Android Camera2 API YUV_420_888到JPEG [英] Android Camera2 API YUV_420_888 to JPEG
问题描述
我正在使用 OnImageAvailableListener 获取预览图:< br>
I'm getting preview frames using OnImageAvailableListener:
@Override
public void onImageAvailable(ImageReader reader) {
Image image = null;
try {
image = reader.acquireLatestImage();
Image.Plane[] planes = image.getPlanes();
ByteBuffer buffer = planes[0].getBuffer();
byte[] data = new byte[buffer.capacity()];
buffer.get(data);
//data.length=332803; width=3264; height=2448
Log.e(TAG, "data.length=" + data.length + "; width=" + image.getWidth() + "; height=" + image.getHeight());
//TODO data processing
} catch (Exception e) {
e.printStackTrace();
}
if (image != null) {
image.close();
}
}
每次数据长度不同但图像宽度和高度是一样的。
主要问题: data.length
太小而无法达到3264x2448这样的分辨率。
数据大小数组应该是3264 * 2448 = 7,990,272,而不是300,000 - 600,000。
有什么问题?
Each time length of data is different but image width and height are the same.
Main problem: data.length
is too small for such resolution as 3264x2448.
Size of data array should be 3264*2448=7,990,272, not 300,000 - 600,000.
What is wrong?
imageReader = ImageReader.newInstance(3264, 2448, ImageFormat.JPEG, 5);
推荐答案
我使用 YUV_420_888 图片格式并将其转换为 < a href =https://developer.android.com/reference/android/graphics/ImageFormat.html#JPEG\"rel =noreferrer> JPEG 手动图像格式。
I solved this problem by using YUV_420_888 image format and converting it to JPEG image format manually.
imageReader = ImageReader.newInstance(MAX_PREVIEW_WIDTH, MAX_PREVIEW_HEIGHT,
ImageFormat.YUV_420_888, 5);
imageReader.setOnImageAvailableListener(this, null);
Surface imageSurface = imageReader.getSurface();
List<Surface> surfaceList = new ArrayList<>();
//...add other surfaces
previewRequestBuilder = cameraDevice.createCaptureRequest(CameraDevice.TEMPLATE_PREVIEW);
previewRequestBuilder.addTarget(imageSurface);
surfaceList.add(imageSurface);
cameraDevice.createCaptureSession(surfaceList,
new CameraCaptureSession.StateCallback() {
//...implement onConfigured, onConfigureFailed for StateCallback
}, null);
@Override
public void onImageAvailable(ImageReader reader) {
Image image = reader.acquireLatestImage();
if (image != null) {
//converting to JPEG
byte[] jpegData = ImageUtils.imageToByteArray(image);
//write to file (for example ..some_path/frame.jpg)
FileManager.writeFrame(FILE_NAME, jpegData);
image.close();
}
}
public final class ImageUtil {
public static byte[] imageToByteArray(Image image) {
byte[] data = null;
if (image.getFormat() == ImageFormat.JPEG) {
Image.Plane[] planes = image.getPlanes();
ByteBuffer buffer = planes[0].getBuffer();
data = new byte[buffer.capacity()];
buffer.get(data);
return data;
} else if (image.getFormat() == ImageFormat.YUV_420_888) {
data = NV21toJPEG(
YUV_420_888toNV21(image),
image.getWidth(), image.getHeight());
}
return data;
}
private static byte[] YUV_420_888toNV21(Image image) {
byte[] nv21;
ByteBuffer yBuffer = image.getPlanes()[0].getBuffer();
ByteBuffer uBuffer = image.getPlanes()[1].getBuffer();
ByteBuffer vBuffer = image.getPlanes()[2].getBuffer();
int ySize = yBuffer.remaining();
int uSize = uBuffer.remaining();
int vSize = vBuffer.remaining();
nv21 = new byte[ySize + uSize + vSize];
//U and V are swapped
yBuffer.get(nv21, 0, ySize);
vBuffer.get(nv21, ySize, vSize);
uBuffer.get(nv21, ySize + vSize, uSize);
return nv21;
}
private static byte[] NV21toJPEG(byte[] nv21, int width, int height) {
ByteArrayOutputStream out = new ByteArrayOutputStream();
YuvImage yuv = new YuvImage(nv21, ImageFormat.NV21, width, height, null);
yuv.compressToJpeg(new Rect(0, 0, width, height), 100, out);
return out.toByteArray();
}
}
public final class FileManager {
public static void writeFrame(String fileName, byte[] data) {
try {
BufferedOutputStream bos = new BufferedOutputStream(new FileOutputStream(fileName));
bos.write(data);
bos.flush();
bos.close();
// Log.e(TAG, "" + data.length + " bytes have been written to " + filesDir + fileName + ".jpg");
} catch (IOException e) {
e.printStackTrace();
}
}
}
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