voice

Documentation

Overview

package voice contains the types used by the SRS audio protocol to send and receive audio data over the network.

Index

• type Frequency
• type VoicePacket
  • func NewVoicePacket(audioBytes []byte, frequencies []Frequency, unitID uint32, packetID uint64, ...) VoicePacket
  • func NewVoicePacketFrom(b []byte) VoicePacket
  • func (vp *VoicePacket) Encode() []byte
  • func (vp *VoicePacket) String() string

Types

type Frequency

type Frequency struct {
	// Frequency is the transmission frequency in Hz.
	// Example: 249.500MHz is encoded as 249500000.0
	//
	// Length: 8 bytes
	Frequency float64
	// Modulation is the transmission modulation mode.
	//
	// Length: 1 byte
	Modulation byte
	// Encryption is the transmission encryption mode.
	//
	// Length: 1 byte
	Encryption byte
}

Frequency describes an audio transmission channel. This struct is only for use in VoicePacket. For client information, use types.Radio instead. Length: 10 bytes

type VoicePacket

type VoicePacket struct {

	// PacketLength is the total packet length in bytes.
	//
	// Bytes: 0:2
	//
	// Length: 2 bytes
	PacketLength uint16
	// AudioSegmentLength is the length of the Audio segment struct.
	//
	// Bytes: 2:4
	//
	// Length: 2 bytes
	AudioSegmentLength uint16
	// FrequenciesSegmentLength is the length of the Frequencies segment.
	//
	// Bytes: 4:6
	//
	// Length: 2 bytes
	FrequenciesSegmentLength uint16

	/* Audio segment */
	// AudioBytes is the AudioPart1 byte array. This is the audio data  as an Opus bitstream, encoded as 16KHz Mono in 40ms frames.
	// The upstream name is directly mirrored from the IDirectSoundBuffer::Lock function in the legacy DirectSound API - Part2 is not used by SRS.
	//
	// Bytes: 6:6+AudioSegmentLength
	//
	// Length: AudioSegmentLength
	AudioBytes []byte

	// Frequencies is an array of information for each frequency, modulation and encryption combination the audio is transmitted on.
	//
	// Bytes: 6+AudioSegmentLength:6+AudioSegmentLength+FrequenciesSegmentLength
	//
	// Length: FrequenciesSegmentLength
	Frequencies []Frequency

	// UnitID is the ID of the in-game unit that originated the packet.
	//
	// Bytes: PacketLength-58:PacketLength-53
	//
	// Length: 4 bytes
	UnitID uint32
	// PacketID is the ID of this packet. Packets from the same transmitter increment by 1 for each transmission.
	//
	// Bytes: PacketLength-53:PacketLength-45
	//
	// Length: 8 bytes
	PacketID uint64
	// Hops is the number of retransmissions. This value is checked in SRS to limit retransmisisons.
	//
	// Bytes: PacketLength-45:PacketLength-44
	//
	// Length: 1 byte
	Hops byte
	// RelayGUID is the GUID of the last transmitter. This may differ from OriginGUID if this is a retransmission.
	//
	// Bytes: PacketLength-44:PacketLength-22
	//
	// Length: 22 bytes
	RelayGUID []byte
	// OriginGUID is the GUID of the original transmitter.
	//
	// Bytes: PacketLength-22:PacketLength
	//
	// Length: 22 bytes
	OriginGUID []byte
}

VoicePacket is a network packet containing: A header segment with packet and segment length headers An audio segment containing Opus audio A frequency segment containing each frequency the audio is transmitted on A fixed segment containing metadata

See SRS source code for packet encoding: https://github.com/ciribob/DCS-SimpleRadioStandalone/blob/master/DCS-SR-Common/Network/UDPVoicePacket.cs

func NewVoicePacket

func NewVoicePacket(audioBytes []byte, frequencies []Frequency, unitID uint32, packetID uint64, hops byte, relay []byte, origin []byte) VoicePacket

func NewVoicePacketFrom

func NewVoicePacketFrom(b []byte) VoicePacket

newVoicePacketFrom deserializes a voice packet from bytes to struct

func (*VoicePacket) Encode

func (vp *VoicePacket) Encode() []byte

Encode serializes a VoicePacket into a byte array.

func (*VoicePacket) String

func (vp *VoicePacket) String() string