Method genFrame

tgcalls/FakeVideoTrackSource.cpp:46–86

  std::vector<Frame> frames_;
  size_t i = 0;
  Frame genFrame(int i, int n) {
    int width = WIDTH;
    int height = HEIGHT;
    auto bytes_ptr = std::make_unique<std::uint8_t[]>(width * height * 4);
    auto bytes = bytes_ptr.get();
    auto set_rgb = [&](int x, int y, std::uint8_t r, std::uint8_t g, std::uint8_t b) {
      auto dest = bytes + (x * width + y) * 4;
      dest[0] = r;
      dest[1] = g;
      dest[2] = b;
      dest[3] = 0;
    };
    auto angle = (double)i / n * M_PI;
    auto co = cos(angle);
    auto si = sin(angle);

    for (int i = 0; i < height; i++) {
      for (int j = 0; j < width; j++) {
        double sx = (i - height / 2) * 20.0 / HEIGHT;
        double sy = (j  - width / 2) * 20.0 / HEIGHT;

        int x, y;
        if (sx * sx + sy * sy < 10) {
          x = int(floor(sx * co - sy * si));
          y = int(floor(sx * si + sy * co));
        } else {
          x = int(floor(sx));
          y = int(floor(sy));
        }
        std::uint8_t color = ((y & 1) ^ (x & 1)) * 255;
        set_rgb(i, j, color, color, color);
      }
    }

    webrtc::scoped_refptr<webrtc::I420Buffer> buffer = webrtc::I420Buffer::Create(width, height);

    libyuv::RGBAToI420(bytes, width * 4, buffer->MutableDataY(), buffer->StrideY(), buffer->MutableDataU(),
                       buffer->StrideU(), buffer->MutableDataV(), buffer->StrideV(), width, height);

    return Frame{webrtc::VideoFrame::Builder().set_video_frame_buffer(buffer).build(), std::move(bytes_ptr)};
  }

};