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[FFmpeg-devel] Since mkvmerge 19 has fonts types from RFC 8081 and mkvmerge 58 on windows use new file/magic library

Message ID 20211003133808.1560-1-wwakabot@gmail.com
State New
Headers show
Series [FFmpeg-devel] Since mkvmerge 19 has fonts types from RFC 8081 and mkvmerge 58 on windows use new file/magic library | expand

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Commit Message

SomeRGuy Oct. 3, 2021, 1:38 p.m. UTC
Signed-off-by: SomeRGuy <wwakabot@gmail.com>
---
 libavfilter/vf_subtitles.c | 991 +++++++++++++++++++------------------
 1 file changed, 499 insertions(+), 492 deletions(-)
diff mbox series

Patch

diff --git a/libavfilter/vf_subtitles.c b/libavfilter/vf_subtitles.c
index f08a7fba9d..511722199c 100644
--- a/libavfilter/vf_subtitles.c
+++ b/libavfilter/vf_subtitles.c
@@ -1,492 +1,499 @@ 
-/*
- * 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},  0, 0, FLAGS }, \
-    {"f",              "set the filename of file to read",                         OFFSET(filename),   AV_OPT_TYPE_STRING,     {.str = NULL},  0, 0, FLAGS }, \
-    {"original_size",  "set the size of the original video (used to scale fonts)", OFFSET(original_w), AV_OPT_TYPE_IMAGE_SIZE, {.str = NULL},  0, 0, FLAGS }, \
-    {"fontsdir",       "set the directory containing the fonts to read",           OFFSET(fontsdir),   AV_OPT_TYPE_STRING,     {.str = NULL},  0, 0, 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_set_extract_fonts(ass->library, 1);
-
-    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,
-        .flags            = AVFILTERPAD_FLAG_NEEDS_WRITABLE,
-        .filter_frame     = filter_frame,
-        .config_props     = config_input,
-    },
-};
-
-static const AVFilterPad ass_outputs[] = {
-    {
-        .name = "default",
-        .type = AVMEDIA_TYPE_VIDEO,
-    },
-};
-
-#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;
-}
-
-const 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,
-    FILTER_INPUTS(ass_inputs),
-    FILTER_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}, 0, 0, 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}, 0, 0, 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;
-    const AVCodec *dec;
-    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));
-        ret = AVERROR_DECODER_NOT_FOUND;
-        goto end;
-    }
-    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");
-        ret = AVERROR_PATCHWELCOME;
-        goto end;
-    }
-    if (ass->charenc)
-        av_dict_set(&codec_opts, "sub_charenc", ass->charenc, 0);
-
-    dec_ctx = avcodec_alloc_context3(dec);
-    if (!dec_ctx) {
-        ret = AVERROR(ENOMEM);
-        goto end;
-    }
-
-    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);
-    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;
-                    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_free_context(&dec_ctx);
-    avformat_close_input(&fmt);
-    return ret;
-}
-
-const 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,
-    FILTER_INPUTS(ass_inputs),
-    FILTER_OUTPUTS(ass_outputs),
-    .priv_class    = &subtitles_class,
-};
-#endif
+/*
+ * 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},  0, 0, FLAGS }, \
+    {"f",              "set the filename of file to read",                         OFFSET(filename),   AV_OPT_TYPE_STRING,     {.str = NULL},  0, 0, FLAGS }, \
+    {"original_size",  "set the size of the original video (used to scale fonts)", OFFSET(original_w), AV_OPT_TYPE_IMAGE_SIZE, {.str = NULL},  0, 0, FLAGS }, \
+    {"fontsdir",       "set the directory containing the fonts to read",           OFFSET(fontsdir),   AV_OPT_TYPE_STRING,     {.str = NULL},  0, 0, 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_set_extract_fonts(ass->library, 1);
+
+    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,
+        .flags            = AVFILTERPAD_FLAG_NEEDS_WRITABLE,
+        .filter_frame     = filter_frame,
+        .config_props     = config_input,
+    },
+};
+
+static const AVFilterPad ass_outputs[] = {
+    {
+        .name = "default",
+        .type = AVMEDIA_TYPE_VIDEO,
+    },
+};
+
+#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;
+}
+
+const 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,
+    FILTER_INPUTS(ass_inputs),
+    FILTER_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}, 0, 0, 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}, 0, 0, FLAGS},
+    {NULL},
+};
+
+static const char * const font_mimetypes[] = {
+    "font/ttf",
+    "font/otf",
+    "font/sfnt",
+    "font/woff",
+    "font/woff2",
+    "application/font-sfnt",
+    "application/font-woff",
+    "application/x-font-ttf",
+    "application/x-truetype-font",
+    "application/vnd.ms-opentype",
+    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;
+    const AVCodec *dec;
+    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));
+        ret = AVERROR_DECODER_NOT_FOUND;
+        goto end;
+    }
+    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");
+        ret = AVERROR_PATCHWELCOME;
+        goto end;
+    }
+    if (ass->charenc)
+        av_dict_set(&codec_opts, "sub_charenc", ass->charenc, 0);
+
+    dec_ctx = avcodec_alloc_context3(dec);
+    if (!dec_ctx) {
+        ret = AVERROR(ENOMEM);
+        goto end;
+    }
+
+    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);
+    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;
+                    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_free_context(&dec_ctx);
+    avformat_close_input(&fmt);
+    return ret;
+}
+
+const 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,
+    FILTER_INPUTS(ass_inputs),
+    FILTER_OUTPUTS(ass_outputs),
+    .priv_class    = &subtitles_class,
+};
+#endif