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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 "libavutil/intreadwrite.h"
32 #include "libavutil/xga_font_data.h"
33 #include "avcodec.h"
34 #include "cga_data.h"
35 #include "bintext.h"
36 #include "internal.h"
37 
38 #define FONT_WIDTH 8
39 
40 typedef struct XbinContext {
41     AVFrame *frame;
42     int palette[16];
43     int flags;
44     int font_height;
45     const uint8_t *font;
46     int x, y;
47 } XbinContext;
48 
decode_init(AVCodecContext * avctx)49 static av_cold int decode_init(AVCodecContext *avctx)
50 {
51     XbinContext *s = avctx->priv_data;
52     uint8_t *p;
53     int i;
54 
55     avctx->pix_fmt = AV_PIX_FMT_PAL8;
56     p = avctx->extradata;
57     if (p) {
58         s->font_height = p[0];
59         s->flags = p[1];
60         p += 2;
61         if(avctx->extradata_size < 2 + (!!(s->flags & BINTEXT_PALETTE))*3*16
62                                      + (!!(s->flags & BINTEXT_FONT))*s->font_height*256) {
63             av_log(avctx, AV_LOG_ERROR, "not enough extradata\n");
64             return AVERROR_INVALIDDATA;
65         }
66         if (!s->font_height) {
67             av_log(avctx, AV_LOG_ERROR, "invalid font height\n");
68             return AVERROR_INVALIDDATA;
69         }
70     } else {
71         s->font_height = 8;
72         s->flags = 0;
73     }
74 
75     if ((s->flags & BINTEXT_PALETTE)) {
76         for (i = 0; i < 16; i++) {
77             s->palette[i] = 0xFF000000 | (AV_RB24(p) << 2) | ((AV_RB24(p) >> 4) & 0x30303);
78             p += 3;
79         }
80     } else {
81         for (i = 0; i < 16; i++)
82             s->palette[i] = 0xFF000000 | ff_cga_palette[i];
83     }
84 
85     if ((s->flags & BINTEXT_FONT)) {
86         s->font = p;
87     } else {
88         switch(s->font_height) {
89         default:
90             av_log(avctx, AV_LOG_WARNING, "font height %i not supported\n", s->font_height);
91             s->font_height = 8;
92         case 8:
93             s->font = avpriv_cga_font;
94             break;
95         case 16:
96             s->font = avpriv_vga16_font;
97             break;
98         }
99     }
100     if (avctx->width < FONT_WIDTH || avctx->height < s->font_height) {
101         av_log(avctx, AV_LOG_ERROR, "Resolution too small for font.\n");
102         return AVERROR_INVALIDDATA;
103     }
104 
105     return 0;
106 }
107 
108 #define DEFAULT_BG_COLOR 0
hscroll(AVCodecContext * avctx)109 av_unused static void hscroll(AVCodecContext *avctx)
110 {
111     XbinContext *s = avctx->priv_data;
112     if (s->y < avctx->height - s->font_height) {
113         s->y += s->font_height;
114     } else {
115         memmove(s->frame->data[0], s->frame->data[0] + s->font_height*s->frame->linesize[0],
116             (avctx->height - s->font_height)*s->frame->linesize[0]);
117         memset(s->frame->data[0] + (avctx->height - s->font_height)*s->frame->linesize[0],
118             DEFAULT_BG_COLOR, s->font_height * s->frame->linesize[0]);
119     }
120 }
121 
122 /**
123  * Draw character to screen
124  */
draw_char(AVCodecContext * avctx,int c,int a)125 static void draw_char(AVCodecContext *avctx, int c, int a)
126 {
127     XbinContext *s = avctx->priv_data;
128     if (s->y > avctx->height - s->font_height)
129         return;
130     ff_draw_pc_font(s->frame->data[0] + s->y * s->frame->linesize[0] + s->x,
131                     s->frame->linesize[0], s->font, s->font_height, c,
132                     a & 0x0F, a >> 4);
133     s->x += FONT_WIDTH;
134     if (s->x > avctx->width - FONT_WIDTH) {
135         s->x = 0;
136         s->y += s->font_height;
137     }
138 }
139 
decode_frame(AVCodecContext * avctx,void * data,int * got_frame,AVPacket * avpkt)140 static int decode_frame(AVCodecContext *avctx,
141                             void *data, int *got_frame,
142                             AVPacket *avpkt)
143 {
144     XbinContext *s = avctx->priv_data;
145     const uint8_t *buf = avpkt->data;
146     int buf_size = avpkt->size;
147     const uint8_t *buf_end = buf+buf_size;
148     int ret;
149 
150     if ((avctx->width / FONT_WIDTH) * (avctx->height / s->font_height) / 256 > buf_size)
151         return AVERROR_INVALIDDATA;
152 
153     s->frame = data;
154     s->x = s->y = 0;
155     if ((ret = ff_get_buffer(avctx, s->frame, 0)) < 0)
156         return ret;
157     s->frame->pict_type           = AV_PICTURE_TYPE_I;
158     s->frame->palette_has_changed = 1;
159     memcpy(s->frame->data[1], s->palette, 16 * 4);
160 
161     if (avctx->codec_id == AV_CODEC_ID_XBIN) {
162         while (buf + 2 < buf_end) {
163             int i,c,a;
164             int type  = *buf >> 6;
165             int count = (*buf & 0x3F) + 1;
166             buf++;
167             switch (type) {
168             case 0: //no compression
169                 for (i = 0; i < count && buf + 1 < buf_end; i++) {
170                     draw_char(avctx, buf[0], buf[1]);
171                     buf += 2;
172                 }
173                 break;
174             case 1: //character compression
175                 c = *buf++;
176                 for (i = 0; i < count && buf < buf_end; i++)
177                     draw_char(avctx, c, *buf++);
178                 break;
179             case 2: //attribute compression
180                 a = *buf++;
181                 for (i = 0; i < count && buf < buf_end; i++)
182                     draw_char(avctx, *buf++, a);
183                 break;
184             case 3: //character/attribute compression
185                 c = *buf++;
186                 a = *buf++;
187                 for (i = 0; i < count && buf < buf_end; i++)
188                     draw_char(avctx, c, a);
189                 break;
190             }
191         }
192     } else if (avctx->codec_id == AV_CODEC_ID_IDF) {
193         while (buf + 2 < buf_end) {
194             if (AV_RL16(buf) == 1) {
195                int i;
196                if (buf + 6 > buf_end)
197                    break;
198                for (i = 0; i < buf[2]; i++)
199                    draw_char(avctx, buf[4], buf[5]);
200                buf += 6;
201             } else {
202                draw_char(avctx, buf[0], buf[1]);
203                buf += 2;
204             }
205         }
206     } else {
207         while (buf + 1 < buf_end) {
208             draw_char(avctx, buf[0], buf[1]);
209             buf += 2;
210         }
211     }
212 
213     *got_frame      = 1;
214     return buf_size;
215 }
216 
217 #if CONFIG_BINTEXT_DECODER
218 AVCodec ff_bintext_decoder = {
219     .name           = "bintext",
220     .long_name      = NULL_IF_CONFIG_SMALL("Binary text"),
221     .type           = AVMEDIA_TYPE_VIDEO,
222     .id             = AV_CODEC_ID_BINTEXT,
223     .priv_data_size = sizeof(XbinContext),
224     .init           = decode_init,
225     .decode         = decode_frame,
226     .capabilities   = AV_CODEC_CAP_DR1,
227 };
228 #endif
229 #if CONFIG_XBIN_DECODER
230 AVCodec ff_xbin_decoder = {
231     .name           = "xbin",
232     .long_name      = NULL_IF_CONFIG_SMALL("eXtended BINary text"),
233     .type           = AVMEDIA_TYPE_VIDEO,
234     .id             = AV_CODEC_ID_XBIN,
235     .priv_data_size = sizeof(XbinContext),
236     .init           = decode_init,
237     .decode         = decode_frame,
238     .capabilities   = AV_CODEC_CAP_DR1,
239 };
240 #endif
241 #if CONFIG_IDF_DECODER
242 AVCodec ff_idf_decoder = {
243     .name           = "idf",
244     .long_name      = NULL_IF_CONFIG_SMALL("iCEDraw text"),
245     .type           = AVMEDIA_TYPE_VIDEO,
246     .id             = AV_CODEC_ID_IDF,
247     .priv_data_size = sizeof(XbinContext),
248     .init           = decode_init,
249     .decode         = decode_frame,
250     .capabilities   = AV_CODEC_CAP_DR1,
251 };
252 #endif
253