/*
* 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(num_output_buffers), AV_OPT_TYPE_INT, { .i64 = 16 }, 6, INT_MAX, FLAGS }
typedef struct V4L2m2mContext {
char devname[PATH_MAX];
int fd;
/* the codec context queues */
V4L2Context capture;
V4L2Context output;
/* dynamic stream reconfig */
AVCodecContext *avctx;
sem_t refsync;
atomic_uint refcount;
int reinit;
/* null frame/packet received */
int draining;
AVPacket buf_pkt;
/* Reference to self; only valid while codec is active. */
AVBufferRef *self_ref;
/* reference back to V4L2m2mPriv */
void *priv;
} V4L2m2mContext;
typedef struct V4L2m2mPriv {
AVClass *class;
V4L2m2mContext *context;
AVBufferRef *context_ref;
int num_output_buffers;
int num_capture_buffers;
} V4L2m2mPriv;
/**
* Allocate a new context and references for a V4L2 M2M instance.
*
* @param[in] ctx The V4L2m2mPriv instantiated by the encoder/decoder.
* @param[out] ctx The V4L2m2mContext.
*
* @returns 0 in success, a negative error code otherwise.
*/
int ff_v4l2_m2m_create_context(V4L2m2mPriv *priv, V4L2m2mContext **s);
/**
* Probes the video nodes looking for the required codec capabilities.
*
* @param[in] ctx The V4L2m2mPriv instantiated by the encoder/decoder.
*
* @returns 0 if a driver is found, a negative number otherwise.
*/
int ff_v4l2_m2m_codec_init(V4L2m2mPriv *priv);
/**
* Releases all the codec resources if all AVBufferRefs have been returned to the
* ctx. Otherwise keep the driver open.
*
* @param[in] The V4L2m2mPriv instantiated by the encoder/decoder.
*
* @returns 0
*
*/
int ff_v4l2_m2m_codec_end(V4L2m2mPriv *priv);
/**
* 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 */