我正在使用 openvidu 开发视频会议应用程序。我们正在尝试在通话中加入 wikiitude AR 会话。问题是他们都需要访问相机，所以我有下一个场景：如果我先实例化本地参与者视频，我无法启动 wikitude AR 会话，因为视频不加载。如果我首先实例化 wikiitude 会话，则呼叫的其他参与者看不到设备视频。我能够为 openvidu 创建一个模仿相机的自定义视频捕捉器。需要发送每一帧才能使其正常工作。
package org.webrtc;
import android.content.Context;
import android.graphics.Bitmap;
import java.util.Timer;
import java.util.TimerTask;
import java.util.concurrent.atomic.AtomicReference;
public class CustomVideoCapturer implements VideoCapturer {
private final static String TAG = "FileVideoCapturer";
//private final FileVideoCapturer.VideoReader videoReader;
private final Timer timer = new Timer();
private CapturerObserver capturerObserver;
private AtomicReference<Bitmap> image = new AtomicReference<Bitmap>();
private final TimerTask tickTask = new TimerTask() {
@Override
public void run() {
tick();
}
};
public CustomVideoCapturer() {
}
public void tick() {
Bitmap frame = image.get();
if (frame != null && !frame.isRecycled()) {
NV21Buffer nv21Buffer = new NV21Buffer(getNV21(frame),frame.getWidth(),frame.getHeight(), null);
VideoFrame videoFrame = new VideoFrame(nv21Buffer, 0, System.nanoTime());
capturerObserver.onFrameCaptured(videoFrame);
}
}
byte [] getNV21(Bitmap image) {
int [] argb = new int[image.getWidth() * image.getHeight()];
image.getPixels(argb, 0, image.getWidth(), 0, 0, image.getWidth(), image.getHeight());
byte [] yuv = new byte[image.getWidth()*image.getHeight()*3/2];
encodeYUV420SP(yuv, argb, image.getWidth(), image.getHeight());
image.recycle();
return yuv;
}
void encodeYUV420SP(byte[] yuv420sp, int[] argb, int width, int height) {
final int frameSize = width * height;
int yIndex = 0;
int uvIndex = frameSize;
int a, R, G, B, Y, U, V;
int index = 0;
for (int j = 0; j < height; j++) {
for (int i = 0; i < width; i++) {
a = (argb[index] & 0xff000000) >> 24; // a is not used obviously
R = (argb[index] & 0xff0000) >> 16;
G = (argb[index] & 0xff00) >> 8;
B = (argb[index] & 0xff) >> 0;
// well known RGB to YUV algorithm
Y = ( ( 66 * R + 129 * G + 25 * B + 128) >> 8) + 16;
U = ( ( -38 * R - 74 * G + 112 * B + 128) >> 8) + 128;
V = ( ( 112 * R - 94 * G - 18 * B + 128) >> 8) + 128;
// NV21 has a plane of Y and interleaved planes of VU each sampled by a factor of 2
// meaning for every 4 Y pixels there are 1 V and 1 U. Note the sampling is every other
// pixel AND every other scanline.
yuv420sp[yIndex++] = (byte) ((Y < 0) ? 0 : ((Y > 255) ? 255 : Y));
if (j % 2 == 0 && index % 2 == 0) {
yuv420sp[uvIndex++] = (byte)((V<0) ? 0 : ((V > 255) ? 255 : V));
yuv420sp[uvIndex++] = (byte)((U<0) ? 0 : ((U > 255) ? 255 : U));
}
index ++;
}
}
}
public void sendFrame(Bitmap bitmap) {
image.set(bitmap);
}
@Override
public void initialize(SurfaceTextureHelper surfaceTextureHelper, Context applicationContext,
CapturerObserver capturerObserver) {
this.capturerObserver = capturerObserver;
}
@Override
public void startCapture(int width, int height, int framerate) {
//timer.schedule(tickTask, 0, 1000 / framerate);
threadCV().start();
}
Thread threadCV() {
return new Thread() {
@Override
public void run() {
while (true) {
if (image.get() != null) {
tick();
}
try {
Thread.sleep(10);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
};
}
@Override
public void stopCapture() throws InterruptedException {
timer.cancel();
}
@Override
public void changeCaptureFormat(int width, int height, int framerate) {
// Empty on purpose
}
@Override
public void dispose() {
//videoReader.close();
}
@Override
public boolean isScreencast() {
return false;
}
private interface VideoReader {
VideoFrame getNextFrame();
void close();
}
/**
* Read video data from file for the .y4m container.
*/
}
在本地参与者上，我使用此功能发送帧：
public void sendFrame(Bitmap frame) {
customVideoCapturer.sendFrame(frame);
}
但我无法从维基相机中取出帧。有办法访问帧并重新发送它们吗？