我正在使用Android应用程序，该应用程序通过camera2 api拍摄照片。我面临的问题是在拍摄照片和照片之间的巨大延迟。按钮和实际的图像捕捉 - 约1800-2000毫秒左右，我个人认为是不可接受的。
如果有人能指出改进方法，我真的很感激。为了它的价值，我稍后将JPEG输出图像处理成位图，如果这有所不同。
＆＃34;拍照＆＃34;课程如下所示。
protected void takePicture() {
if (null == cameraDevice) {
Log.e(TAG, "cameraDevice is null");
return;
}
debugTime(1,"");
try {
Log.e(TAG, "Taking a picture");
int width, height;
Size trySize = defineSize();
width = trySize.getWidth();
height = trySize.getHeight();
debugTime(3,"Defining sizes took ");
ImageReader reader = ImageReader.newInstance(width, height, ImageFormat.JPEG, 1);
List<Surface> outputSurfaces = new ArrayList<>(2);
outputSurfaces.add(reader.getSurface());
outputSurfaces.add(new Surface(textureView.getSurfaceTexture()));
debugTime(3,"Defining output surfaces took ");
final CaptureRequest.Builder captureBuilder = cameraDevice.createCaptureRequest(CameraDevice.TEMPLATE_STILL_CAPTURE);
captureBuilder.addTarget(reader.getSurface());
captureBuilder.set(CaptureRequest.CONTROL_MODE, CameraMetadata.CONTROL_MODE_AUTO);
debugTime(3,"Creating capture request took ");
// Orientation
int rotation = getWindowManager().getDefaultDisplay().getRotation();
captureBuilder.set(CaptureRequest.JPEG_ORIENTATION, ORIENTATIONS.get(rotation));
debugTime(3,"Defining rotation took ");
final File file = new File(Environment.getExternalStorageDirectory() + "/pic.jpg");
debugTime(3,"Creating new file took ");
ImageReader.OnImageAvailableListener readerListener = new ImageReader.OnImageAvailableListener() {
@Override
public void onImageAvailable(ImageReader reader) {
Log.e(TAG, "Running method onImageAvailable");
Image image = null;
try {
debugTime(3,"Image becoming available took ");
image = reader.acquireLatestImage();
debugTime(2,"");
ByteBuffer buffer = image.getPlanes()[0].getBuffer();
bytes = new byte[buffer.capacity()];
buffer.get(bytes); //My final output
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} finally {
if (image != null) {
image.close();
}
}
}
};
reader.setOnImageAvailableListener(readerListener, mBackgroundHandler);
final CameraCaptureSession.CaptureCallback captureListener = new CameraCaptureSession.CaptureCallback() {
@Override
public void onCaptureCompleted(CameraCaptureSession session, CaptureRequest request, TotalCaptureResult result) {
super.onCaptureCompleted(session, request, result);
Log.e(TAG, "Invoking running method sendToScan");
sendToScan();
}
};
cameraDevice.createCaptureSession(outputSurfaces, new CameraCaptureSession.StateCallback() {
@Override
public void onConfigured(CameraCaptureSession session) {
Log.e(TAG, "Running method onConfigured");
try {
session.capture(captureBuilder.build(), captureListener, mBackgroundHandler);
} catch (CameraAccessException e) {
e.printStackTrace();
}
debugTime(3,"Configuring capture session took ");
}
@Override
public void onConfigureFailed(CameraCaptureSession session) {
}
}, mBackgroundHandler);
//stopBackgroundThread();
} catch (CameraAccessException e) {
e.printStackTrace();
}
}
这是日志
E/CameraActivity: Taking a picture
E/CameraActivity: Defining Size
E/CameraActivity: CHOOSING at size 720x1280
E/DEBUG_TIME: Defining sizes took 25 ms
E/DEBUG_TIME: Defining output surfaces took 20 ms
E/DEBUG_TIME: Creating capture request took 4 ms
E/DEBUG_TIME: Defining rotation took 1 ms
E/DEBUG_TIME: Creating new file took 5 ms
I/RequestQueue: Repeating capture request cancelled.
I/CameraDeviceState: Legacy camera service transitioning to state IDLE
I/CameraDeviceState: Legacy camera service transitioning to state CONFIGURING
I/RequestThread-0: Configure outputs: 2 surfaces configured.
D/Camera: app passed NULL surface
I/RequestThread-0: configureOutputs - set take picture size to 1280x720
I/CameraDeviceState: Legacy camera service transitioning to state IDLE
E/CameraActivity: Running method onConfigured
I/Choreographer: Skipped 38 frames! The application may be doing too much work on its main thread.
W/art: Long monitor contention event with owner method=void java.lang.Object.wait!() from Object.java:4294967294 waiters=0 for 563ms
W/LegacyRequestMapper: convertRequestMetadata - control.awbRegions setting is not supported, ignoring value
W/LegacyRequestMapper: Only received metering rectangles with weight 0.
E/DEBUG_TIME: Configuring capture session took 586 ms
E/BufferQueueProducer: [SurfaceTexture-0-17825-3] dequeueBuffer: min undequeued buffer count (2) exceeded (dequeued=13 undequeued=0)
E/BufferQueueProducer: [SurfaceTexture-0-17825-3] dequeueBuffer: min undequeued buffer count (2) exceeded (dequeued=12 undequeued=1)
I/CameraDeviceState: Legacy camera service transitioning to state CAPTURING
I/RequestThread-0: Received jpeg.
I/RequestThread-0: Producing jpeg buffer...
E/CameraActivity: Running method onImageAvailable
E/DEBUG_TIME: Image becoming available took 1110 ms
D/ImageReader_JNI: ImageReader_lockedImageSetup: Receiving JPEG in HAL_PIXEL_FORMAT_RGBA_8888 buffer.
W/ImageReader_JNI: Unable to acquire a lockedBuffer, very likely client tries to lock more than maxImages buffers
E/DEBUG_TIME: Taking picture took 1752 ms in TOTAL
根据它，配置捕获会话（！）需要大约500-600ms，但更糟糕的是，图像在imageReader中可用大约需要1100-1200ms！ / p>
显然有些不对劲，我无法弄明白。我很乐意提供任何帮助。
P.S。为了记录，我试图将结果保存为YUV_420_888格式，但这只能加速到我总共1000左右。