/* * Copyright (c) 2011 Baptiste Coudurier * Copyright (c) 2011 Stefano Sabatini * * This file is part of FFmpeg. * * FFmpeg is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * FFmpeg is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with FFmpeg; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ /** * @file * Libass subtitles burning filter. * * @see{http://www.matroska.org/technical/specs/subtitles/ssa.html} */ #include <ass/ass.h> #include "libavutil/avstring.h" #include "libavutil/imgutils.h" #include "libavutil/pixdesc.h" #include "drawutils.h" #include "avfilter.h" typedef struct { ASS_Library *library; ASS_Renderer *renderer; ASS_Track *track; int hsub, vsub; char *filename; uint8_t rgba_map[4]; int pix_step[4]; ///< steps per pixel for each plane of the main output } AssContext; /* libass supports a log level ranging from 0 to 7 */ int ass_libav_log_level_map[] = { AV_LOG_QUIET, /* 0 */ AV_LOG_PANIC, /* 1 */ AV_LOG_FATAL, /* 2 */ AV_LOG_ERROR, /* 3 */ AV_LOG_WARNING, /* 4 */ AV_LOG_INFO, /* 5 */ AV_LOG_VERBOSE, /* 6 */ AV_LOG_DEBUG, /* 7 */ }; static void ass_log(int ass_level, const char *fmt, va_list args, void *ctx) { int level = ass_libav_log_level_map[ass_level]; av_vlog(ctx, level, fmt, args); av_log(ctx, level, "\n"); } static av_cold int init(AVFilterContext *ctx, const char *args, void *opaque) { AssContext *ass = ctx->priv; if (args) ass->filename = av_get_token(&args, ":"); if (!ass->filename || !*ass->filename) { av_log(ctx, AV_LOG_ERROR, "No filename provided!\n"); return AVERROR(EINVAL); } ass->library = ass_library_init(); if (!ass->library) { av_log(ctx, AV_LOG_ERROR, "Could not initialize libass.\n"); return AVERROR(EINVAL); } ass_set_message_cb(ass->library, ass_log, ctx); ass->renderer = ass_renderer_init(ass->library); if (!ass->renderer) { av_log(ctx, AV_LOG_ERROR, "Could not initialize libass renderer.\n"); return AVERROR(EINVAL); } ass->track = ass_read_file(ass->library, ass->filename, NULL); if (!ass->track) { av_log(ctx, AV_LOG_ERROR, "Could not create a libass track when reading file '%s'\n", ass->filename); return AVERROR(EINVAL); } ass_set_fonts(ass->renderer, NULL, NULL, 1, NULL, 1); return 0; } static av_cold void uninit(AVFilterContext *ctx) { AssContext *ass = ctx->priv; av_freep(&ass->filename); if (ass->track) ass_free_track(ass->track); if (ass->renderer) ass_renderer_done(ass->renderer); if (ass->library) ass_library_done(ass->library); } static int query_formats(AVFilterContext *ctx) { static const enum PixelFormat pix_fmts[] = { PIX_FMT_ARGB, PIX_FMT_RGBA, PIX_FMT_ABGR, PIX_FMT_BGRA, PIX_FMT_RGB24, PIX_FMT_BGR24, PIX_FMT_NONE }; avfilter_set_common_pixel_formats(ctx, avfilter_make_format_list(pix_fmts)); return 0; } static int config_input(AVFilterLink *inlink) { AssContext *ass = inlink->dst->priv; const AVPixFmtDescriptor *pix_desc = &av_pix_fmt_descriptors[inlink->format]; double sar = inlink->sample_aspect_ratio.num ? av_q2d(inlink->sample_aspect_ratio) : 1; double dar = inlink->w / inlink->h * sar; av_image_fill_max_pixsteps(ass->pix_step, NULL, pix_desc); ff_fill_rgba_map(ass->rgba_map, inlink->format); ass->hsub = pix_desc->log2_chroma_w; ass->vsub = pix_desc->log2_chroma_h; ass_set_frame_size (ass->renderer, inlink->w, inlink->h); ass_set_aspect_ratio(ass->renderer, dar, sar); return 0; } static void null_draw_slice(AVFilterLink *link, int y, int h, int slice_dir) { } #define R 0 #define G 1 #define B 2 #define A 3 #define SET_PIXEL_RGB(picref, rgba_color, val, x, y, pixel_step, r_off, g_off, b_off) { \ p = picref->data[0] + (x) * pixel_step + ((y) * picref->linesize[0]); \ alpha = rgba_color[A] * (val) * 129; \ *(p+r_off) = (alpha * rgba_color[R] + (255*255*129 - alpha) * *(p+r_off)) >> 23; \ *(p+g_off) = (alpha * rgba_color[G] + (255*255*129 - alpha) * *(p+g_off)) >> 23; \ *(p+b_off) = (alpha * rgba_color[B] + (255*255*129 - alpha) * *(p+b_off)) >> 23; \ } /* libass stores an RGBA color in the format RRGGBBTT, where TT is the transparency level */ #define AR(c) ( (c)>>24) #define AG(c) (((c)>>16)&0xFF) #define AB(c) (((c)>>8) &0xFF) #define AA(c) ((0xFF-c) &0xFF) static void overlay_ass_image(AVFilterBufferRef *picref, const uint8_t *rgba_map, const int pix_step, const ASS_Image *image) { int i, j; int alpha; uint8_t *p; const int ro = rgba_map[R]; const int go = rgba_map[G]; const int bo = rgba_map[B]; for (; image; image = image->next) { uint8_t rgba_color[] = {AR(image->color), AG(image->color), AB(image->color), AA(image->color)}; unsigned char *row = image->bitmap; for (i = 0; i < image->h; i++) { for (j = 0; j < image->w; j++) { if (row[j]) { SET_PIXEL_RGB(picref, rgba_color, row[j], image->dst_x + j, image->dst_y + i, pix_step, ro, go, bo); } } row += image->stride; } } } static void end_frame(AVFilterLink *inlink) { AVFilterContext *ctx = inlink->dst; AVFilterLink *outlink = ctx->outputs[0]; AssContext *ass = ctx->priv; AVFilterBufferRef *picref = inlink->cur_buf; int detect_change = 0; double time_ms = picref->pts * av_q2d(inlink->time_base) * 1000; ASS_Image *image = ass_render_frame(ass->renderer, ass->track, time_ms, &detect_change); if (detect_change) av_log(ctx, AV_LOG_DEBUG, "Change happened at time ms:%f\n", time_ms); overlay_ass_image(picref, ass->rgba_map, ass->pix_step[0], image); avfilter_draw_slice(outlink, 0, picref->video->h, 1); avfilter_end_frame(outlink); } AVFilter avfilter_vf_ass = { .name = "ass", .description = NULL_IF_CONFIG_SMALL("Render subtitles onto input video using the libass library."), .priv_size = sizeof(AssContext), .init = init, .uninit = uninit, .query_formats = query_formats, .inputs = (const AVFilterPad[]) { { .name = "default", .type = AVMEDIA_TYPE_VIDEO, .get_video_buffer = avfilter_null_get_video_buffer, .start_frame = avfilter_null_start_frame, .draw_slice = null_draw_slice, .end_frame = end_frame, .config_props = config_input, .min_perms = AV_PERM_WRITE | AV_PERM_READ, .rej_perms = AV_PERM_PRESERVE }, { .name = NULL} }, .outputs = (const AVFilterPad[]) { { .name = "default", .type = AVMEDIA_TYPE_VIDEO, }, { .name = NULL} }, };