/*
  * V4L2 mem2mem 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_M2M_H
 #define AVCODEC_V4L2_M2M_H
 
 #include <semaphore.h>
 #include <unistd.h>
 #include <dirent.h>

 #include <linux/videodev2.h>
 

 #include "libavcodec/avcodec.h"
 #include "v4l2_context.h"
 
 #define container_of(ptr, type, member) ({ \
         const __typeof__(((type *)0)->member ) *__mptr = (ptr); \
         (type *)((char *)__mptr - offsetof(type,member) );})
 
 #define V4L_M2M_DEFAULT_OPTS \
     { "num_output_buffers", "Number of buffers in the output context",\
         OFFSET(output.num_buffers), AV_OPT_TYPE_INT, { .i64 = 16 }, 6, INT_MAX, FLAGS }
 
 typedef struct V4L2m2mContext
 {
     AVClass *class;
     char devname[PATH_MAX];
     int fd;
 
     /* the codec context queues */
     V4L2Context capture;
     V4L2Context output;
 
     /* refcount of buffers held by the user */
     atomic_uint refcount;
 
     /* dynamic stream reconfig */
     AVCodecContext *avctx;
     sem_t refsync;
     int reinit;
 
     /* null frame/packet received */
     int draining;
 } V4L2m2mContext;
 
 /**
  * Probes the video nodes looking for the required codec capabilities.
  *
  * @param[in] ctx The AVCodecContext instantiated by the encoder/decoder.
  *
  * @returns 0 if a driver is found, a negative number otherwise.
  */
 int ff_v4l2_m2m_codec_init(AVCodecContext *avctx);
 
 /**
  * Releases all the codec resources if all AVBufferRefs have been returned to the
  * ctx. Otherwise keep the driver open.
  *
  * @param[in] The AVCodecContext instantiated by the encoder/decoder.
  *
  * @returns 0
  *
  */
 int ff_v4l2_m2m_codec_end(AVCodecContext *avctx);
 
 /**

  * Reinitializes the V4L2m2mContext when the driver cannot continue processing

  * with the capture parameters.
  *
  * @param[in] ctx The V4L2m2mContext instantiated by the encoder/decoder.
  *
  * @returns 0 in case of success, negative number otherwise
  */
 int ff_v4l2_m2m_codec_reinit(V4L2m2mContext *ctx);
 
 /**

  * Reinitializes the V4L2m2mContext when the driver cannot continue processing

  * with the  any of the current V4L2Contexts (ie, changes in output and capture).
  *
  * @param[in] ctx The V4L2m2mContext instantiated by the encoder/decoder.
  *
  * @returns 0 in case of success, negative number otherwise
  */
 int ff_v4l2_m2m_codec_full_reinit(V4L2m2mContext *ctx);
 
 #endif /* AVCODEC_V4L2_M2M_H */