text: /*
   * Register all the grabbing devices.
   *
   * This file is part of FFmpeg.
   *
   * FFmpeg is free software; you can redistribute it and/or
   * modify it under the terms of the GNU Lesser General Public
   * License as published by the Free Software Foundation; either
   * version 2.1 of the License, or (at your option) any later version.
   *
   * FFmpeg is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   * Lesser General Public License for more details.
   *
   * You should have received a copy of the GNU Lesser General Public
   * License along with FFmpeg; if not, write to the Free Software
   * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
   */
  
  #include "config.h"
  #include "libavutil/thread.h"
  #include "avdevice.h"
  
  #define REGISTER_OUTDEV(X, x)                                           \
      {                                                                   \
          extern AVOutputFormat ff_##x##_muxer;                           \
          if (CONFIG_##X##_OUTDEV)                                        \
              av_register_output_format(&ff_##x##_muxer);                 \
      }
  
  #define REGISTER_INDEV(X, x)                                            \
      {                                                                   \
          extern AVInputFormat ff_##x##_demuxer;                          \
          if (CONFIG_##X##_INDEV)                                         \
              av_register_input_format(&ff_##x##_demuxer);                \
      }
  
  #define REGISTER_INOUTDEV(X, x) REGISTER_OUTDEV(X, x); REGISTER_INDEV(X, x)
  
  static void register_all(void)
  {
      /* devices */
      REGISTER_INOUTDEV(ALSA,             alsa);
      REGISTER_INDEV   (AVFOUNDATION,     avfoundation);
      REGISTER_INDEV   (BKTR,             bktr);
      REGISTER_OUTDEV  (CACA,             caca);
      REGISTER_INOUTDEV(DECKLINK,         decklink);
      REGISTER_INOUTDEV(LIBNDI_NEWTEK,    libndi_newtek);
      REGISTER_INDEV   (DSHOW,            dshow);
      REGISTER_INOUTDEV(FBDEV,            fbdev);
      REGISTER_INDEV   (GDIGRAB,          gdigrab);
      REGISTER_INDEV   (IEC61883,         iec61883);
      REGISTER_INDEV   (JACK,             jack);
      REGISTER_INDEV   (KMSGRAB,          kmsgrab);
      REGISTER_INDEV   (LAVFI,            lavfi);
      REGISTER_INDEV   (OPENAL,           openal);
      REGISTER_OUTDEV  (OPENGL,           opengl);
      REGISTER_INOUTDEV(OSS,              oss);
      REGISTER_INOUTDEV(PULSE,            pulse);
      REGISTER_OUTDEV  (SDL2,             sdl2);
      REGISTER_INOUTDEV(SNDIO,            sndio);
      REGISTER_INOUTDEV(V4L2,             v4l2);
      REGISTER_INDEV   (VFWCAP,           vfwcap);
      REGISTER_INDEV   (XCBGRAB,          xcbgrab);
      REGISTER_OUTDEV  (XV,               xv);
  
      /* external libraries */
      REGISTER_INDEV   (LIBCDIO,          libcdio);
      REGISTER_INDEV   (LIBDC1394,        libdc1394);
  }
  
  void avdevice_register_all(void)
  {
      static AVOnce control = AV_ONCE_INIT;
  
      ff_thread_once(&control, register_all);
  }
  