/*
* Copyright (c) 2011 Baptiste Coudurier
* Copyright (c) 2011 Stefano Sabatini
* Copyright (c) 2012 Clément Bœsch
*
* 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 "config.h"
#if CONFIG_SUBTITLES_FILTER
# include "libavcodec/avcodec.h"
# include "libavformat/avformat.h"
#endif
#include "libavutil/avstring.h"
#include "libavutil/imgutils.h"
#include "libavutil/opt.h"
#include "libavutil/parseutils.h"
#include "drawutils.h"
#include "avfilter.h"
#include "internal.h"
#include "formats.h"
#include "video.h"
typedef struct AssContext {
const AVClass *class;
ASS_Library *library;
ASS_Renderer *renderer;
ASS_Track *track;
char *filename;
char *fontsdir;
char *charenc;
char *force_style;
int stream_index;
int alpha;
uint8_t rgba_map[4];
int pix_step[4]; ///< steps per pixel for each plane of the main output
int original_w, original_h;
int shaping;
FFDrawContext draw;
} AssContext;
#define OFFSET(x) offsetof(AssContext, x)
#define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
#define COMMON_OPTIONS \
{"filename", "set the filename of file to read", OFFSET(filename), AV_OPT_TYPE_STRING, {.str = NULL}, CHAR_MIN, CHAR_MAX, FLAGS }, \
{"f", "set the filename of file to read", OFFSET(filename), AV_OPT_TYPE_STRING, {.str = NULL}, CHAR_MIN, CHAR_MAX, FLAGS }, \
{"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 }, \
{"fontsdir", "set the directory containing the fonts to read", OFFSET(fontsdir), AV_OPT_TYPE_STRING, {.str = NULL}, CHAR_MIN, CHAR_MAX, FLAGS }, \
{"alpha", "enable processing of alpha channel", OFFSET(alpha), AV_OPT_TYPE_BOOL, {.i64 = 0 }, 0, 1, FLAGS }, \
/* libass supports a log level ranging from 0 to 7 */
static const int ass_libavfilter_log_level_map[] = {
[0] = AV_LOG_FATAL, /* MSGL_FATAL */
[1] = AV_LOG_ERROR, /* MSGL_ERR */
[2] = AV_LOG_WARNING, /* MSGL_WARN */
[3] = AV_LOG_WARNING, /* <undefined> */
[4] = AV_LOG_INFO, /* MSGL_INFO */
[5] = AV_LOG_INFO, /* <undefined> */
[6] = AV_LOG_VERBOSE, /* MSGL_V */
[7] = AV_LOG_DEBUG, /* MSGL_DBG2 */
};
static void ass_log(int ass_level, const char *fmt, va_list args, void *ctx)
{
const int ass_level_clip = av_clip(ass_level, 0,
FF_ARRAY_ELEMS(ass_libavfilter_log_level_map) - 1);
const int level = ass_libavfilter_log_level_map[ass_level_clip];
av_vlog(ctx, level, fmt, args);
av_log(ctx, level, "\n");
}
static av_cold int init(AVFilterContext *ctx)
{
AssContext *ass = ctx->priv;
if (!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_set_fonts_dir(ass->library, ass->fontsdir);
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);
}
return 0;
}
static av_cold void uninit(AVFilterContext *ctx)
{
AssContext *ass = ctx->priv;
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)
{
return ff_set_common_formats(ctx, ff_draw_supported_pixel_formats(0));
}
static int config_input(AVFilterLink *inlink)
{
AssContext *ass = inlink->dst->priv;
ff_draw_init(&ass->draw, inlink->format, ass->alpha ? FF_DRAW_PROCESS_ALPHA : 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);
if (ass->shaping != -1)
ass_set_shaper(ass->renderer, ass->shaping);
return 0;
}
/* 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, AVFrame *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->width, picref->height,
image->bitmap, image->stride, image->w, image->h,
3, 0, image->dst_x, image->dst_y);
}
}
static int filter_frame(AVFilterLink *inlink, AVFrame *picref)
{
AVFilterContext *ctx = inlink->dst;
AVFilterLink *outlink = ctx->outputs[0];
AssContext *ass = ctx->priv;
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);
return ff_filter_frame(outlink, picref);
}
static const AVFilterPad ass_inputs[] = {
{
.name = "default",
.type = AVMEDIA_TYPE_VIDEO,
.filter_frame = filter_frame,
.config_props = config_input,
.needs_writable = 1,
},
{ NULL }
};
static const AVFilterPad ass_outputs[] = {
{
.name = "default",
.type = AVMEDIA_TYPE_VIDEO,
},
{ NULL }
};
#if CONFIG_ASS_FILTER
static const AVOption ass_options[] = {
COMMON_OPTIONS
{"shaping", "set shaping engine", OFFSET(shaping), AV_OPT_TYPE_INT, { .i64 = -1 }, -1, 1, FLAGS, "shaping_mode"},
{"auto", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = -1}, INT_MIN, INT_MAX, FLAGS, "shaping_mode"},
{"simple", "simple shaping", 0, AV_OPT_TYPE_CONST, {.i64 = ASS_SHAPING_SIMPLE}, INT_MIN, INT_MAX, FLAGS, "shaping_mode"},
{"complex", "complex shaping", 0, AV_OPT_TYPE_CONST, {.i64 = ASS_SHAPING_COMPLEX}, INT_MIN, INT_MAX, FLAGS, "shaping_mode"},
{NULL},
};
AVFILTER_DEFINE_CLASS(ass);
static av_cold int init_ass(AVFilterContext *ctx)
{
AssContext *ass = ctx->priv;
int ret = init(ctx);
if (ret < 0)
return ret;
/* Initialize fonts */
ass_set_fonts(ass->renderer, NULL, NULL, 1, NULL, 1);
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);
}
return 0;
}
AVFilter ff_vf_ass = {
.name = "ass",
.description = NULL_IF_CONFIG_SMALL("Render ASS subtitles onto input video using the libass library."),
.priv_size = sizeof(AssContext),
.init = init_ass,
.uninit = uninit,
.query_formats = query_formats,
.inputs = ass_inputs,
.outputs = ass_outputs,
.priv_class = &ass_class,
};
#endif
#if CONFIG_SUBTITLES_FILTER
static const AVOption subtitles_options[] = {
COMMON_OPTIONS
{"charenc", "set input character encoding", OFFSET(charenc), AV_OPT_TYPE_STRING, {.str = NULL}, CHAR_MIN, CHAR_MAX, FLAGS},
{"stream_index", "set stream index", OFFSET(stream_index), AV_OPT_TYPE_INT, { .i64 = -1 }, -1, INT_MAX, FLAGS},
{"si", "set stream index", OFFSET(stream_index), AV_OPT_TYPE_INT, { .i64 = -1 }, -1, INT_MAX, FLAGS},
{"force_style", "force subtitle style", OFFSET(force_style), AV_OPT_TYPE_STRING, {.str = NULL}, CHAR_MIN, CHAR_MAX, FLAGS},
{NULL},
};
static const char * const font_mimetypes[] = {
"application/x-truetype-font",
"application/vnd.ms-opentype",
"application/x-font-ttf",
NULL
};
static int attachment_is_font(AVStream * st)
{
const AVDictionaryEntry *tag = NULL;
int n;
tag = av_dict_get(st->metadata, "mimetype", NULL, AV_DICT_MATCH_CASE);
if (tag) {
for (n = 0; font_mimetypes[n]; n++) {
if (av_strcasecmp(font_mimetypes[n], tag->value) == 0)
return 1;
}
}
return 0;
}
AVFILTER_DEFINE_CLASS(subtitles);
static av_cold int init_subtitles(AVFilterContext *ctx)
{
int j, ret, sid;
int k = 0;
AVDictionary *codec_opts = NULL;
AVFormatContext *fmt = NULL;
AVCodecContext *dec_ctx = NULL;
AVCodec *dec = NULL;
const AVCodecDescriptor *dec_desc;
AVStream *st;
AVPacket pkt;
AssContext *ass = ctx->priv;
/* Init libass */
ret = init(ctx);
if (ret < 0)
return ret;
ass->track = ass_new_track(ass->library);
if (!ass->track) {
av_log(ctx, AV_LOG_ERROR, "Could not create a libass track\n");
return AVERROR(EINVAL);
}
/* Open subtitles file */
ret = avformat_open_input(&fmt, ass->filename, NULL, NULL);
if (ret < 0) {
av_log(ctx, AV_LOG_ERROR, "Unable to open %s\n", ass->filename);
goto end;
}
ret = avformat_find_stream_info(fmt, NULL);
if (ret < 0)
goto end;
/* Locate subtitles stream */
if (ass->stream_index < 0)
ret = av_find_best_stream(fmt, AVMEDIA_TYPE_SUBTITLE, -1, -1, NULL, 0);
else {
ret = -1;
if (ass->stream_index < fmt->nb_streams) {
for (j = 0; j < fmt->nb_streams; j++) {
if (fmt->streams[j]->codecpar->codec_type == AVMEDIA_TYPE_SUBTITLE) {
if (ass->stream_index == k) {
ret = j;
break;
}
k++;
}
}
}
}
if (ret < 0) {
av_log(ctx, AV_LOG_ERROR, "Unable to locate subtitle stream in %s\n",
ass->filename);
goto end;
}
sid = ret;
st = fmt->streams[sid];
/* Load attached fonts */
for (j = 0; j < fmt->nb_streams; j++) {
AVStream *st = fmt->streams[j];
if (st->codecpar->codec_type == AVMEDIA_TYPE_ATTACHMENT &&
attachment_is_font(st)) {
const AVDictionaryEntry *tag = NULL;
tag = av_dict_get(st->metadata, "filename", NULL,
AV_DICT_MATCH_CASE);
if (tag) {
av_log(ctx, AV_LOG_DEBUG, "Loading attached font: %s\n",
tag->value);
ass_add_font(ass->library, tag->value,
st->codecpar->extradata,
st->codecpar->extradata_size);
} else {
av_log(ctx, AV_LOG_WARNING,
"Font attachment has no filename, ignored.\n");
}
}
}
/* Initialize fonts */
ass_set_fonts(ass->renderer, NULL, NULL, 1, NULL, 1);
/* Open decoder */
dec = avcodec_find_decoder(st->codecpar->codec_id);
if (!dec) {
av_log(ctx, AV_LOG_ERROR, "Failed to find subtitle codec %s\n",
avcodec_get_name(st->codecpar->codec_id));
return AVERROR(EINVAL);
}
dec_desc = avcodec_descriptor_get(st->codecpar->codec_id);
if (dec_desc && !(dec_desc->props & AV_CODEC_PROP_TEXT_SUB)) {
av_log(ctx, AV_LOG_ERROR,
"Only text based subtitles are currently supported\n");
return AVERROR_PATCHWELCOME;
}
if (ass->charenc)
av_dict_set(&codec_opts, "sub_charenc", ass->charenc, 0);
if (LIBAVCODEC_VERSION_INT >= AV_VERSION_INT(57,26,100))
av_dict_set(&codec_opts, "sub_text_format", "ass", 0);
dec_ctx = avcodec_alloc_context3(dec);
if (!dec_ctx)
return AVERROR(ENOMEM);
ret = avcodec_parameters_to_context(dec_ctx, st->codecpar);
if (ret < 0)
goto end;
/*
* This is required by the decoding process in order to rescale the
* timestamps: in the current API the decoded subtitles have their pts
* expressed in AV_TIME_BASE, and thus the lavc internals need to know the
* stream time base in order to achieve the rescaling.
*
* That API is old and needs to be reworked to match behaviour with A/V.
*/
dec_ctx->pkt_timebase = st->time_base;
ret = avcodec_open2(dec_ctx, NULL, &codec_opts);
if (ret < 0)
goto end;
if (ass->force_style) {
char **list = NULL;
char *temp = NULL;
char *ptr = av_strtok(ass->force_style, ",", &temp);
int i = 0;
while (ptr) {
av_dynarray_add(&list, &i, ptr);
if (!list) {
ret = AVERROR(ENOMEM);
goto end;
}
ptr = av_strtok(NULL, ",", &temp);
}
av_dynarray_add(&list, &i, NULL);
if (!list) {
ret = AVERROR(ENOMEM);
goto end;
}
ass_set_style_overrides(ass->library, list);
av_free(list);
}
/* Decode subtitles and push them into the renderer (libass) */
if (dec_ctx->subtitle_header)
ass_process_codec_private(ass->track,
dec_ctx->subtitle_header,
dec_ctx->subtitle_header_size);
av_init_packet(&pkt);
pkt.data = NULL;
pkt.size = 0;
while (av_read_frame(fmt, &pkt) >= 0) {
int i, got_subtitle;
AVSubtitle sub = {0};
if (pkt.stream_index == sid) {
ret = avcodec_decode_subtitle2(dec_ctx, &sub, &got_subtitle, &pkt);
if (ret < 0) {
av_log(ctx, AV_LOG_WARNING, "Error decoding: %s (ignored)\n",
av_err2str(ret));
} else if (got_subtitle) {
const int64_t start_time = av_rescale_q(sub.pts, AV_TIME_BASE_Q, av_make_q(1, 1000));
const int64_t duration = sub.end_display_time;
for (i = 0; i < sub.num_rects; i++) {
char *ass_line = sub.rects[i]->ass;
if (!ass_line)
break;
if (LIBAVCODEC_VERSION_INT < AV_VERSION_INT(57,25,100))
ass_process_data(ass->track, ass_line, strlen(ass_line));
else
ass_process_chunk(ass->track, ass_line, strlen(ass_line),
start_time, duration);
}
}
}
av_packet_unref(&pkt);
avsubtitle_free(&sub);
}
end:
av_dict_free(&codec_opts);
avcodec_close(dec_ctx);
avcodec_free_context(&dec_ctx);
avformat_close_input(&fmt);
return ret;
}
AVFilter ff_vf_subtitles = {
.name = "subtitles",
.description = NULL_IF_CONFIG_SMALL("Render text subtitles onto input video using the libass library."),
.priv_size = sizeof(AssContext),
.init = init_subtitles,
.uninit = uninit,
.query_formats = query_formats,
.inputs = ass_inputs,
.outputs = ass_outputs,
.priv_class = &subtitles_class,
};
#endif