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 Libav.
   9  *
  10  * Libav 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  * Libav 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 Libav; if not, write to the Free Software
  22  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  23  */
  24
  25 #include "libavutil/imgutils.h"
  26 #include "avcodec.h"
  27 #include "bytestream.h"
  28 #include "get_bits.h"
  29 #include "internal.h"
  30
  31 typedef struct PCXContext {
  32     AVFrame picture;
  33 } PCXContext;
  34
  35 static av_cold int pcx_init(AVCodecContext *avctx) {
  36     PCXContext *s = avctx->priv_data;
  37
  38     avcodec_get_frame_defaults(&s->picture);
  39     avctx->coded_frame= &s->picture;
  40
  41     return 0;
  42 }
  43
  44 /**
  45  * @return advanced src pointer
  46  */
  47 static const uint8_t *pcx_rle_decode(const uint8_t *src, uint8_t *dst,
  48                             unsigned int bytes_per_scanline, int compressed) {
  49     unsigned int i = 0;
  50     unsigned char run, value;
  51
  52     if (compressed) {
  53         while (i<bytes_per_scanline) {
  54             run = 1;
  55             value = *src++;
  56             if (value >= 0xc0) {
  57                 run = value & 0x3f;
  58                 value = *src++;
  59             }
  60             while (i<bytes_per_scanline && run--)
  61                 dst[i++] = value;
  62         }
  63     } else {
  64         memcpy(dst, src, bytes_per_scanline);
  65         src += bytes_per_scanline;
  66     }
  67
  68     return src;
  69 }
  70
  71 static void pcx_palette(const uint8_t **src, uint32_t *dst, unsigned int pallen) {
  72     unsigned int i;
  73
  74     for (i=0; i<pallen; i++)
  75         *dst++ = bytestream_get_be24(src);
  76     if (pallen < 256)
  77         memset(dst, 0, (256 - pallen) * sizeof(*dst));
  78 }
  79
  80 static int pcx_decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
  81                             AVPacket *avpkt) {
  82     const uint8_t *buf = avpkt->data;
  83     int buf_size = avpkt->size;
  84     PCXContext * const s = avctx->priv_data;
  85     AVFrame *picture = data;
  86     AVFrame * const p = &s->picture;
  87     int compressed, xmin, ymin, xmax, ymax;
  88     unsigned int w, h, bits_per_pixel, bytes_per_line, nplanes, stride, y, x,
  89                  bytes_per_scanline;
  90     uint8_t *ptr;
  91     uint8_t const *bufstart = buf;
  92     uint8_t *scanline;
  93     int ret = -1;
  94
  95     if (buf[0] != 0x0a || buf[1] > 5) {
  96         av_log(avctx, AV_LOG_ERROR, "this is not PCX encoded data\n");
  97         return AVERROR_INVALIDDATA;
  98     }
  99
 100     compressed = buf[2];
 101     xmin = AV_RL16(buf+ 4);
 102     ymin = AV_RL16(buf+ 6);
 103     xmax = AV_RL16(buf+ 8);
 104     ymax = AV_RL16(buf+10);
 105
 106     if (xmax < xmin || ymax < ymin) {
 107         av_log(avctx, AV_LOG_ERROR, "invalid image dimensions\n");
 108         return AVERROR_INVALIDDATA;
 109     }
 110
 111     w = xmax - xmin + 1;
 112     h = ymax - ymin + 1;
 113
 114     bits_per_pixel     = buf[3];
 115     bytes_per_line     = AV_RL16(buf+66);
 116     nplanes            = buf[65];
 117     bytes_per_scanline = nplanes * bytes_per_line;
 118
 119     if (bytes_per_scanline < w * bits_per_pixel * nplanes / 8) {
 120         av_log(avctx, AV_LOG_ERROR, "PCX data is corrupted\n");
 121         return AVERROR_INVALIDDATA;
 122     }
 123
 124     switch ((nplanes<<8) + bits_per_pixel) {
 125         case 0x0308:
 126             avctx->pix_fmt = AV_PIX_FMT_RGB24;
 127             break;
 128         case 0x0108:
 129         case 0x0104:
 130         case 0x0102:
 131         case 0x0101:
 132         case 0x0401:
 133         case 0x0301:
 134         case 0x0201:
 135             avctx->pix_fmt = AV_PIX_FMT_PAL8;
 136             break;
 137         default:
 138             av_log(avctx, AV_LOG_ERROR, "invalid PCX file\n");
 139             return AVERROR_INVALIDDATA;
 140     }
 141
 142     buf += 128;
 143
 144     if (p->data[0])
 145         avctx->release_buffer(avctx, p);
 146
 147     if ((ret = av_image_check_size(w, h, 0, avctx)) < 0)
 148         return ret;
 149     if (w != avctx->width || h != avctx->height)
 150         avcodec_set_dimensions(avctx, w, h);
 151     if ((ret = ff_get_buffer(avctx, p)) < 0) {
 152         av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
 153         return ret;
 154     }
 155
 156     p->pict_type = AV_PICTURE_TYPE_I;
 157
 158     ptr    = p->data[0];
 159     stride = p->linesize[0];
 160
 161     scanline = av_malloc(bytes_per_scanline);
 162     if (!scanline)
 163         return AVERROR(ENOMEM);
 164
 165     if (nplanes == 3 && bits_per_pixel == 8) {
 166         for (y=0; y<h; y++) {
 167             buf = pcx_rle_decode(buf, scanline, bytes_per_scanline, compressed);
 168
 169             for (x=0; x<w; x++) {
 170                 ptr[3*x  ] = scanline[x                    ];
 171                 ptr[3*x+1] = scanline[x+ bytes_per_line    ];
 172                 ptr[3*x+2] = scanline[x+(bytes_per_line<<1)];
 173             }
 174
 175             ptr += stride;
 176         }
 177
 178     } else if (nplanes == 1 && bits_per_pixel == 8) {
 179         const uint8_t *palstart = bufstart + buf_size - 769;
 180
 181         for (y=0; y<h; y++, ptr+=stride) {
 182             buf = pcx_rle_decode(buf, scanline, bytes_per_scanline, compressed);
 183             memcpy(ptr, scanline, w);
 184         }
 185
 186         if (buf != palstart) {
 187             av_log(avctx, AV_LOG_WARNING, "image data possibly corrupted\n");
 188             buf = palstart;
 189         }
 190         if (*buf++ != 12) {
 191             av_log(avctx, AV_LOG_ERROR, "expected palette after image data\n");
 192             goto end;
 193         }
 194
 195     } else if (nplanes == 1) {   /* all packed formats, max. 16 colors */
 196         GetBitContext s;
 197
 198         for (y=0; y<h; y++) {
 199             init_get_bits(&s, scanline, bytes_per_scanline<<3);
 200
 201             buf = pcx_rle_decode(buf, scanline, bytes_per_scanline, compressed);
 202
 203             for (x=0; x<w; x++)
 204                 ptr[x] = get_bits(&s, bits_per_pixel);
 205             ptr += stride;
 206         }
 207
 208     } else {    /* planar, 4, 8 or 16 colors */
 209         int i;
 210
 211         for (y=0; y<h; y++) {
 212             buf = pcx_rle_decode(buf, scanline, bytes_per_scanline, compressed);
 213
 214             for (x=0; x<w; x++) {
 215                 int m = 0x80 >> (x&7), v = 0;
 216                 for (i=nplanes - 1; i>=0; i--) {
 217                     v <<= 1;
 218                     v  += !!(scanline[i*bytes_per_line + (x>>3)] & m);
 219                 }
 220                 ptr[x] = v;
 221             }
 222             ptr += stride;
 223         }
 224     }
 225
 226     if (nplanes == 1 && bits_per_pixel == 8) {
 227         pcx_palette(&buf, (uint32_t *) p->data[1], 256);
 228     } else if (bits_per_pixel < 8) {
 229         const uint8_t *palette = bufstart+16;
 230         pcx_palette(&palette, (uint32_t *) p->data[1], 16);
 231     }
 232
 233     *picture = s->picture;
 234     *got_frame = 1;
 235
 236     ret = buf - bufstart;
 237 end:
 238     av_free(scanline);
 239     return ret;
 240 }
 241
 242 static av_cold int pcx_end(AVCodecContext *avctx) {
 243     PCXContext *s = avctx->priv_data;
 244
 245     if(s->picture.data[0])
 246         avctx->release_buffer(avctx, &s->picture);
 247
 248     return 0;
 249 }
 250
 251 AVCodec ff_pcx_decoder = {
 252     .name           = "pcx",
 253     .type           = AVMEDIA_TYPE_VIDEO,
 254     .id             = AV_CODEC_ID_PCX,
 255     .priv_data_size = sizeof(PCXContext),
 256     .init           = pcx_init,
 257     .close          = pcx_end,
 258     .decode         = pcx_decode_frame,
 259     .capabilities   = CODEC_CAP_DR1,
 260     .long_name      = NULL_IF_CONFIG_SMALL("PC Paintbrush PCX image"),
 261 };