/*

 * Copyright (C) 2003 The FFmpeg project

 *

 * 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

 */

/**

 * @file

 * id RoQ Video Decoder by Dr. Tim Ferguson

 * For more information about the id RoQ format, visit:

 *   http://www.csse.monash.edu.au/~timf/

 */

#include "libavutil/avassert.h"

#include "avcodec.h"

#include "bytestream.h"

#include "codec_internal.h"

#include "decode.h"

#include "roqvideo.h"

static void roqvideo_decode_frame(RoqContext *ri, GetByteContext *gb)

{

    unsigned int chunk_id = 0, chunk_arg = 0;

    unsigned long chunk_size = 0;

    int i, j, k, nv1, nv2, vqflg = 0, vqflg_pos = -1;

    int vqid, xpos, ypos, xp, yp, x, y, mx, my;

    roq_qcell *qcell;

    int64_t chunk_start;

    while (bytestream2_get_bytes_left(gb) >= 8) {

        chunk_id   = bytestream2_get_le16(gb);

        chunk_size = bytestream2_get_le32(gb);

        chunk_arg  = bytestream2_get_le16(gb);

        if(chunk_id == RoQ_QUAD_VQ)

            break;

        if(chunk_id == RoQ_QUAD_CODEBOOK) {

            if((nv1 = chunk_arg >> 8) == 0)

                nv1 = 256;

            if((nv2 = chunk_arg & 0xff) == 0 && nv1 * 6 < chunk_size)

                nv2 = 256;

            for(i = 0; i < nv1; i++) {

                ri->cb2x2[i].y[0] = bytestream2_get_byte(gb);

                ri->cb2x2[i].y[1] = bytestream2_get_byte(gb);

                ri->cb2x2[i].y[2] = bytestream2_get_byte(gb);

                ri->cb2x2[i].y[3] = bytestream2_get_byte(gb);

                ri->cb2x2[i].u    = bytestream2_get_byte(gb);

                ri->cb2x2[i].v    = bytestream2_get_byte(gb);

            }

            for(i = 0; i < nv2; i++)

                for(j = 0; j < 4; j++)

                    ri->cb4x4[i].idx[j] = bytestream2_get_byte(gb);

        }

    }

    chunk_start = bytestream2_tell(gb);

    xpos = ypos = 0;

    if (chunk_size > bytestream2_get_bytes_left(gb)) {

        av_log(ri->logctx, AV_LOG_ERROR, "Chunk does not fit in input buffer\n");

        chunk_size = bytestream2_get_bytes_left(gb);

    }

    while (bytestream2_tell(gb) < chunk_start + chunk_size) {

        for (yp = ypos; yp < ypos + 16; yp += 8)

            for (xp = xpos; xp < xpos + 16; xp += 8) {

                if (bytestream2_tell(gb) >= chunk_start + chunk_size) {

                    av_log(ri->logctx, AV_LOG_VERBOSE, "Chunk is too short\n");

                    return;

                }

                if (vqflg_pos < 0) {

                    vqflg = bytestream2_get_le16(gb);

                    vqflg_pos = 7;

                }

                vqid = (vqflg >> (vqflg_pos * 2)) & 0x3;

                vqflg_pos--;

                switch(vqid) {

                case RoQ_ID_MOT:

                    break;

                case RoQ_ID_FCC: {

                    int byte = bytestream2_get_byte(gb);

                    mx = 8 - (byte >> 4) - ((signed char) (chunk_arg >> 8));

                    my = 8 - (byte & 0xf) - ((signed char) chunk_arg);

                    ff_apply_motion_8x8(ri, xp, yp, mx, my);

                    break;

                }

                case RoQ_ID_SLD:

                    qcell = ri->cb4x4 + bytestream2_get_byte(gb);

                    ff_apply_vector_4x4(ri, xp,     yp,     ri->cb2x2 + qcell->idx[0]);

                    ff_apply_vector_4x4(ri, xp + 4, yp,     ri->cb2x2 + qcell->idx[1]);

                    ff_apply_vector_4x4(ri, xp,     yp + 4, ri->cb2x2 + qcell->idx[2]);

                    ff_apply_vector_4x4(ri, xp + 4, yp + 4, ri->cb2x2 + qcell->idx[3]);

                    break;

                case RoQ_ID_CCC:

                    for (k = 0; k < 4; k++) {

                        x = xp; y = yp;

                        if(k & 0x01) x += 4;

                        if(k & 0x02) y += 4;

                        if (bytestream2_tell(gb) >= chunk_start + chunk_size) {

                            av_log(ri->logctx, AV_LOG_VERBOSE, "Chunk is too short\n");

                            return;

                        }

                        if (vqflg_pos < 0) {

                            vqflg = bytestream2_get_le16(gb);

                            vqflg_pos = 7;

                        }

                        vqid = (vqflg >> (vqflg_pos * 2)) & 0x3;

                        vqflg_pos--;

                        switch(vqid) {

                        case RoQ_ID_MOT:

                            break;

                        case RoQ_ID_FCC: {

                            int byte = bytestream2_get_byte(gb);

                            mx = 8 - (byte >> 4) - ((signed char) (chunk_arg >> 8));

                            my = 8 - (byte & 0xf) - ((signed char) chunk_arg);

                            ff_apply_motion_4x4(ri, x, y, mx, my);

                            break;

                        }

                        case RoQ_ID_SLD:

                            qcell = ri->cb4x4 + bytestream2_get_byte(gb);

                            ff_apply_vector_2x2(ri, x,     y,     ri->cb2x2 + qcell->idx[0]);

                            ff_apply_vector_2x2(ri, x + 2, y,     ri->cb2x2 + qcell->idx[1]);

                            ff_apply_vector_2x2(ri, x,     y + 2, ri->cb2x2 + qcell->idx[2]);

                            ff_apply_vector_2x2(ri, x + 2, y + 2, ri->cb2x2 + qcell->idx[3]);

                            break;

                        case RoQ_ID_CCC:

                            ff_apply_vector_2x2(ri, x,     y,     ri->cb2x2 + bytestream2_get_byte(gb));

                            ff_apply_vector_2x2(ri, x + 2, y,     ri->cb2x2 + bytestream2_get_byte(gb));

                            ff_apply_vector_2x2(ri, x,     y + 2, ri->cb2x2 + bytestream2_get_byte(gb));

                            ff_apply_vector_2x2(ri, x + 2, y + 2, ri->cb2x2 + bytestream2_get_byte(gb));

                            break;

                        }

                    }

                    break;

                default:

                    av_assert2(0);

            }

        }

        xpos += 16;

        if (xpos >= ri->width) {

            xpos -= ri->width;

            ypos += 16;

        }

        if(ypos >= ri->height)

            break;

    }

}

static av_cold int roq_decode_init(AVCodecContext *avctx)

{

    RoqContext *s = avctx->priv_data;

    s->logctx = avctx;

    if (avctx->width % 16 || avctx->height % 16) {

        avpriv_request_sample(avctx, "Dimensions not being a multiple of 16");

        return AVERROR_PATCHWELCOME;

    }

    s->width = avctx->width;

    s->height = avctx->height;

    s->last_frame    = av_frame_alloc();

    s->current_frame = av_frame_alloc();

    if (!s->current_frame || !s->last_frame)

        return AVERROR(ENOMEM);

    avctx->pix_fmt = AV_PIX_FMT_YUVJ444P;

    avctx->color_range = AVCOL_RANGE_JPEG;

    return 0;

}

static int roq_decode_frame(AVCodecContext *avctx, AVFrame *rframe,

                            int *got_frame, AVPacket *avpkt)

{

    const uint8_t *buf = avpkt->data;

    int buf_size = avpkt->size;

    RoqContext *s = avctx->priv_data;

    int copy = !s->current_frame->data[0] && s->last_frame->data[0];

    GetByteContext gb;

    int ret;

    if ((ret = ff_reget_buffer(avctx, s->current_frame, 0)) < 0)

        return ret;

    if (copy) {

        ret = av_frame_copy(s->current_frame, s->last_frame);

        if (ret < 0)

            return ret;

    }

    bytestream2_init(&gb, buf, buf_size);

    roqvideo_decode_frame(s, &gb);

    if ((ret = av_frame_ref(rframe, s->current_frame)) < 0)

        return ret;

    *got_frame      = 1;

    /* shuffle frames */

    FFSWAP(AVFrame *, s->current_frame, s->last_frame);

    return buf_size;

}

static av_cold int roq_decode_end(AVCodecContext *avctx)

{

    RoqContext *s = avctx->priv_data;

    av_frame_free(&s->current_frame);

    av_frame_free(&s->last_frame);

    return 0;

}

const FFCodec ff_roq_decoder = {

    .p.name         = "roqvideo",

    CODEC_LONG_NAME("id RoQ video"),

    .p.type         = AVMEDIA_TYPE_VIDEO,

    .p.id           = AV_CODEC_ID_ROQ,

    .priv_data_size = sizeof(RoqContext),

    .init           = roq_decode_init,

    .close          = roq_decode_end,

    FF_CODEC_DECODE_CB(roq_decode_frame),

    .p.capabilities = AV_CODEC_CAP_DR1,

    .caps_internal  = FF_CODEC_CAP_INIT_CLEANUP,

};