53 do VoiceDibits[54 + i] := Burst[90 + i];
+  DMRExtractAMBEFrames(Burst, Frames);
+  for i := 12 to 65 do Burst[i] := 0;
+  for i := 90 to 143 do Burst[i] := 0;
+  DMRInsertAMBEFrames(Frames, Burst);
+  for i := 0 to 53 do Check(Burst[12 + i] = VoiceDibits[i],
+    'AMBE frame 1/2 interleave mismatch');
+  for i := 0 to 53 do Check(Burst[90 + i] = VoiceDibits[54 + i],
+    'AMBE frame 2/3 interleave mismatch');
+
+  WriteLn('DMR protocol, FEC, Full LC and AMBE extraction tests passed');
 end.