/*

 * Copyright (c) 2016 Michael Niedermayer

 *

 * 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

 */

#include "libavutil/intreadwrite.h"

#include "avcodec.h"

#include "codec_internal.h"

#include "decode.h"

static av_cold int m101_decode_init(AVCodecContext *avctx)

{

    if (avctx->extradata_size < 6*4) {

        avpriv_request_sample(avctx, "Missing or too small extradata (size %d)", avctx->extradata_size);

        return AVERROR_INVALIDDATA;

    }

    if (avctx->extradata[2*4] == 10)

        avctx->pix_fmt = AV_PIX_FMT_YUV422P10;

    else if (avctx->extradata[2*4] == 8) {

        avctx->pix_fmt = AV_PIX_FMT_YUYV422;

    } else {

        avpriv_request_sample(avctx, "BPS %d", avctx->extradata[2*4]);

        return AVERROR_INVALIDDATA;

    }

    return 0;

}

static int m101_decode_frame(AVCodecContext *avctx, AVFrame *frame,

                             int *got_frame, AVPacket *avpkt)

{

    const uint8_t *buf = avpkt->data;

    int stride, ret;

    int x, y;

    int min_stride = 2 * avctx->width;

    int bits = avctx->extradata[2*4];

    stride = AV_RL32(avctx->extradata + 5*4);

    if (avctx->pix_fmt == AV_PIX_FMT_YUV422P10)

        min_stride = (avctx->width + 15) / 16 * 40;

    if (stride < min_stride || avpkt->size < stride * (uint64_t)avctx->height) {

        av_log(avctx, AV_LOG_ERROR, "stride (%d) is invalid for packet sized %d\n",

               stride, avpkt->size);

        return AVERROR_INVALIDDATA;

    }

    if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)

        return ret;

    if ((avctx->extradata[3*4] & 3) != 3) {

        frame->flags |= AV_FRAME_FLAG_INTERLACED;

        if (avctx->extradata[3*4] & 1)

            frame->flags |= AV_FRAME_FLAG_TOP_FIELD_FIRST;

    }

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

        int src_y = y;

        if (frame->flags & AV_FRAME_FLAG_INTERLACED)

            src_y = ((y&1) ^ !!(frame->flags & AV_FRAME_FLAG_TOP_FIELD_FIRST)) ? y/2 : (y/2 + avctx->height/2);

        if (bits == 8) {

            uint8_t *line = frame->data[0] + y*frame->linesize[0];

            memcpy(line, buf + src_y*stride, 2*avctx->width);

        } else {

            int block;

            uint16_t *luma = (uint16_t*)&frame->data[0][y*frame->linesize[0]];

            uint16_t *cb   = (uint16_t*)&frame->data[1][y*frame->linesize[1]];

            uint16_t *cr   = (uint16_t*)&frame->data[2][y*frame->linesize[2]];

            for (block = 0; 16*block < avctx->width; block ++) {

                const uint8_t *buf_src = buf + src_y*stride + 40*block;

                for (x = 0; x < 16 && x + 16*block < avctx->width; x++) {

                    int xd = x + 16*block;

                    if (x&1) {

                        luma [xd] = (4*buf_src[2*x + 0]) + ((buf_src[32 + (x>>1)]>>4)&3);

                    } else {

                        luma [xd] = (4*buf_src[2*x + 0]) +  (buf_src[32 + (x>>1)]    &3);

                        cb[xd>>1] = (4*buf_src[2*x + 1]) + ((buf_src[32 + (x>>1)]>>2)&3);

                        cr[xd>>1] = (4*buf_src[2*x + 3]) +  (buf_src[32 + (x>>1)]>>6);

                    }

                }

            }

        }

    }

    *got_frame = 1;

    return avpkt->size;

}

const FFCodec ff_m101_decoder = {

    .p.name         = "m101",

    CODEC_LONG_NAME("Matrox Uncompressed SD"),

    .p.type         = AVMEDIA_TYPE_VIDEO,

    .p.id           = AV_CODEC_ID_M101,

    .init           = m101_decode_init,

    FF_CODEC_DECODE_CB(m101_decode_frame),

    .p.capabilities = AV_CODEC_CAP_DR1,

};