libavcodec/pictordec.c

   1 /*
   2  * Pictor/PC Paint decoder
   3  * Copyright (c) 2010 Peter Ross <pross@xvid.org>
   4  *
   5  * This file is part of Libav.
   6  *
   7  * Libav is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Lesser General Public
   9  * License as published by the Free Software Foundation; either
  10  * version 2.1 of the License, or (at your option) any later version.
  11  *
  12  * Libav is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public
  18  * License along with Libav; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  20  */
  21
  22 /**
  23  * @file
  24  * Pictor/PC Paint decoder
  25  */
  26
  27 #include "libavutil/imgutils.h"
  28 #include "avcodec.h"
  29 #include "bytestream.h"
  30 #include "cga_data.h"
  31 #include "internal.h"
  32
  33 typedef struct PicContext {
  34     AVFrame frame;
  35     int width, height;
  36     int nb_planes;
  37     GetByteContext g;
  38 } PicContext;
  39
  40 static void picmemset_8bpp(PicContext *s, int value, int run, int *x, int *y)
  41 {
  42     while (run > 0) {
  43         uint8_t *d = s->frame.data[0] + *y * s->frame.linesize[0];
  44         if (*x + run >= s->width) {
  45             int n = s->width - *x;
  46             memset(d + *x, value, n);
  47             run -= n;
  48             *x = 0;
  49             *y -= 1;
  50             if (*y < 0)
  51                 break;
  52         } else {
  53             memset(d + *x, value, run);
  54             *x += run;
  55             break;
  56         }
  57     }
  58 }
  59
  60 static void picmemset(PicContext *s, int value, int run,
  61                       int *x, int *y, int *plane, int bits_per_plane)
  62 {
  63     uint8_t *d;
  64     int shift = *plane * bits_per_plane;
  65     int mask  = ((1 << bits_per_plane) - 1) << shift;
  66     value   <<= shift;
  67
  68     while (run > 0) {
  69         int j;
  70         for (j = 8-bits_per_plane; j >= 0; j -= bits_per_plane) {
  71             d = s->frame.data[0] + *y * s->frame.linesize[0];
  72             d[*x] |= (value >> j) & mask;
  73             *x += 1;
  74             if (*x == s->width) {
  75                 *y -= 1;
  76                 *x = 0;
  77                 if (*y < 0) {
  78                    *y = s->height - 1;
  79                    *plane += 1;
  80                    value <<= bits_per_plane;
  81                    mask  <<= bits_per_plane;
  82                    if (*plane >= s->nb_planes)
  83                        break;
  84                 }
  85             }
  86         }
  87         run--;
  88     }
  89 }
  90
  91 static const uint8_t cga_mode45_index[6][4] = {
  92     [0] = { 0, 3,  5,   7 }, // mode4, palette#1, low intensity
  93     [1] = { 0, 2,  4,   6 }, // mode4, palette#2, low intensity
  94     [2] = { 0, 3,  4,   7 }, // mode5, low intensity
  95     [3] = { 0, 11, 13, 15 }, // mode4, palette#1, high intensity
  96     [4] = { 0, 10, 12, 14 }, // mode4, palette#2, high intensity
  97     [5] = { 0, 11, 12, 15 }, // mode5, high intensity
  98 };
  99
 100 static int decode_frame(AVCodecContext *avctx,
 101                         void *data, int *got_frame,
 102                         AVPacket *avpkt)
 103 {
 104     PicContext *s = avctx->priv_data;
 105     uint32_t *palette;
 106     int bits_per_plane, bpp, etype, esize, npal, pos_after_pal;
 107     int i, x, y, plane, tmp;
 108
 109     bytestream2_init(&s->g, avpkt->data, avpkt->size);
 110
 111     if (bytestream2_get_bytes_left(&s->g) < 11)
 112         return AVERROR_INVALIDDATA;
 113
 114     if (bytestream2_get_le16u(&s->g) != 0x1234)
 115         return AVERROR_INVALIDDATA;
 116
 117     s->width       = bytestream2_get_le16u(&s->g);
 118     s->height      = bytestream2_get_le16u(&s->g);
 119     bytestream2_skip(&s->g, 4);
 120     tmp            = bytestream2_get_byteu(&s->g);
 121     bits_per_plane = tmp & 0xF;
 122     s->nb_planes   = (tmp >> 4) + 1;
 123     bpp            = bits_per_plane * s->nb_planes;
 124     if (bits_per_plane > 8 || bpp < 1 || bpp > 32) {
 125         av_log_ask_for_sample(s, "unsupported bit depth\n");
 126         return AVERROR_PATCHWELCOME;
 127     }
 128
 129     if (bytestream2_peek_byte(&s->g) == 0xFF) {
 130         bytestream2_skip(&s->g, 2);
 131         etype = bytestream2_get_le16(&s->g);
 132         esize = bytestream2_get_le16(&s->g);
 133         if (bytestream2_get_bytes_left(&s->g) < esize)
 134             return AVERROR_INVALIDDATA;
 135     } else {
 136         etype = -1;
 137         esize = 0;
 138     }
 139
 140     avctx->pix_fmt = AV_PIX_FMT_PAL8;
 141
 142     if (s->width != avctx->width && s->height != avctx->height) {
 143         if (av_image_check_size(s->width, s->height, 0, avctx) < 0)
 144             return -1;
 145         avcodec_set_dimensions(avctx, s->width, s->height);
 146         if (s->frame.data[0])
 147             avctx->release_buffer(avctx, &s->frame);
 148     }
 149
 150     if (ff_get_buffer(avctx, &s->frame) < 0){
 151         av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
 152         return -1;
 153     }
 154     memset(s->frame.data[0], 0, s->height * s->frame.linesize[0]);
 155     s->frame.pict_type           = AV_PICTURE_TYPE_I;
 156     s->frame.palette_has_changed = 1;
 157
 158     pos_after_pal = bytestream2_tell(&s->g) + esize;
 159     palette = (uint32_t*)s->frame.data[1];
 160     if (etype == 1 && esize > 1 && bytestream2_peek_byte(&s->g) < 6) {
 161         int idx = bytestream2_get_byte(&s->g);
 162         npal = 4;
 163         for (i = 0; i < npal; i++)
 164             palette[i] = ff_cga_palette[ cga_mode45_index[idx][i] ];
 165     } else if (etype == 2) {
 166         npal = FFMIN(esize, 16);
 167         for (i = 0; i < npal; i++) {
 168             int pal_idx = bytestream2_get_byte(&s->g);
 169             palette[i]  = ff_cga_palette[FFMIN(pal_idx, 16)];
 170         }
 171     } else if (etype == 3) {
 172         npal = FFMIN(esize, 16);
 173         for (i = 0; i < npal; i++) {
 174             int pal_idx = bytestream2_get_byte(&s->g);
 175             palette[i]  = ff_ega_palette[FFMIN(pal_idx, 63)];
 176         }
 177     } else if (etype == 4 || etype == 5) {
 178         npal = FFMIN(esize / 3, 256);
 179         for (i = 0; i < npal; i++)
 180             palette[i] = bytestream2_get_be24(&s->g) << 2;
 181     } else {
 182         if (bpp == 1) {
 183             npal = 2;
 184             palette[0] = 0x000000;
 185             palette[1] = 0xFFFFFF;
 186         } else if (bpp == 2) {
 187             npal = 4;
 188             for (i = 0; i < npal; i++)
 189                 palette[i] = ff_cga_palette[ cga_mode45_index[0][i] ];
 190         } else {
 191             npal = 16;
 192             memcpy(palette, ff_cga_palette, npal * 4);
 193         }
 194     }
 195     // fill remaining palette entries
 196     memset(palette + npal, 0, AVPALETTE_SIZE - npal * 4);
 197     // skip remaining palette bytes
 198     bytestream2_seek(&s->g, pos_after_pal, SEEK_SET);
 199
 200     x = 0;
 201     y = s->height - 1;
 202     plane = 0;
 203     if (bytestream2_get_le16(&s->g)) {
 204         while (bytestream2_get_bytes_left(&s->g) >= 6) {
 205             int stop_size, marker, t1, t2;
 206
 207             t1        = bytestream2_get_bytes_left(&s->g);
 208             t2        = bytestream2_get_le16(&s->g);
 209             stop_size = t1 - FFMIN(t1, t2);
 210             // ignore uncompressed block size
 211             bytestream2_skip(&s->g, 2);
 212             marker    = bytestream2_get_byte(&s->g);
 213
 214             while (plane < s->nb_planes &&
 215                    bytestream2_get_bytes_left(&s->g) > stop_size) {
 216                 int run = 1;
 217                 int val = bytestream2_get_byte(&s->g);
 218                 if (val == marker) {
 219                     run = bytestream2_get_byte(&s->g);
 220                     if (run == 0)
 221                         run = bytestream2_get_le16(&s->g);
 222                     val = bytestream2_get_byte(&s->g);
 223                 }
 224                 if (!bytestream2_get_bytes_left(&s->g))
 225                     break;
 226
 227                 if (bits_per_plane == 8) {
 228                     picmemset_8bpp(s, val, run, &x, &y);
 229                     if (y < 0)
 230                         break;
 231                 } else {
 232                     picmemset(s, val, run, &x, &y, &plane, bits_per_plane);
 233                 }
 234             }
 235         }
 236     } else {
 237         av_log_ask_for_sample(s, "uncompressed image\n");
 238         return avpkt->size;
 239     }
 240
 241     *got_frame      = 1;
 242     *(AVFrame*)data = s->frame;
 243     return avpkt->size;
 244 }
 245
 246 static av_cold int decode_end(AVCodecContext *avctx)
 247 {
 248     PicContext *s = avctx->priv_data;
 249     if (s->frame.data[0])
 250         avctx->release_buffer(avctx, &s->frame);
 251     return 0;
 252 }
 253
 254 AVCodec ff_pictor_decoder = {
 255     .name           = "pictor",
 256     .type           = AVMEDIA_TYPE_VIDEO,
 257     .id             = AV_CODEC_ID_PICTOR,
 258     .priv_data_size = sizeof(PicContext),
 259     .close          = decode_end,
 260     .decode         = decode_frame,
 261     .capabilities   = CODEC_CAP_DR1,
 262     .long_name      = NULL_IF_CONFIG_SMALL("Pictor/PC Paint"),
 263 };