/*

 * ZeroCodec Decoder

 *

 * Copyright (c) 2012, Derek Buitenhuis

 *

 * Permission to use, copy, modify, and/or distribute this software for any

 * purpose with or without fee is hereby granted, provided that the above

 * copyright notice and this permission notice appear in all copies.

 *

 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES

 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF

 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR

 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES

 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN

 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF

 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.

 */

#include <zlib.h>

#include "avcodec.h"

#include "codec_internal.h"

#include "decode.h"

#include "zlib_wrapper.h"

#include "libavutil/attributes.h"

#include "libavutil/common.h"

typedef struct ZeroCodecContext {

    AVFrame  *previous_frame;

    FFZStream zstream;

} ZeroCodecContext;

static int zerocodec_decode_frame(AVCodecContext *avctx, AVFrame *pic,

                                  int *got_frame, AVPacket *avpkt)

{

    ZeroCodecContext *zc = avctx->priv_data;

    AVFrame *prev_pic    = zc->previous_frame;

    z_stream *const zstream = &zc->zstream.zstream;

    uint8_t *prev        = prev_pic->data[0];

    uint8_t *dst;

    int i, j, zret, ret;

    if (avpkt->flags & AV_PKT_FLAG_KEY) {

        pic->flags |= AV_FRAME_FLAG_KEY;

        pic->pict_type = AV_PICTURE_TYPE_I;

    } else {

        if (!prev) {

            av_log(avctx, AV_LOG_ERROR, "Missing reference frame.\n");

            return AVERROR_INVALIDDATA;

        }

        prev += (avctx->height - 1) * prev_pic->linesize[0];

        pic->flags &= ~AV_FRAME_FLAG_KEY;

        pic->pict_type = AV_PICTURE_TYPE_P;

    }

    zret = inflateReset(zstream);

    if (zret != Z_OK) {

        av_log(avctx, AV_LOG_ERROR, "Could not reset inflate: %d.\n", zret);

        return AVERROR_INVALIDDATA;

    }

    if ((ret = ff_get_buffer(avctx, pic, AV_GET_BUFFER_FLAG_REF)) < 0)

        return ret;

    zstream->next_in  = avpkt->data;

    zstream->avail_in = avpkt->size;

    dst = pic->data[0] + (avctx->height - 1) * pic->linesize[0];

    /**

     * ZeroCodec has very simple interframe compression. If a value

     * is the same as the previous frame, set it to 0.

     */

    for (i = 0; i < avctx->height; i++) {

        zstream->next_out  = dst;

        zstream->avail_out = avctx->width << 1;

        zret = inflate(zstream, Z_SYNC_FLUSH);

        if (zret != Z_OK && zret != Z_STREAM_END) {

            av_log(avctx, AV_LOG_ERROR,

                   "Inflate failed with return code: %d.\n", zret);

            return AVERROR_INVALIDDATA;

        }

        if (!(avpkt->flags & AV_PKT_FLAG_KEY)) {

            for (j = 0; j < avctx->width << 1; j++)

                dst[j] += prev[j] & -!dst[j];

            prev -= prev_pic->linesize[0];

        }

        dst  -= pic->linesize[0];

    }

    if ((ret = av_frame_replace(zc->previous_frame, pic)) < 0)

        return ret;

    *got_frame = 1;

    return avpkt->size;

}

static av_cold int zerocodec_decode_close(AVCodecContext *avctx)

{

    ZeroCodecContext *zc = avctx->priv_data;

    av_frame_free(&zc->previous_frame);

    ff_inflate_end(&zc->zstream);

    return 0;

}

static av_cold int zerocodec_decode_init(AVCodecContext *avctx)

{

    ZeroCodecContext *zc = avctx->priv_data;

    avctx->pix_fmt             = AV_PIX_FMT_UYVY422;

    avctx->bits_per_raw_sample = 8;

    zc->previous_frame = av_frame_alloc();

    if (!zc->previous_frame)

        return AVERROR(ENOMEM);

    return ff_inflate_init(&zc->zstream, avctx);

}

static av_cold void zerocodec_decode_flush(AVCodecContext *avctx)

{

    ZeroCodecContext *zc = avctx->priv_data;

    av_frame_unref(zc->previous_frame);

}

const FFCodec ff_zerocodec_decoder = {

    .p.type         = AVMEDIA_TYPE_VIDEO,

    .p.name         = "zerocodec",

    CODEC_LONG_NAME("ZeroCodec Lossless Video"),

    .p.id           = AV_CODEC_ID_ZEROCODEC,

    .priv_data_size = sizeof(ZeroCodecContext),

    .init           = zerocodec_decode_init,

    FF_CODEC_DECODE_CB(zerocodec_decode_frame),

    .flush          = zerocodec_decode_flush,

    .close          = zerocodec_decode_close,

    .p.capabilities = AV_CODEC_CAP_DR1,

    .caps_internal  = FF_CODEC_CAP_INIT_CLEANUP,

};