yading@11: /*
yading@11:  * Copyright (c) 2011 Baptiste Coudurier
yading@11:  * Copyright (c) 2011 Stefano Sabatini
yading@11:  * Copyright (c) 2012 Clément Bœsch
yading@11:  *
yading@11:  * This file is part of FFmpeg.
yading@11:  *
yading@11:  * FFmpeg is free software; you can redistribute it and/or
yading@11:  * modify it under the terms of the GNU Lesser General Public
yading@11:  * License as published by the Free Software Foundation; either
yading@11:  * version 2.1 of the License, or (at your option) any later version.
yading@11:  *
yading@11:  * FFmpeg is distributed in the hope that it will be useful,
yading@11:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
yading@11:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
yading@11:  * Lesser General Public License for more details.
yading@11:  *
yading@11:  * You should have received a copy of the GNU Lesser General Public
yading@11:  * License along with FFmpeg; if not, write to the Free Software
yading@11:  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
yading@11:  */
yading@11: 
yading@11: /**
yading@11:  * @file
yading@11:  * Libass subtitles burning filter.
yading@11:  *
yading@11:  * @see{http://www.matroska.org/technical/specs/subtitles/ssa.html}
yading@11:  */
yading@11: 
yading@11: #include <ass/ass.h>
yading@11: 
yading@11: #include "config.h"
yading@11: #if CONFIG_SUBTITLES_FILTER
yading@11: # include "libavcodec/avcodec.h"
yading@11: # include "libavformat/avformat.h"
yading@11: #endif
yading@11: #include "libavutil/avstring.h"
yading@11: #include "libavutil/imgutils.h"
yading@11: #include "libavutil/opt.h"
yading@11: #include "libavutil/parseutils.h"
yading@11: #include "drawutils.h"
yading@11: #include "avfilter.h"
yading@11: #include "internal.h"
yading@11: #include "formats.h"
yading@11: #include "video.h"
yading@11: 
yading@11: typedef struct {
yading@11:     const AVClass *class;
yading@11:     ASS_Library  *library;
yading@11:     ASS_Renderer *renderer;
yading@11:     ASS_Track    *track;
yading@11:     char *filename;
yading@11:     char *charenc;
yading@11:     uint8_t rgba_map[4];
yading@11:     int     pix_step[4];       ///< steps per pixel for each plane of the main output
yading@11:     int original_w, original_h;
yading@11:     FFDrawContext draw;
yading@11: } AssContext;
yading@11: 
yading@11: #define OFFSET(x) offsetof(AssContext, x)
yading@11: #define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
yading@11: 
yading@11: #define COMMON_OPTIONS \
yading@11:     {"filename",       "set the filename of file to read",                         OFFSET(filename),   AV_OPT_TYPE_STRING,     {.str = NULL},  CHAR_MIN, CHAR_MAX, FLAGS }, \
yading@11:     {"f",              "set the filename of file to read",                         OFFSET(filename),   AV_OPT_TYPE_STRING,     {.str = NULL},  CHAR_MIN, CHAR_MAX, FLAGS }, \
yading@11:     {"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 }, \
yading@11: 
yading@11: /* libass supports a log level ranging from 0 to 7 */
yading@11: static const int ass_libavfilter_log_level_map[] = {
yading@11:     AV_LOG_QUIET,               /* 0 */
yading@11:     AV_LOG_PANIC,               /* 1 */
yading@11:     AV_LOG_FATAL,               /* 2 */
yading@11:     AV_LOG_ERROR,               /* 3 */
yading@11:     AV_LOG_WARNING,             /* 4 */
yading@11:     AV_LOG_INFO,                /* 5 */
yading@11:     AV_LOG_VERBOSE,             /* 6 */
yading@11:     AV_LOG_DEBUG,               /* 7 */
yading@11: };
yading@11: 
yading@11: static void ass_log(int ass_level, const char *fmt, va_list args, void *ctx)
yading@11: {
yading@11:     int level = ass_libavfilter_log_level_map[ass_level];
yading@11: 
yading@11:     av_vlog(ctx, level, fmt, args);
yading@11:     av_log(ctx, level, "\n");
yading@11: }
yading@11: 
yading@11: static av_cold int init(AVFilterContext *ctx)
yading@11: {
yading@11:     AssContext *ass = ctx->priv;
yading@11: 
yading@11:     if (!ass->filename) {
yading@11:         av_log(ctx, AV_LOG_ERROR, "No filename provided!\n");
yading@11:         return AVERROR(EINVAL);
yading@11:     }
yading@11: 
yading@11:     ass->library = ass_library_init();
yading@11:     if (!ass->library) {
yading@11:         av_log(ctx, AV_LOG_ERROR, "Could not initialize libass.\n");
yading@11:         return AVERROR(EINVAL);
yading@11:     }
yading@11:     ass_set_message_cb(ass->library, ass_log, ctx);
yading@11: 
yading@11:     ass->renderer = ass_renderer_init(ass->library);
yading@11:     if (!ass->renderer) {
yading@11:         av_log(ctx, AV_LOG_ERROR, "Could not initialize libass renderer.\n");
yading@11:         return AVERROR(EINVAL);
yading@11:     }
yading@11: 
yading@11:     ass_set_fonts(ass->renderer, NULL, NULL, 1, NULL, 1);
yading@11:     return 0;
yading@11: }
yading@11: 
yading@11: static av_cold void uninit(AVFilterContext *ctx)
yading@11: {
yading@11:     AssContext *ass = ctx->priv;
yading@11: 
yading@11:     if (ass->track)
yading@11:         ass_free_track(ass->track);
yading@11:     if (ass->renderer)
yading@11:         ass_renderer_done(ass->renderer);
yading@11:     if (ass->library)
yading@11:         ass_library_done(ass->library);
yading@11: }
yading@11: 
yading@11: static int query_formats(AVFilterContext *ctx)
yading@11: {
yading@11:     ff_set_common_formats(ctx, ff_draw_supported_pixel_formats(0));
yading@11:     return 0;
yading@11: }
yading@11: 
yading@11: static int config_input(AVFilterLink *inlink)
yading@11: {
yading@11:     AssContext *ass = inlink->dst->priv;
yading@11: 
yading@11:     ff_draw_init(&ass->draw, inlink->format, 0);
yading@11: 
yading@11:     ass_set_frame_size  (ass->renderer, inlink->w, inlink->h);
yading@11:     if (ass->original_w && ass->original_h)
yading@11:         ass_set_aspect_ratio(ass->renderer, (double)inlink->w / inlink->h,
yading@11:                              (double)ass->original_w / ass->original_h);
yading@11: 
yading@11:     return 0;
yading@11: }
yading@11: 
yading@11: /* libass stores an RGBA color in the format RRGGBBTT, where TT is the transparency level */
yading@11: #define AR(c)  ( (c)>>24)
yading@11: #define AG(c)  (((c)>>16)&0xFF)
yading@11: #define AB(c)  (((c)>>8) &0xFF)
yading@11: #define AA(c)  ((0xFF-c) &0xFF)
yading@11: 
yading@11: static void overlay_ass_image(AssContext *ass, AVFrame *picref,
yading@11:                               const ASS_Image *image)
yading@11: {
yading@11:     for (; image; image = image->next) {
yading@11:         uint8_t rgba_color[] = {AR(image->color), AG(image->color), AB(image->color), AA(image->color)};
yading@11:         FFDrawColor color;
yading@11:         ff_draw_color(&ass->draw, &color, rgba_color);
yading@11:         ff_blend_mask(&ass->draw, &color,
yading@11:                       picref->data, picref->linesize,
yading@11:                       picref->width, picref->height,
yading@11:                       image->bitmap, image->stride, image->w, image->h,
yading@11:                       3, 0, image->dst_x, image->dst_y);
yading@11:     }
yading@11: }
yading@11: 
yading@11: static int filter_frame(AVFilterLink *inlink, AVFrame *picref)
yading@11: {
yading@11:     AVFilterContext *ctx = inlink->dst;
yading@11:     AVFilterLink *outlink = ctx->outputs[0];
yading@11:     AssContext *ass = ctx->priv;
yading@11:     int detect_change = 0;
yading@11:     double time_ms = picref->pts * av_q2d(inlink->time_base) * 1000;
yading@11:     ASS_Image *image = ass_render_frame(ass->renderer, ass->track,
yading@11:                                         time_ms, &detect_change);
yading@11: 
yading@11:     if (detect_change)
yading@11:         av_log(ctx, AV_LOG_DEBUG, "Change happened at time ms:%f\n", time_ms);
yading@11: 
yading@11:     overlay_ass_image(ass, picref, image);
yading@11: 
yading@11:     return ff_filter_frame(outlink, picref);
yading@11: }
yading@11: 
yading@11: static const AVFilterPad ass_inputs[] = {
yading@11:     {
yading@11:         .name             = "default",
yading@11:         .type             = AVMEDIA_TYPE_VIDEO,
yading@11:         .filter_frame     = filter_frame,
yading@11:         .config_props     = config_input,
yading@11:         .needs_writable   = 1,
yading@11:     },
yading@11:     { NULL }
yading@11: };
yading@11: 
yading@11: static const AVFilterPad ass_outputs[] = {
yading@11:     {
yading@11:         .name = "default",
yading@11:         .type = AVMEDIA_TYPE_VIDEO,
yading@11:     },
yading@11:     { NULL }
yading@11: };
yading@11: 
yading@11: #if CONFIG_ASS_FILTER
yading@11: 
yading@11: static const AVOption ass_options[] = {
yading@11:     COMMON_OPTIONS
yading@11:     {NULL},
yading@11: };
yading@11: 
yading@11: AVFILTER_DEFINE_CLASS(ass);
yading@11: 
yading@11: static av_cold int init_ass(AVFilterContext *ctx)
yading@11: {
yading@11:     AssContext *ass = ctx->priv;
yading@11:     int ret = init(ctx);
yading@11: 
yading@11:     if (ret < 0)
yading@11:         return ret;
yading@11: 
yading@11:     ass->track = ass_read_file(ass->library, ass->filename, NULL);
yading@11:     if (!ass->track) {
yading@11:         av_log(ctx, AV_LOG_ERROR,
yading@11:                "Could not create a libass track when reading file '%s'\n",
yading@11:                ass->filename);
yading@11:         return AVERROR(EINVAL);
yading@11:     }
yading@11:     return 0;
yading@11: }
yading@11: 
yading@11: AVFilter avfilter_vf_ass = {
yading@11:     .name          = "ass",
yading@11:     .description   = NULL_IF_CONFIG_SMALL("Render ASS subtitles onto input video using the libass library."),
yading@11:     .priv_size     = sizeof(AssContext),
yading@11:     .init          = init_ass,
yading@11:     .uninit        = uninit,
yading@11:     .query_formats = query_formats,
yading@11:     .inputs        = ass_inputs,
yading@11:     .outputs       = ass_outputs,
yading@11:     .priv_class    = &ass_class,
yading@11: };
yading@11: #endif
yading@11: 
yading@11: #if CONFIG_SUBTITLES_FILTER
yading@11: 
yading@11: static const AVOption subtitles_options[] = {
yading@11:     COMMON_OPTIONS
yading@11:     {"charenc", "set input character encoding", OFFSET(charenc), AV_OPT_TYPE_STRING, {.str = NULL}, CHAR_MIN, CHAR_MAX, FLAGS},
yading@11:     {NULL},
yading@11: };
yading@11: 
yading@11: AVFILTER_DEFINE_CLASS(subtitles);
yading@11: 
yading@11: static av_cold int init_subtitles(AVFilterContext *ctx)
yading@11: {
yading@11:     int ret, sid;
yading@11:     AVDictionary *codec_opts = NULL;
yading@11:     AVFormatContext *fmt = NULL;
yading@11:     AVCodecContext *dec_ctx = NULL;
yading@11:     AVCodec *dec = NULL;
yading@11:     const AVCodecDescriptor *dec_desc;
yading@11:     AVStream *st;
yading@11:     AVPacket pkt;
yading@11:     AssContext *ass = ctx->priv;
yading@11: 
yading@11:     /* Init libass */
yading@11:     ret = init(ctx);
yading@11:     if (ret < 0)
yading@11:         return ret;
yading@11:     ass->track = ass_new_track(ass->library);
yading@11:     if (!ass->track) {
yading@11:         av_log(ctx, AV_LOG_ERROR, "Could not create a libass track\n");
yading@11:         return AVERROR(EINVAL);
yading@11:     }
yading@11: 
yading@11:     /* Open subtitles file */
yading@11:     ret = avformat_open_input(&fmt, ass->filename, NULL, NULL);
yading@11:     if (ret < 0) {
yading@11:         av_log(ctx, AV_LOG_ERROR, "Unable to open %s\n", ass->filename);
yading@11:         goto end;
yading@11:     }
yading@11:     ret = avformat_find_stream_info(fmt, NULL);
yading@11:     if (ret < 0)
yading@11:         goto end;
yading@11: 
yading@11:     /* Locate subtitles stream */
yading@11:     ret = av_find_best_stream(fmt, AVMEDIA_TYPE_SUBTITLE, -1, -1, NULL, 0);
yading@11:     if (ret < 0) {
yading@11:         av_log(ctx, AV_LOG_ERROR, "Unable to locate subtitle stream in %s\n",
yading@11:                ass->filename);
yading@11:         goto end;
yading@11:     }
yading@11:     sid = ret;
yading@11:     st = fmt->streams[sid];
yading@11: 
yading@11:     /* Open decoder */
yading@11:     dec_ctx = st->codec;
yading@11:     dec = avcodec_find_decoder(dec_ctx->codec_id);
yading@11:     if (!dec) {
yading@11:         av_log(ctx, AV_LOG_ERROR, "Failed to find subtitle codec %s\n",
yading@11:                avcodec_get_name(dec_ctx->codec_id));
yading@11:         return AVERROR(EINVAL);
yading@11:     }
yading@11:     dec_desc = avcodec_descriptor_get(dec_ctx->codec_id);
yading@11:     if (dec_desc && !(dec_desc->props & AV_CODEC_PROP_TEXT_SUB)) {
yading@11:         av_log(ctx, AV_LOG_ERROR,
yading@11:                "Only text based subtitles are currently supported\n");
yading@11:         return AVERROR_PATCHWELCOME;
yading@11:     }
yading@11:     if (ass->charenc)
yading@11:         av_dict_set(&codec_opts, "sub_charenc", ass->charenc, 0);
yading@11:     ret = avcodec_open2(dec_ctx, dec, &codec_opts);
yading@11:     if (ret < 0)
yading@11:         goto end;
yading@11: 
yading@11:     /* Decode subtitles and push them into the renderer (libass) */
yading@11:     if (dec_ctx->subtitle_header)
yading@11:         ass_process_codec_private(ass->track,
yading@11:                                   dec_ctx->subtitle_header,
yading@11:                                   dec_ctx->subtitle_header_size);
yading@11:     av_init_packet(&pkt);
yading@11:     pkt.data = NULL;
yading@11:     pkt.size = 0;
yading@11:     while (av_read_frame(fmt, &pkt) >= 0) {
yading@11:         int i, got_subtitle;
yading@11:         AVSubtitle sub;
yading@11: 
yading@11:         if (pkt.stream_index == sid) {
yading@11:             ret = avcodec_decode_subtitle2(dec_ctx, &sub, &got_subtitle, &pkt);
yading@11:             if (ret < 0) {
yading@11:                 av_log(ctx, AV_LOG_WARNING, "Error decoding: %s (ignored)\n",
yading@11:                        av_err2str(ret));
yading@11:             } else if (got_subtitle) {
yading@11:                 for (i = 0; i < sub.num_rects; i++) {
yading@11:                     char *ass_line = sub.rects[i]->ass;
yading@11:                     if (!ass_line)
yading@11:                         break;
yading@11:                     ass_process_data(ass->track, ass_line, strlen(ass_line));
yading@11:                 }
yading@11:             }
yading@11:         }
yading@11:         av_free_packet(&pkt);
yading@11:         avsubtitle_free(&sub);
yading@11:     }
yading@11: 
yading@11: end:
yading@11:     av_dict_free(&codec_opts);
yading@11:     if (dec_ctx)
yading@11:         avcodec_close(dec_ctx);
yading@11:     if (fmt)
yading@11:         avformat_close_input(&fmt);
yading@11:     return ret;
yading@11: }
yading@11: 
yading@11: AVFilter avfilter_vf_subtitles = {
yading@11:     .name          = "subtitles",
yading@11:     .description   = NULL_IF_CONFIG_SMALL("Render text subtitles onto input video using the libass library."),
yading@11:     .priv_size     = sizeof(AssContext),
yading@11:     .init          = init_subtitles,
yading@11:     .uninit        = uninit,
yading@11:     .query_formats = query_formats,
yading@11:     .inputs        = ass_inputs,
yading@11:     .outputs       = ass_outputs,
yading@11:     .priv_class    = &subtitles_class,
yading@11: };
yading@11: #endif