/*
  * ATI VCR1 codec
  * Copyright (c) 2003 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

  */

 /**

  * @file

  * ATI VCR1 codec

  */

 #include "avcodec.h"

 #include "internal.h"

 #include "libavutil/avassert.h"

 #include "libavutil/internal.h"

 typedef struct VCR1Context {

     int delta[16];
     int offset[4];
 } VCR1Context;
 

 static av_cold int vcr1_decode_init(AVCodecContext *avctx)

 {

     avctx->pix_fmt = AV_PIX_FMT_YUV410P;

     if (avctx->width % 8 || avctx->height%4) {

         avpriv_request_sample(avctx, "odd dimensions (%d x %d) support", avctx->width, avctx->height);

         return AVERROR_INVALIDDATA;

     }

     return 0;
 }
 

 static int vcr1_decode_frame(AVCodecContext *avctx, void *data,

                              int *got_frame, AVPacket *avpkt)

 {

     VCR1Context *const a      = avctx->priv_data;

     AVFrame *const p          = data;

     const uint8_t *bytestream = avpkt->data;

     const uint8_t *bytestream_end = bytestream + avpkt->size;

     int i, x, y, ret;

     if(avpkt->size < 32 + avctx->height + avctx->width*avctx->height*5/8){

         av_log(avctx, AV_LOG_ERROR, "Insufficient input data. %d < %d\n", avpkt->size ,  32 + avctx->height + avctx->width*avctx->height*5/8);

         return AVERROR(EINVAL);
     }
 

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

         return ret;

     p->pict_type = AV_PICTURE_TYPE_I;
     p->key_frame = 1;

     for (i = 0; i < 16; i++) {
         a->delta[i] = *bytestream++;

         bytestream++;
     }

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

         int offset;

         uint8_t *luma = &p->data[0][y * p->linesize[0]];

         if ((y & 3) == 0) {

             uint8_t *cb = &p->data[1][(y >> 2) * p->linesize[1]];
             uint8_t *cr = &p->data[2][(y >> 2) * p->linesize[2]];

             av_assert0 (bytestream_end - bytestream >= 4 + avctx->width);

             for (i = 0; i < 4; i++)
                 a->offset[i] = *bytestream++;

             offset = a->offset[0] - a->delta[bytestream[2] & 0xF];
             for (x = 0; x < avctx->width; x += 4) {
                 luma[0]     = offset += a->delta[bytestream[2] & 0xF];
                 luma[1]     = offset += a->delta[bytestream[2] >>  4];
                 luma[2]     = offset += a->delta[bytestream[0] & 0xF];
                 luma[3]     = offset += a->delta[bytestream[0] >>  4];
                 luma       += 4;

                 *cb++       = bytestream[3];
                 *cr++       = bytestream[1];

                 bytestream += 4;

             }

         } else {

             av_assert0 (bytestream_end - bytestream >= avctx->width / 2);

             offset = a->offset[y & 3] - a->delta[bytestream[2] & 0xF];
 
             for (x = 0; x < avctx->width; x += 8) {
                 luma[0]     = offset += a->delta[bytestream[2] & 0xF];
                 luma[1]     = offset += a->delta[bytestream[2] >>  4];
                 luma[2]     = offset += a->delta[bytestream[3] & 0xF];
                 luma[3]     = offset += a->delta[bytestream[3] >>  4];
                 luma[4]     = offset += a->delta[bytestream[0] & 0xF];
                 luma[5]     = offset += a->delta[bytestream[0] >>  4];
                 luma[6]     = offset += a->delta[bytestream[1] & 0xF];
                 luma[7]     = offset += a->delta[bytestream[1] >>  4];
                 luma       += 8;
                 bytestream += 4;

             }
         }
     }
 

     *got_frame = 1;

     return bytestream - avpkt->data;

 }
 

 AVCodec ff_vcr1_decoder = {

     .name           = "vcr1",

     .long_name      = NULL_IF_CONFIG_SMALL("ATI VCR1"),

     .type           = AVMEDIA_TYPE_VIDEO,

     .id             = AV_CODEC_ID_VCR1,

     .priv_data_size = sizeof(VCR1Context),

     .init           = vcr1_decode_init,
     .decode         = vcr1_decode_frame,

     .capabilities   = AV_CODEC_CAP_DR1,

 };