我目前正在学习一个github项目ScreenCapture的代码,它可以捕获屏幕并在surfaceview中显示图像,这是项目https://github.com/Charlesjean/android-ScreenCapture。我尝试使用以下代码替换SurfaceView表面和ImageReader对象的表面:
mImgReader = ImageReader.newInstance(mWidth, mHeight, ImageFormat.JPEG, 5);
mSurface = mImgReader.getSurface();// mSurfaceView.getHolder().getSurface();
mImgReader.setOnImageAvailableListener(new ImageReader.OnImageAvailableListener() {
@Override
public void onImageAvailable(ImageReader reader) {
Log.i(TAG, "in OnImageAvailable");
}
}, mHandler);
并像这样创建VirtualDisplay:
mVirtualDisplay = mMediaProjection.createVirtualDisplay("ScreenCapture",
mWidth, mHeight, mScreenDensity,
DisplayManager.VIRTUAL_DISPLAY_FLAG_OWN_CONTENT_ONLY |
DisplayManager.VIRTUAL_DISPLAY_FLAG_PUBLIC,
mSurface, new VirtualDisplay.Callback() {
@Override
public void onResumed() {
Log.i(TAG, "onResumed");
super.onResumed();
}
@Override
public void onPaused() {
Log.i(TAG, "onPaused");
super.onPaused();
}
}, mHandler);
但永远不会调用onImageAvailable
方法,有没有人对此有任何经验?我无法弄清楚为什么这不起作用。
答案 0 :(得分:5)
感谢Simon,我通过将图像格式更改为PixelFormat.RGBA_8888解决了这个问题,但是当你做我做的事情时还需要注意其他一些要点,我在这里发布以防万一它会帮助未来。
Image.Plane
的数据缓冲区与Bitmap
所需的数据缓冲区不完全相同:1。我们用于创建ImageReader
的图像格式为PixelFormat.RGBA_8888 ,因此Image.Plane的缓冲区首先放置R(ed)通道,然后放置G(reen)通道,依此类推。为了将此缓冲区转换为位图,我们需要像这样创建位图bitmap = Bitmap.createBitmap(metrics,width, height, Bitmap.Config.ARGB_8888);
,并且位图缓冲区需要将Alpha通道放在第一个位置。
2.我们从Image.Plane
获得的缓冲区每行都有一些填充,我个人认为硬件设备使用它来加速缓冲区操作或对齐。因此,为了复制这个缓冲区,我们需要删除这些填充。
要理解这两点,请参阅代码打击:
public void onImageAvailable(ImageReader reader) {
Log.i(TAG, "in OnImageAvailable");
FileOutputStream fos = null;
Bitmap bitmap = null;
Image img = null;
try {
img = reader.acquireLatestImage();
if (img != null) {
Image.Plane[] planes = img.getPlanes();
if (planes[0].getBuffer() == null) {
return;
}
int width = img.getWidth();
int height = img.getHeight();
int pixelStride = planes[0].getPixelStride();
int rowStride = planes[0].getRowStride();
int rowPadding = rowStride - pixelStride * width;
byte[] newData = new byte[width * height * 4];
int offset = 0;
bitmap = Bitmap.createBitmap(metrics,width, height, Bitmap.Config.ARGB_8888);
ByteBuffer buffer = planes[0].getBuffer();
for (int i = 0; i < height; ++i) {
for (int j = 0; j < width; ++j) {
int pixel = 0;
pixel |= (buffer.get(offset) & 0xff) << 16; // R
pixel |= (buffer.get(offset + 1) & 0xff) << 8; // G
pixel |= (buffer.get(offset + 2) & 0xff); // B
pixel |= (buffer.get(offset + 3) & 0xff) << 24; // A
bitmap.setPixel(j, i, pixel);
offset += pixelStride;
}
offset += rowPadding;
}
String name = "/myscreen" + count + ".png";
count++;
File file = new File(Environment.getExternalStorageDirectory(), name);
fos = new FileOutputStream(file);
bitmap.compress(Bitmap.CompressFormat.JPEG, 100, fos);
Log.i(TAG, "image saved in" + Environment.getExternalStorageDirectory() + name);
img.close();
}
} catch (Exception e) {
e.printStackTrace();
} finally {
if (null != fos) {
try {
fos.close();
} catch (IOException e) {
e.printStackTrace();
}
}
if (null != bitmap) {
bitmap.recycle();
}
if (null != img) {
img.close();
}
}
}
答案 1 :(得分:-1)
aiohttp.web.run_app