android camera预览数据,使用Android L和Camera2 API的相机预览图像数据处理

将一些答案组合成更易于理解的答案，因为@VP的答案虽然技术上很明确，但如果您是第一次从Camera转到Camera2，则很难理解：

在createCameraPreviewSession()从mImageReader初始化一个新的Surface

Surface mImageSurface = mImageReader.getSurface();

将新表面添加为CaptureRequest.Builder变量的输出目标。使用Camera2Basic示例，该变量将为mPreviewRequestBuilder

mPreviewRequestBuilder.addTarget(mImageSurface);

这是带有新行的代码段(请参阅我的@AngeloS评论)：

private void createCameraPreviewSession() {

try {

SurfaceTexture texture = mTextureView.getSurfaceTexture();

assert texture != null;

// We configure the size of default buffer to be the size of camera preview we want.

texture.setDefaultBufferSize(mPreviewSize.getWidth(), mPreviewSize.getHeight());

// This is the output Surface we need to start preview.

Surface surface = new Surface(texture);

//@AngeloS - Our new output surface for preview frame data

Surface mImageSurface = mImageReader.getSurface();

// We set up a CaptureRequest.Builder with the output Surface.

mPreviewRequestBuilder = mCameraDevice.createCaptureRequest(CameraDevice.TEMPLATE_PREVIEW);

//@AngeloS - Add the new target to our CaptureRequest.Builder

mPreviewRequestBuilder.addTarget(mImageSurface);

mPreviewRequestBuilder.addTarget(surface);

...

接下来，在setUpCameraOutputs() ，在初始化ImageReader时将格式从ImageFormat.JPEG更改为ImageFormat.YUV_420_888 。 (PS，我也建议您减小预览尺寸以实现更流畅的操作-Camera2的一项不错功能)

mImageReader = ImageReader.newInstance(largest.getWidth() / 16, largest.getHeight() / 16, ImageFormat.YUV_420_888, 2);

最后，在ImageReader.OnImageAvailableListener onImageAvailable()方法中，确保使用onImageAvailable()的建议，因为如果不关闭预览，预览将在几帧后停止

@Override

public void onImageAvailable(ImageReader reader) {

Log.d(TAG, "I'm an image frame!");

Image image = reader.acquireNextImage();

...

if (image != null)

image.close();

}