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