xref: /third_party/ffmpeg/libavcodec/bintext.c (revision cabdff1a)
1/*
2 * Binary text decoder
3 * eXtended BINary text (XBIN) decoder
4 * iCEDraw File decoder
5 * Copyright (c) 2010 Peter Ross (pross@xvid.org)
6 *
7 * This file is part of FFmpeg.
8 *
9 * FFmpeg is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU Lesser General Public
11 * License as published by the Free Software Foundation; either
12 * version 2.1 of the License, or (at your option) any later version.
13 *
14 * FFmpeg is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
17 * Lesser General Public License for more details.
18 *
19 * You should have received a copy of the GNU Lesser General Public
20 * License along with FFmpeg; if not, write to the Free Software
21 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
22 */
23
24/**
25 * @file
26 * Binary text decoder
27 * eXtended BINary text (XBIN) decoder
28 * iCEDraw File decoder
29 */
30
31#include "config_components.h"
32
33#include "libavutil/intreadwrite.h"
34#include "libavutil/xga_font_data.h"
35#include "avcodec.h"
36#include "cga_data.h"
37#include "bintext.h"
38#include "codec_internal.h"
39#include "internal.h"
40
41#define FONT_WIDTH 8
42
43typedef struct XbinContext {
44    AVFrame *frame;
45    int palette[16];
46    int flags;
47    int font_height;
48    const uint8_t *font;
49    int x, y;
50} XbinContext;
51
52static av_cold int decode_init(AVCodecContext *avctx)
53{
54    XbinContext *s = avctx->priv_data;
55    uint8_t *p;
56    int i;
57
58    avctx->pix_fmt = AV_PIX_FMT_PAL8;
59    p = avctx->extradata;
60    if (p) {
61        s->font_height = p[0];
62        s->flags = p[1];
63        p += 2;
64        if(avctx->extradata_size < 2 + (!!(s->flags & BINTEXT_PALETTE))*3*16
65                                     + (!!(s->flags & BINTEXT_FONT))*s->font_height*256) {
66            av_log(avctx, AV_LOG_ERROR, "not enough extradata\n");
67            return AVERROR_INVALIDDATA;
68        }
69        if (!s->font_height) {
70            av_log(avctx, AV_LOG_ERROR, "invalid font height\n");
71            return AVERROR_INVALIDDATA;
72        }
73    } else {
74        s->font_height = 8;
75        s->flags = 0;
76    }
77
78    if ((s->flags & BINTEXT_PALETTE)) {
79        for (i = 0; i < 16; i++) {
80            s->palette[i] = 0xFF000000 | (AV_RB24(p) << 2) | ((AV_RB24(p) >> 4) & 0x30303);
81            p += 3;
82        }
83    } else {
84        for (i = 0; i < 16; i++)
85            s->palette[i] = 0xFF000000 | ff_cga_palette[i];
86    }
87
88    if ((s->flags & BINTEXT_FONT)) {
89        s->font = p;
90    } else {
91        switch(s->font_height) {
92        default:
93            av_log(avctx, AV_LOG_WARNING, "font height %i not supported\n", s->font_height);
94            s->font_height = 8;
95        case 8:
96            s->font = avpriv_cga_font;
97            break;
98        case 16:
99            s->font = avpriv_vga16_font;
100            break;
101        }
102    }
103    if (avctx->width < FONT_WIDTH || avctx->height < s->font_height) {
104        av_log(avctx, AV_LOG_ERROR, "Resolution too small for font.\n");
105        return AVERROR_INVALIDDATA;
106    }
107
108    return 0;
109}
110
111#define DEFAULT_BG_COLOR 0
112av_unused static void hscroll(AVCodecContext *avctx)
113{
114    XbinContext *s = avctx->priv_data;
115    if (s->y < avctx->height - s->font_height) {
116        s->y += s->font_height;
117    } else {
118        memmove(s->frame->data[0], s->frame->data[0] + s->font_height*s->frame->linesize[0],
119            (avctx->height - s->font_height)*s->frame->linesize[0]);
120        memset(s->frame->data[0] + (avctx->height - s->font_height)*s->frame->linesize[0],
121            DEFAULT_BG_COLOR, s->font_height * s->frame->linesize[0]);
122    }
123}
124
125/**
126 * Draw character to screen
127 */
128static void draw_char(AVCodecContext *avctx, int c, int a)
129{
130    XbinContext *s = avctx->priv_data;
131    if (s->y > avctx->height - s->font_height)
132        return;
133    ff_draw_pc_font(s->frame->data[0] + s->y * s->frame->linesize[0] + s->x,
134                    s->frame->linesize[0], s->font, s->font_height, c,
135                    a & 0x0F, a >> 4);
136    s->x += FONT_WIDTH;
137    if (s->x > avctx->width - FONT_WIDTH) {
138        s->x = 0;
139        s->y += s->font_height;
140    }
141}
142
143static int decode_frame(AVCodecContext *avctx, AVFrame *frame,
144                        int *got_frame, AVPacket *avpkt)
145{
146    XbinContext *s = avctx->priv_data;
147    const uint8_t *buf = avpkt->data;
148    int buf_size = avpkt->size;
149    const uint8_t *buf_end = buf+buf_size;
150    int ret;
151
152    if ((avctx->width / FONT_WIDTH) * (avctx->height / s->font_height) / 256 > buf_size)
153        return AVERROR_INVALIDDATA;
154
155    s->frame = frame;
156    s->x = s->y = 0;
157    if ((ret = ff_get_buffer(avctx, s->frame, 0)) < 0)
158        return ret;
159    s->frame->pict_type           = AV_PICTURE_TYPE_I;
160    s->frame->palette_has_changed = 1;
161    memcpy(s->frame->data[1], s->palette, 16 * 4);
162
163    if (avctx->codec_id == AV_CODEC_ID_XBIN) {
164        while (buf + 2 < buf_end) {
165            int i,c,a;
166            int type  = *buf >> 6;
167            int count = (*buf & 0x3F) + 1;
168            buf++;
169            switch (type) {
170            case 0: //no compression
171                for (i = 0; i < count && buf + 1 < buf_end; i++) {
172                    draw_char(avctx, buf[0], buf[1]);
173                    buf += 2;
174                }
175                break;
176            case 1: //character compression
177                c = *buf++;
178                for (i = 0; i < count && buf < buf_end; i++)
179                    draw_char(avctx, c, *buf++);
180                break;
181            case 2: //attribute compression
182                a = *buf++;
183                for (i = 0; i < count && buf < buf_end; i++)
184                    draw_char(avctx, *buf++, a);
185                break;
186            case 3: //character/attribute compression
187                c = *buf++;
188                a = *buf++;
189                for (i = 0; i < count && buf < buf_end; i++)
190                    draw_char(avctx, c, a);
191                break;
192            }
193        }
194    } else if (avctx->codec_id == AV_CODEC_ID_IDF) {
195        while (buf + 2 < buf_end) {
196            if (AV_RL16(buf) == 1) {
197               int i;
198               if (buf + 6 > buf_end)
199                   break;
200               for (i = 0; i < buf[2]; i++)
201                   draw_char(avctx, buf[4], buf[5]);
202               buf += 6;
203            } else {
204               draw_char(avctx, buf[0], buf[1]);
205               buf += 2;
206            }
207        }
208    } else {
209        while (buf + 1 < buf_end) {
210            draw_char(avctx, buf[0], buf[1]);
211            buf += 2;
212        }
213    }
214
215    *got_frame      = 1;
216    return buf_size;
217}
218
219#if CONFIG_BINTEXT_DECODER
220const FFCodec ff_bintext_decoder = {
221    .p.name         = "bintext",
222    .p.long_name    = NULL_IF_CONFIG_SMALL("Binary text"),
223    .p.type         = AVMEDIA_TYPE_VIDEO,
224    .p.id           = AV_CODEC_ID_BINTEXT,
225    .priv_data_size = sizeof(XbinContext),
226    .init           = decode_init,
227    FF_CODEC_DECODE_CB(decode_frame),
228    .p.capabilities = AV_CODEC_CAP_DR1,
229    .caps_internal  = FF_CODEC_CAP_INIT_THREADSAFE,
230};
231#endif
232#if CONFIG_XBIN_DECODER
233const FFCodec ff_xbin_decoder = {
234    .p.name         = "xbin",
235    .p.long_name    = NULL_IF_CONFIG_SMALL("eXtended BINary text"),
236    .p.type         = AVMEDIA_TYPE_VIDEO,
237    .p.id           = AV_CODEC_ID_XBIN,
238    .priv_data_size = sizeof(XbinContext),
239    .init           = decode_init,
240    FF_CODEC_DECODE_CB(decode_frame),
241    .p.capabilities = AV_CODEC_CAP_DR1,
242    .caps_internal  = FF_CODEC_CAP_INIT_THREADSAFE,
243};
244#endif
245#if CONFIG_IDF_DECODER
246const FFCodec ff_idf_decoder = {
247    .p.name         = "idf",
248    .p.long_name    = NULL_IF_CONFIG_SMALL("iCEDraw text"),
249    .p.type         = AVMEDIA_TYPE_VIDEO,
250    .p.id           = AV_CODEC_ID_IDF,
251    .priv_data_size = sizeof(XbinContext),
252    .init           = decode_init,
253    FF_CODEC_DECODE_CB(decode_frame),
254    .p.capabilities = AV_CODEC_CAP_DR1,
255    .caps_internal  = FF_CODEC_CAP_INIT_THREADSAFE,
256};
257#endif
258