如何使用camera2和mediacodec api录制和保存视频？

<uses-permission android:name="android.permission.CAMERA" />

CameraManager cameraManager = (CameraManager) getSystemService(Context.CAMERA_SERVICE);
String[] cameraIds = cameraManager.getCameraIdList();

String cameraId = cameraIds[0]; // 选择第一个相机设备
cameraManager.openCamera(cameraId, cameraStateCallback, null);

CameraDevice.StateCallback cameraStateCallback = new CameraDevice.StateCallback() {
    @Override
    public void onOpened(@NonNull CameraDevice camera) {
        // 相机已打开，可以进行下一步操作
        cameraDevice = camera;
        createCaptureSession();
    }

    @Override
    public void onDisconnected(@NonNull CameraDevice camera) {
        // 相机断开连接
        camera.close();
        cameraDevice = null;
    }

    @Override
    public void onError(@NonNull CameraDevice camera, int error) {
        // 相机打开错误
        camera.close();
        cameraDevice = null;
    }
};

private void createCaptureSession() {
    List<Surface> surfaces = new ArrayList<>();
    surfaces.add(previewSurface); // 预览的Surface
    surfaces.add(encoderSurface); // 编码的Surface

    cameraDevice.createCaptureSession(surfaces, captureSessionStateCallback, null);
}

CameraCaptureSession.StateCallback captureSessionStateCallback = new CameraCaptureSession.StateCallback() {
    @Override
    public void onConfigured(@NonNull CameraCaptureSession session) {
        // 会话已创建，可以进行预览
        cameraCaptureSession = session;
        createPreviewRequest();
    }

    @Override
    public void onConfigureFailed(@NonNull CameraCaptureSession session) {
        // 会话创建失败
    }
};

private void createPreviewRequest() {
    try {
        CaptureRequest.Builder builder = cameraDevice.createCaptureRequest(CameraDevice.TEMPLATE_PREVIEW);
        builder.addTarget(previewSurface);

        cameraCaptureSession.setRepeatingRequest(builder.build(), null, null);
    } catch (CameraAccessException e) {
        e.printStackTrace();
    }
}

MediaCodec encoder = MediaCodec.createEncoderByType(MediaFormat.MIMETYPE_VIDEO_AVC);
MediaFormat format = MediaFormat.createVideoFormat(MediaFormat.MIMETYPE_VIDEO_AVC, width, height);
format.setInteger(MediaFormat.KEY_BIT_RATE, bitRate);
format.setInteger(MediaFormat.KEY_FRAME_RATE, frameRate);
format.setInteger(MediaFormat.KEY_COLOR_FORMAT, MediaCodecInfo.CodecCapabilities.COLOR_FormatSurface);
format.setInteger(MediaFormat.KEY_I_FRAME_INTERVAL, iFrameInterval);
encoder.configure(format, null, null, MediaCodec.CONFIGURE_FLAG_ENCODE);

Surface encoderSurface = encoder.createInputSurface();
builder.addTarget(encoderSurface);

encoder.start();

cameraCaptureSession.setRepeatingRequest(builder.build(), new CameraCaptureSession.CaptureCallback() {
    @Override
    public void onCaptureCompleted(@NonNull CameraCaptureSession session, @NonNull CaptureRequest request, @NonNull TotalCaptureResult result) {
        // 获取预览数据
        Image image = result.get(CaptureResult.STATISTICS_PREVIEW_DATA);
        ByteBuffer buffer = image.getPlanes()[0].getBuffer();

        // 将数据传递给编码器
        int inputBufferIndex = encoder.dequeueInputBuffer(-1);
        if (inputBufferIndex >= 0) {
            ByteBuffer inputBuffer = encoder.getInputBuffer(inputBufferIndex);
            inputBuffer.clear();
            inputBuffer.put(buffer);
            encoder.queueInputBuffer(inputBufferIndex, 0, buffer.limit(), 0, 0);
        }

        image.close();
    }
}, null);

MediaCodec.BufferInfo bufferInfo = new MediaCodec.BufferInfo();
int outputBufferIndex = encoder.dequeueOutputBuffer(bufferInfo, 0);
while (outputBufferIndex >= 0) {
    ByteBuffer outputBuffer = encoder.getOutputBuffer(outputBufferIndex);
    // 将编码后的数据保存到文件
    saveToFile(outputBuffer, bufferInfo);

    encoder.releaseOutputBuffer(outputBufferIndex, false);
    outputBufferIndex = encoder.dequeueOutputBuffer(bufferInfo, 0);
}

encoder.stop();
encoder.release();
cameraCaptureSession.close();
cameraDevice.close();