summaryrefslogtreecommitdiff
path: root/libavcodec/xbmdec.c
blob: b3e4cf2f89e651f0a313d70272fbb7d60e7d3281 (plain)
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
/*
 * XBM image format
 *
 * Copyright (c) 2012 Paul B Mahol
 *
 * 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 "internal.h"

static av_cold int xbm_decode_init(AVCodecContext *avctx)
{
    avctx->coded_frame = avcodec_alloc_frame();
    if (!avctx->coded_frame)
        return AVERROR(ENOMEM);

    return 0;
}

static int convert(uint8_t x)
{
    if (x >= 'a')
        x -= 87;
    else if (x >= 'A')
        x -= 55;
    else
        x -= '0';
    return x;
}

static int xbm_decode_frame(AVCodecContext *avctx, void *data,
                            int *data_size, AVPacket *avpkt)
{
    AVFrame *p = avctx->coded_frame;
    const uint8_t *end, *ptr = avpkt->data;
    uint8_t *dst;
    int ret, linesize, i, j;

    end = avpkt->data + avpkt->size;
    while (!avctx->width || !avctx->height) {
        char name[256];
        int number, len;

        ptr += strcspn(ptr, "#");
        if (sscanf(ptr, "#define %256s %u", name, &number) != 2) {
            av_log(avctx, AV_LOG_ERROR, "Unexpected preprocessor directive\n");
            return AVERROR_INVALIDDATA;
        }

        len = strlen(name);
        if ((len > 6) && !avctx->height && !memcmp(name + len - 7, "_height", 7)) {
                avctx->height = number;
        } else if ((len > 5) && !avctx->width && !memcmp(name + len - 6, "_width", 6)) {
                avctx->width = number;
        } else {
            av_log(avctx, AV_LOG_ERROR, "Unknown define '%s'\n", name);
            return AVERROR_INVALIDDATA;
        }
        ptr += strcspn(ptr, "\n\r") + 1;
    }

    avctx->pix_fmt = PIX_FMT_MONOWHITE;

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

    p->reference = 0;
    if ((ret = avctx->get_buffer(avctx, p)) < 0)
        return ret;

    // goto start of image data
    ptr += strcspn(ptr, "{") + 1;

    linesize = (avctx->width + 7) / 8;
    for (i = 0; i < avctx->height; i++) {
        dst = p->data[0] + i * p->linesize[0];
        for (j = 0; j < linesize; j++) {
            uint8_t val;

            ptr += strcspn(ptr, "x") + 1;
            if (ptr < end && isxdigit(*ptr)) {
                val = convert(*ptr);
                ptr++;
                if (isxdigit(*ptr))
                    val = (val << 4) + convert(*ptr);
                *dst++ = av_reverse[val];
            } else {
                av_log(avctx, AV_LOG_ERROR, "Unexpected data at '%.8s'\n", ptr);
                return AVERROR_INVALIDDATA;
            }
        }
    }

    p->key_frame = 1;
    p->pict_type = AV_PICTURE_TYPE_I;

    *data_size       = sizeof(AVFrame);
    *(AVFrame *)data = *p;

    return avpkt->size;
}

static av_cold int xbm_decode_close(AVCodecContext *avctx)
{
    if (avctx->coded_frame->data[0])
        avctx->release_buffer(avctx, avctx->coded_frame);

    av_freep(&avctx->coded_frame);

    return 0;
}

AVCodec ff_xbm_decoder = {
    .name         = "xbm",
    .type         = AVMEDIA_TYPE_VIDEO,
    .id           = CODEC_ID_XBM,
    .init         = xbm_decode_init,
    .close        = xbm_decode_close,
    .decode       = xbm_decode_frame,
    .capabilities = CODEC_CAP_DR1,
    .long_name    = NULL_IF_CONFIG_SMALL("XBM (X BitMap) image"),
};