lavfi: rename vf_ass.c to vf_subtitles.c
authorClément Bœsch <ubitux@gmail.com>
Mon, 31 Dec 2012 10:18:29 +0000 (11:18 +0100)
committerClément Bœsch <ubitux@gmail.com>
Sun, 17 Feb 2013 11:58:20 +0000 (12:58 +0100)
libavfilter/Makefile
libavfilter/vf_ass.c [deleted file]
libavfilter/vf_subtitles.c [new file with mode: 0644]

index ff69d09..2449da4 100644 (file)
@@ -94,7 +94,7 @@ OBJS-$(CONFIG_FLITE_FILTER)                  += asrc_flite.o
 
 OBJS-$(CONFIG_ANULLSINK_FILTER)              += asink_anullsink.o
 
-OBJS-$(CONFIG_ASS_FILTER)                    += vf_ass.o
+OBJS-$(CONFIG_ASS_FILTER)                    += vf_subtitles.o
 OBJS-$(CONFIG_ALPHAEXTRACT_FILTER)           += vf_alphaextract.o
 OBJS-$(CONFIG_ALPHAMERGE_FILTER)             += vf_alphamerge.o
 OBJS-$(CONFIG_BBOX_FILTER)                   += bbox.o vf_bbox.o
@@ -153,7 +153,7 @@ OBJS-$(CONFIG_SETTB_FILTER)                  += f_settb.o
 OBJS-$(CONFIG_SHOWINFO_FILTER)               += vf_showinfo.o
 OBJS-$(CONFIG_SMARTBLUR_FILTER)              += vf_smartblur.o
 OBJS-$(CONFIG_SPLIT_FILTER)                  += split.o
-OBJS-$(CONFIG_SUBTITLES_FILTER)              += vf_ass.o
+OBJS-$(CONFIG_SUBTITLES_FILTER)              += vf_subtitles.o
 OBJS-$(CONFIG_SUPER2XSAI_FILTER)             += vf_super2xsai.o
 OBJS-$(CONFIG_SWAPUV_FILTER)                 += vf_swapuv.o
 OBJS-$(CONFIG_THUMBNAIL_FILTER)              += vf_thumbnail.o
diff --git a/libavfilter/vf_ass.c b/libavfilter/vf_ass.c
deleted file mode 100644 (file)
index c4bc755..0000000
+++ /dev/null
@@ -1,368 +0,0 @@
-/*
- * 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 {
-    const AVClass *class;
-    ASS_Library  *library;
-    ASS_Renderer *renderer;
-    ASS_Track    *track;
-    char *filename;
-    char *charenc;
-    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)
-#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 }, \
-
-/* libass supports a log level ranging from 0 to 7 */
-static const int ass_libavfilter_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_libavfilter_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, const AVClass *class)
-{
-    AssContext *ass = ctx->priv;
-    static const char *shorthand[] = { "filename", NULL };
-    int ret;
-
-    ass->class = class;
-    av_opt_set_defaults(ass);
-
-    if ((ret = av_opt_set_from_string(ass, args, shorthand, "=", ":")) < 0)
-        return ret;
-
-    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->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_set_fonts(ass->renderer, NULL, NULL, 1, NULL, 1);
-    return 0;
-}
-
-static av_cold void uninit(AVFilterContext *ctx)
-{
-    AssContext *ass = ctx->priv;
-
-    av_opt_free(ass);
-    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)
-{
-    ff_set_common_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;
-}
-
-/* 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 int filter_frame(AVFilterLink *inlink, AVFilterBufferRef *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,
-        .min_perms        = AV_PERM_READ | AV_PERM_WRITE,
-    },
-    { NULL }
-};
-
-static const AVFilterPad ass_outputs[] = {
-    {
-        .name = "default",
-        .type = AVMEDIA_TYPE_VIDEO,
-    },
-    { NULL }
-};
-
-#if CONFIG_ASS_FILTER
-
-static const AVOption ass_options[] = {
-    COMMON_OPTIONS
-    {NULL},
-};
-
-AVFILTER_DEFINE_CLASS(ass);
-
-static av_cold int init_ass(AVFilterContext *ctx, const char *args)
-{
-    AssContext *ass = ctx->priv;
-    int ret = init(ctx, args, &ass_class);
-
-    if (ret < 0)
-        return ret;
-
-    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 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_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},
-    {NULL},
-};
-
-AVFILTER_DEFINE_CLASS(subtitles);
-
-static av_cold int init_subtitles(AVFilterContext *ctx, const char *args)
-{
-    int ret, sid;
-    AVDictionary *codec_opts = NULL;
-    AVFormatContext *fmt = NULL;
-    AVCodecContext *dec_ctx = NULL;
-    AVCodec *dec = NULL;
-    AVStream *st;
-    AVPacket pkt;
-    AssContext *ass = ctx->priv;
-
-    /* Init libass */
-    ret = init(ctx, args, &subtitles_class);
-    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 */
-    ret = av_find_best_stream(fmt, AVMEDIA_TYPE_SUBTITLE, -1, -1, NULL, 0);
-    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];
-
-    /* Open decoder */
-    dec_ctx = st->codec;
-    dec = avcodec_find_decoder(dec_ctx->codec_id);
-    if (!dec) {
-        av_log(ctx, AV_LOG_ERROR, "Failed to find subtitle codec %s\n",
-               avcodec_get_name(dec_ctx->codec_id));
-        return AVERROR(EINVAL);
-    }
-    if (ass->charenc)
-        av_dict_set(&codec_opts, "sub_charenc", ass->charenc, 0);
-    ret = avcodec_open2(dec_ctx, dec, &codec_opts);
-    if (ret < 0)
-        goto end;
-
-    /* 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;
-
-        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) {
-                for (i = 0; i < sub.num_rects; i++) {
-                    char *ass_line = sub.rects[i]->ass;
-                    if (!ass_line)
-                        break;
-                    ass_process_data(ass->track, ass_line, strlen(ass_line));
-                }
-            }
-        }
-        av_free_packet(&pkt);
-        avsubtitle_free(&sub);
-    }
-
-end:
-    av_dict_free(&codec_opts);
-    if (dec_ctx)
-        avcodec_close(dec_ctx);
-    if (fmt)
-        avformat_close_input(&fmt);
-    return ret;
-}
-
-AVFilter avfilter_vf_subtitles = {
-    .name          = "subtitles",
-    .description   = NULL_IF_CONFIG_SMALL("Render 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
diff --git a/libavfilter/vf_subtitles.c b/libavfilter/vf_subtitles.c
new file mode 100644 (file)
index 0000000..c4bc755
--- /dev/null
@@ -0,0 +1,368 @@
+/*
+ * 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 {
+    const AVClass *class;
+    ASS_Library  *library;
+    ASS_Renderer *renderer;
+    ASS_Track    *track;
+    char *filename;
+    char *charenc;
+    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)
+#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 }, \
+
+/* libass supports a log level ranging from 0 to 7 */
+static const int ass_libavfilter_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_libavfilter_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, const AVClass *class)
+{
+    AssContext *ass = ctx->priv;
+    static const char *shorthand[] = { "filename", NULL };
+    int ret;
+
+    ass->class = class;
+    av_opt_set_defaults(ass);
+
+    if ((ret = av_opt_set_from_string(ass, args, shorthand, "=", ":")) < 0)
+        return ret;
+
+    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->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_set_fonts(ass->renderer, NULL, NULL, 1, NULL, 1);
+    return 0;
+}
+
+static av_cold void uninit(AVFilterContext *ctx)
+{
+    AssContext *ass = ctx->priv;
+
+    av_opt_free(ass);
+    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)
+{
+    ff_set_common_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;
+}
+
+/* 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 int filter_frame(AVFilterLink *inlink, AVFilterBufferRef *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,
+        .min_perms        = AV_PERM_READ | AV_PERM_WRITE,
+    },
+    { NULL }
+};
+
+static const AVFilterPad ass_outputs[] = {
+    {
+        .name = "default",
+        .type = AVMEDIA_TYPE_VIDEO,
+    },
+    { NULL }
+};
+
+#if CONFIG_ASS_FILTER
+
+static const AVOption ass_options[] = {
+    COMMON_OPTIONS
+    {NULL},
+};
+
+AVFILTER_DEFINE_CLASS(ass);
+
+static av_cold int init_ass(AVFilterContext *ctx, const char *args)
+{
+    AssContext *ass = ctx->priv;
+    int ret = init(ctx, args, &ass_class);
+
+    if (ret < 0)
+        return ret;
+
+    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 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_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},
+    {NULL},
+};
+
+AVFILTER_DEFINE_CLASS(subtitles);
+
+static av_cold int init_subtitles(AVFilterContext *ctx, const char *args)
+{
+    int ret, sid;
+    AVDictionary *codec_opts = NULL;
+    AVFormatContext *fmt = NULL;
+    AVCodecContext *dec_ctx = NULL;
+    AVCodec *dec = NULL;
+    AVStream *st;
+    AVPacket pkt;
+    AssContext *ass = ctx->priv;
+
+    /* Init libass */
+    ret = init(ctx, args, &subtitles_class);
+    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 */
+    ret = av_find_best_stream(fmt, AVMEDIA_TYPE_SUBTITLE, -1, -1, NULL, 0);
+    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];
+
+    /* Open decoder */
+    dec_ctx = st->codec;
+    dec = avcodec_find_decoder(dec_ctx->codec_id);
+    if (!dec) {
+        av_log(ctx, AV_LOG_ERROR, "Failed to find subtitle codec %s\n",
+               avcodec_get_name(dec_ctx->codec_id));
+        return AVERROR(EINVAL);
+    }
+    if (ass->charenc)
+        av_dict_set(&codec_opts, "sub_charenc", ass->charenc, 0);
+    ret = avcodec_open2(dec_ctx, dec, &codec_opts);
+    if (ret < 0)
+        goto end;
+
+    /* 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;
+
+        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) {
+                for (i = 0; i < sub.num_rects; i++) {
+                    char *ass_line = sub.rects[i]->ass;
+                    if (!ass_line)
+                        break;
+                    ass_process_data(ass->track, ass_line, strlen(ass_line));
+                }
+            }
+        }
+        av_free_packet(&pkt);
+        avsubtitle_free(&sub);
+    }
+
+end:
+    av_dict_free(&codec_opts);
+    if (dec_ctx)
+        avcodec_close(dec_ctx);
+    if (fmt)
+        avformat_close_input(&fmt);
+    return ret;
+}
+
+AVFilter avfilter_vf_subtitles = {
+    .name          = "subtitles",
+    .description   = NULL_IF_CONFIG_SMALL("Render 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