aboutsummaryrefslogtreecommitdiffstats
path: root/libavcodec/pcx.c
blob: 6487aa573b121a477b539c83d508c2ec22d94093 (plain) (blame)
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
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
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
167
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
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
/*
 * 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 "libavutil/imgutils.h"
#include "avcodec.h"
#include "bytestream.h"
#include "get_bits.h"
#include "internal.h"

static void pcx_rle_decode(GetByteContext *gb,
                           uint8_t *dst,
                           unsigned int bytes_per_scanline,
                           int compressed)
{
    unsigned int i = 0;
    unsigned char run, value;

    if (compressed) {
        while (i < bytes_per_scanline && bytestream2_get_bytes_left(gb)>0) {
            run   = 1;
            value = bytestream2_get_byte(gb);
            if (value >= 0xc0 && bytestream2_get_bytes_left(gb)>0) {
                run   = value & 0x3f;
                value = bytestream2_get_byte(gb);
            }
            while (i < bytes_per_scanline && run--)
                dst[i++] = value;
        }
    } else {
        bytestream2_get_buffer(gb, dst, bytes_per_scanline);
    }
}

static void pcx_palette(GetByteContext *gb, uint32_t *dst, int pallen)
{
    int i;

    pallen = FFMIN(pallen, bytestream2_get_bytes_left(gb) / 3);
    for (i = 0; i < pallen; i++)
        *dst++ = 0xFF000000 | bytestream2_get_be24u(gb);
    if (pallen < 256)
        memset(dst, 0, (256 - pallen) * sizeof(*dst));
}

static int pcx_decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
                            AVPacket *avpkt)
{
    GetByteContext gb;
    AVFrame * const p  = data;
    int compressed, xmin, ymin, xmax, ymax;
    int ret;
    unsigned int w, h, bits_per_pixel, bytes_per_line, nplanes, stride, y, x,
                 bytes_per_scanline;
    uint8_t *ptr, *scanline;

    if (avpkt->size < 128)
        return AVERROR_INVALIDDATA;

    bytestream2_init(&gb, avpkt->data, avpkt->size);

    if (bytestream2_get_byteu(&gb) != 0x0a || bytestream2_get_byteu(&gb) > 5) {
        av_log(avctx, AV_LOG_ERROR, "this is not PCX encoded data\n");
        return AVERROR_INVALIDDATA;
    }

    compressed                     = bytestream2_get_byteu(&gb);
    bits_per_pixel                 = bytestream2_get_byteu(&gb);
    xmin                           = bytestream2_get_le16u(&gb);
    ymin                           = bytestream2_get_le16u(&gb);
    xmax                           = bytestream2_get_le16u(&gb);
    ymax                           = bytestream2_get_le16u(&gb);
    avctx->sample_aspect_ratio.num = bytestream2_get_le16u(&gb);
    avctx->sample_aspect_ratio.den = bytestream2_get_le16u(&gb);

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

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

    bytestream2_skipu(&gb, 49);
    nplanes            = bytestream2_get_byteu(&gb);
    bytes_per_line     = bytestream2_get_le16u(&gb);
    bytes_per_scanline = nplanes * bytes_per_line;

    if (bytes_per_scanline < (w * bits_per_pixel * nplanes + 7) / 8 ||
        (!compressed && bytes_per_scanline > bytestream2_get_bytes_left(&gb) / h)) {
        av_log(avctx, AV_LOG_ERROR, "PCX data is corrupted\n");
        return AVERROR_INVALIDDATA;
    }

    switch ((nplanes << 8) + bits_per_pixel) {
    case 0x0308:
        avctx->pix_fmt = AV_PIX_FMT_RGB24;
        break;
    case 0x0108:
    case 0x0104:
    case 0x0102:
    case 0x0101:
    case 0x0401:
    case 0x0301:
    case 0x0201:
        avctx->pix_fmt = AV_PIX_FMT_PAL8;
        break;
    default:
        av_log(avctx, AV_LOG_ERROR, "invalid PCX file\n");
        return AVERROR_INVALIDDATA;
    }

    bytestream2_skipu(&gb, 60);

    if ((ret = ff_set_dimensions(avctx, w, h)) < 0)
        return ret;

    if ((ret = ff_get_buffer(avctx, p, 0)) < 0)
        return ret;

    p->pict_type = AV_PICTURE_TYPE_I;

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

    scanline = av_malloc(bytes_per_scanline + FF_INPUT_BUFFER_PADDING_SIZE);
    if (!scanline)
        return AVERROR(ENOMEM);

    if (nplanes == 3 && bits_per_pixel == 8) {
        for (y = 0; y < h; y++) {
            pcx_rle_decode(&gb, scanline, bytes_per_scanline, compressed);

            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) {
        int palstart = avpkt->size - 769;

        if (avpkt->size < 769) {
            av_log(avctx, AV_LOG_ERROR, "File is too short\n");
            ret = avctx->err_recognition & AV_EF_EXPLODE ?
                  AVERROR_INVALIDDATA : avpkt->size;
            goto end;
        }

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

        if (bytestream2_tell(&gb) != palstart) {
            av_log(avctx, AV_LOG_WARNING, "image data possibly corrupted\n");
            bytestream2_seek(&gb, palstart, SEEK_SET);
        }
        if (bytestream2_get_byte(&gb) != 12) {
            av_log(avctx, AV_LOG_ERROR, "expected palette after image data\n");
            ret = avctx->err_recognition & AV_EF_EXPLODE ?
                  AVERROR_INVALIDDATA : avpkt->size;
            goto end;
        }
    } else if (nplanes == 1) {   /* all packed formats, max. 16 colors */
        GetBitContext s;

        for (y = 0; y < h; y++) {
            init_get_bits8(&s, scanline, bytes_per_scanline);

            pcx_rle_decode(&gb, scanline, bytes_per_scanline, compressed);

            for (x = 0; x < w; x++)
                ptr[x] = get_bits(&s, bits_per_pixel);
            ptr += stride;
        }
    } else {    /* planar, 4, 8 or 16 colors */
        int i;

        for (y = 0; y < h; y++) {
            pcx_rle_decode(&gb, scanline, bytes_per_scanline, compressed);

            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;
        }
    }

    ret = bytestream2_tell(&gb);
    if (nplanes == 1 && bits_per_pixel == 8) {
        pcx_palette(&gb, (uint32_t *)p->data[1], 256);
        ret += 256 * 3;
    } else if (bits_per_pixel * nplanes == 1) {
        AV_WN32A(p->data[1]  , 0xFF000000);
        AV_WN32A(p->data[1]+4, 0xFFFFFFFF);
    } else if (bits_per_pixel < 8) {
        bytestream2_seek(&gb, 16, SEEK_SET);
        pcx_palette(&gb, (uint32_t *)p->data[1], 16);
    }

    *got_frame = 1;

end:
    av_free(scanline);
    return ret;
}

AVCodec ff_pcx_decoder = {
    .name         = "pcx",
    .long_name    = NULL_IF_CONFIG_SMALL("PC Paintbrush PCX image"),
    .type         = AVMEDIA_TYPE_VIDEO,
    .id           = AV_CODEC_ID_PCX,
    .decode       = pcx_decode_frame,
    .capabilities = CODEC_CAP_DR1,
};