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     int width, height;
  35     int nb_planes;
  36     GetByteContext g;
  37 } PicContext;
  38
  39 static void picmemset_8bpp(PicContext *s, AVFrame *frame, int value, int run,
  40                            int *x, int *y)
  41 {
  42     while (run > 0) {
  43         uint8_t *d = frame->data[0] + *y * 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, AVFrame *frame, 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 = frame->data[0] + *y * 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     AVFrame *frame = data;
 106     uint32_t *palette;
 107     int bits_per_plane, bpp, etype, esize, npal, pos_after_pal;
 108     int i, x, y, plane, tmp, ret;
 109
 110     bytestream2_init(&s->g, avpkt->data, avpkt->size);
 111
 112     if (bytestream2_get_bytes_left(&s->g) < 11)
 113         return AVERROR_INVALIDDATA;
 114
 115     if (bytestream2_get_le16u(&s->g) != 0x1234)
 116         return AVERROR_INVALIDDATA;
 117
 118     s->width       = bytestream2_get_le16u(&s->g);
 119     s->height      = bytestream2_get_le16u(&s->g);
 120     bytestream2_skip(&s->g, 4);
 121     tmp            = bytestream2_get_byteu(&s->g);
 122     bits_per_plane = tmp & 0xF;
 123     s->nb_planes   = (tmp >> 4) + 1;
 124     bpp            = bits_per_plane * s->nb_planes;
 125     if (bits_per_plane > 8 || bpp < 1 || bpp > 32) {
 126         avpriv_request_sample(avctx, "Unsupported bit depth");
 127         return AVERROR_PATCHWELCOME;
 128     }
 129
 130     if (bytestream2_peek_byte(&s->g) == 0xFF) {
 131         bytestream2_skip(&s->g, 2);
 132         etype = bytestream2_get_le16(&s->g);
 133         esize = bytestream2_get_le16(&s->g);
 134         if (bytestream2_get_bytes_left(&s->g) < esize)
 135             return AVERROR_INVALIDDATA;
 136     } else {
 137         etype = -1;
 138         esize = 0;
 139     }
 140
 141     avctx->pix_fmt = AV_PIX_FMT_PAL8;
 142
 143     if (s->width != avctx->width || s->height != avctx->height) {
 144         ret = ff_set_dimensions(avctx, s->width, s->height);
 145         if (ret < 0)
 146             return ret;
 147     }
 148
 149     if ((ret = ff_get_buffer(avctx, frame, 0)) < 0) {
 150         av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
 151         return ret;
 152     }
 153     memset(frame->data[0], 0, s->height * frame->linesize[0]);
 154     frame->pict_type           = AV_PICTURE_TYPE_I;
 155     frame->palette_has_changed = 1;
 156
 157     pos_after_pal = bytestream2_tell(&s->g) + esize;
 158     palette = (uint32_t*)frame->data[1];
 159     if (etype == 1 && esize > 1 && bytestream2_peek_byte(&s->g) < 6) {
 160         int idx = bytestream2_get_byte(&s->g);
 161         npal = 4;
 162         for (i = 0; i < npal; i++)
 163             palette[i] = ff_cga_palette[ cga_mode45_index[idx][i] ];
 164     } else if (etype == 2) {
 165         npal = FFMIN(esize, 16);
 166         for (i = 0; i < npal; i++) {
 167             int pal_idx = bytestream2_get_byte(&s->g);
 168             palette[i]  = ff_cga_palette[FFMIN(pal_idx, 16)];
 169         }
 170     } else if (etype == 3) {
 171         npal = FFMIN(esize, 16);
 172         for (i = 0; i < npal; i++) {
 173             int pal_idx = bytestream2_get_byte(&s->g);
 174             palette[i]  = ff_ega_palette[FFMIN(pal_idx, 63)];
 175         }
 176     } else if (etype == 4 || etype == 5) {
 177         npal = FFMIN(esize / 3, 256);
 178         for (i = 0; i < npal; i++)
 179             palette[i] = bytestream2_get_be24(&s->g) << 2;
 180     } else {
 181         if (bpp == 1) {
 182             npal = 2;
 183             palette[0] = 0x000000;
 184             palette[1] = 0xFFFFFF;
 185         } else if (bpp == 2) {
 186             npal = 4;
 187             for (i = 0; i < npal; i++)
 188                 palette[i] = ff_cga_palette[ cga_mode45_index[0][i] ];
 189         } else {
 190             npal = 16;
 191             memcpy(palette, ff_cga_palette, npal * 4);
 192         }
 193     }
 194     // fill remaining palette entries
 195     memset(palette + npal, 0, AVPALETTE_SIZE - npal * 4);
 196     // skip remaining palette bytes
 197     bytestream2_seek(&s->g, pos_after_pal, SEEK_SET);
 198
 199     x = 0;
 200     y = s->height - 1;
 201     plane = 0;
 202     if (bytestream2_get_le16(&s->g)) {
 203         while (bytestream2_get_bytes_left(&s->g) >= 6) {
 204             int stop_size, marker, t1, t2;
 205
 206             t1        = bytestream2_get_bytes_left(&s->g);
 207             t2        = bytestream2_get_le16(&s->g);
 208             stop_size = t1 - FFMIN(t1, t2);
 209             // ignore uncompressed block size
 210             bytestream2_skip(&s->g, 2);
 211             marker    = bytestream2_get_byte(&s->g);
 212
 213             while (plane < s->nb_planes &&
 214                    bytestream2_get_bytes_left(&s->g) > stop_size) {
 215                 int run = 1;
 216                 int val = bytestream2_get_byte(&s->g);
 217                 if (val == marker) {
 218                     run = bytestream2_get_byte(&s->g);
 219                     if (run == 0)
 220                         run = bytestream2_get_le16(&s->g);
 221                     val = bytestream2_get_byte(&s->g);
 222                 }
 223                 if (!bytestream2_get_bytes_left(&s->g))
 224                     break;
 225
 226                 if (bits_per_plane == 8) {
 227                     picmemset_8bpp(s, frame, val, run, &x, &y);
 228                     if (y < 0)
 229                         goto finish;
 230                 } else {
 231                     picmemset(s, frame, val, run, &x, &y, &plane, bits_per_plane);
 232                 }
 233             }
 234         }
 235     } else {
 236         avpriv_request_sample(avctx, "Uncompressed image");
 237         return avpkt->size;
 238     }
 239 finish:
 240
 241     *got_frame      = 1;
 242     return avpkt->size;
 243 }
 244
 245 AVCodec ff_pictor_decoder = {
 246     .name           = "pictor",
 247     .long_name      = NULL_IF_CONFIG_SMALL("Pictor/PC Paint"),
 248     .type           = AVMEDIA_TYPE_VIDEO,
 249     .id             = AV_CODEC_ID_PICTOR,
 250     .priv_data_size = sizeof(PicContext),
 251     .decode         = decode_frame,
 252     .capabilities   = AV_CODEC_CAP_DR1,
 253 };