pcx.c 6.9 KB
Newer Older
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26
/*
 * PC Paintbrush PCX (.pcx) image decoder
 * Copyright (c) 2007, 2008 Ivo van Poorten
 *
 * This decoder does not support CGA palettes. I am unable to find samples
 * and Netpbm cannot generate them.
 *
 * 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
 */

#include "avcodec.h"
#include "bytestream.h"
27
#include "get_bits.h"
28 29 30 31 32

typedef struct PCXContext {
    AVFrame picture;
} PCXContext;

33
static av_cold int pcx_init(AVCodecContext *avctx) {
34 35 36 37 38 39 40 41 42 43 44
    PCXContext *s = avctx->priv_data;

    avcodec_get_frame_defaults(&s->picture);
    avctx->coded_frame= &s->picture;

    return 0;
}

/**
 * @return advanced src pointer
 */
45
static const uint8_t *pcx_rle_decode(const uint8_t *src, uint8_t *dst,
46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63
                            unsigned int bytes_per_scanline) {
    unsigned int i = 0;
    unsigned char run, value;

    while (i<bytes_per_scanline) {
        run = 1;
        value = *src++;
        if (value >= 0xc0) {
            run = value & 0x3f;
            value = *src++;
        }
        while (i<bytes_per_scanline && run--)
            dst[i++] = value;
    }

    return src;
}

Michael Niedermayer's avatar
const  
Michael Niedermayer committed
64
static void pcx_palette(const uint8_t **src, uint32_t *dst, unsigned int pallen) {
65 66 67 68 69 70 71 72
    unsigned int i;

    for (i=0; i<pallen; i++)
        *dst++ = bytestream_get_be24(src);
    memset(dst, 0, (256 - pallen) * sizeof(*dst));
}

static int pcx_decode_frame(AVCodecContext *avctx, void *data, int *data_size,
73 74 75
                            AVPacket *avpkt) {
    const uint8_t *buf = avpkt->data;
    int buf_size = avpkt->size;
76 77
    PCXContext * const s = avctx->priv_data;
    AVFrame *picture = data;
Ivo van Poorten's avatar
Ivo van Poorten committed
78
    AVFrame * const p = &s->picture;
79 80 81
    int xmin, ymin, xmax, ymax;
    unsigned int w, h, bits_per_pixel, bytes_per_line, nplanes, stride, y, x,
                 bytes_per_scanline;
Michael Niedermayer's avatar
const  
Michael Niedermayer committed
82 83
    uint8_t *ptr;
    uint8_t const *bufstart = buf;
84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166

    if (buf[0] != 0x0a || buf[1] > 5 || buf[1] == 1 || buf[2] != 1) {
        av_log(avctx, AV_LOG_ERROR, "this is not PCX encoded data\n");
        return -1;
    }

    xmin = AV_RL16(buf+ 4);
    ymin = AV_RL16(buf+ 6);
    xmax = AV_RL16(buf+ 8);
    ymax = AV_RL16(buf+10);

    if (xmax < xmin || ymax < ymin) {
        av_log(avctx, AV_LOG_ERROR, "invalid image dimensions\n");
        return -1;
    }

    w = xmax - xmin + 1;
    h = ymax - ymin + 1;

    bits_per_pixel     = buf[3];
    bytes_per_line     = AV_RL16(buf+66);
    nplanes            = buf[65];
    bytes_per_scanline = nplanes * bytes_per_line;

    if (bytes_per_scanline < w * bits_per_pixel * nplanes / 8) {
        av_log(avctx, AV_LOG_ERROR, "PCX data is corrupted\n");
        return -1;
    }

    switch ((nplanes<<8) + bits_per_pixel) {
        case 0x0308:
            avctx->pix_fmt = PIX_FMT_RGB24;
            break;
        case 0x0108:
        case 0x0104:
        case 0x0102:
        case 0x0101:
        case 0x0401:
        case 0x0301:
        case 0x0201:
            avctx->pix_fmt = PIX_FMT_PAL8;
            break;
        default:
            av_log(avctx, AV_LOG_ERROR, "invalid PCX file\n");
            return -1;
    }

    buf += 128;

    if (p->data[0])
        avctx->release_buffer(avctx, p);

    if (avcodec_check_dimensions(avctx, w, h))
        return -1;
    if (w != avctx->width || h != avctx->height)
        avcodec_set_dimensions(avctx, w, h);
    if (avctx->get_buffer(avctx, p) < 0) {
        av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
        return -1;
    }

    p->pict_type = FF_I_TYPE;

    ptr    = p->data[0];
    stride = p->linesize[0];

    if (nplanes == 3 && bits_per_pixel == 8) {
        uint8_t scanline[bytes_per_scanline];

        for (y=0; y<h; y++) {
            buf = pcx_rle_decode(buf, scanline, bytes_per_scanline);

            for (x=0; x<w; x++) {
                ptr[3*x  ] = scanline[x                    ];
                ptr[3*x+1] = scanline[x+ bytes_per_line    ];
                ptr[3*x+2] = scanline[x+(bytes_per_line<<1)];
            }

            ptr += stride;
        }

    } else if (nplanes == 1 && bits_per_pixel == 8) {
        uint8_t scanline[bytes_per_scanline];
Michael Niedermayer's avatar
const  
Michael Niedermayer committed
167
        const uint8_t *palstart = bufstart + buf_size - 769;
168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218

        for (y=0; y<h; y++, ptr+=stride) {
            buf = pcx_rle_decode(buf, scanline, bytes_per_scanline);
            memcpy(ptr, scanline, w);
        }

        if (buf != palstart) {
            av_log(avctx, AV_LOG_WARNING, "image data possibly corrupted\n");
            buf = palstart;
        }
        if (*buf++ != 12) {
            av_log(avctx, AV_LOG_ERROR, "expected palette after image data\n");
            return -1;
        }

    } else if (nplanes == 1) {   /* all packed formats, max. 16 colors */
        uint8_t scanline[bytes_per_scanline];
        GetBitContext s;

        for (y=0; y<h; y++) {
            init_get_bits(&s, scanline, bytes_per_scanline<<3);

            buf = pcx_rle_decode(buf, scanline, bytes_per_scanline);

            for (x=0; x<w; x++)
                ptr[x] = get_bits(&s, bits_per_pixel);
            ptr += stride;
        }

    } else {    /* planar, 4, 8 or 16 colors */
        uint8_t scanline[bytes_per_scanline];
        int i;

        for (y=0; y<h; y++) {
            buf = pcx_rle_decode(buf, scanline, bytes_per_scanline);

            for (x=0; x<w; x++) {
                int m = 0x80 >> (x&7), v = 0;
                for (i=nplanes - 1; i>=0; i--) {
                    v <<= 1;
                    v  += !!(scanline[i*bytes_per_line + (x>>3)] & m);
                }
                ptr[x] = v;
            }
            ptr += stride;
        }
    }

    if (nplanes == 1 && bits_per_pixel == 8) {
        pcx_palette(&buf, (uint32_t *) p->data[1], 256);
    } else if (bits_per_pixel < 8) {
Michael Niedermayer's avatar
const  
Michael Niedermayer committed
219
        const uint8_t *palette = bufstart+16;
220 221 222 223 224 225 226 227 228
        pcx_palette(&palette, (uint32_t *) p->data[1], 16);
    }

    *picture = s->picture;
    *data_size = sizeof(AVFrame);

    return buf - bufstart;
}

229
static av_cold int pcx_end(AVCodecContext *avctx) {
230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246
    PCXContext *s = avctx->priv_data;

    if(s->picture.data[0])
        avctx->release_buffer(avctx, &s->picture);

    return 0;
}

AVCodec pcx_decoder = {
    "pcx",
    CODEC_TYPE_VIDEO,
    CODEC_ID_PCX,
    sizeof(PCXContext),
    pcx_init,
    NULL,
    pcx_end,
    pcx_decode_frame,
247
    CODEC_CAP_DR1,
248
    NULL,
249
    .long_name = NULL_IF_CONFIG_SMALL("PC Paintbrush PCX image"),
250
};