/*
  * Pictor/PC Paint decoder
  * Copyright (c) 2010 Peter Ross <pross@xvid.org>
  *
  * 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

  * Pictor/PC Paint decoder
  */
 

 #include "libavutil/imgutils.h"

 #include "avcodec.h"
 #include "bytestream.h"
 #include "cga_data.h"

 #include "internal.h"

 
 typedef struct PicContext {
     int width, height;
     int nb_planes;

     GetByteContext g;

 } PicContext;
 

 static void picmemset_8bpp(PicContext *s, AVFrame *frame, int value, int run,
                            int *x, int *y)

 {
     while (run > 0) {

         uint8_t *d = frame->data[0] + *y * frame->linesize[0];

         if (*x + run >= s->width) {
             int n = s->width - *x;
             memset(d + *x, value, n);
             run -= n;
             *x = 0;
             *y -= 1;
             if (*y < 0)
                 break;
         } else {
             memset(d + *x, value, run);
             *x += run;
             break;
         }
     }
 }
 

 static void picmemset(PicContext *s, AVFrame *frame, int value, int run,

                       int *x, int *y, int *plane, int bits_per_plane)

 {
     uint8_t *d;
     int shift = *plane * bits_per_plane;
     int mask  = ((1 << bits_per_plane) - 1) << shift;
     value   <<= shift;
 
     while (run > 0) {
         int j;
         for (j = 8-bits_per_plane; j >= 0; j -= bits_per_plane) {

             d = frame->data[0] + *y * frame->linesize[0];

             d[*x] |= (value >> j) & mask;
             *x += 1;
             if (*x == s->width) {
                 *y -= 1;
                 *x = 0;
                 if (*y < 0) {
                    *y = s->height - 1;
                    *plane += 1;
                    value <<= bits_per_plane;
                    mask  <<= bits_per_plane;
                    if (*plane >= s->nb_planes)
                        break;
                 }
             }
         }
         run--;
     }
 }
 
 static const uint8_t cga_mode45_index[6][4] = {
     [0] = { 0, 3,  5,   7 }, // mode4, palette#1, low intensity
     [1] = { 0, 2,  4,   6 }, // mode4, palette#2, low intensity
     [2] = { 0, 3,  4,   7 }, // mode5, low intensity
     [3] = { 0, 11, 13, 15 }, // mode4, palette#1, high intensity
     [4] = { 0, 10, 12, 14 }, // mode4, palette#2, high intensity
     [5] = { 0, 11, 12, 15 }, // mode5, high intensity
 };
 
 static int decode_frame(AVCodecContext *avctx,

                         void *data, int *got_frame,

                         AVPacket *avpkt)
 {
     PicContext *s = avctx->priv_data;

     AVFrame *frame = data;

     uint32_t *palette;

     int bits_per_plane, bpp, etype, esize, npal, pos_after_pal;

     int i, x, y, plane, tmp, ret, val;

     bytestream2_init(&s->g, avpkt->data, avpkt->size);
 
     if (bytestream2_get_bytes_left(&s->g) < 11)

         return AVERROR_INVALIDDATA;
 

     if (bytestream2_get_le16u(&s->g) != 0x1234)

         return AVERROR_INVALIDDATA;

 
     s->width       = bytestream2_get_le16u(&s->g);
     s->height      = bytestream2_get_le16u(&s->g);
     bytestream2_skip(&s->g, 4);
     tmp            = bytestream2_get_byteu(&s->g);
     bits_per_plane = tmp & 0xF;
     s->nb_planes   = (tmp >> 4) + 1;
     bpp            = bits_per_plane * s->nb_planes;

     if (bits_per_plane > 8 || bpp < 1 || bpp > 32) {

         avpriv_request_sample(avctx, "Unsupported bit depth");

         return AVERROR_PATCHWELCOME;

     }
 

     if (bytestream2_peek_byte(&s->g) == 0xFF || bpp == 1 || bpp == 4 || bpp == 8) {

         bytestream2_skip(&s->g, 2);
         etype = bytestream2_get_le16(&s->g);
         esize = bytestream2_get_le16(&s->g);
         if (bytestream2_get_bytes_left(&s->g) < esize)

             return AVERROR_INVALIDDATA;
     } else {
         etype = -1;
         esize = 0;
     }
 

     avctx->pix_fmt = AV_PIX_FMT_PAL8;

     if (av_image_check_size(s->width, s->height, 0, avctx) < 0)
         return -1;

     if (s->width != avctx->width && s->height != avctx->height) {

         ret = ff_set_dimensions(avctx, s->width, s->height);
         if (ret < 0)
             return ret;

     }
 

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

         return ret;
     memset(frame->data[0], 0, s->height * frame->linesize[0]);
     frame->pict_type           = AV_PICTURE_TYPE_I;
     frame->palette_has_changed = 1;

     pos_after_pal = bytestream2_tell(&s->g) + esize;

     palette = (uint32_t*)frame->data[1];

     if (etype == 1 && esize > 1 && bytestream2_peek_byte(&s->g) < 6) {
         int idx = bytestream2_get_byte(&s->g);

         npal = 4;
         for (i = 0; i < npal; i++)
             palette[i] = ff_cga_palette[ cga_mode45_index[idx][i] ];
     } else if (etype == 2) {
         npal = FFMIN(esize, 16);

         for (i = 0; i < npal; i++) {
             int pal_idx = bytestream2_get_byte(&s->g);

             palette[i]  = ff_cga_palette[FFMIN(pal_idx, 15)];

         }

     } else if (etype == 3) {
         npal = FFMIN(esize, 16);

         for (i = 0; i < npal; i++) {
             int pal_idx = bytestream2_get_byte(&s->g);
             palette[i]  = ff_ega_palette[FFMIN(pal_idx, 63)];
         }

     } else if (etype == 4 || etype == 5) {
         npal = FFMIN(esize / 3, 256);

         for (i = 0; i < npal; i++) {

             palette[i] = bytestream2_get_be24(&s->g) << 2;

             palette[i] |= 0xFFU << 24 | palette[i] >> 6 & 0x30303;

         }

     } else {
         if (bpp == 1) {
             npal = 2;

             palette[0] = 0xFF000000;
             palette[1] = 0xFFFFFFFF;

         } else if (bpp == 2) {
             npal = 4;
             for (i = 0; i < npal; i++)
                 palette[i] = ff_cga_palette[ cga_mode45_index[0][i] ];
         } else {
             npal = 16;
             memcpy(palette, ff_cga_palette, npal * 4);
         }
     }
     // fill remaining palette entries
     memset(palette + npal, 0, AVPALETTE_SIZE - npal * 4);

     // skip remaining palette bytes
     bytestream2_seek(&s->g, pos_after_pal, SEEK_SET);

     val = 0;

     y = s->height - 1;

     if (bytestream2_get_le16(&s->g)) {

         x = 0;
         plane = 0;

         while (bytestream2_get_bytes_left(&s->g) >= 6) {

             int stop_size, marker, t1, t2;
 
             t1        = bytestream2_get_bytes_left(&s->g);
             t2        = bytestream2_get_le16(&s->g);
             stop_size = t1 - FFMIN(t1, t2);
             // ignore uncompressed block size
             bytestream2_skip(&s->g, 2);
             marker    = bytestream2_get_byte(&s->g);

             while (plane < s->nb_planes &&

                    bytestream2_get_bytes_left(&s->g) > stop_size) {

                 int run = 1;

                 val = bytestream2_get_byte(&s->g);

                 if (val == marker) {

                     run = bytestream2_get_byte(&s->g);

                     if (run == 0)

                         run = bytestream2_get_le16(&s->g);
                     val = bytestream2_get_byte(&s->g);

                 }

                 if (!bytestream2_get_bytes_left(&s->g))

                     break;
 
                 if (bits_per_plane == 8) {

                     picmemset_8bpp(s, frame, val, run, &x, &y);

                     if (y < 0)

                         goto finish;

                 } else {

                     picmemset(s, frame, val, run, &x, &y, &plane, bits_per_plane);

                 }
             }
         }

         if (x < avctx->width) {

             int run = (y + 1) * avctx->width - x;
             if (bits_per_plane == 8)

                 picmemset_8bpp(s, frame, val, run, &x, &y);

             else

                 picmemset(s, frame, val, run / (8 / bits_per_plane), &x, &y, &plane, bits_per_plane);

         }

     } else {

         while (y >= 0 && bytestream2_get_bytes_left(&s->g) > 0) {

             memcpy(frame->data[0] + y * frame->linesize[0], s->g.buffer, FFMIN(avctx->width, bytestream2_get_bytes_left(&s->g)));

             bytestream2_skip(&s->g, avctx->width);

             y--;
         }

     }

 finish:

     *got_frame      = 1;

     return avpkt->size;

 }
 

 AVCodec ff_pictor_decoder = {

     .name           = "pictor",

     .long_name      = NULL_IF_CONFIG_SMALL("Pictor/PC Paint"),

     .type           = AVMEDIA_TYPE_VIDEO,

     .id             = AV_CODEC_ID_PICTOR,

     .priv_data_size = sizeof(PicContext),
     .decode         = decode_frame,
     .capabilities   = CODEC_CAP_DR1,

 };