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/*
* 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/opt.h"
#include "libavutil/parseutils.h"
#include "drawutils.h"
#include "avfilter.h"
typedef struct {
const AVClass *class;
ASS_Library *library;
ASS_Renderer *renderer;
ASS_Track *track;
char *filename;
uint8_t rgba_map[4];
int pix_step[4]; ///< steps per pixel for each plane of the main output
int original_w, original_h;
FFDrawContext draw;
} AssContext;
#define OFFSET(x) offsetof(AssContext, x)
static const AVOption ass_options[] = {
{"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 },
{NULL},
};
static const char *ass_get_name(void *ctx)
{
return "ass";
}
static const AVClass ass_class = {
"AssContext",
ass_get_name,
ass_options
};
/* 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;
int ret;
ass->class = &ass_class;
av_opt_set_defaults(ass);
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);
}
if (*args++ == ':' && (ret = av_set_options_string(ass, args, "=", ":")) < 0) {
av_log(ctx, AV_LOG_ERROR, "Error parsing options string: '%s'\n", args);
return ret;
}
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)
{
avfilter_set_common_pixel_formats(ctx, ff_draw_supported_pixel_formats(0));
return 0;
}
static int config_input(AVFilterLink *inlink)
{
AssContext *ass = inlink->dst->priv;
ff_draw_init(&ass->draw, inlink->format, 0);
ass_set_frame_size (ass->renderer, inlink->w, inlink->h);
if (ass->original_w && ass->original_h)
ass_set_aspect_ratio(ass->renderer, (double)inlink->w / inlink->h,
(double)ass->original_w / ass->original_h);
return 0;
}
static void null_draw_slice(AVFilterLink *link, int y, int h, int slice_dir) { }
/* 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(AssContext *ass, AVFilterBufferRef *picref,
const ASS_Image *image)
{
for (; image; image = image->next) {
uint8_t rgba_color[] = {AR(image->color), AG(image->color), AB(image->color), AA(image->color)};
FFDrawColor color;
ff_draw_color(&ass->draw, &color, rgba_color);
ff_blend_mask(&ass->draw, &color,
picref->data, picref->linesize,
picref->video->w, picref->video->h,
image->bitmap, image->stride, image->w, image->h,
3, 0, image->dst_x, image->dst_y);
}
}
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(ass, picref, 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}
},
};
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