Android Camera2 API-通過套接字將預覽幀傳輸到服務器

Question

我已經通過了android docs和camera2basic存儲庫，並能夠在TextureView上顯示相機預覽幀。 我有兩個按鈕：一個可以錄制視頻，另一個可以捕獲靜態圖像並將其存儲在設備的內存中。 我想要實現的是不同的東西，我想將所有攝像機幀通過套接字實時地順序發送到服務器。 我已將任務分解為較小的塊，目前正在嘗試將所有相機幀捕獲為jpeg圖像。 這是CameraCaptureSession.CaptureCallback代碼，據此，我調用savePreviewShot（），它實際上復制了Camera2basic存儲庫的原始captureStillPicture（）函數：

private CameraCaptureSession.CaptureCallback mCaptureCallback
        = new CameraCaptureSession.CaptureCallback() {

    private void process(CaptureResult result) {
        switch (mState) {
            case STATE_PREVIEW: {
                // We have nothing to do when the camera preview is working normally.
                    savePreviewShot();
                break;
            }
            case STATE_WAITING_LOCK: {
                Integer afState = result.get(CaptureResult.CONTROL_AF_STATE);
                if (afState == null) {
                    captureStillPicture();
                } else if (CaptureResult.CONTROL_AF_STATE_FOCUSED_LOCKED == afState ||
                        CaptureResult.CONTROL_AF_STATE_NOT_FOCUSED_LOCKED == afState) {
                    // CONTROL_AE_STATE can be null on some devices
                    Integer aeState = result.get(CaptureResult.CONTROL_AE_STATE);
                    if (aeState == null ||
                            aeState == CaptureResult.CONTROL_AE_STATE_CONVERGED) {
                        mState = STATE_PICTURE_TAKEN;
                        captureStillPicture();
                    } else {
                        runPrecaptureSequence();
                    }
                }
                break;
            }
            case STATE_WAITING_PRECAPTURE: {
                // CONTROL_AE_STATE can be null on some devices
                Integer aeState = result.get(CaptureResult.CONTROL_AE_STATE);
                if (aeState == null ||
                        aeState == CaptureResult.CONTROL_AE_STATE_PRECAPTURE ||
                        aeState == CaptureRequest.CONTROL_AE_STATE_FLASH_REQUIRED) {
                    mState = STATE_WAITING_NON_PRECAPTURE;
                }
                break;
            }
            case STATE_WAITING_NON_PRECAPTURE: {
                // CONTROL_AE_STATE can be null on some devices
                Integer aeState = result.get(CaptureResult.CONTROL_AE_STATE);
                if (aeState == null || aeState != CaptureResult.CONTROL_AE_STATE_PRECAPTURE) {
                    mState = STATE_PICTURE_TAKEN;
                    captureStillPicture();
                }
                break;
            }
        }
    }

這是savePreviewShot（）函數：

private void savePreviewShot(){
    try {
        final Activity activity = getActivity();
        if (null == activity || null == mCameraDevice) {
            return;
        }
        // This is the CaptureRequest.Builder that we use to take a picture.
        final CaptureRequest.Builder captureBuilder =
                mCameraDevice.createCaptureRequest(CameraDevice.TEMPLATE_PREVIEW);
        captureBuilder.addTarget(mImageReader.getSurface());

        // Orientation
        int rotation = activity.getWindowManager().getDefaultDisplay().getRotation();
        captureBuilder.set(CaptureRequest.JPEG_ORIENTATION, ORIENTATIONS.get(rotation));

        CameraCaptureSession.CaptureCallback CaptureCallback
                = new CameraCaptureSession.CaptureCallback() {

            @Override
            public void onCaptureCompleted(CameraCaptureSession session, CaptureRequest request,
                                           TotalCaptureResult result) {
                SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd_HH:mm:ss:SSS");
                Date resultdate = new Date(System.currentTimeMillis());
                String mFileName = sdf.format(resultdate);
                mFile = new File(getActivity().getExternalFilesDir(null), "pic "+mFileName+" preview.jpg");

                Log.i("Saved file", ""+mFile.toString());
                unlockFocus();
            }
        };

        mCaptureSession.stopRepeating();
        mCaptureSession.capture(captureBuilder.build(), CaptureCallback, null);
    } catch (Exception e) {
        e.printStackTrace();
    }
};

但是，您可能已經知道了，這樣的調用在地圖上顯示預覽時會造成很大的滯后，而且我也沒有保存幀。 希望您有我的目標和面臨的問題。 我已經在SO和Google上進行了很多研究，但是沒有一個對我們有幫助。

Answer 1

有同樣的確切問題，我想知道您是否已解決。 我所做的是設置了一個ImageReader；

private ImageReader videoReader;
private final ImageReader.OnImageAvailableListener onVideoFrameAvailableListener

當我打開相機時加載了它

videoReader = ImageReader.newInstance(videoImageSize.getWidth(), videoImageSize.getHeight(), ImageFormat.JPEG, 2);
videoReader.setOnImageAvailableListener(onVideoFrameAvailableListener, backgroundHandler);

將Surface添加到captureSession並使用frame = reader.acquireLatestImage();在偵聽器中處理圖像 但是，是的，預覽工作滯后很多，並且不知道解決方案可能是什么。