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author | Stefano Sabatini <stefasab@gmail.com> | 2011-09-17 15:52:19 +0200 |
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committer | Stefano Sabatini <stefasab@gmail.com> | 2011-11-26 10:42:33 +0100 |
commit | 28338bc2a3bb316cde2dfc308722c3cdc3d7b046 (patch) | |
tree | 120c8fbbaf4f5d2e203265f2994931d2f61a41be /libavfilter/vf_ass.c | |
parent | 31a1342e7a84235eab725bc11e2a708d293624a3 (diff) | |
download | ffmpeg-streaming-28338bc2a3bb316cde2dfc308722c3cdc3d7b046.zip ffmpeg-streaming-28338bc2a3bb316cde2dfc308722c3cdc3d7b046.tar.gz |
lavfi: add libass based subtitles renderer
Diffstat (limited to 'libavfilter/vf_ass.c')
-rw-r--r-- | libavfilter/vf_ass.c | 242 |
1 files changed, 242 insertions, 0 deletions
diff --git a/libavfilter/vf_ass.c b/libavfilter/vf_ass.c new file mode 100644 index 0000000..7ef78f1 --- /dev/null +++ b/libavfilter/vf_ass.c @@ -0,0 +1,242 @@ +/* + * 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} + }, +}; |