Agora.io audio working but video not transmitting

Question

I am new to Agora.io and I am creating an android app for 1 to 1 video calling. Everything is working fine in my app - I can join/leave the channel and even see my own local image through my camera. However, in the call, only the audio is being transmitted and video is not being transmitted.

When I debug the app, I can see that the event 'onFirstRemoteVideoFrame' is not being triggered. I tried changing it to 'onFirstRemoteVideoDecoded'(which I saw in many tutorials but android studio says the method is depreciated) but it is still not working.

Also, please note that when I add the line '-keep class io.agora.**{;}' in my proguard-rules.pro file, it says that it can't find the class. So instead I am using '-keep class io.agora.{*;}'.

Below is the java code for my activity. I am using agora 3.1.3.

package com.guideu.helloagora;

import androidx.appcompat.app.AppCompatActivity;
import androidx.core.app.ActivityCompat;
import androidx.core.content.ContextCompat;

import android.Manifest;
import android.content.pm.PackageManager;
import android.os.Bundle;
import android.text.TextUtils;
import android.util.Log;
import android.view.SurfaceView;
import android.view.View;
import android.widget.FrameLayout;
import android.widget.ImageView;
import android.widget.RelativeLayout;
import android.widget.Toast;

import io.agora.rtc.IRtcEngineEventHandler;
import io.agora.rtc.RtcEngine;
import io.agora.rtc.video.VideoCanvas;

import io.agora.rtc.video.VideoEncoderConfiguration;

public class MainActivity extends AppCompatActivity {

    private static final String TAG=MainActivity.class.getSimpleName();

    private static final int PERMISSION_REQ_ID=22;

    private static final String[] REQUESTED_PERMISSIONS={
            Manifest.permission.RECORD_AUDIO,
            Manifest.permission.CAMERA,
            Manifest.permission.WRITE_EXTERNAL_STORAGE
    };

    private RtcEngine mRtcEngine; // Agora engine reference

    private FrameLayout mLocalContainer;
    private RelativeLayout mRemoteContainer;
    private SurfaceView mLocalView;
    private SurfaceView mRemoteView;

    private ImageView mCallBtn;
    private ImageView mMuteBtn;
    private ImageView mSwitchCameraBtn;

    private boolean mCallEnd;
    private boolean mMuted;

    //Agora engine event handler
    private final IRtcEngineEventHandler mRTCHandler=new IRtcEngineEventHandler() {
        @Override
        public void onJoinChannelSuccess(String channel, final int uid, int elapsed) {
            super.onJoinChannelSuccess(channel, uid, elapsed);
            runOnUiThread(new Runnable() {
                @Override
                public void run() {
                    Log.i("agora","Join channel success, uid: " + (uid & 0xFFFFFFFFL));
                }
            });
        }

        @Override
        public void onUserOffline(final int uid, int reason) {
            super.onUserOffline(uid, reason);
            runOnUiThread(new Runnable() {
                @Override
                public void run() {
                    Log.i("agora","User offline, uid: " + (uid & 0xFFFFFFFFL));
                    removeRemoteView();
                }
            });
        }

        @Override
        public void onFirstRemoteVideoFrame(final int uid, int width, int height, int elapsed) {
            super.onFirstRemoteVideoFrame(uid, width, height, elapsed);
            runOnUiThread(new Runnable() {
                @Override
                public void run() {
                    Log.i("agora","First remote video decoded, uid: " + (uid & 0xFFFFFFFFL));
                    setupRemoteVideo(uid);
                }
            });
        }
    };

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        initUI();

        if(checkSelfPermission(REQUESTED_PERMISSIONS[0],PERMISSION_REQ_ID) &&
                checkSelfPermission(REQUESTED_PERMISSIONS[1],PERMISSION_REQ_ID) &&
        checkSelfPermission(REQUESTED_PERMISSIONS[2],PERMISSION_REQ_ID)){
            //init engine
            initEngineAndJoinChannel();
        }
    }

    @Override
    protected void onDestroy(){
        super.onDestroy();
        if(!mCallEnd){
            leaveChannel();
        }
        RtcEngine.destroy();
    }

    private void initUI(){
        mLocalContainer=findViewById(R.id.local_video_view_container);
        mRemoteContainer=findViewById(R.id.remote_video_view_container);

        mCallBtn=findViewById(R.id.btn_call);
        mMuteBtn=findViewById(R.id.btn_mute);
        mSwitchCameraBtn=findViewById(R.id.btn_switch_camera);
    }

    private void initEngineAndJoinChannel(){
        //initialize engine
        initializeEngine();
        //setup video config
        setupVideoConfig();
        //setup local video
        setupLocalVideo();
        //join channel
        joinChannel();
    }

    private void initializeEngine(){
        try {
            mRtcEngine = RtcEngine.create(getBaseContext(), getString(R.string.agora_app_id), mRTCHandler);
        }
        catch (Exception e){
            Log.e(TAG,Log.getStackTraceString(e));
            throw new RuntimeException("Need to check rtc sdk init fatal error\n" + Log.getStackTraceString(e));
        }
    }

    private void setupVideoConfig(){
        mRtcEngine.enableVideo();

        mRtcEngine.setVideoEncoderConfiguration(new VideoEncoderConfiguration(
                VideoEncoderConfiguration.VD_640x360,
                VideoEncoderConfiguration.FRAME_RATE.FRAME_RATE_FPS_15,
                VideoEncoderConfiguration.STANDARD_BITRATE,
                VideoEncoderConfiguration.ORIENTATION_MODE.ORIENTATION_MODE_FIXED_PORTRAIT
        ));
    }

    private void setupLocalVideo(){
        mRtcEngine.enableVideo();

        mLocalView=RtcEngine.CreateRendererView(getBaseContext());
        mLocalView.setZOrderMediaOverlay(true);
        mLocalContainer.addView(mLocalView);

        VideoCanvas localVideoCanvas=new VideoCanvas(mLocalView,VideoCanvas.RENDER_MODE_HIDDEN,0);
        mRtcEngine.setupLocalVideo(localVideoCanvas);
    }

    private void setupRemoteVideo(int uid){
        /*int count=mRemoteContainer.getChildCount();
        View view=null;
        for(int i=0;i<count;i++){
            View v=mRemoteContainer.getChildAt(i);
            if(v.getTag() instanceof  Integer && ((int) v.getTag())==uid){
                view=v;
            }
        }

        if(view!=null){
            return;
        }*/

        mRemoteView=RtcEngine.CreateRendererView(getBaseContext());
        mRemoteContainer.addView(mRemoteView);
        mRtcEngine.setupRemoteVideo(new VideoCanvas(mRemoteView,VideoCanvas.RENDER_MODE_HIDDEN,uid));
        mRemoteView.setTag(uid);
    }

    private void removeRemoteView(){
        if(mRemoteView!=null){
            mRemoteContainer.removeView(mRemoteView);
        }

        mRemoteView=null;
    }

    private void joinChannel(){
        String token=getString(R.string.agora_access_token);
        if(TextUtils.isEmpty(token)){
            token=null;
        }

        mRtcEngine.joinChannel(token,"HelloAgora","",0);
    }

    private void leaveChannel(){
        mRtcEngine.leaveChannel();
    }

    public void onLocalAudioMuteClicked(View view){
        mMuted=!mMuted;
        mRtcEngine.muteLocalAudioStream(mMuted);
        int res=mMuted?R.drawable.btn_mutecall:R.drawable.btn_unmute;
        mMuteBtn.setImageResource(res);
    }

    public void onSwitchCameraClicked(View view){
        mRtcEngine.switchCamera();
    }

    public void onCallClicked(View view){
        if(mCallEnd){
            startCall();
            mCallEnd=false;
            mCallBtn.setImageResource(R.drawable.btn_endcall);
        }
        else{
            endCall();
            mCallEnd=true;
            mCallBtn.setImageResource(R.drawable.btn_startcall);
        }

        showButtons(!mCallEnd);
    }

    private void startCall(){
        setupLocalVideo();
        joinChannel();
    }

    private void endCall(){
        removeLocalVideo();
        removeRemoteView();
        leaveChannel();
    }

    private void removeLocalVideo(){
        if(mLocalView!=null){
            mLocalContainer.removeView(mLocalView);
        }
        mLocalView=null;
    }

    private void showButtons(boolean show){
        int visibility=show?View.VISIBLE:View.GONE;
        mMuteBtn.setVisibility(visibility);
        mSwitchCameraBtn.setVisibility(visibility);
    }

    private boolean checkSelfPermission(String permission, int requestCode){
        if(ContextCompat.checkSelfPermission(this,permission)!= PackageManager.PERMISSION_GRANTED){
            ActivityCompat.requestPermissions(this,REQUESTED_PERMISSIONS,requestCode);
            Toast.makeText(this,"No Permission",Toast.LENGTH_LONG);
            return false;
        }

        return true;
    }
}
'''

Answer 1

You can try "onRemoteVideoStateChanged" callback instead of "onFirstRemoteVideoFrame".

Here is the code snippet:

@Override
    public void onRemoteVideoStateChanged(final int uid, int state, int reason, int elapsed) {
        super.onRemoteVideoStateChanged(uid, state, reason, elapsed);
        if (state == Constants.REMOTE_VIDEO_STATE_STARTING) {
            runOnUiThread(new Runnable() {
                @Override
                public void run() {
                    setupRemoteVideo(uid);
                }
            });
        }
    }