1 /*
2 * ARIB STD-B24 caption decoder using the libaribb24 library
3 * Copyright (c) 2019 Jan Ekström
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 "avcodec.h"
23 #include "libavcodec/ass.h"
24 #include "codec_internal.h"
25 #include "libavutil/log.h"
26 #include "libavutil/opt.h"
27
28 #include <aribb24/aribb24.h>
29 #include <aribb24/parser.h>
30 #include <aribb24/decoder.h>
31
32 typedef struct Libaribb24Context {
33 AVClass *class;
34
35 arib_instance_t *lib_instance;
36 arib_parser_t *parser;
37 arib_decoder_t *decoder;
38
39 int read_order;
40
41 char *aribb24_base_path;
42 unsigned int aribb24_skip_ruby;
43 } Libaribb24Context;
44
get_profile_font_size(int profile)45 static unsigned int get_profile_font_size(int profile)
46 {
47 switch (profile) {
48 case FF_PROFILE_ARIB_PROFILE_A:
49 return 36;
50 case FF_PROFILE_ARIB_PROFILE_C:
51 return 18;
52 default:
53 return 0;
54 }
55 }
56
libaribb24_log(void *p, const char *msg)57 static void libaribb24_log(void *p, const char *msg)
58 {
59 av_log((AVCodecContext *)p, AV_LOG_INFO, "%s\n", msg);
60 }
61
libaribb24_generate_ass_header(AVCodecContext *avctx)62 static int libaribb24_generate_ass_header(AVCodecContext *avctx)
63 {
64 unsigned int plane_width = 0;
65 unsigned int plane_height = 0;
66 unsigned int font_size = 0;
67
68 switch (avctx->profile) {
69 case FF_PROFILE_ARIB_PROFILE_A:
70 plane_width = 960;
71 plane_height = 540;
72 font_size = get_profile_font_size(avctx->profile);
73 break;
74 case FF_PROFILE_ARIB_PROFILE_C:
75 plane_width = 320;
76 plane_height = 180;
77 font_size = get_profile_font_size(avctx->profile);
78 break;
79 default:
80 av_log(avctx, AV_LOG_ERROR, "Unknown or unsupported profile set!\n");
81 return AVERROR(EINVAL);
82 }
83
84 avctx->subtitle_header = av_asprintf(
85 "[Script Info]\r\n"
86 "; Script generated by FFmpeg/Lavc%s\r\n"
87 "ScriptType: v4.00+\r\n"
88 "PlayResX: %d\r\n"
89 "PlayResY: %d\r\n"
90 "\r\n"
91 "[V4+ Styles]\r\n"
92
93 /* ASSv4 header */
94 "Format: Name, "
95 "Fontname, Fontsize, "
96 "PrimaryColour, SecondaryColour, OutlineColour, BackColour, "
97 "Bold, Italic, Underline, StrikeOut, "
98 "ScaleX, ScaleY, "
99 "Spacing, Angle, "
100 "BorderStyle, Outline, Shadow, "
101 "Alignment, MarginL, MarginR, MarginV, "
102 "Encoding\r\n"
103
104 "Style: "
105 "Default," /* Name */
106 "%s,%d," /* Font{name,size} */
107 "&H%x,&H%x,&H%x,&H%x," /* {Primary,Secondary,Outline,Back}Colour */
108 "%d,%d,%d,0," /* Bold, Italic, Underline, StrikeOut */
109 "100,100," /* Scale{X,Y} */
110 "0,0," /* Spacing, Angle */
111 "%d,1,0," /* BorderStyle, Outline, Shadow */
112 "%d,10,10,10," /* Alignment, Margin[LRV] */
113 "0\r\n" /* Encoding */
114
115 "\r\n"
116 "[Events]\r\n"
117 "Format: Layer, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text\r\n",
118 !(avctx->flags & AV_CODEC_FLAG_BITEXACT) ? AV_STRINGIFY(LIBAVCODEC_VERSION) : "",
119 plane_width, plane_height,
120 ASS_DEFAULT_FONT, font_size, ASS_DEFAULT_COLOR,
121 ASS_DEFAULT_COLOR, ASS_DEFAULT_BACK_COLOR, ASS_DEFAULT_BACK_COLOR,
122 -ASS_DEFAULT_BOLD, -ASS_DEFAULT_ITALIC, -ASS_DEFAULT_UNDERLINE,
123 ASS_DEFAULT_BORDERSTYLE, ASS_DEFAULT_ALIGNMENT);
124
125 if (!avctx->subtitle_header)
126 return AVERROR(ENOMEM);
127
128 avctx->subtitle_header_size = strlen(avctx->subtitle_header);
129
130 return 0;
131 }
132
libaribb24_init(AVCodecContext *avctx)133 static int libaribb24_init(AVCodecContext *avctx)
134 {
135 Libaribb24Context *b24 = avctx->priv_data;
136 void(* arib_dec_init)(arib_decoder_t* decoder) = NULL;
137 int ret_code = AVERROR_EXTERNAL;
138
139 if (!(b24->lib_instance = arib_instance_new(avctx))) {
140 av_log(avctx, AV_LOG_ERROR, "Failed to initialize libaribb24!\n");
141 goto init_fail;
142 }
143
144 if (b24->aribb24_base_path) {
145 av_log(avctx, AV_LOG_INFO, "Setting the libaribb24 base path to '%s'\n",
146 b24->aribb24_base_path);
147 arib_set_base_path(b24->lib_instance, b24->aribb24_base_path);
148 }
149
150 arib_register_messages_callback(b24->lib_instance, libaribb24_log);
151
152 if (!(b24->parser = arib_get_parser(b24->lib_instance))) {
153 av_log(avctx, AV_LOG_ERROR, "Failed to initialize libaribb24 PES parser!\n");
154 goto init_fail;
155 }
156 if (!(b24->decoder = arib_get_decoder(b24->lib_instance))) {
157 av_log(avctx, AV_LOG_ERROR, "Failed to initialize libaribb24 decoder!\n");
158 goto init_fail;
159 }
160
161 switch (avctx->profile) {
162 case FF_PROFILE_ARIB_PROFILE_A:
163 arib_dec_init = arib_initialize_decoder_a_profile;
164 break;
165 case FF_PROFILE_ARIB_PROFILE_C:
166 arib_dec_init = arib_initialize_decoder_c_profile;
167 break;
168 default:
169 av_log(avctx, AV_LOG_ERROR, "Unknown or unsupported profile set!\n");
170 ret_code = AVERROR(EINVAL);
171 goto init_fail;
172 }
173
174 arib_dec_init(b24->decoder);
175
176 if (libaribb24_generate_ass_header(avctx) < 0) {
177 ret_code = AVERROR(ENOMEM);
178 goto init_fail;
179 }
180
181 return 0;
182
183 init_fail:
184 if (b24->decoder)
185 arib_finalize_decoder(b24->decoder);
186
187 if (b24->lib_instance)
188 arib_instance_destroy(b24->lib_instance);
189
190 return ret_code;
191 }
192
libaribb24_close(AVCodecContext *avctx)193 static int libaribb24_close(AVCodecContext *avctx)
194 {
195 Libaribb24Context *b24 = avctx->priv_data;
196
197 if (b24->decoder)
198 arib_finalize_decoder(b24->decoder);
199
200 if (b24->lib_instance)
201 arib_instance_destroy(b24->lib_instance);
202
203 return 0;
204 }
205
206 #define RGB_TO_BGR(c) (((c) & 0xff) << 16 | ((c) & 0xff00) | (((c) >> 16) & 0xff))
207
libaribb24_handle_regions(AVCodecContext *avctx, AVSubtitle *sub)208 static int libaribb24_handle_regions(AVCodecContext *avctx, AVSubtitle *sub)
209 {
210 Libaribb24Context *b24 = avctx->priv_data;
211 const arib_buf_region_t *region = arib_decoder_get_regions(b24->decoder);
212 unsigned int profile_font_size = get_profile_font_size(avctx->profile);
213 AVBPrint buf = { 0 };
214 int ret = 0;
215
216 av_bprint_init(&buf, 0, AV_BPRINT_SIZE_UNLIMITED);
217
218 while (region) {
219 ptrdiff_t region_length = region->p_end - region->p_start;
220 unsigned int ruby_region =
221 region->i_fontheight == (profile_font_size / 2);
222
223 // ASS requires us to make the colors BGR, so we convert here
224 int foreground_bgr_color = RGB_TO_BGR(region->i_foreground_color);
225 int background_bgr_color = RGB_TO_BGR(region->i_background_color);
226
227 if (region_length < 0) {
228 av_log(avctx, AV_LOG_ERROR, "Invalid negative region length!\n");
229 ret = AVERROR_INVALIDDATA;
230 break;
231 }
232
233 if (region_length == 0 || (ruby_region && b24->aribb24_skip_ruby)) {
234 goto next_region;
235 }
236
237 // color and alpha
238 if (foreground_bgr_color != ASS_DEFAULT_COLOR)
239 av_bprintf(&buf, "{\\1c&H%06x&}", foreground_bgr_color);
240
241 if (region->i_foreground_alpha != 0)
242 av_bprintf(&buf, "{\\1a&H%02x&}", region->i_foreground_alpha);
243
244 if (background_bgr_color != ASS_DEFAULT_BACK_COLOR)
245 av_bprintf(&buf, "{\\3c&H%06x&}", background_bgr_color);
246
247 if (region->i_background_alpha != 0)
248 av_bprintf(&buf, "{\\3a&H%02x&}", region->i_background_alpha);
249
250 // font size
251 if (region->i_fontwidth != profile_font_size ||
252 region->i_fontheight != profile_font_size) {
253 av_bprintf(&buf, "{\\fscx%"PRId64"\\fscy%"PRId64"}",
254 av_rescale(region->i_fontwidth, 100,
255 profile_font_size),
256 av_rescale(region->i_fontheight, 100,
257 profile_font_size));
258 }
259
260 // TODO: positioning
261
262 av_bprint_append_data(&buf, region->p_start, region_length);
263
264 av_bprintf(&buf, "{\\r}");
265
266 next_region:
267 region = region->p_next;
268 }
269
270 if (!av_bprint_is_complete(&buf))
271 ret = AVERROR(ENOMEM);
272
273 if (ret == 0) {
274 av_log(avctx, AV_LOG_DEBUG, "Styled ASS line: %s\n",
275 buf.str);
276
277 ret = ff_ass_add_rect(sub, buf.str, b24->read_order++,
278 0, NULL, NULL);
279 }
280
281 av_bprint_finalize(&buf, NULL);
282
283 return ret;
284 }
285
libaribb24_decode(AVCodecContext *avctx, AVSubtitle *sub, int *got_sub_ptr, const AVPacket *pkt)286 static int libaribb24_decode(AVCodecContext *avctx, AVSubtitle *sub,
287 int *got_sub_ptr, const AVPacket *pkt)
288 {
289 Libaribb24Context *b24 = avctx->priv_data;
290 size_t parsed_data_size = 0;
291 size_t decoded_subtitle_size = 0;
292 const unsigned char *parsed_data = NULL;
293 char *decoded_subtitle = NULL;
294 time_t subtitle_duration = 0;
295 int ret = 0;
296
297 if (pkt->size <= 0)
298 return pkt->size;
299
300 arib_parse_pes(b24->parser, pkt->data, pkt->size);
301
302 parsed_data = arib_parser_get_data(b24->parser,
303 &parsed_data_size);
304 if (!parsed_data || !parsed_data_size) {
305 av_log(avctx, AV_LOG_DEBUG, "No decode'able data was received from "
306 "packet (dts: %"PRId64", pts: %"PRId64").\n",
307 pkt->dts, pkt->pts);
308 return pkt->size;
309 }
310
311 decoded_subtitle_size = parsed_data_size * 4;
312 if (!(decoded_subtitle = av_mallocz(decoded_subtitle_size + 1))) {
313 av_log(avctx, AV_LOG_ERROR,
314 "Failed to allocate buffer for decoded subtitle!\n");
315 return AVERROR(ENOMEM);
316 }
317
318 decoded_subtitle_size = arib_decode_buffer(b24->decoder,
319 parsed_data,
320 parsed_data_size,
321 decoded_subtitle,
322 decoded_subtitle_size);
323
324 subtitle_duration = arib_decoder_get_time(b24->decoder);
325
326 if (avctx->pkt_timebase.num && pkt->pts != AV_NOPTS_VALUE)
327 sub->pts = av_rescale_q(pkt->pts,
328 avctx->pkt_timebase, AV_TIME_BASE_Q);
329
330 sub->end_display_time = subtitle_duration ?
331 av_rescale_q(subtitle_duration,
332 AV_TIME_BASE_Q,
333 (AVRational){1, 1000}) :
334 UINT32_MAX;
335
336 av_log(avctx, AV_LOG_DEBUG,
337 "Result: '%s' (size: %zu, pkt_pts: %"PRId64", sub_pts: %"PRId64" "
338 "duration: %"PRIu32", pkt_timebase: %d/%d, time_base: %d/%d')\n",
339 decoded_subtitle ? decoded_subtitle : "<no subtitle>",
340 decoded_subtitle_size,
341 pkt->pts, sub->pts,
342 sub->end_display_time,
343 avctx->pkt_timebase.num, avctx->pkt_timebase.den,
344 avctx->time_base.num, avctx->time_base.den);
345
346 if (decoded_subtitle)
347 ret = libaribb24_handle_regions(avctx, sub);
348
349 *got_sub_ptr = sub->num_rects > 0;
350
351 av_free(decoded_subtitle);
352
353 // flush the region buffers, otherwise the linked list keeps getting
354 // longer and longer...
355 arib_finalize_decoder(b24->decoder);
356
357 return ret < 0 ? ret : pkt->size;
358 }
359
libaribb24_flush(AVCodecContext *avctx)360 static void libaribb24_flush(AVCodecContext *avctx)
361 {
362 Libaribb24Context *b24 = avctx->priv_data;
363 if (!(avctx->flags2 & AV_CODEC_FLAG2_RO_FLUSH_NOOP))
364 b24->read_order = 0;
365 }
366
367 #define OFFSET(x) offsetof(Libaribb24Context, x)
368 #define SD AV_OPT_FLAG_SUBTITLE_PARAM | AV_OPT_FLAG_DECODING_PARAM
369 static const AVOption options[] = {
370 { "aribb24-base-path", "set the base path for the libaribb24 library",
371 OFFSET(aribb24_base_path), AV_OPT_TYPE_STRING, { .str = NULL }, 0, 0, SD },
372 { "aribb24-skip-ruby-text", "skip ruby text blocks during decoding",
373 OFFSET(aribb24_skip_ruby), AV_OPT_TYPE_BOOL, { .i64 = 1 }, 0, 1, SD },
374 { NULL }
375 };
376
377 static const AVClass aribb24_class = {
378 .class_name = "libaribb24 decoder",
379 .item_name = av_default_item_name,
380 .option = options,
381 .version = LIBAVUTIL_VERSION_INT,
382 };
383
384 const FFCodec ff_libaribb24_decoder = {
385 .p.name = "libaribb24",
386 .p.long_name = NULL_IF_CONFIG_SMALL("libaribb24 ARIB STD-B24 caption decoder"),
387 .p.type = AVMEDIA_TYPE_SUBTITLE,
388 .p.id = AV_CODEC_ID_ARIB_CAPTION,
389 .p.priv_class = &aribb24_class,
390 .p.wrapper_name = "libaribb24",
391 .priv_data_size = sizeof(Libaribb24Context),
392 .init = libaribb24_init,
393 .close = libaribb24_close,
394 FF_CODEC_DECODE_SUB_CB(libaribb24_decode),
395 .flush = libaribb24_flush,
396 };
397