/*

  * Psygnosis YOP decoder
  *
  * Copyright (C) 2010 Mohamed Naufal Basheer <naufal11@gmail.com>
  * derived from the code by
  * Copyright (C) 2009 Thomas P. Higdon <thomas.p.higdon@gmail.com>
  *
  * 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 "libavutil/intreadwrite.h"

 #include "libavutil/imgutils.h"

 
 #include "avcodec.h"
 #include "get_bits.h"

 #include "internal.h"

 
 typedef struct YopDecContext {
     AVFrame frame;
     AVCodecContext *avctx;
 
     int num_pal_colors;
     int first_color[2];
     int frame_data_length;
 
     uint8_t *low_nibble;
     uint8_t *srcptr;

     uint8_t *src_end;

     uint8_t *dstptr;
     uint8_t *dstbuf;
 } YopDecContext;
 
 // These tables are taken directly from:
 // http://wiki.multimedia.cx/index.php?title=Psygnosis_YOP
 
 /**
  * Lookup table for painting macroblocks. Bytes 0-2 of each entry contain
  * the macroblock positions to be painted (taken as (0, B0, B1, B2)).
  * Byte 3 contains the number of bytes consumed on the input,
  * equal to max(bytes 0-2) + 1.
  */
 static const uint8_t paint_lut[15][4] =
     {{1, 2, 3, 4}, {1, 2, 0, 3},
      {1, 2, 1, 3}, {1, 2, 2, 3},
      {1, 0, 2, 3}, {1, 0, 0, 2},
      {1, 0, 1, 2}, {1, 1, 2, 3},
      {0, 1, 2, 3}, {0, 1, 0, 2},
      {1, 1, 0, 2}, {0, 1, 1, 2},
      {0, 0, 1, 2}, {0, 0, 0, 1},
      {1, 1, 1, 2},
     };
 
 /**
  * Lookup table for copying macroblocks. Each entry contains the respective
  * x and y pixel offset for the copy source.
  */
 static const int8_t motion_vector[16][2] =
     {{-4, -4}, {-2, -4},
      { 0, -4}, { 2, -4},
      {-4, -2}, {-4,  0},
      {-3, -3}, {-1, -3},
      { 1, -3}, { 3, -3},
      {-3, -1}, {-2, -2},
      { 0, -2}, { 2, -2},
      { 4, -2}, {-2,  0},
     };
 
 static av_cold int yop_decode_init(AVCodecContext *avctx)
 {
     YopDecContext *s = avctx->priv_data;
     s->avctx = avctx;
 
     if (avctx->width & 1 || avctx->height & 1 ||

         av_image_check_size(avctx->width, avctx->height, 0, avctx) < 0) {

         return -1;
     }
 

     if (avctx->extradata_size < 3) {
         av_log(avctx, AV_LOG_ERROR, "Missing or incomplete extradata.\n");

         return AVERROR_INVALIDDATA;
     }
 

     avctx->pix_fmt = AV_PIX_FMT_PAL8;

     avcodec_get_frame_defaults(&s->frame);

     s->num_pal_colors = avctx->extradata[0];
     s->first_color[0] = avctx->extradata[1];
     s->first_color[1] = avctx->extradata[2];
 
     if (s->num_pal_colors + s->first_color[0] > 256 ||
         s->num_pal_colors + s->first_color[1] > 256) {
         av_log(avctx, AV_LOG_ERROR,

                "Palette parameters invalid, header probably corrupt\n");

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

  * Paint a macroblock using the pattern in paint_lut.

  * @param s codec context
  * @param tag the tag that was in the nibble
  */

 static int yop_paint_block(YopDecContext *s, int tag)

 {

     if (s->src_end - s->srcptr < paint_lut[tag][3]) {
         av_log(s->avctx, AV_LOG_ERROR, "Packet too small.\n");
         return AVERROR_INVALIDDATA;
     }
 

     s->dstptr[0]                        = s->srcptr[0];
     s->dstptr[1]                        = s->srcptr[paint_lut[tag][0]];
     s->dstptr[s->frame.linesize[0]]     = s->srcptr[paint_lut[tag][1]];
     s->dstptr[s->frame.linesize[0] + 1] = s->srcptr[paint_lut[tag][2]];
 
     // The number of src bytes consumed is in the last part of the lut entry.
     s->srcptr += paint_lut[tag][3];

     return 0;

 }
 
 /**

  * Copy a previously painted macroblock to the current_block.

  * @param copy_tag the tag that was in the nibble
  */
 static int yop_copy_previous_block(YopDecContext *s, int copy_tag)
 {
     uint8_t *bufptr;
 
     // Calculate position for the copy source
     bufptr = s->dstptr + motion_vector[copy_tag][0] +
              s->frame.linesize[0] * motion_vector[copy_tag][1];
     if (bufptr < s->dstbuf) {

         av_log(s->avctx, AV_LOG_ERROR, "File probably corrupt\n");

         return AVERROR_INVALIDDATA;
     }
 
     s->dstptr[0]                        = bufptr[0];
     s->dstptr[1]                        = bufptr[1];
     s->dstptr[s->frame.linesize[0]]     = bufptr[s->frame.linesize[0]];
     s->dstptr[s->frame.linesize[0] + 1] = bufptr[s->frame.linesize[0] + 1];
 
     return 0;
 }
 
 /**

  * Return the next nibble in sequence, consuming a new byte on the input

  * only if necessary.
  */
 static uint8_t yop_get_next_nibble(YopDecContext *s)
 {
     int ret;
 
     if (s->low_nibble) {
         ret           = *s->low_nibble & 0xf;
         s->low_nibble = NULL;
     }else {
         s->low_nibble = s->srcptr++;
         ret           = *s->low_nibble >> 4;
     }
     return ret;
 }
 

 static int yop_decode_frame(AVCodecContext *avctx, void *data, int *got_frame,

                             AVPacket *avpkt)
 {
     YopDecContext *s = avctx->priv_data;
     int tag, firstcolor, is_odd_frame;

     int ret, i, x, y;

     uint32_t *palette;
 

     if (avpkt->size < 4 + 3 * s->num_pal_colors) {
         av_log(avctx, AV_LOG_ERROR, "Packet too small.\n");
         return AVERROR_INVALIDDATA;
     }
 

     if (s->frame.data[0])
         avctx->release_buffer(avctx, &s->frame);
 

     if (avpkt->size < 4 + 3*s->num_pal_colors) {
         av_log(avctx, AV_LOG_ERROR, "packet of size %d too small\n", avpkt->size);
         return AVERROR_INVALIDDATA;
     }
 

     ret = ff_get_buffer(avctx, &s->frame);

     if (ret < 0) {
         av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
         return ret;
     }
 
     s->dstbuf     = s->frame.data[0];
     s->dstptr     = s->frame.data[0];
     s->srcptr     = avpkt->data + 4;

     s->src_end    = avpkt->data + avpkt->size;

     s->low_nibble = NULL;
 
     is_odd_frame = avpkt->data[0];

     if(is_odd_frame>1){
         av_log(avctx, AV_LOG_ERROR, "frame is too odd %d\n", is_odd_frame);
         return AVERROR_INVALIDDATA;
     }

     firstcolor   = s->first_color[is_odd_frame];
     palette      = (uint32_t *)s->frame.data[1];
 

     for (i = 0; i < s->num_pal_colors; i++, s->srcptr += 3) {

         palette[i + firstcolor] = (s->srcptr[0] << 18) |
                                   (s->srcptr[1] << 10) |
                                   (s->srcptr[2] << 2);

         palette[i + firstcolor] |= 0xFFU << 24 |

                                    (palette[i + firstcolor] >> 6) & 0x30303;

     }

 
     s->frame.palette_has_changed = 1;
 

     for (y = 0; y < avctx->height; y += 2) {
         for (x = 0; x < avctx->width; x += 2) {
             if (s->srcptr - avpkt->data >= avpkt->size) {
                 av_log(avctx, AV_LOG_ERROR, "Packet too small.\n");
                 return AVERROR_INVALIDDATA;
             }

 
             tag = yop_get_next_nibble(s);

 
             if (tag != 0xf) {

                 ret = yop_paint_block(s, tag);
                 if (ret < 0)
                     return ret;

             } else {
                 tag = yop_get_next_nibble(s);
                 ret = yop_copy_previous_block(s, tag);
                 if (ret < 0) {
                     avctx->release_buffer(avctx, &s->frame);
                     return ret;
                 }

             }

             s->dstptr += 2;

         }

         s->dstptr += 2*s->frame.linesize[0] - x;

     }
 

     *got_frame = 1;

     *(AVFrame *) data = s->frame;
     return avpkt->size;
 }
 

 AVCodec ff_yop_decoder = {

     .name           = "yop",
     .type           = AVMEDIA_TYPE_VIDEO,

     .id             = AV_CODEC_ID_YOP,

     .priv_data_size = sizeof(YopDecContext),
     .init           = yop_decode_init,
     .close          = yop_decode_close,
     .decode         = yop_decode_frame,

     .long_name      = NULL_IF_CONFIG_SMALL("Psygnosis YOP Video"),

 };