Imported Debian version 2.5.3~trusty1
[deb_ffmpeg.git] / ffmpeg / libavcodec / srtenc.c
1 /*
2 * SubRip subtitle encoder
3 * Copyright (c) 2010 Aurelien Jacobs <aurel@gnuage.org>
4 *
5 * This file is part of FFmpeg.
6 *
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
11 *
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
16 *
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20 */
21
22 #include <stdarg.h>
23 #include "avcodec.h"
24 #include "libavutil/avstring.h"
25 #include "libavutil/bprint.h"
26 #include "ass_split.h"
27 #include "ass.h"
28
29
30 #define SRT_STACK_SIZE 64
31
32 typedef struct {
33 AVCodecContext *avctx;
34 ASSSplitContext *ass_ctx;
35 AVBPrint buffer;
36 char stack[SRT_STACK_SIZE];
37 int stack_ptr;
38 int alignment_applied;
39 } SRTContext;
40
41
42 #ifdef __GNUC__
43 __attribute__ ((__format__ (__printf__, 2, 3)))
44 #endif
45 static void srt_print(SRTContext *s, const char *str, ...)
46 {
47 va_list vargs;
48 va_start(vargs, str);
49 av_vbprintf(&s->buffer, str, vargs);
50 va_end(vargs);
51 }
52
53 static int srt_stack_push(SRTContext *s, const char c)
54 {
55 if (s->stack_ptr >= SRT_STACK_SIZE)
56 return -1;
57 s->stack[s->stack_ptr++] = c;
58 return 0;
59 }
60
61 static char srt_stack_pop(SRTContext *s)
62 {
63 if (s->stack_ptr <= 0)
64 return 0;
65 return s->stack[--s->stack_ptr];
66 }
67
68 static int srt_stack_find(SRTContext *s, const char c)
69 {
70 int i;
71 for (i = s->stack_ptr-1; i >= 0; i--)
72 if (s->stack[i] == c)
73 break;
74 return i;
75 }
76
77 static void srt_close_tag(SRTContext *s, char tag)
78 {
79 srt_print(s, "</%c%s>", tag, tag == 'f' ? "ont" : "");
80 }
81
82 static void srt_stack_push_pop(SRTContext *s, const char c, int close)
83 {
84 if (close) {
85 int i = c ? srt_stack_find(s, c) : 0;
86 if (i < 0)
87 return;
88 while (s->stack_ptr != i)
89 srt_close_tag(s, srt_stack_pop(s));
90 } else if (srt_stack_push(s, c) < 0)
91 av_log(s->avctx, AV_LOG_ERROR, "tag stack overflow\n");
92 }
93
94 static void srt_style_apply(SRTContext *s, const char *style)
95 {
96 ASSStyle *st = ff_ass_style_get(s->ass_ctx, style);
97 if (st) {
98 int c = st->primary_color & 0xFFFFFF;
99 if (st->font_name && strcmp(st->font_name, ASS_DEFAULT_FONT) ||
100 st->font_size != ASS_DEFAULT_FONT_SIZE ||
101 c != ASS_DEFAULT_COLOR) {
102 srt_print(s, "<font");
103 if (st->font_name && strcmp(st->font_name, ASS_DEFAULT_FONT))
104 srt_print(s, " face=\"%s\"", st->font_name);
105 if (st->font_size != ASS_DEFAULT_FONT_SIZE)
106 srt_print(s, " size=\"%d\"", st->font_size);
107 if (c != ASS_DEFAULT_COLOR)
108 srt_print(s, " color=\"#%06x\"",
109 (c & 0xFF0000) >> 16 | c & 0xFF00 | (c & 0xFF) << 16);
110 srt_print(s, ">");
111 srt_stack_push(s, 'f');
112 }
113 if (st->bold != ASS_DEFAULT_BOLD) {
114 srt_print(s, "<b>");
115 srt_stack_push(s, 'b');
116 }
117 if (st->italic != ASS_DEFAULT_ITALIC) {
118 srt_print(s, "<i>");
119 srt_stack_push(s, 'i');
120 }
121 if (st->underline != ASS_DEFAULT_UNDERLINE) {
122 srt_print(s, "<u>");
123 srt_stack_push(s, 'u');
124 }
125 if (st->alignment != ASS_DEFAULT_ALIGNMENT) {
126 srt_print(s, "{\\an%d}", st->alignment);
127 s->alignment_applied = 1;
128 }
129 }
130 }
131
132
133 static av_cold int srt_encode_init(AVCodecContext *avctx)
134 {
135 SRTContext *s = avctx->priv_data;
136 s->avctx = avctx;
137 s->ass_ctx = ff_ass_split(avctx->subtitle_header);
138 av_bprint_init(&s->buffer, 0, AV_BPRINT_SIZE_UNLIMITED);
139 return s->ass_ctx ? 0 : AVERROR_INVALIDDATA;
140 }
141
142 static void srt_text_cb(void *priv, const char *text, int len)
143 {
144 SRTContext *s = priv;
145 av_bprint_append_data(&s->buffer, text, len);
146 }
147
148 static void srt_new_line_cb(void *priv, int forced)
149 {
150 srt_print(priv, "\r\n");
151 }
152
153 static void srt_style_cb(void *priv, char style, int close)
154 {
155 srt_stack_push_pop(priv, style, close);
156 if (!close)
157 srt_print(priv, "<%c>", style);
158 }
159
160 static void srt_color_cb(void *priv, unsigned int color, unsigned int color_id)
161 {
162 if (color_id > 1)
163 return;
164 srt_stack_push_pop(priv, 'f', color == 0xFFFFFFFF);
165 if (color != 0xFFFFFFFF)
166 srt_print(priv, "<font color=\"#%06x\">",
167 (color & 0xFF0000) >> 16 | color & 0xFF00 | (color & 0xFF) << 16);
168 }
169
170 static void srt_font_name_cb(void *priv, const char *name)
171 {
172 srt_stack_push_pop(priv, 'f', !name);
173 if (name)
174 srt_print(priv, "<font face=\"%s\">", name);
175 }
176
177 static void srt_font_size_cb(void *priv, int size)
178 {
179 srt_stack_push_pop(priv, 'f', size < 0);
180 if (size >= 0)
181 srt_print(priv, "<font size=\"%d\">", size);
182 }
183
184 static void srt_alignment_cb(void *priv, int alignment)
185 {
186 SRTContext *s = priv;
187 if (!s->alignment_applied && alignment >= 0) {
188 srt_print(s, "{\\an%d}", alignment);
189 s->alignment_applied = 1;
190 }
191 }
192
193 static void srt_cancel_overrides_cb(void *priv, const char *style)
194 {
195 srt_stack_push_pop(priv, 0, 1);
196 srt_style_apply(priv, style);
197 }
198
199 static void srt_move_cb(void *priv, int x1, int y1, int x2, int y2,
200 int t1, int t2)
201 {
202 // TODO: add a AV_PKT_DATA_SUBTITLE_POSITION side data when a new subtitles
203 // encoding API passing the AVPacket is available.
204 }
205
206 static void srt_end_cb(void *priv)
207 {
208 srt_stack_push_pop(priv, 0, 1);
209 }
210
211 static const ASSCodesCallbacks srt_callbacks = {
212 .text = srt_text_cb,
213 .new_line = srt_new_line_cb,
214 .style = srt_style_cb,
215 .color = srt_color_cb,
216 .font_name = srt_font_name_cb,
217 .font_size = srt_font_size_cb,
218 .alignment = srt_alignment_cb,
219 .cancel_overrides = srt_cancel_overrides_cb,
220 .move = srt_move_cb,
221 .end = srt_end_cb,
222 };
223
224 static int srt_encode_frame(AVCodecContext *avctx,
225 unsigned char *buf, int bufsize, const AVSubtitle *sub)
226 {
227 SRTContext *s = avctx->priv_data;
228 ASSDialog *dialog;
229 int i, num;
230
231 av_bprint_clear(&s->buffer);
232
233 for (i=0; i<sub->num_rects; i++) {
234
235 if (sub->rects[i]->type != SUBTITLE_ASS) {
236 av_log(avctx, AV_LOG_ERROR, "Only SUBTITLE_ASS type supported.\n");
237 return AVERROR(ENOSYS);
238 }
239
240 dialog = ff_ass_split_dialog(s->ass_ctx, sub->rects[i]->ass, 0, &num);
241 for (; dialog && num--; dialog++) {
242 s->alignment_applied = 0;
243 srt_style_apply(s, dialog->style);
244 ff_ass_split_override_codes(&srt_callbacks, s, dialog->text);
245 }
246 }
247
248 if (!av_bprint_is_complete(&s->buffer))
249 return AVERROR(ENOMEM);
250 if (!s->buffer.len)
251 return 0;
252
253 if (s->buffer.len > bufsize) {
254 av_log(avctx, AV_LOG_ERROR, "Buffer too small for ASS event.\n");
255 return -1;
256 }
257 memcpy(buf, s->buffer.str, s->buffer.len);
258
259 return s->buffer.len;
260 }
261
262 static int srt_encode_close(AVCodecContext *avctx)
263 {
264 SRTContext *s = avctx->priv_data;
265 ff_ass_split_free(s->ass_ctx);
266 av_bprint_finalize(&s->buffer, NULL);
267 return 0;
268 }
269
270 #if CONFIG_SRT_ENCODER
271 /* deprecated encoder */
272 AVCodec ff_srt_encoder = {
273 .name = "srt",
274 .long_name = NULL_IF_CONFIG_SMALL("SubRip subtitle"),
275 .type = AVMEDIA_TYPE_SUBTITLE,
276 .id = AV_CODEC_ID_SUBRIP,
277 .priv_data_size = sizeof(SRTContext),
278 .init = srt_encode_init,
279 .encode_sub = srt_encode_frame,
280 .close = srt_encode_close,
281 };
282 #endif
283
284 #if CONFIG_SUBRIP_ENCODER
285 AVCodec ff_subrip_encoder = {
286 .name = "subrip",
287 .long_name = NULL_IF_CONFIG_SMALL("SubRip subtitle"),
288 .type = AVMEDIA_TYPE_SUBTITLE,
289 .id = AV_CODEC_ID_SUBRIP,
290 .priv_data_size = sizeof(SRTContext),
291 .init = srt_encode_init,
292 .encode_sub = srt_encode_frame,
293 .close = srt_encode_close,
294 };
295 #endif