/*

  * Creative YUV (CYUV) Video Decoder
  *   by Mike Melanson (melanson@pcisys.net)
  * based on "Creative YUV (CYUV) stream format for AVI":
  *   http://www.csse.monash.edu.au/~timf/videocodec/cyuv.txt

  *
  * Copyright (C) 2003 the ffmpeg project
  *

  * 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

  * Creative YUV (CYUV) Video Decoder.
  */

 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 
 #include "avcodec.h"
 #include "dsputil.h"
 
 
 typedef struct CyuvDecodeContext {
     AVCodecContext *avctx;
     int width, height;
     AVFrame frame;
 } CyuvDecodeContext;
 

 static av_cold int cyuv_decode_init(AVCodecContext *avctx)

 {
     CyuvDecodeContext *s = avctx->priv_data;
 
     s->avctx = avctx;
     s->width = avctx->width;

     /* width needs to be divisible by 4 for this codec to work */
     if (s->width & 0x3)
         return -1;

     s->height = avctx->height;
     avctx->pix_fmt = PIX_FMT_YUV411P;

     avcodec_get_frame_defaults(&s->frame);

 
     return 0;
 }
 

 static int cyuv_decode_frame(AVCodecContext *avctx,

                              void *data, int *data_size,

                              AVPacket *avpkt)

 {

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

     CyuvDecodeContext *s=avctx->priv_data;
 
     unsigned char *y_plane;
     unsigned char *u_plane;
     unsigned char *v_plane;
     int y_ptr;
     int u_ptr;
     int v_ptr;
 
     /* prediction error tables (make it clear that they are signed values) */

     const signed char *y_table = (const signed char*)buf +  0;
     const signed char *u_table = (const signed char*)buf + 16;
     const signed char *v_table = (const signed char*)buf + 32;

 
     unsigned char y_pred, u_pred, v_pred;
     int stream_ptr;
     unsigned char cur_byte;
     int pixel_groups;
 

     if (avctx->codec_id == CODEC_ID_AURA) {
         y_table = u_table;
         u_table = v_table;
     }

     /* sanity check the buffer size: A buffer has 3x16-bytes tables
      * followed by (height) lines each with 3 bytes to represent groups
      * of 4 pixels. Thus, the total size of the buffer ought to be:
      *    (3 * 16) + height * (width * 3 / 4) */
     if (buf_size != 48 + s->height * (s->width * 3 / 4)) {

         av_log(avctx, AV_LOG_ERROR, "got a buffer with %d bytes when %d were expected\n",

                buf_size, 48 + s->height * (s->width * 3 / 4));
         return -1;

     }
 
     /* pixel data starts 48 bytes in, after 3x16-byte tables */
     stream_ptr = 48;
 

     if (s->frame.data[0])

         avctx->release_buffer(avctx, &s->frame);
 

     s->frame.buffer_hints = FF_BUFFER_HINTS_VALID;

     s->frame.reference = 0;

     if (avctx->get_buffer(avctx, &s->frame) < 0) {

         av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");

         return -1;
     }
 
     y_plane = s->frame.data[0];
     u_plane = s->frame.data[1];
     v_plane = s->frame.data[2];
 
     /* iterate through each line in the height */
     for (y_ptr = 0, u_ptr = 0, v_ptr = 0;

          y_ptr < (s->height * s->frame.linesize[0]);

          y_ptr += s->frame.linesize[0] - s->width,
          u_ptr += s->frame.linesize[1] - s->width / 4,
          v_ptr += s->frame.linesize[2] - s->width / 4) {
 
         /* reset predictors */
         cur_byte = buf[stream_ptr++];
         u_plane[u_ptr++] = u_pred = cur_byte & 0xF0;
         y_plane[y_ptr++] = y_pred = (cur_byte & 0x0F) << 4;
 
         cur_byte = buf[stream_ptr++];
         v_plane[v_ptr++] = v_pred = cur_byte & 0xF0;
         y_pred += y_table[cur_byte & 0x0F];
         y_plane[y_ptr++] = y_pred;
 
         cur_byte = buf[stream_ptr++];
         y_pred += y_table[cur_byte & 0x0F];
         y_plane[y_ptr++] = y_pred;
         y_pred += y_table[(cur_byte & 0xF0) >> 4];
         y_plane[y_ptr++] = y_pred;
 
         /* iterate through the remaining pixel groups (4 pixels/group) */
         pixel_groups = s->width / 4 - 1;
         while (pixel_groups--) {
 
             cur_byte = buf[stream_ptr++];
             u_pred += u_table[(cur_byte & 0xF0) >> 4];
             u_plane[u_ptr++] = u_pred;
             y_pred += y_table[cur_byte & 0x0F];
             y_plane[y_ptr++] = y_pred;
 
             cur_byte = buf[stream_ptr++];
             v_pred += v_table[(cur_byte & 0xF0) >> 4];
             v_plane[v_ptr++] = v_pred;
             y_pred += y_table[cur_byte & 0x0F];
             y_plane[y_ptr++] = y_pred;
 
             cur_byte = buf[stream_ptr++];
             y_pred += y_table[cur_byte & 0x0F];
             y_plane[y_ptr++] = y_pred;
             y_pred += y_table[(cur_byte & 0xF0) >> 4];
             y_plane[y_ptr++] = y_pred;
 
         }
     }
 
     *data_size=sizeof(AVFrame);
     *(AVFrame*)data= s->frame;
 
     return buf_size;
 }
 

 static av_cold int cyuv_decode_end(AVCodecContext *avctx)
 {
     CyuvDecodeContext *s = avctx->priv_data;
 
     if (s->frame.data[0])
         avctx->release_buffer(avctx, &s->frame);
 
     return 0;
 }
 

 #if CONFIG_AURA_DECODER

 AVCodec ff_aura_decoder = {

     "aura",

     AVMEDIA_TYPE_VIDEO,

     CODEC_ID_AURA,
     sizeof(CyuvDecodeContext),
     cyuv_decode_init,
     NULL,

     cyuv_decode_end,

     cyuv_decode_frame,
     CODEC_CAP_DR1,
     NULL,
     .long_name = NULL_IF_CONFIG_SMALL("Auravision AURA"),
 };
 #endif
 
 #if CONFIG_CYUV_DECODER

 AVCodec ff_cyuv_decoder = {

     "cyuv",

     AVMEDIA_TYPE_VIDEO,

     CODEC_ID_CYUV,
     sizeof(CyuvDecodeContext),
     cyuv_decode_init,
     NULL,

     cyuv_decode_end,

     cyuv_decode_frame,

     CODEC_CAP_DR1,

     NULL,

     .long_name = NULL_IF_CONFIG_SMALL("Creative YUV (CYUV)"),

 };

 #endif