2 * Copyright (c) 2011 Baptiste Coudurier
3 * Copyright (c) 2011 Stefano Sabatini
5 * This file is part of FFmpeg.
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.
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.
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
24 * Libass subtitles burning filter.
26 * @see{http://www.matroska.org/technical/specs/subtitles/ssa.html}
31 #include "libavutil/avstring.h"
32 #include "libavutil/imgutils.h"
33 #include "libavutil/opt.h"
34 #include "libavutil/parseutils.h"
35 #include "drawutils.h"
41 ASS_Renderer *renderer;
45 int pix_step[4]; ///< steps per pixel for each plane of the main output
46 int original_w, original_h;
50 #define OFFSET(x) offsetof(AssContext, x)
52 static const AVOption ass_options[] = {
53 {"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 },
57 static const char *ass_get_name(void *ctx)
62 static const AVClass ass_class = {
68 /* libass supports a log level ranging from 0 to 7 */
69 int ass_libav_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_libav_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, void *opaque)
90 AssContext *ass = ctx->priv;
93 ass->class = &ass_class;
94 av_opt_set_defaults(ass);
97 ass->filename = av_get_token(&args, ":");
98 if (!ass->filename || !*ass->filename) {
99 av_log(ctx, AV_LOG_ERROR, "No filename provided!\n");
100 return AVERROR(EINVAL);
103 if (*args++ == ':' && (ret = av_set_options_string(ass, args, "=", ":")) < 0) {
104 av_log(ctx, AV_LOG_ERROR, "Error parsing options string: '%s'\n", args);
108 ass->library = ass_library_init();
110 av_log(ctx, AV_LOG_ERROR, "Could not initialize libass.\n");
111 return AVERROR(EINVAL);
113 ass_set_message_cb(ass->library, ass_log, ctx);
115 ass->renderer = ass_renderer_init(ass->library);
116 if (!ass->renderer) {
117 av_log(ctx, AV_LOG_ERROR, "Could not initialize libass renderer.\n");
118 return AVERROR(EINVAL);
121 ass->track = ass_read_file(ass->library, ass->filename, NULL);
123 av_log(ctx, AV_LOG_ERROR,
124 "Could not create a libass track when reading file '%s'\n",
126 return AVERROR(EINVAL);
129 ass_set_fonts(ass->renderer, NULL, NULL, 1, NULL, 1);
133 static av_cold void uninit(AVFilterContext *ctx)
135 AssContext *ass = ctx->priv;
137 av_freep(&ass->filename);
139 ass_free_track(ass->track);
141 ass_renderer_done(ass->renderer);
143 ass_library_done(ass->library);
146 static int query_formats(AVFilterContext *ctx)
148 avfilter_set_common_pixel_formats(ctx, ff_draw_supported_pixel_formats(0));
152 static int config_input(AVFilterLink *inlink)
154 AssContext *ass = inlink->dst->priv;
156 ff_draw_init(&ass->draw, inlink->format, 0);
158 ass_set_frame_size (ass->renderer, inlink->w, inlink->h);
159 if (ass->original_w && ass->original_h)
160 ass_set_aspect_ratio(ass->renderer, (double)inlink->w / inlink->h,
161 (double)ass->original_w / ass->original_h);
166 static void null_draw_slice(AVFilterLink *link, int y, int h, int slice_dir) { }
168 /* libass stores an RGBA color in the format RRGGBBTT, where TT is the transparency level */
169 #define AR(c) ( (c)>>24)
170 #define AG(c) (((c)>>16)&0xFF)
171 #define AB(c) (((c)>>8) &0xFF)
172 #define AA(c) ((0xFF-c) &0xFF)
174 static void overlay_ass_image(AssContext *ass, AVFilterBufferRef *picref,
175 const ASS_Image *image)
177 for (; image; image = image->next) {
178 uint8_t rgba_color[] = {AR(image->color), AG(image->color), AB(image->color), AA(image->color)};
180 ff_draw_color(&ass->draw, &color, rgba_color);
181 ff_blend_mask(&ass->draw, &color,
182 picref->data, picref->linesize,
183 picref->video->w, picref->video->h,
184 image->bitmap, image->stride, image->w, image->h,
185 3, 0, image->dst_x, image->dst_y);
189 static void end_frame(AVFilterLink *inlink)
191 AVFilterContext *ctx = inlink->dst;
192 AVFilterLink *outlink = ctx->outputs[0];
193 AssContext *ass = ctx->priv;
194 AVFilterBufferRef *picref = inlink->cur_buf;
195 int detect_change = 0;
196 double time_ms = picref->pts * av_q2d(inlink->time_base) * 1000;
197 ASS_Image *image = ass_render_frame(ass->renderer, ass->track,
198 time_ms, &detect_change);
201 av_log(ctx, AV_LOG_DEBUG, "Change happened at time ms:%f\n", time_ms);
203 overlay_ass_image(ass, picref, image);
205 avfilter_draw_slice(outlink, 0, picref->video->h, 1);
206 avfilter_end_frame(outlink);
209 AVFilter avfilter_vf_ass = {
211 .description = NULL_IF_CONFIG_SMALL("Render subtitles onto input video using the libass library."),
212 .priv_size = sizeof(AssContext),
215 .query_formats = query_formats,
217 .inputs = (const AVFilterPad[]) {
219 .type = AVMEDIA_TYPE_VIDEO,
220 .get_video_buffer = avfilter_null_get_video_buffer,
221 .start_frame = avfilter_null_start_frame,
222 .draw_slice = null_draw_slice,
223 .end_frame = end_frame,
224 .config_props = config_input,
225 .min_perms = AV_PERM_WRITE | AV_PERM_READ,
226 .rej_perms = AV_PERM_PRESERVE },
229 .outputs = (const AVFilterPad[]) {
231 .type = AVMEDIA_TYPE_VIDEO, },