/*
  * Dxtory decoder
  *
  * Copyright (c) 2011 Konstantin Shishkov
  *
  * This file is part of Libav.
  *
  * Libav 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.
  *
  * Libav 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 Libav; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
 #include "avcodec.h"
 #include "libavutil/intreadwrite.h"
 
 static av_cold int decode_init(AVCodecContext *avctx)
 {
     avctx->pix_fmt     = PIX_FMT_YUV420P;
     avctx->coded_frame = avcodec_alloc_frame();
     if (!avctx->coded_frame)
         return AVERROR(ENOMEM);
 
     return 0;
 }
 
 static int decode_frame(AVCodecContext *avctx, void *data, int *data_size,
                         AVPacket *avpkt)
 {
     int h, w;
     AVFrame *pic = avctx->coded_frame;
     const uint8_t *src = avpkt->data;
     uint8_t *Y1, *Y2, *U, *V;
     int ret;
 
     if (pic->data[0])
         avctx->release_buffer(avctx, pic);
 
     if (avpkt->size < avctx->width * avctx->height * 3 / 2 + 16) {
         av_log(avctx, AV_LOG_ERROR, "packet too small\n");
         return AVERROR_INVALIDDATA;
     }
 
     pic->reference = 0;
     if ((ret = avctx->get_buffer(avctx, pic)) < 0)
         return ret;
 
     pic->pict_type = AV_PICTURE_TYPE_I;
     pic->key_frame = 1;
 
     if (AV_RL32(src) != 0x01000002) {
         av_log_ask_for_sample(avctx, "Unknown frame header %X\n", AV_RL32(src));
         return AVERROR_PATCHWELCOME;
     }
     src += 16;
 
     Y1 = pic->data[0];
     Y2 = pic->data[0] + pic->linesize[0];
     U  = pic->data[1];
     V  = pic->data[2];
     for (h = 0; h < avctx->height; h += 2) {
         for (w = 0; w < avctx->width; w += 2) {
             AV_WN16A(Y1 + w, AV_RN16A(src));
             AV_WN16A(Y2 + w, AV_RN16A(src + 2));
             U[w >> 1] = src[4] + 0x80;
             V[w >> 1] = src[5] + 0x80;
             src += 6;
         }
         Y1 += pic->linesize[0] << 1;
         Y2 += pic->linesize[0] << 1;
         U  += pic->linesize[1];
         V  += pic->linesize[2];
     }
 
     *data_size      = sizeof(AVFrame);
     *(AVFrame*)data = *pic;
 
     return avpkt->size;
 }
 
 static av_cold int decode_close(AVCodecContext *avctx)
 {
     AVFrame *pic = avctx->coded_frame;
     if (pic->data[0])
         avctx->release_buffer(avctx, pic);
     av_freep(&avctx->coded_frame);
 
     return 0;
 }
 
 AVCodec ff_dxtory_decoder = {
     .name           = "dxtory",
     .long_name      = NULL_IF_CONFIG_SMALL("Dxtory"),
     .type           = AVMEDIA_TYPE_VIDEO,
     .id             = CODEC_ID_DXTORY,
     .init           = decode_init,
     .close          = decode_close,
     .decode         = decode_frame,
     .capabilities   = CODEC_CAP_DR1,
 };