libavcodec/pcx.c

   1 /*
   2  * PC Paintbrush PCX (.pcx) image decoder
   3  * Copyright (c) 2007, 2008 Ivo van Poorten
   4  *
   5  * This decoder does not support CGA palettes. I am unable to find samples
   6  * and Netpbm cannot generate them.
   7  *
   8  * This file is part of FFmpeg.
   9  *
  10  * FFmpeg is free software; you can redistribute it and/or
  11  * modify it under the terms of the GNU Lesser General Public
  12  * License as published by the Free Software Foundation; either
  13  * version 2.1 of the License, or (at your option) any later version.
  14  *
  15  * FFmpeg is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  18  * Lesser General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU Lesser General Public
  21  * License along with FFmpeg; if not, write to the Free Software
  22  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  23  */
  24
  25 #include "avcodec.h"
  26 #include "bytestream.h"
  27 #include "bitstream.h"
  28
  29 typedef struct PCXContext {
  30     AVFrame picture;
  31 } PCXContext;
  32
  33 static av_cold int pcx_init(AVCodecContext *avctx) {
  34     PCXContext *s = avctx->priv_data;
  35
  36     avcodec_get_frame_defaults(&s->picture);
  37     avctx->coded_frame= &s->picture;
  38
  39     return 0;
  40 }
  41
  42 /**
  43  * @return advanced src pointer
  44  */
  45 static const uint8_t *pcx_rle_decode(const uint8_t *src, uint8_t *dst,
  46                             unsigned int bytes_per_scanline) {
  47     unsigned int i = 0;
  48     unsigned char run, value;
  49
  50     while (i<bytes_per_scanline) {
  51         run = 1;
  52         value = *src++;
  53         if (value >= 0xc0) {
  54             run = value & 0x3f;
  55             value = *src++;
  56         }
  57         while (i<bytes_per_scanline && run--)
  58             dst[i++] = value;
  59     }
  60
  61     return src;
  62 }
  63
  64 static void pcx_palette(const uint8_t **src, uint32_t *dst, unsigned int pallen) {
  65     unsigned int i;
  66
  67     for (i=0; i<pallen; i++)
  68         *dst++ = bytestream_get_be24(src);
  69     memset(dst, 0, (256 - pallen) * sizeof(*dst));
  70 }
  71
  72 static int pcx_decode_frame(AVCodecContext *avctx, void *data, int *data_size,
  73                             const uint8_t *buf, int buf_size) {
  74     PCXContext * const s = avctx->priv_data;
  75     AVFrame *picture = data;
  76     AVFrame * const p = &s->picture;
  77     int xmin, ymin, xmax, ymax;
  78     unsigned int w, h, bits_per_pixel, bytes_per_line, nplanes, stride, y, x,
  79                  bytes_per_scanline;
  80     uint8_t *ptr;
  81     uint8_t const *bufstart = buf;
  82
  83     if (buf[0] != 0x0a || buf[1] > 5 || buf[1] == 1 || buf[2] != 1) {
  84         av_log(avctx, AV_LOG_ERROR, "this is not PCX encoded data\n");
  85         return -1;
  86     }
  87
  88     xmin = AV_RL16(buf+ 4);
  89     ymin = AV_RL16(buf+ 6);
  90     xmax = AV_RL16(buf+ 8);
  91     ymax = AV_RL16(buf+10);
  92
  93     if (xmax < xmin || ymax < ymin) {
  94         av_log(avctx, AV_LOG_ERROR, "invalid image dimensions\n");
  95         return -1;
  96     }
  97
  98     w = xmax - xmin + 1;
  99     h = ymax - ymin + 1;
 100
 101     bits_per_pixel     = buf[3];
 102     bytes_per_line     = AV_RL16(buf+66);
 103     nplanes            = buf[65];
 104     bytes_per_scanline = nplanes * bytes_per_line;
 105
 106     if (bytes_per_scanline < w * bits_per_pixel * nplanes / 8) {
 107         av_log(avctx, AV_LOG_ERROR, "PCX data is corrupted\n");
 108         return -1;
 109     }
 110
 111     switch ((nplanes<<8) + bits_per_pixel) {
 112         case 0x0308:
 113             avctx->pix_fmt = PIX_FMT_RGB24;
 114             break;
 115         case 0x0108:
 116         case 0x0104:
 117         case 0x0102:
 118         case 0x0101:
 119         case 0x0401:
 120         case 0x0301:
 121         case 0x0201:
 122             avctx->pix_fmt = PIX_FMT_PAL8;
 123             break;
 124         default:
 125             av_log(avctx, AV_LOG_ERROR, "invalid PCX file\n");
 126             return -1;
 127     }
 128
 129     buf += 128;
 130
 131     if (p->data[0])
 132         avctx->release_buffer(avctx, p);
 133
 134     if (avcodec_check_dimensions(avctx, w, h))
 135         return -1;
 136     if (w != avctx->width || h != avctx->height)
 137         avcodec_set_dimensions(avctx, w, h);
 138     if (avctx->get_buffer(avctx, p) < 0) {
 139         av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
 140         return -1;
 141     }
 142
 143     p->pict_type = FF_I_TYPE;
 144
 145     ptr    = p->data[0];
 146     stride = p->linesize[0];
 147
 148     if (nplanes == 3 && bits_per_pixel == 8) {
 149         uint8_t scanline[bytes_per_scanline];
 150
 151         for (y=0; y<h; y++) {
 152             buf = pcx_rle_decode(buf, scanline, bytes_per_scanline);
 153
 154             for (x=0; x<w; x++) {
 155                 ptr[3*x  ] = scanline[x                    ];
 156                 ptr[3*x+1] = scanline[x+ bytes_per_line    ];
 157                 ptr[3*x+2] = scanline[x+(bytes_per_line<<1)];
 158             }
 159
 160             ptr += stride;
 161         }
 162
 163     } else if (nplanes == 1 && bits_per_pixel == 8) {
 164         uint8_t scanline[bytes_per_scanline];
 165         const uint8_t *palstart = bufstart + buf_size - 769;
 166
 167         for (y=0; y<h; y++, ptr+=stride) {
 168             buf = pcx_rle_decode(buf, scanline, bytes_per_scanline);
 169             memcpy(ptr, scanline, w);
 170         }
 171
 172         if (buf != palstart) {
 173             av_log(avctx, AV_LOG_WARNING, "image data possibly corrupted\n");
 174             buf = palstart;
 175         }
 176         if (*buf++ != 12) {
 177             av_log(avctx, AV_LOG_ERROR, "expected palette after image data\n");
 178             return -1;
 179         }
 180
 181     } else if (nplanes == 1) {   /* all packed formats, max. 16 colors */
 182         uint8_t scanline[bytes_per_scanline];
 183         GetBitContext s;
 184
 185         for (y=0; y<h; y++) {
 186             init_get_bits(&s, scanline, bytes_per_scanline<<3);
 187
 188             buf = pcx_rle_decode(buf, scanline, bytes_per_scanline);
 189
 190             for (x=0; x<w; x++)
 191                 ptr[x] = get_bits(&s, bits_per_pixel);
 192             ptr += stride;
 193         }
 194
 195     } else {    /* planar, 4, 8 or 16 colors */
 196         uint8_t scanline[bytes_per_scanline];
 197         int i;
 198
 199         for (y=0; y<h; y++) {
 200             buf = pcx_rle_decode(buf, scanline, bytes_per_scanline);
 201
 202             for (x=0; x<w; x++) {
 203                 int m = 0x80 >> (x&7), v = 0;
 204                 for (i=nplanes - 1; i>=0; i--) {
 205                     v <<= 1;
 206                     v  += !!(scanline[i*bytes_per_line + (x>>3)] & m);
 207                 }
 208                 ptr[x] = v;
 209             }
 210             ptr += stride;
 211         }
 212     }
 213
 214     if (nplanes == 1 && bits_per_pixel == 8) {
 215         pcx_palette(&buf, (uint32_t *) p->data[1], 256);
 216     } else if (bits_per_pixel < 8) {
 217         const uint8_t *palette = bufstart+16;
 218         pcx_palette(&palette, (uint32_t *) p->data[1], 16);
 219     }
 220
 221     *picture = s->picture;
 222     *data_size = sizeof(AVFrame);
 223
 224     return buf - bufstart;
 225 }
 226
 227 static av_cold int pcx_end(AVCodecContext *avctx) {
 228     PCXContext *s = avctx->priv_data;
 229
 230     if(s->picture.data[0])
 231         avctx->release_buffer(avctx, &s->picture);
 232
 233     return 0;
 234 }
 235
 236 AVCodec pcx_decoder = {
 237     "pcx",
 238     CODEC_TYPE_VIDEO,
 239     CODEC_ID_PCX,
 240     sizeof(PCXContext),
 241     pcx_init,
 242     NULL,
 243     pcx_end,
 244     pcx_decode_frame,
 245     0,
 246     NULL,
 247     .long_name = NULL_IF_CONFIG_SMALL("PC Paintbrush PCX image"),
 248 };