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1 /*
2  * Copyright (c) 2012 Clément Bœsch
3  *
4  * This file is part of FFmpeg.
5  *
6  * FFmpeg is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Lesser General Public
8  * License as published by the Free Software Foundation; either
9  * version 2.1 of the License, or (at your option) any later version.
10  *
11  * FFmpeg is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14  * Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public
17  * License along with FFmpeg; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19  */
20 
21 /**
22  * @file
23  * JACOsub subtitle decoder
24  * @see http://unicorn.us.com/jacosub/jscripts.html
25  */
26 
27 #include <time.h>
28 #include "ass.h"
29 #include "jacosub.h"
30 #include "libavutil/avstring.h"
31 #include "libavutil/bprint.h"
32 #include "libavutil/time_internal.h"
33 
34 #undef time
35 
insert_text(AVBPrint * dst,const char * in,const char * arg)36 static int insert_text(AVBPrint *dst, const char *in, const char *arg)
37 {
38     av_bprintf(dst, "%s", arg);
39     return 0;
40 }
41 
insert_datetime(AVBPrint * dst,const char * in,const char * arg)42 static int insert_datetime(AVBPrint *dst, const char *in, const char *arg)
43 {
44     char buf[16] = {0};
45     time_t now = time(0);
46     struct tm ltime;
47 
48     localtime_r(&now, &ltime);
49     if (strftime(buf, sizeof(buf), arg, &ltime))
50         av_bprintf(dst, "%s", buf);
51     return 0;
52 }
53 
insert_color(AVBPrint * dst,const char * in,const char * arg)54 static int insert_color(AVBPrint *dst, const char *in, const char *arg)
55 {
56     return 1; // skip id
57 }
58 
insert_font(AVBPrint * dst,const char * in,const char * arg)59 static int insert_font(AVBPrint *dst, const char *in, const char *arg)
60 {
61     return 1; // skip id
62 }
63 
64 static const struct {
65     const char *from;
66     const char *arg;
67     int (*func)(AVBPrint *dst, const char *in, const char *arg);
68 } ass_codes_map[] = {
69     {"\\~", "~",        insert_text},       // tilde doesn't need escaping
70     {"~",   "{\\h}",    insert_text},       // hard space
71     {"\\n", "\\N",      insert_text},       // newline
72     {"\\D", "%d %b %Y", insert_datetime},   // current date
73     {"\\T", "%H:%M",    insert_datetime},   // current time
74     {"\\N", "{\\r}",    insert_text},       // reset to default style
75     {"\\I", "{\\i1}",   insert_text},       // italic on
76     {"\\i", "{\\i0}",   insert_text},       // italic off
77     {"\\B", "{\\b1}",   insert_text},       // bold on
78     {"\\b", "{\\b0}",   insert_text},       // bold off
79     {"\\U", "{\\u1}",   insert_text},       // underline on
80     {"\\u", "{\\u0}",   insert_text},       // underline off
81     {"\\C", "",         insert_color},      // TODO: color
82     {"\\F", "",         insert_font},       // TODO: font
83 };
84 
85 enum {
86     ALIGN_VB = 1<<0, // vertical bottom, default
87     ALIGN_VM = 1<<1, // vertical middle
88     ALIGN_VT = 1<<2, // vertical top
89     ALIGN_JC = 1<<3, // justify center, default
90     ALIGN_JL = 1<<4, // justify left
91     ALIGN_JR = 1<<5, // justify right
92 };
93 
jacosub_to_ass(AVCodecContext * avctx,AVBPrint * dst,const char * src)94 static void jacosub_to_ass(AVCodecContext *avctx, AVBPrint *dst, const char *src)
95 {
96     int i, valign = 0, halign = 0;
97     char c = av_toupper(*src);
98     char directives[128] = {0};
99 
100     /* extract the optional directives */
101     if ((c >= 'A' && c <= 'Z') || c == '[') {
102         char *p    = directives;
103         char *pend = directives + sizeof(directives) - 1;
104 
105         do *p++ = av_toupper(*src++);
106         while (*src && !jss_whitespace(*src) && p < pend);
107         *p = 0;
108         src = jss_skip_whitespace(src);
109     }
110 
111     /* handle directives (TODO: handle more of them, and more reliably) */
112     if      (strstr(directives, "VB")) valign = ALIGN_VB;
113     else if (strstr(directives, "VM")) valign = ALIGN_VM;
114     else if (strstr(directives, "VT")) valign = ALIGN_VT;
115     if      (strstr(directives, "JC")) halign = ALIGN_JC;
116     else if (strstr(directives, "JL")) halign = ALIGN_JL;
117     else if (strstr(directives, "JR")) halign = ALIGN_JR;
118     if (valign || halign) {
119         if (!valign) valign = ALIGN_VB;
120         if (!halign) halign = ALIGN_JC;
121         switch (valign | halign) {
122         case ALIGN_VB | ALIGN_JL: av_bprintf(dst, "{\\an1}"); break; // bottom left
123         case ALIGN_VB | ALIGN_JC: av_bprintf(dst, "{\\an2}"); break; // bottom center
124         case ALIGN_VB | ALIGN_JR: av_bprintf(dst, "{\\an3}"); break; // bottom right
125         case ALIGN_VM | ALIGN_JL: av_bprintf(dst, "{\\an4}"); break; // middle left
126         case ALIGN_VM | ALIGN_JC: av_bprintf(dst, "{\\an5}"); break; // middle center
127         case ALIGN_VM | ALIGN_JR: av_bprintf(dst, "{\\an6}"); break; // middle right
128         case ALIGN_VT | ALIGN_JL: av_bprintf(dst, "{\\an7}"); break; // top left
129         case ALIGN_VT | ALIGN_JC: av_bprintf(dst, "{\\an8}"); break; // top center
130         case ALIGN_VT | ALIGN_JR: av_bprintf(dst, "{\\an9}"); break; // top right
131         }
132     }
133 
134     /* process timed line */
135     while (*src && *src != '\n') {
136 
137         /* text continue on the next line */
138         if (src[0] == '\\' && src[1] == '\n') {
139             src += 2;
140             while (jss_whitespace(*src))
141                 src++;
142             continue;
143         }
144 
145         /* special character codes */
146         for (i = 0; i < FF_ARRAY_ELEMS(ass_codes_map); i++) {
147             const char *from = ass_codes_map[i].from;
148             const char *arg  = ass_codes_map[i].arg;
149             size_t codemap_len = strlen(from);
150 
151             if (!strncmp(src, from, codemap_len)) {
152                 src += codemap_len;
153                 src += ass_codes_map[i].func(dst, src, arg);
154                 break;
155             }
156         }
157 
158         /* simple char copy */
159         if (i == FF_ARRAY_ELEMS(ass_codes_map))
160             av_bprintf(dst, "%c", *src++);
161     }
162 }
163 
jacosub_decode_frame(AVCodecContext * avctx,void * data,int * got_sub_ptr,AVPacket * avpkt)164 static int jacosub_decode_frame(AVCodecContext *avctx,
165                                 void *data, int *got_sub_ptr, AVPacket *avpkt)
166 {
167     int ret;
168     AVSubtitle *sub = data;
169     const char *ptr = avpkt->data;
170     FFASSDecoderContext *s = avctx->priv_data;
171 
172     if (avpkt->size <= 0)
173         goto end;
174 
175     if (*ptr) {
176         AVBPrint buffer;
177 
178         // skip timers
179         ptr = jss_skip_whitespace(ptr);
180         ptr = strchr(ptr, ' '); if (!ptr) goto end; ptr++;
181         ptr = strchr(ptr, ' '); if (!ptr) goto end; ptr++;
182 
183         av_bprint_init(&buffer, JSS_MAX_LINESIZE, JSS_MAX_LINESIZE);
184         jacosub_to_ass(avctx, &buffer, ptr);
185         ret = ff_ass_add_rect(sub, buffer.str, s->readorder++, 0, NULL, NULL);
186         av_bprint_finalize(&buffer, NULL);
187         if (ret < 0)
188             return ret;
189     }
190 
191 end:
192     *got_sub_ptr = sub->num_rects > 0;
193     return avpkt->size;
194 }
195 
196 AVCodec ff_jacosub_decoder = {
197     .name           = "jacosub",
198     .long_name      = NULL_IF_CONFIG_SMALL("JACOsub subtitle"),
199     .type           = AVMEDIA_TYPE_SUBTITLE,
200     .id             = AV_CODEC_ID_JACOSUB,
201     .init           = ff_ass_subtitle_header_default,
202     .decode         = jacosub_decode_frame,
203     .flush          = ff_ass_decoder_flush,
204     .priv_data_size = sizeof(FFASSDecoderContext),
205 };
206