aboutsummaryrefslogtreecommitdiffstats
path: root/libavcodec/bintext.c
blob: 0fad8305f84b05b0145102d8184dcc37c8ee648d (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
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
/*
 * Binary text decoder
 * eXtended BINary text (XBIN) decoder
 * iCEDraw File decoder
 * Copyright (c) 2010 Peter Ross (pross@xvid.org)
 *
 * 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
 */

/**
 * @file
 * Binary text decoder
 * eXtended BINary text (XBIN) decoder
 * iCEDraw File decoder
 */

#include "config_components.h"

#include "libavutil/intreadwrite.h"
#include "libavutil/xga_font_data.h"
#include "avcodec.h"
#include "cga_data.h"
#include "bintext.h"
#include "codec_internal.h"
#include "internal.h"

#define FONT_WIDTH 8

typedef struct XbinContext {
    AVFrame *frame;
    int palette[16];
    int flags;
    int font_height;
    const uint8_t *font;
    int x, y;
} XbinContext;

static av_cold int decode_init(AVCodecContext *avctx)
{
    XbinContext *s = avctx->priv_data;
    uint8_t *p;
    int i;

    avctx->pix_fmt = AV_PIX_FMT_PAL8;
    p = avctx->extradata;
    if (p) {
        s->font_height = p[0];
        s->flags = p[1];
        p += 2;
        if(avctx->extradata_size < 2 + (!!(s->flags & BINTEXT_PALETTE))*3*16
                                     + (!!(s->flags & BINTEXT_FONT))*s->font_height*256) {
            av_log(avctx, AV_LOG_ERROR, "not enough extradata\n");
            return AVERROR_INVALIDDATA;
        }
        if (!s->font_height) {
            av_log(avctx, AV_LOG_ERROR, "invalid font height\n");
            return AVERROR_INVALIDDATA;
        }
    } else {
        s->font_height = 8;
        s->flags = 0;
    }

    if ((s->flags & BINTEXT_PALETTE)) {
        for (i = 0; i < 16; i++) {
            s->palette[i] = 0xFF000000 | (AV_RB24(p) << 2) | ((AV_RB24(p) >> 4) & 0x30303);
            p += 3;
        }
    } else {
        for (i = 0; i < 16; i++)
            s->palette[i] = 0xFF000000 | ff_cga_palette[i];
    }

    if ((s->flags & BINTEXT_FONT)) {
        s->font = p;
    } else {
        switch(s->font_height) {
        default:
            av_log(avctx, AV_LOG_WARNING, "font height %i not supported\n", s->font_height);
            s->font_height = 8;
        case 8:
            s->font = avpriv_cga_font;
            break;
        case 16:
            s->font = avpriv_vga16_font;
            break;
        }
    }
    if (avctx->width < FONT_WIDTH || avctx->height < s->font_height) {
        av_log(avctx, AV_LOG_ERROR, "Resolution too small for font.\n");
        return AVERROR_INVALIDDATA;
    }

    return 0;
}

#define DEFAULT_BG_COLOR 0
av_unused static void hscroll(AVCodecContext *avctx)
{
    XbinContext *s = avctx->priv_data;
    if (s->y < avctx->height - s->font_height) {
        s->y += s->font_height;
    } else {
        memmove(s->frame->data[0], s->frame->data[0] + s->font_height*s->frame->linesize[0],
            (avctx->height - s->font_height)*s->frame->linesize[0]);
        memset(s->frame->data[0] + (avctx->height - s->font_height)*s->frame->linesize[0],
            DEFAULT_BG_COLOR, s->font_height * s->frame->linesize[0]);
    }
}

/**
 * Draw character to screen
 */
static void draw_char(AVCodecContext *avctx, int c, int a)
{
    XbinContext *s = avctx->priv_data;
    if (s->y > avctx->height - s->font_height)
        return;
    ff_draw_pc_font(s->frame->data[0] + s->y * s->frame->linesize[0] + s->x,
                    s->frame->linesize[0], s->font, s->font_height, c,
                    a & 0x0F, a >> 4);
    s->x += FONT_WIDTH;
    if (s->x > avctx->width - FONT_WIDTH) {
        s->x = 0;
        s->y += s->font_height;
    }
}

static int decode_frame(AVCodecContext *avctx,
                            void *data, int *got_frame,
                            AVPacket *avpkt)
{
    XbinContext *s = avctx->priv_data;
    const uint8_t *buf = avpkt->data;
    int buf_size = avpkt->size;
    const uint8_t *buf_end = buf+buf_size;
    int ret;

    if ((avctx->width / FONT_WIDTH) * (avctx->height / s->font_height) / 256 > buf_size)
        return AVERROR_INVALIDDATA;

    s->frame = data;
    s->x = s->y = 0;
    if ((ret = ff_get_buffer(avctx, s->frame, 0)) < 0)
        return ret;
    s->frame->pict_type           = AV_PICTURE_TYPE_I;
    s->frame->palette_has_changed = 1;
    memcpy(s->frame->data[1], s->palette, 16 * 4);

    if (avctx->codec_id == AV_CODEC_ID_XBIN) {
        while (buf + 2 < buf_end) {
            int i,c,a;
            int type  = *buf >> 6;
            int count = (*buf & 0x3F) + 1;
            buf++;
            switch (type) {
            case 0: //no compression
                for (i = 0; i < count && buf + 1 < buf_end; i++) {
                    draw_char(avctx, buf[0], buf[1]);
                    buf += 2;
                }
                break;
            case 1: //character compression
                c = *buf++;
                for (i = 0; i < count && buf < buf_end; i++)
                    draw_char(avctx, c, *buf++);
                break;
            case 2: //attribute compression
                a = *buf++;
                for (i = 0; i < count && buf < buf_end; i++)
                    draw_char(avctx, *buf++, a);
                break;
            case 3: //character/attribute compression
                c = *buf++;
                a = *buf++;
                for (i = 0; i < count && buf < buf_end; i++)
                    draw_char(avctx, c, a);
                break;
            }
        }
    } else if (avctx->codec_id == AV_CODEC_ID_IDF) {
        while (buf + 2 < buf_end) {
            if (AV_RL16(buf) == 1) {
               int i;
               if (buf + 6 > buf_end)
                   break;
               for (i = 0; i < buf[2]; i++)
                   draw_char(avctx, buf[4], buf[5]);
               buf += 6;
            } else {
               draw_char(avctx, buf[0], buf[1]);
               buf += 2;
            }
        }
    } else {
        while (buf + 1 < buf_end) {
            draw_char(avctx, buf[0], buf[1]);
            buf += 2;
        }
    }

    *got_frame      = 1;
    return buf_size;
}

#if CONFIG_BINTEXT_DECODER
const FFCodec ff_bintext_decoder = {
    .p.name         = "bintext",
    .p.long_name    = NULL_IF_CONFIG_SMALL("Binary text"),
    .p.type         = AVMEDIA_TYPE_VIDEO,
    .p.id           = AV_CODEC_ID_BINTEXT,
    .priv_data_size = sizeof(XbinContext),
    .init           = decode_init,
    .decode         = decode_frame,
    .p.capabilities = AV_CODEC_CAP_DR1,
    .caps_internal  = FF_CODEC_CAP_INIT_THREADSAFE,
};
#endif
#if CONFIG_XBIN_DECODER
const FFCodec ff_xbin_decoder = {
    .p.name         = "xbin",
    .p.long_name    = NULL_IF_CONFIG_SMALL("eXtended BINary text"),
    .p.type         = AVMEDIA_TYPE_VIDEO,
    .p.id           = AV_CODEC_ID_XBIN,
    .priv_data_size = sizeof(XbinContext),
    .init           = decode_init,
    .decode         = decode_frame,
    .p.capabilities = AV_CODEC_CAP_DR1,
    .caps_internal  = FF_CODEC_CAP_INIT_THREADSAFE,
};
#endif
#if CONFIG_IDF_DECODER
const FFCodec ff_idf_decoder = {
    .p.name         = "idf",
    .p.long_name    = NULL_IF_CONFIG_SMALL("iCEDraw text"),
    .p.type         = AVMEDIA_TYPE_VIDEO,
    .p.id           = AV_CODEC_ID_IDF,
    .priv_data_size = sizeof(XbinContext),
    .init           = decode_init,
    .decode         = decode_frame,
    .p.capabilities = AV_CODEC_CAP_DR1,
    .caps_internal  = FF_CODEC_CAP_INIT_THREADSAFE,
};
#endif