/*
  * 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 "internal.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, void *data, 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];
     AVFrame *frame = data;
 
     if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
         return ret;
     frame->pict_type = AV_PICTURE_TYPE_I;
     frame->key_frame = 1;
 
     stride = AV_RL32(avctx->extradata + 5*4);
 
     if (avctx->pix_fmt == AV_PIX_FMT_YUV422P10)
         min_stride = (avctx->width + 15) / 16 * 20;
 
     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;
     }
 
     frame->interlaced_frame = ((avctx->extradata[3*4] & 3) != 3);
     if (frame->interlaced_frame)
         frame->top_field_first = avctx->extradata[3*4] & 1;
 
     for (y = 0; y < avctx->height; y++) {
         int src_y = y;
         if (frame->interlaced_frame)
             src_y = ((y&1)^frame->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;
 }
 
 AVCodec ff_m101_decoder = {
     .name           = "m101",
     .long_name      = NULL_IF_CONFIG_SMALL("Matrox Uncompressed SD"),
     .type           = AVMEDIA_TYPE_VIDEO,
     .id             = AV_CODEC_ID_M101,
     .init           = m101_decode_init,
     .decode         = m101_decode_frame,
     .capabilities   = AV_CODEC_CAP_DR1,
 };