/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

#ifndef GUACENC_FFMPEG_COMPAT_H
#define GUACENC_FFMPEG_COMPAT_H

#include "config.h"
#include "video.h"

#include <libavcodec/avcodec.h>

/*
 * For a full list of FFmpeg API changes over the years, see:
 *
 *     https://github.com/FFmpeg/FFmpeg/blob/master/doc/APIchanges
 */

/* For libavcodec < 55.28.1: av_frame_*() was avcodec_*_frame(). */
#if LIBAVCODEC_VERSION_INT < AV_VERSION_INT(55,28,1)
#define av_frame_alloc avcodec_alloc_frame
#define av_frame_free avcodec_free_frame
#endif

/* For libavcodec < 54.28.0: old avcodec_free_frame() did not exist. */
#if LIBAVCODEC_VERSION_INT < AV_VERSION_INT(54,28,0)
#define avcodec_free_frame av_freep
#endif

/* For libavcodec < 55.52.0: avcodec_free_context did not exist */
#if LIBAVCODEC_VERSION_INT < AV_VERSION_INT(55,52,0)
#define avcodec_free_context av_freep
#endif

/* For libavcodec < 57.7.0: av_packet_unref() was av_free_packet() */
#if LIBAVCODEC_VERSION_INT < AV_VERSION_INT(57,7,0)
#define av_packet_unref av_free_packet
#endif

/* For libavcodec <= 56.41.100: Global header flag didn't have AV_ prefix.
 * Guacenc defines its own flag here to avoid conflicts with libavcodec
 * macros.
 */
#if LIBAVCODEC_VERSION_INT <= AV_VERSION_INT(56,41,100)
#define GUACENC_FLAG_GLOBAL_HEADER CODEC_FLAG_GLOBAL_HEADER
#else
#define GUACENC_FLAG_GLOBAL_HEADER AV_CODEC_FLAG_GLOBAL_HEADER
#endif

/* For libavutil < 51.42.0: AV_PIX_FMT_* was PIX_FMT_* */
#if LIBAVUTIL_VERSION_INT < AV_VERSION_INT(51,42,0)
#define AV_PIX_FMT_RGB32 PIX_FMT_RGB32
#define AV_PIX_FMT_YUV420P PIX_FMT_YUV420P
#endif

/**
 * Writes the specied frame as a new frame of video. If pending frames of the
 * video are being flushed, the given frame may be NULL (as required by
 * avcodec_encode_video2()). If avcodec_encode_video2() does not exist, this
 * function will transparently use avcodec_encode_video().
 *
 * @param video
 *     The video to write the given frame to.
 *
 * @param frame
 *     The frame to write to the video, or NULL if previously-written frames
 *     are being flushed.
 *
 * @return
 *     A positive value if the frame was successfully written, zero if the
 *     frame has been saved for later writing / reordering, negative if an
 *     error occurs.
 */
int guacenc_avcodec_encode_video(guacenc_video* video, AVFrame* frame);

/**
 * Creates and sets up the AVCodecContext for the appropriate version of
 * libavformat installed. The AVCodecContext will be built, but the AVStream
 * will also be affected by having its time_base field set to the value passed
 * into this function.
 *
 * @param stream
 *     The open AVStream.
 *
 * @param codec
 *     The codec used on the AVStream.
 *
 * @param bitrate
 *     The target bitrate for the encoded video
 *
 * @param width
 *     The target width for the encoded video.
 *
 * @param height
 *     The target height for the encoded video.
 *
 * @param gop_size
 *     The size of the Group of Pictures.
 *
 * @param qmax
 *     The max value of the quantizer.
 *
 * @param qmin
 *     The min value of the quantizer.
 *
 * @param pix_fmt
 *     The target pixel format for the encoded video.
 *
 * @param time_base
 *     The target time base for the encoded video.
 *
 * @return
 *     The pointer to the configured AVCodecContext.
 *
 */
AVCodecContext* guacenc_build_avcodeccontext(AVStream* stream, AVCodec* codec,
        int bitrate, int width, int height, int gop_size, int qmax, int qmin,
        int pix_fmt, AVRational time_base);

/**
 * A wrapper for avcodec_open2(). Because libavformat ver 57.33.100 and greater
 * use stream->codecpar rather than stream->codec to handle information to the
 * codec, there needs to be an additional step in that version.  So this
 * wrapper handles that. Otherwise, it's the same as avcodec_open2().
 *
 * @param avcodec_context
 *     The context to initialize.
 *
 * @param codec
 *     The codec to open this context for. If a non-NULL codec has been
 *     previously passed to avcodec_alloc_context3() or for this context, then
 *     this parameter MUST be either NULL or equal to the previously passed
 *     codec.
 *
 * @param options
 *     A dictionary filled with AVCodecContext and codec-private options. On
 *     return this object will be filled with options that were not found.
 *
 * @param stream
 *     The stream for the codec context.
 *
 * @return
 *     Zero on success, a negative value on error.
 */
int guacenc_open_avcodec(AVCodecContext *avcodec_context,
        AVCodec *codec, AVDictionary **options,
        AVStream* stream);

#endif