This document describes the GME APIs for range voice so that developers can easily debug and access them.

GME's range voice service is specially developed for games similar to PUBG. Unlike a team voice room, a range voice room has the following core capabilities:

1. It provides the "Team only" and "Everyone" voice modes unique to games like PUBG and Battle Royale.
2. Relying on its range determination capability, it enables a large number of users to voice chat using their mic in the same voice room. Users within a certain range can turn on the mic, and the local receives up to 20 audio channels.

Concepts

Range voice room

Before using range voice, you need to call the SetRangeAudioTeamID API to set the team ID (TeamID) and then call the EnterRoom API to enter the room. If the specified TeamID is not equal to 0 during room entry, range voice room mode will be triggered.

Voice mode

When the user enters a range voice room, the user can choose from two voice modes:

Voice Mode	Parameter Name	Feature
Everyone	RANGE_AUDIO_MODE_WORLD	In this mode, everyone within a certain range can hear the player as he or she chats with his or her teammates
Team only	RANGE_AUDIO_MODE_TEAM	Only teammates can hear the user

In different voice modes, the specific sound reachability is as follows:
a. Players in the same team can hear each other no matter how far apart they are or what voice modes they use.
b. Players in different teams can hear each other only if they are all in the "Everyone" voice mode and within a certain distance.

Note：

For more information on the specific sound reachability of players, please see “Appendix” in Range Voice.

Voice reception range

If the voice mode is set to Everyone (RANGE_AUDIO_MODE_WORLD), the voice reachability will be subject to the UpdateAudioRecvRange API.

• Regardless of whether teammates are within the voice range, they can always talk with each other.
• To set the voice reception range, use the UpdateAudioRecvRange API.
• Voice modes can be switched in real time in the range voice room. However, changing the TeamID, which must be specified before room entry, in the range voice room is not supported.
• To use range voice, you must choose smooth sound quality when entering the room (i.e., RoomType = 1).

Directions

A range voice room is different from a team voice room because you must choose smooth sound quality when entering the range voice room. In addition, SetRangeAudioTeamID and SetRangeAudioMode must be called before EnterRoom is called. Call UpdateAudioRecvRange after successful room entry and call UpdateSelfPosition once per frame.

If you want to use the 3D sound effect at the same time, please do so as instructed in “Simultaneous Use of the 3D Sound Effect” in Range Voice after completing steps 1 and 2 below.

1. Set TeamID

• The team ID (TeamID) must be set by calling the API SetRangeAudioTeamID before EnterRoom. Otherwise, GME will return the error code AV_ERR_ROOM_NOT_EXITED(1202). If you enter the room after exiting the room, please call the API SetRangeAudioTeamID after exiting the room successfully.

Note：

This parameter will not be automatically reset to 0 upon room exit. Therefore, once you decide to use range voice, please use this method to set TeamID before calling EnterRoom each time.

Function prototype

ITMGContext SetRangeAudioTeamID(int teamID)

Parameter	Type	Description
teamID	int	Team ID, which is used for audio upstream/downstream control in range voice. When it is set to 0 (default), the team voice mode is used.

2. Set the voice mode

• The voice mode can be modified by calling the method SetRangeAudioMode either before or after room entry.
• Calling this method before room entry will affect the next room entry.
• Calling this method after room entry will directly change the current voice mode.
• This parameter will not be automatically reset to MODE_WORLD upon room exit. Therefore, once you decide to call this method, please do so before each call of EnterRoom.

Function prototype

ITMGRoom int SetRangeAudioMode(RANGE_AUDIO_MODE rangeAudioMode)

Parameter	Type	Description
rangeAudioMode	int	0 (MODE_WORLD): everyone; 1 (MODE_TEAM): team only

3. Enter a voice room

Before entering a voice room by calling EnterRoom, you need to call the following two APIs: SetRangeAudioTeamID and SetRangeAudioMode.

ITMGContext.GetInstance(this).EnterRoom(roomId,ITMG_ROOM_TYPE_FLUENCY, authBuffer); 

Choose smooth sound quality when entering the voice room, and monitor and process the callback for room entry.

public void OnEvent(ITMGContext.ITMG_MAIN_EVENT_TYPE type, Intent data) {
if (ITMGContext.ITMG_MAIN_EVENT_TYPE.ITMG_MAIN_EVENT_TYPE_ENTER_ROOM == type)
       {
              //Analyze the returned result
           int nErrCode = data.getIntExtra("result" , -1);
           String strErrMsg = data.getStringExtra("error_info");
            if (nErrCode == AVError.AV_OK)
           {
               //If you receive a success response for room entry, you can proceed with your operation
               ScrollView_ShowLog("EnterRoom success");
               Log.i(TAG,"EnterRoom success!");
           }
           else
           {
               //If you fail to enter the room, you need to analyze the returned error message
               ScrollView_ShowLog("EnterRoom fail :" + strErrMsg);
               Log.i(TAG,"EnterRoom fail!");
           }  
       }
}

Once you enter the room, call UpdateAudioRecvRange (once at least), and call UpdateSelfPosition once per frame.

4. Set the voice reception range

• This method is used to set the voice reception range (subject to the game engine) and can be called only after successful room entry.
• This method must be used in conjunction with UpdateSelfPosition to update the sound source position.
• This method only needs to be called once.

Function prototype

ITMGRoom int UpdateAudioRecvRange(int range)

Parameter	Type	Description
range	int	Maximum voice reception range in the distance unit used by the game engine

Sample code

ITMGContext.GetInstance().GetRoom().UpdateAudioRecvRange(300);

5. Update the sound source position

The purpose of updating the sound source position is to inform the server of the local player's position. The system implements range voice by checking the local coordinates and voice reception range against the remote coordinates and voice reception range.

• This function is used to update the sound source position information. It can be called only after successful room entry and needs to be called once per frame. Taking the Unity engine as an example, this API needs to be called in Update.
• If range voice is enabled, the sound source position must be updated. Even if range determination is not required, this API still needs to be called once after room entry.
• If you want to enable the 3D sound effect at the same time, set the axisForward, axisRight, and axisUp parameters as specified in the “Simultaneous Use of the 3D Sound Effect” section below.

Function prototype

public abstract int UpdateSelfPosition(int position[3], float axisForward[3], float axisRight[3], float axisUp[3])

Parameter	Type	Description
position	int[]	Local position (forward, right and up) in the world coordinate system
axisForward	float[]	This parameter can be ignored in this product
axisRight	float[]	This parameter can be ignored in this product
axisUp	float[]	This parameter can be ignored in this product

Simultaneous Use of the 3D Sound Effect

You can enable both the 3D sound effect and the range voice at the same time by following the steps below:

The following steps need to be performed after steps 1, 2 and 3 are completed.

1. Initialize the 3D sound effect engine

This function is used to initialize the 3D sound effect engine and needs to be called after room entry. You must call this API before using the 3D sound effect, even if you want to enable only the 3D sound effect reception rather than the 3D sound effect playback.

Function prototype

public abstract int InitSpatializer(string modelPath)

Parameter	Type	Description
modelPath	string	Path of the 3D sound effect resource file. Please download the 3D sound effect model file here (md5: d0b76aa64c46598788c2f35f5a8a8694) and store it locally. Its storage path is passed to the SDK through this parameter. You must use this official file.

2. Enable/disable the 3D sound effect

This function is used to enable/disable the 3D sound effect. You can hear the 3D sound after enabling it.

Function prototype

public abstract int EnableSpatializer(bool enable, bool applyToTeam)

Parameter	Type	Description
enable	bool	You can hear the 3D sound effect after enabling it,
applyToTeam	bool	Specifies whether the 3D sound effect is enabled within the team and takes effect only when enable is true

The IsEnableSpatializer API can be used to get the 3D sound effect status.

3. Set the voice reception range (for the 3D sound effect)

• This method is used to set the voice reception range (subject to the game engine) and can be called only after successful room entry.
• This method must be used in conjunction with UpdateSelfPosition to update the sound source position.
• This method only needs to be called once.
• In the 3D sound effect, the volume level of the sound source attenuates as the distance to the sound source increases. If the unit distance exceeds the range, the volume level will attenuate to almost zero.
• For more information on the relationship between the distance and sound attenuation, please see the appendix.

Function prototype

ITMGRoom int UpdateAudioRecvRange(int range)

Parameter	Type	Description
range	int	Maximum voice reception range in the distance unit used by the game engine

Sample code

ITMGContext.GetInstance().GetRoom().UpdateAudioRecvRange(300);

4. Update the sound source position (for the 3D sound effect)

The purpose of updating the sound source position is to inform the server of the local player's position. The system implements range voice by checking the local coordinates and voice reception range against the remote coordinates and voice reception range.

• This function is used to update the sound source position information. It can be called only after successful room entry and needs to be called once per frame. Taking the Unity engine as an example, this API needs to be called in Update.
• Please directly copy the sample code to use this feature.

Function prototype

public abstract int UpdateSelfPosition(int position[3], float axisForward[3], float axisRight[3], float axisUp[3])

Parameter	Type	Description
position	int[]	Local position (forward, right and up) in the world coordinate system
axisForward	float[]	Forward vector in the local coordinate system
axisRight	float[]	Right vector in the local coordinate system
axisUp	float[]	Up vector in the local coordinate system

Sample code

Unreal

FVector cameraLocation = UGameplayStatics::GetPlayerCameraManager(GetWorld(), 0)->GetCameraLocation();
FRotator cameraRotation = UGameplayStatics::GetPlayerCameraManager(GetWorld(), 0)->GetCameraRotation();
int position[] = { 
  (int)cameraLocation.X,
  (int)cameraLocation.Y,
  (int)cameraLocation.Z };
FMatrix matrix = ((FRotationMatrix)cameraRotation);
float forward[] = { 
  matrix.GetColumn(0).X,
  matrix.GetColumn(1).X,
  matrix.GetColumn(2).X };
float right[] = { 
  matrix.GetColumn(0).Y,
  matrix.GetColumn(1).Y,
  matrix.GetColumn(2).Y };
float up[] = { 
  matrix.GetColumn(0).Z,
  matrix.GetColumn(1).Z,
  matrix.GetColumn(2).Z};
ITMGContextGetInstance()->GetRoom()->UpdateSelfPosition(position, forward, right, up); 

Unity

Transform selftrans = currentPlayer.gameObject.transform;
Matrix4x4 matrix = Matrix4x4.TRS(Vector3.zero, selftrans.rotation, Vector3.one);
int[] position = new int[3] { 
  selftrans.position.z,
  selftrans.position.x,
  selftrans.position.y};
float[] axisForward = new float[3] { 
  matrix.m22,
  matrix.m02,
  matrix.m12 };
float[] axisRight = new float[3] { 
  matrix.m20,
  matrix.m00,
  matrix.m10 };
float[] axisUp = new float[3] { 
  matrix.m21,
  matrix.m01,
  matrix.m11 };
ITMGContext.GetInstance().GetRoom().UpdateSelfPosition(position, axisForward, axisRight, axisUp);

Appendix

Voice modes

Player voice reachability in different voice modes is as follows:

• The table below lists the possible cases of sound reachability for player B in different voice modes if player A selects the "Everyone" mode:

  In the Same Team	Within the Range	Voice Mode	Can A and B Hear Each Other
  Yes	Yes	MODE_WORLD	Yes
  		MODE_TEAM	Yes
  	No	MODE_WORLD	Yes
  		MODE_TEAM	Yes
  No	Yes	MODE_WORLD	Yes
  		MODE_TEAM	No
  	No	MODE_WORLD	No
  		MODE_TEAM	No

• The table below lists the possible cases of sound reachability for player B in different voice modes if player A selects the "Team only" mode:

  In the Same Team	Within the Range	Voice Mode	Can A and B Hear Each Other
  Yes	Yes	MODE_WORLD	Yes
  		MODE_TEAM	Yes
  	No	MODE_WORLD	Yes
  		MODE_TEAM	Yes
  No	Yes	MODE_WORLD	No
  		MODE_TEAM	No
  	No	MODE_WORLD	No
  		MODE_TEAM	No

The relationship between distance and sound attenuation

In the 3D sound effect, the sound will begin to attenuate to almost zero as the distance to the sound source exceeds a specified threshold (range/10).

Distance (Unit in Engine)	Attenuation Coefficient
0 < N < range/10	1.0 (no attenuation)
N ≥ range/10	range/10/N