/*
  * V4L2 buffer helper functions.
  *
  * Copyright (C) 2017 Alexis Ballier <aballier@gentoo.org>
  * Copyright (C) 2017 Jorge Ramirez <jorge.ramirez-ortiz@linaro.org>
  *
  * 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
  */
 
 #ifndef AVCODEC_V4L2_BUFFERS_H
 #define AVCODEC_V4L2_BUFFERS_H
 

 #include <linux/videodev2.h>
 

 #include "avcodec.h"
 

 enum V4L2Buffer_status {
     V4L2BUF_AVAILABLE,
     V4L2BUF_IN_DRIVER,
     V4L2BUF_RET_USER,
 };
 
 /**
  * V4L2Buffer (wrapper for v4l2_buffer management)
  */
 typedef struct V4L2Buffer {
     /* each buffer needs to have a reference to its context */
     struct V4L2Context *context;
 
     /* keep track of the mmap address and mmap length */
     struct V4L2Plane_info {
         int bytesperline;
         void * mm_addr;
         size_t length;
     } plane_info[VIDEO_MAX_PLANES];
 
     int num_planes;
 
     /* the v4l2_buffer buf.m.planes pointer uses the planes[] mem */
     struct v4l2_buffer buf;
     struct v4l2_plane planes[VIDEO_MAX_PLANES];
 
     int flags;
     enum V4L2Buffer_status status;
 
 } V4L2Buffer;
 
 /**
  * Extracts the data from a V4L2Buffer to an AVFrame
  *
  * @param[in] frame The AVFRame to push the information to
  * @param[in] buf The V4L2Buffer to get the information from
  *

  * @returns 0 in case of success, AVERROR(EINVAL) if the number of planes is incorrect,
  * AVERROR(ENOMEM) if the AVBufferRef cant be created.

  */
 int ff_v4l2_buffer_buf_to_avframe(AVFrame *frame, V4L2Buffer *buf);
 
 /**
  * Extracts the data from a V4L2Buffer to an AVPacket
  *
  * @param[in] pkt The AVPacket to push the information to
  * @param[in] buf The V4L2Buffer to get the information from
  *

  * @returns 0 in case of success, AVERROR(EINVAL) if the number of planes is incorrect,
  * AVERROR(ENOMEM) if the AVBufferRef cant be created.

  *
  */
 int ff_v4l2_buffer_buf_to_avpkt(AVPacket *pkt, V4L2Buffer *buf);
 
 /**
  * Extracts the data from an AVPacket to a V4L2Buffer
  *
  * @param[in]  frame AVPacket to get the data from
  * @param[in]  avbuf V4L2Bfuffer to push the information to
  *

  * @returns 0 in case of success, a negative AVERROR code otherwise

  */
 int ff_v4l2_buffer_avpkt_to_buf(const AVPacket *pkt, V4L2Buffer *out);
 
 /**
  * Extracts the data from an AVFrame to a V4L2Buffer
  *
  * @param[in]  frame AVFrame to get the data from
  * @param[in]  avbuf V4L2Bfuffer to push the information to
  *

  * @returns 0 in case of success, a negative AVERROR code otherwise

  */
 int ff_v4l2_buffer_avframe_to_buf(const AVFrame *frame, V4L2Buffer* out);
 
 /**
  * Initializes a V4L2Buffer
  *
  * @param[in]  avbuf V4L2Bfuffer to initialize
  * @param[in]  index v4l2 buffer id
  *

  * @returns 0 in case of success, a negative AVERROR code otherwise

  */
 int ff_v4l2_buffer_initialize(V4L2Buffer* avbuf, int index);
 
 /**
  * Enqueues a V4L2Buffer
  *
  * @param[in] avbuf V4L2Bfuffer to push to the driver
  *

  * @returns 0 in case of success, a negative AVERROR code otherwise

  */
 int ff_v4l2_buffer_enqueue(V4L2Buffer* avbuf);
 
 
 #endif // AVCODEC_V4L2_BUFFERS_H