Program Listing for File v4l2_video_capture.hpp

            

            
/*
* SPDX-FileCopyrightText: Copyright (c) 2023-2024 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
* SPDX-License-Identifier: Apache-2.0
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/

#ifndef HOLOSCAN_OPERATORS_V4L2_VIDEO_CAPTURE_HPP
#define HOLOSCAN_OPERATORS_V4L2_VIDEO_CAPTURE_HPP

#include <linux/videodev2.h>
#include <memory>
#include <string>

#include "holoscan/core/operator.hpp"

namespace holoscan::ops {

class V4L2VideoCaptureOp : public Operator {
 public:
  HOLOSCAN_OPERATOR_FORWARD_ARGS(V4L2VideoCaptureOp)

  V4L2VideoCaptureOp() = default;

  void setup(OperatorSpec& spec) override;
  void start() override;
  void initialize() override;
  void compute(InputContext& op_input, OutputContext& op_output,
               ExecutionContext& context) override;
  void stop() override;

 private:
  Parameter<holoscan::IOSpec*> signal_;

  Parameter<std::shared_ptr<Allocator>> allocator_;
  Parameter<std::string> device_;
  Parameter<uint32_t> width_;
  Parameter<uint32_t> height_;
  Parameter<uint32_t> num_buffers_;
  Parameter<std::string> pixel_format_;
  Parameter<uint32_t> exposure_time_;
  Parameter<uint32_t> gain_;

  void v4l2_initialize();
  void v4l2_requestbuffers();
  void v4l2_check_formats();
  void v4l2_set_mode();
  void v4l2_set_formats();
  bool v4l2_camera_supports_control(int cid, const char* control_name);
  void v4l2_set_camera_control(v4l2_control control, const char* control_name, bool warn);
  void v4l2_set_camera_settings();
  void v4l2_start();
  void v4l2_read_buffer(v4l2_buffer& buf);

  void YUYVToRGBA(const void* yuyv, void* rgba, size_t width, size_t height);
  void MJPEGToRGBA(const void* mjpg, void* rgba, size_t width, size_t height);

  struct Buffer {
    void* ptr;
    size_t length;
  };
  Buffer* buffers_ = nullptr;
  int fd_ = -1;

  uint32_t width_use_{0};
  uint32_t height_use_{0};
  uint32_t pixel_format_use_{V4L2_PIX_FMT_RGBA32};
};

}  // namespace holoscan::ops

#endif/* HOLOSCAN_OPERATORS_V4L2_VIDEO_CAPTURE_HPP */