2 * Copyright (c) 2011 Baptiste Coudurier
3 * Copyright (c) 2011 Stefano Sabatini
4 * Copyright (c) 2012 Clément Bœsch
6 * This file is part of FFmpeg.
8 * FFmpeg is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Lesser General Public
10 * License as published by the Free Software Foundation; either
11 * version 2.1 of the License, or (at your option) any later version.
13 * FFmpeg is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * Lesser General Public License for more details.
18 * You should have received a copy of the GNU Lesser General Public
19 * License along with FFmpeg; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
25 * Libass subtitles burning filter.
27 * @see{http://www.matroska.org/technical/specs/subtitles/ssa.html}
33 #if CONFIG_SUBTITLES_FILTER
34 # include "libavcodec/avcodec.h"
35 # include "libavformat/avformat.h"
37 #include "libavutil/avstring.h"
38 #include "libavutil/imgutils.h"
39 #include "libavutil/opt.h"
40 #include "libavutil/parseutils.h"
41 #include "drawutils.h"
50 ASS_Renderer *renderer;
55 int pix_step[4]; ///< steps per pixel for each plane of the main output
56 int original_w, original_h;
60 #define OFFSET(x) offsetof(AssContext, x)
61 #define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
63 #define COMMON_OPTIONS \
64 {"filename", "set the filename of file to read", OFFSET(filename), AV_OPT_TYPE_STRING, {.str = NULL}, CHAR_MIN, CHAR_MAX, FLAGS }, \
65 {"f", "set the filename of file to read", OFFSET(filename), AV_OPT_TYPE_STRING, {.str = NULL}, CHAR_MIN, CHAR_MAX, FLAGS }, \
66 {"original_size", "set the size of the original video (used to scale fonts)", OFFSET(original_w), AV_OPT_TYPE_IMAGE_SIZE, {.str = NULL}, CHAR_MIN, CHAR_MAX, FLAGS }, \
68 /* libass supports a log level ranging from 0 to 7 */
69 static const int ass_libavfilter_log_level_map[] = {
74 AV_LOG_WARNING, /* 4 */
76 AV_LOG_VERBOSE, /* 6 */
80 static void ass_log(int ass_level, const char *fmt, va_list args, void *ctx)
82 int level = ass_libavfilter_log_level_map[ass_level];
84 av_vlog(ctx, level, fmt, args);
85 av_log(ctx, level, "\n");
88 static av_cold int init(AVFilterContext *ctx, const char *args, const AVClass *class)
90 AssContext *ass = ctx->priv;
91 static const char *shorthand[] = { "filename", NULL };
95 av_opt_set_defaults(ass);
97 if ((ret = av_opt_set_from_string(ass, args, shorthand, "=", ":")) < 0)
100 if (!ass->filename) {
101 av_log(ctx, AV_LOG_ERROR, "No filename provided!\n");
102 return AVERROR(EINVAL);
105 ass->library = ass_library_init();
107 av_log(ctx, AV_LOG_ERROR, "Could not initialize libass.\n");
108 return AVERROR(EINVAL);
110 ass_set_message_cb(ass->library, ass_log, ctx);
112 ass->renderer = ass_renderer_init(ass->library);
113 if (!ass->renderer) {
114 av_log(ctx, AV_LOG_ERROR, "Could not initialize libass renderer.\n");
115 return AVERROR(EINVAL);
118 ass_set_fonts(ass->renderer, NULL, NULL, 1, NULL, 1);
122 static av_cold void uninit(AVFilterContext *ctx)
124 AssContext *ass = ctx->priv;
128 ass_free_track(ass->track);
130 ass_renderer_done(ass->renderer);
132 ass_library_done(ass->library);
135 static int query_formats(AVFilterContext *ctx)
137 ff_set_common_formats(ctx, ff_draw_supported_pixel_formats(0));
141 static int config_input(AVFilterLink *inlink)
143 AssContext *ass = inlink->dst->priv;
145 ff_draw_init(&ass->draw, inlink->format, 0);
147 ass_set_frame_size (ass->renderer, inlink->w, inlink->h);
148 if (ass->original_w && ass->original_h)
149 ass_set_aspect_ratio(ass->renderer, (double)inlink->w / inlink->h,
150 (double)ass->original_w / ass->original_h);
155 /* libass stores an RGBA color in the format RRGGBBTT, where TT is the transparency level */
156 #define AR(c) ( (c)>>24)
157 #define AG(c) (((c)>>16)&0xFF)
158 #define AB(c) (((c)>>8) &0xFF)
159 #define AA(c) ((0xFF-c) &0xFF)
161 static void overlay_ass_image(AssContext *ass, AVFilterBufferRef *picref,
162 const ASS_Image *image)
164 for (; image; image = image->next) {
165 uint8_t rgba_color[] = {AR(image->color), AG(image->color), AB(image->color), AA(image->color)};
167 ff_draw_color(&ass->draw, &color, rgba_color);
168 ff_blend_mask(&ass->draw, &color,
169 picref->data, picref->linesize,
170 picref->video->w, picref->video->h,
171 image->bitmap, image->stride, image->w, image->h,
172 3, 0, image->dst_x, image->dst_y);
176 static int filter_frame(AVFilterLink *inlink, AVFilterBufferRef *picref)
178 AVFilterContext *ctx = inlink->dst;
179 AVFilterLink *outlink = ctx->outputs[0];
180 AssContext *ass = ctx->priv;
181 int detect_change = 0;
182 double time_ms = picref->pts * av_q2d(inlink->time_base) * 1000;
183 ASS_Image *image = ass_render_frame(ass->renderer, ass->track,
184 time_ms, &detect_change);
187 av_log(ctx, AV_LOG_DEBUG, "Change happened at time ms:%f\n", time_ms);
189 overlay_ass_image(ass, picref, image);
191 return ff_filter_frame(outlink, picref);
194 static const AVFilterPad ass_inputs[] = {
197 .type = AVMEDIA_TYPE_VIDEO,
198 .filter_frame = filter_frame,
199 .config_props = config_input,
200 .min_perms = AV_PERM_READ | AV_PERM_WRITE,
205 static const AVFilterPad ass_outputs[] = {
208 .type = AVMEDIA_TYPE_VIDEO,
213 #if CONFIG_ASS_FILTER
215 static const AVOption ass_options[] = {
220 AVFILTER_DEFINE_CLASS(ass);
222 static av_cold int init_ass(AVFilterContext *ctx, const char *args)
224 AssContext *ass = ctx->priv;
225 int ret = init(ctx, args, &ass_class);
230 ass->track = ass_read_file(ass->library, ass->filename, NULL);
232 av_log(ctx, AV_LOG_ERROR,
233 "Could not create a libass track when reading file '%s'\n",
235 return AVERROR(EINVAL);
240 AVFilter avfilter_vf_ass = {
242 .description = NULL_IF_CONFIG_SMALL("Render ASS subtitles onto input video using the libass library."),
243 .priv_size = sizeof(AssContext),
246 .query_formats = query_formats,
247 .inputs = ass_inputs,
248 .outputs = ass_outputs,
249 .priv_class = &ass_class,
253 #if CONFIG_SUBTITLES_FILTER
255 static const AVOption subtitles_options[] = {
257 {"charenc", "set input character encoding", OFFSET(charenc), AV_OPT_TYPE_STRING, {.str = NULL}, CHAR_MIN, CHAR_MAX, FLAGS},
261 AVFILTER_DEFINE_CLASS(subtitles);
263 static av_cold int init_subtitles(AVFilterContext *ctx, const char *args)
266 AVDictionary *codec_opts = NULL;
267 AVFormatContext *fmt = NULL;
268 AVCodecContext *dec_ctx = NULL;
270 const AVCodecDescriptor *dec_desc;
273 AssContext *ass = ctx->priv;
276 ret = init(ctx, args, &subtitles_class);
279 ass->track = ass_new_track(ass->library);
281 av_log(ctx, AV_LOG_ERROR, "Could not create a libass track\n");
282 return AVERROR(EINVAL);
285 /* Open subtitles file */
286 ret = avformat_open_input(&fmt, ass->filename, NULL, NULL);
288 av_log(ctx, AV_LOG_ERROR, "Unable to open %s\n", ass->filename);
291 ret = avformat_find_stream_info(fmt, NULL);
295 /* Locate subtitles stream */
296 ret = av_find_best_stream(fmt, AVMEDIA_TYPE_SUBTITLE, -1, -1, NULL, 0);
298 av_log(ctx, AV_LOG_ERROR, "Unable to locate subtitle stream in %s\n",
303 st = fmt->streams[sid];
307 dec = avcodec_find_decoder(dec_ctx->codec_id);
309 av_log(ctx, AV_LOG_ERROR, "Failed to find subtitle codec %s\n",
310 avcodec_get_name(dec_ctx->codec_id));
311 return AVERROR(EINVAL);
313 dec_desc = avcodec_descriptor_get(dec_ctx->codec_id);
314 if (dec_desc && (dec_desc->props & AV_CODEC_PROP_BITMAP_SUB)) {
315 av_log(ctx, AV_LOG_ERROR,
316 "Only text based subtitles are currently supported\n");
317 return AVERROR_PATCHWELCOME;
320 av_dict_set(&codec_opts, "sub_charenc", ass->charenc, 0);
321 ret = avcodec_open2(dec_ctx, dec, &codec_opts);
325 /* Decode subtitles and push them into the renderer (libass) */
326 if (dec_ctx->subtitle_header)
327 ass_process_codec_private(ass->track,
328 dec_ctx->subtitle_header,
329 dec_ctx->subtitle_header_size);
330 av_init_packet(&pkt);
333 while (av_read_frame(fmt, &pkt) >= 0) {
337 if (pkt.stream_index == sid) {
338 ret = avcodec_decode_subtitle2(dec_ctx, &sub, &got_subtitle, &pkt);
340 av_log(ctx, AV_LOG_WARNING, "Error decoding: %s (ignored)\n",
342 } else if (got_subtitle) {
343 for (i = 0; i < sub.num_rects; i++) {
344 char *ass_line = sub.rects[i]->ass;
347 ass_process_data(ass->track, ass_line, strlen(ass_line));
351 av_free_packet(&pkt);
352 avsubtitle_free(&sub);
356 av_dict_free(&codec_opts);
358 avcodec_close(dec_ctx);
360 avformat_close_input(&fmt);
364 AVFilter avfilter_vf_subtitles = {
366 .description = NULL_IF_CONFIG_SMALL("Render text subtitles onto input video using the libass library."),
367 .priv_size = sizeof(AssContext),
368 .init = init_subtitles,
370 .query_formats = query_formats,
371 .inputs = ass_inputs,
372 .outputs = ass_outputs,
373 .priv_class = &subtitles_class,