/*
  * Miro VideoXL codec
  * Copyright (c) 2004 Konstantin Shishkov
  *

  * 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

  * Miro VideoXL codec.
  */

 #include "libavutil/intreadwrite.h"

 #include "avcodec.h"
 
 typedef struct VideoXLContext{
     AVCodecContext *avctx;
     AVFrame pic;
 } VideoXLContext;
 

 static const int xl_table[32] = {

    0,   1,   2,   3,   4,   5,   6,   7,
    8,   9,  12,  15,  20,  25,  34,  46,
   64,  82,  94, 103, 108, 113, 116, 119,
  120, 121, 122, 123, 124, 125, 126, 127};
 

 static int decode_frame(AVCodecContext *avctx,

                         void *data, int *data_size,

                         AVPacket *avpkt)

 {

     const uint8_t *buf = avpkt->data;
     int buf_size = avpkt->size;

     VideoXLContext * const a = avctx->priv_data;
     AVFrame * const p= (AVFrame*)&a->pic;
     uint8_t *Y, *U, *V;
     int i, j;
     int stride;
     uint32_t val;

     int y0, y1, y2, y3 = 0, c0 = 0, c1 = 0;

 
     if(p->data[0])
         avctx->release_buffer(avctx, p);
 
     p->reference = 0;
     if(avctx->get_buffer(avctx, p) < 0){
         av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
         return -1;
     }

     p->pict_type= AV_PICTURE_TYPE_I;

     p->key_frame= 1;
 
     Y = a->pic.data[0];
     U = a->pic.data[1];
     V = a->pic.data[2];

     stride = avctx->width - 4;
     for (i = 0; i < avctx->height; i++) {
         /* lines are stored in reversed order */
         buf += stride;

         for (j = 0; j < avctx->width; j += 4) {
             /* value is stored in LE dword with word swapped */

             val = AV_RL32(buf);

             buf -= 4;
             val = ((val >> 16) & 0xFFFF) | ((val & 0xFFFF) << 16);

             if(!j)
                 y0 = (val & 0x1F) << 2;
             else
                 y0 = y3 + xl_table[val & 0x1F];
             val >>= 5;
             y1 = y0 + xl_table[val & 0x1F];
             val >>= 5;
             y2 = y1 + xl_table[val & 0x1F];
             val >>= 6; /* align to word */
             y3 = y2 + xl_table[val & 0x1F];
             val >>= 5;
             if(!j)
                 c0 = (val & 0x1F) << 2;
             else
                 c0 += xl_table[val & 0x1F];
             val >>= 5;
             if(!j)
                 c1 = (val & 0x1F) << 2;
             else
                 c1 += xl_table[val & 0x1F];

             Y[j + 0] = y0 << 1;
             Y[j + 1] = y1 << 1;
             Y[j + 2] = y2 << 1;
             Y[j + 3] = y3 << 1;

             U[j >> 2] = c0 << 1;
             V[j >> 2] = c1 << 1;
         }

         buf += avctx->width + 4;
         Y += a->pic.linesize[0];
         U += a->pic.linesize[1];
         V += a->pic.linesize[2];
     }
 
     *data_size = sizeof(AVFrame);
     *(AVFrame*)data = a->pic;

     return buf_size;
 }
 

 static av_cold int decode_init(AVCodecContext *avctx){

     VideoXLContext * const a = avctx->priv_data;

     avcodec_get_frame_defaults(&a->pic);

     avctx->pix_fmt= PIX_FMT_YUV411P;
 
     return 0;
 }
 

 static av_cold int decode_end(AVCodecContext *avctx){
     VideoXLContext * const a = avctx->priv_data;
     AVFrame *pic = &a->pic;
 
     if (pic->data[0])
         avctx->release_buffer(avctx, pic);
 
     return 0;
 }
 

 AVCodec ff_xl_decoder = {

     "xl",

     AVMEDIA_TYPE_VIDEO,

     CODEC_ID_VIXL,
     sizeof(VideoXLContext),
     decode_init,
     NULL,

     decode_end,

     decode_frame,
     CODEC_CAP_DR1,

     .long_name = NULL_IF_CONFIG_SMALL("Miro VideoXL"),

 };