Checkpoint

bits.go

@@ -1,10 +1,11 @@
 package dmr
 
+// Various sizes of information chunks.
 const (
 	PayloadBits                 = 98 + 10 + 48 + 10 + 98
-	PayloadSize                 = 33
 	InfoHalfBits                = 98
 	InfoBits                    = 2 * InfoHalfBits
+	InfoSize                    = 12 // After BPTC(196, 96) decoding
 	SlotTypeHalfBits            = 10
 	SlotTypeBits                = 2 * SlotTypeHalfBits
 	SignalBits                  = 48

bptc/bptc.go

@@ -3,11 +3,11 @@ package bptc
 import (
 	"fmt"
 
-	"github.com/tehmaze/go-dmr"
-	"github.com/tehmaze/go-dmr/fec"
+	"github.com/pd0mz/go-dmr"
+	"github.com/pd0mz/go-dmr/fec"
 )
 
-func Process(info []byte, payload []byte) error {
+func Decode(info []byte, payload []byte) error {
 	if len(info) < 196 {
 		return fmt.Errorf("bptc: info size %d too small, need at least 196 bits", len(info))
 	}

controlblock.go

@@ -0,0 +1,206 @@
+package dmr
+
+import (
+	"errors"
+	"fmt"
+)
+
+// Control Block Options
+const (
+	CBSKOOutboundActivation                   = B00111000
+	CBSKOUnitToUnitVoiceServiceRequest        = B00000100
+	CBSKOUnitToUnitVoiceServiceAnswerResponse = B00000101
+	CBSKONegativeAcknowledgeResponse          = B00100100
+	CBSKOPreamble                             = B00111101
+)
+
+type ControlBlock struct {
+	Last         bool
+	CBSKO        uint8
+	SrcID, DstID uint32
+	Data         ControlBlockData
+}
+
+type ControlBlockData interface {
+	Write([]byte) error
+	Parse([]byte) error
+}
+
+type OutboundActivation struct{}
+
+func (d *OutboundActivation) Parse(data []byte) error {
+	if len(data) != InfoSize {
+		return fmt.Errorf("dmr: expected %d info bytes, got %d", InfoSize, len(data))
+	}
+	return nil
+}
+
+func (d *OutboundActivation) Write(data []byte) error {
+	if len(data) != InfoSize {
+		return fmt.Errorf("dmr: expected %d info bytes, got %d", InfoSize, len(data))
+	}
+	data[0] |= B00111000
+	return nil
+}
+
+type UnitToUnitVoiceServiceRequest struct {
+	Options uint8
+}
+
+func (d *UnitToUnitVoiceServiceRequest) Parse(data []byte) error {
+	if len(data) != InfoSize {
+		return fmt.Errorf("dmr: expected %d info bytes, got %d", InfoSize, len(data))
+	}
+	d.Options = data[2]
+	return nil
+}
+
+func (d *UnitToUnitVoiceServiceRequest) Write(data []byte) error {
+	if len(data) != InfoSize {
+		return fmt.Errorf("dmr: expected %d info bytes, got %d", InfoSize, len(data))
+	}
+	data[0] |= B00000100
+	data[2] = d.Options
+	return nil
+}
+
+var _ (ControlBlockData) = (*UnitToUnitVoiceServiceRequest)(nil)
+
+type UnitToUnitVoiceServiceAnswerResponse struct {
+	Options  uint8
+	Response uint8
+}
+
+func (d *UnitToUnitVoiceServiceAnswerResponse) Parse(data []byte) error {
+	if len(data) != InfoSize {
+		return fmt.Errorf("dmr: expected %d info bytes, got %d", InfoSize, len(data))
+	}
+	d.Options = data[2]
+	d.Response = data[3]
+	return nil
+}
+
+func (d *UnitToUnitVoiceServiceAnswerResponse) Write(data []byte) error {
+	if len(data) != InfoSize {
+		return fmt.Errorf("dmr: expected %d info bytes, got %d", InfoSize, len(data))
+	}
+	data[0] |= B00000101
+	data[2] = d.Options
+	data[3] = d.Response
+	return nil
+}
+
+var _ (ControlBlockData) = (*UnitToUnitVoiceServiceAnswerResponse)(nil)
+
+type NegativeAcknowledgeResponse struct {
+	SourceType  bool
+	ServiceType uint8
+	Reason      uint8
+}
+
+func (d *NegativeAcknowledgeResponse) Parse(data []byte) error {
+	if len(data) != InfoSize {
+		return fmt.Errorf("dmr: expected %d info bytes, got %d", InfoSize, len(data))
+	}
+	d.SourceType = (data[2] & B01000000) > 0
+	d.ServiceType = (data[2] & B00011111)
+	d.Reason = data[3]
+	return nil
+}
+
+func (d *NegativeAcknowledgeResponse) Write(data []byte) error {
+	if len(data) != InfoSize {
+		return fmt.Errorf("dmr: expected %d info bytes, got %d", InfoSize, len(data))
+	}
+	data[0] |= B00100110
+	data[2] = d.ServiceType
+	if d.SourceType {
+		data[2] |= B01000000
+	}
+	data[3] = d.Reason
+	return nil
+}
+
+var _ (ControlBlockData) = (*NegativeAcknowledgeResponse)(nil)
+
+type ControlBlockPreamble struct {
+	DataFollows bool
+	DstIsGroup  bool
+	Blocks      uint8
+}
+
+func (d *ControlBlockPreamble) Parse(data []byte) error {
+	if len(data) != InfoSize {
+		return fmt.Errorf("dmr: expected %d info bytes, got %d", InfoSize, len(data))
+	}
+	d.DataFollows = (data[2] & B10000000) > 0
+	d.DstIsGroup = (data[2] & B01000000) > 0
+	d.Blocks = data[3]
+	return nil
+}
+
+func (d *ControlBlockPreamble) Write(data []byte) error {
+	if len(data) != InfoSize {
+		return fmt.Errorf("dmr: expected %d info bytes, got %d", InfoSize, len(data))
+	}
+	data[0] |= B00100110
+	if d.DataFollows {
+		data[2] |= B10000000
+	}
+	if d.DstIsGroup {
+		data[2] |= B01000000
+	}
+	data[3] = d.Blocks
+	return nil
+}
+
+var _ (ControlBlockData) = (*ControlBlockPreamble)(nil)
+
+func ParseControlBlock(data []byte) (*ControlBlock, error) {
+	if len(data) != InfoSize {
+		return nil, fmt.Errorf("dmr: expected %d info bytes, got %d", InfoSize, len(data))
+	}
+
+	// Calculate CRC16
+
+	// Check packet
+	if data[0]&B01000000 > 0 {
+		return nil, errors.New("dmr: CBSK protect flag is set")
+	}
+	if data[1] != 0 {
+		return nil, errors.New("dmr: CBSK feature set ID is set")
+	}
+
+	cb := &ControlBlock{
+		Last:  (data[0] & B10000000) > 0,
+		CBSKO: (data[0] & B00111111),
+		DstID: uint32(data[4])<<16 | uint32(data[5])<<8 | uint32(data[6]),
+		SrcID: uint32(data[7])<<16 | uint32(data[8])<<8 | uint32(data[9]),
+	}
+
+	switch cb.CBSKO {
+	case CBSKOOutboundActivation:
+		cb.Data = &OutboundActivation{}
+		break
+	case CBSKOUnitToUnitVoiceServiceRequest:
+		cb.Data = &UnitToUnitVoiceServiceRequest{}
+		break
+	case CBSKOUnitToUnitVoiceServiceAnswerResponse:
+		cb.Data = &UnitToUnitVoiceServiceAnswerResponse{}
+		break
+	case CBSKONegativeAcknowledgeResponse:
+		cb.Data = &NegativeAcknowledgeResponse{}
+		break
+	case CBSKOPreamble:
+		cb.Data = &ControlBlockPreamble{}
+		break
+	default:
+		return nil, fmt.Errorf("dmr: unknown CBSKO %#02x (%#06b)", cb.CBSKO, cb.CBSKO)
+	}
+
+	if err := cb.Data.Parse(data); err != nil {
+		return nil, err
+	}
+
+	return cb, nil
+}

data.go

@@ -0,0 +1,9 @@
+package dmr
+
+type DataBlock struct {
+	Serial uint8
+	CRC    uint16
+	OK     bool
+	Data   [24]byte
+	Length uint8
+}

dataheader.go

@@ -2,25 +2,6 @@ package dmr
 
 import "fmt"
 
-var DataTypeName = [16]string{
-	"PI Header",        // 0000
-	"VOICE Header:",    // 0001
-	"TLC:",             // 0010
-	"CSBK:",            // 0011
-	"MBC Header:",      // 0100
-	"MBC:",             // 0101
-	"DATA Header:",     // 0110
-	"RATE 1/2 DATA:",   // 0111
-	"RATE 3/4 DATA:",   // 1000
-	"Slot idle",        // 1001
-	"Rate 1 DATA",      // 1010
-	"Unknown/Bad (11)", // 1011
-	"Unknown/Bad (12)", // 1100
-	"Unknown/Bad (13)", // 1101
-	"Unknown/Bad (14)", // 1110
-	"Unknown/Bad (15)", // 1111
-}
-
 // Data Header Packet Format
 const (
 	PacketFormatUDT              uint8 = iota // 0b0000