/*
  * Forward Uncompressed
  *
  * Copyright (c) 2009 Reimar Döffinger <Reimar.Doeffinger@gmx.de>
  *
  * 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 "avcodec.h"
 #include "bytestream.h"
 #include "libavutil/intreadwrite.h"
 
 static av_cold int decode_init(AVCodecContext *avctx)
 {
     if (avctx->width & 1) {

         av_log(avctx, AV_LOG_ERROR, "frwu needs even width\n");

         return -1;
     }
     avctx->pix_fmt = PIX_FMT_UYVY422;
 
     avctx->coded_frame = avcodec_alloc_frame();
 
     return 0;
 }
 
 static int decode_frame(AVCodecContext *avctx, void *data, int *data_size,
                         AVPacket *avpkt)
 {
     int field;
     AVFrame *pic = avctx->coded_frame;
     const uint8_t *buf = avpkt->data;
     const uint8_t *buf_end = buf + avpkt->size;
 
     if (pic->data[0])
         avctx->release_buffer(avctx, pic);
 
     if (avpkt->size < avctx->width * 2 * avctx->height + 4 + 2*8) {
         av_log(avctx, AV_LOG_ERROR, "Packet is too small.\n");
         return -1;
     }
     if (bytestream_get_le32(&buf) != AV_RL32("FRW1")) {
         av_log(avctx, AV_LOG_ERROR, "incorrect marker\n");
         return -1;
     }
 
     pic->reference = 0;
     if (avctx->get_buffer(avctx, pic) < 0)
         return -1;
 

     pic->pict_type = AV_PICTURE_TYPE_I;

     pic->key_frame = 1;
     pic->interlaced_frame = 1;
     pic->top_field_first = 1;
 
     for (field = 0; field < 2; field++) {
         int i;
         int field_h = (avctx->height + !field) >> 1;
         int field_size, min_field_size = avctx->width * 2 * field_h;
         uint8_t *dst = pic->data[0];
         if (buf_end - buf < 8)
             return -1;
         buf += 4; // flags? 0x80 == bottom field maybe?
         field_size = bytestream_get_le32(&buf);
         if (field_size < min_field_size) {
             av_log(avctx, AV_LOG_ERROR, "Field size %i is too small (required %i)\n", field_size, min_field_size);
             return -1;
         }
         if (buf_end - buf < field_size) {
             av_log(avctx, AV_LOG_ERROR, "Packet is too small, need %i, have %i\n", field_size, (int)(buf_end - buf));
             return -1;
         }
         if (field)
             dst += pic->linesize[0];
         for (i = 0; i < field_h; i++) {
             memcpy(dst, buf, avctx->width * 2);
             buf += avctx->width * 2;
             dst += pic->linesize[0] << 1;
         }
         buf += field_size - min_field_size;
     }
 
     *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_frwu_decoder = {

     "frwu",

     AVMEDIA_TYPE_VIDEO,

     CODEC_ID_FRWU,
     0,
     decode_init,
     NULL,
     decode_close,
     decode_frame,
     CODEC_CAP_DR1,
     .long_name = NULL_IF_CONFIG_SMALL("Forward Uncompressed"),
 };