[FFmpeg-devel] [PATCH v9 21/25] avfilter/text2graphicsub: Added text2graphicsub subtitle filter
softworkz
ffmpegagent at gmail.com
Tue Oct 25 12:13:42 EEST 2022
From: softworkz <softworkz at hotmail.com>
Added a text2graphicsub subtitle filter which converts text-based
subtitle tracks to bitmap-based subtitle tracks. The filter uses libass
to render the subtitles.
It takes as parameters an output height and width, as well as a number
of colors in the output palette as well as sources of fonts. All its
arguments are optional.
Reviewed-by: softworkz <softworkz at hotmail.com>
Signed-off-by: softworkz <softworkz at hotmail.com>
Signed-off-by: tcoza <traian.coza at gmail.com>
---
configure | 1 +
doc/filters.texi | 51 +++
libavfilter/Makefile | 1 +
libavfilter/allfilters.c | 1 +
libavfilter/sf_text2graphicsub.c | 634 +++++++++++++++++++++++++++++++
5 files changed, 688 insertions(+)
create mode 100644 libavfilter/sf_text2graphicsub.c
diff --git a/configure b/configure
index 8968851571..3703aa216b 100755
--- a/configure
+++ b/configure
@@ -3759,6 +3759,7 @@ subscale_filter_deps="swscale avcodec"
subtitles_filter_deps="avformat avcodec libass"
super2xsai_filter_deps="gpl"
pixfmts_super2xsai_test_deps="super2xsai_filter"
+text2graphicsub_filter_deps="avformat avcodec libass"
textsub2video_filter_deps="avcodec libass"
tinterlace_filter_deps="gpl"
tinterlace_merge_test_deps="tinterlace_filter"
diff --git a/doc/filters.texi b/doc/filters.texi
index 5b058e8f3f..ebd398386b 100644
--- a/doc/filters.texi
+++ b/doc/filters.texi
@@ -28118,6 +28118,57 @@ ffmpeg -y -y -loglevel verbose -i "https://streams.videolan.org/samples/sub/larg
@end example
@end itemize
+ at section text2graphicsub
+
+Converts a text-based subtitle track to a bitmap-based subtitle track.
+
+The text2graphicsub filter uses libass to render all the subtitle
+frames in a text-based subtitle track (such as srt or ass) to allow
+its encoding with a bitmap-based subtitle encoder (such as dvd_subtitle).
+
+Inputs:
+- 0: Subtitles [text]
+
+Outputs:
+- 0: Subtitles [bitmap]
+
+It accepts the following parameters:
+
+ at table @option
+
+ at item s, size
+Set the size of the output. Default from input track.
+
+ at item n, num_colors
+Set the number of palette colors for output images,
+Range [2,256]. Default 16.
+
+ at item f, filename
+Set the media container from which to extract fonts required
+for rendering the subtitles, usually the same as the input
+track's media container. Can be omitted.
+
+ at item fd, fontsdir
+Set the directory from which to load fonts required for
+rendering the subtitles. Can be used with 'fonts'. Can be omitted.
+
+ at item ss, stripstyles
+Remove certain styles from an ass track which do not render well.
+Stripped styles include blurs, fades, and other animations.
+Default yes.
+
+ at end table
+
+ at subsection Examples
+
+ at itemize
+ at item
+Convert a video's text-based subtitle track to a dvd_subtitle subtitle track.
+ at example
+ffmpeg -i video.mkv -map 0:v -map 0:a -filter_complex [0:s]text2graphicsub=f=video.mkv[dvd_sub] -map [dvd_sub] -c copy -c:s dvd_subtitle output.mkv
+ at end example
+ at end itemize
+
@c man end SUBTITLE FILTERS
@chapter Multimedia Filters
diff --git a/libavfilter/Makefile b/libavfilter/Makefile
index 4a8badeddf..c6dfa517e8 100644
--- a/libavfilter/Makefile
+++ b/libavfilter/Makefile
@@ -595,6 +595,7 @@ OBJS-$(CONFIG_SPLITCC_FILTER) += sf_splitcc.o
OBJS-$(CONFIG_STRIPSTYLES_FILTER) += sf_stripstyles.o
OBJS-$(CONFIG_SUBFEED_FILTER) += sf_subfeed.o
OBJS-$(CONFIG_SUBSCALE_FILTER) += sf_subscale.o
+OBJS-$(CONFIG_TEXT2GRAPHICSUB_FILTER) += sf_text2graphicsub.o
OBJS-$(CONFIG_TEXTMOD_FILTER) += sf_textmod.o
# multimedia filters
diff --git a/libavfilter/allfilters.c b/libavfilter/allfilters.c
index fe5f815731..8779141aad 100644
--- a/libavfilter/allfilters.c
+++ b/libavfilter/allfilters.c
@@ -583,6 +583,7 @@ extern const AVFilter ff_sf_splitcc;
extern const AVFilter ff_sf_stripstyles;
extern const AVFilter ff_sf_subfeed;
extern const AVFilter ff_sf_subscale;
+extern const AVFilter ff_sf_text2graphicsub;
extern const AVFilter ff_sf_textmod;
/* those filters are part of public or internal API,
diff --git a/libavfilter/sf_text2graphicsub.c b/libavfilter/sf_text2graphicsub.c
new file mode 100644
index 0000000000..1fd7a76c53
--- /dev/null
+++ b/libavfilter/sf_text2graphicsub.c
@@ -0,0 +1,634 @@
+/*
+ * Copyright (c) 2021 tcoza
+ *
+ * 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
+ * convert text subtitles to bitmap subtitles filter
+ */
+
+#include <ass/ass.h>
+#include "libavutil/avstring.h"
+
+#include "internal.h"
+#include "avfilter.h"
+#include "drawutils.h"
+#include "libavutil/opt.h"
+#include "libavutil/buffer.h"
+#include "libavutil/internal.h"
+#include "libavformat/avformat.h"
+#include "libavcodec/elbg.h"
+#include "libavutil/ass_split_internal.h"
+#include "libavutil/ass_internal.h"
+#include "libavutil/lfg.h"
+
+typedef struct PalettizeContext {
+ int *codeword, *codebook;
+ int *codeword_closest_codebook_idxs;
+ int r_idx, g_idx, b_idx, a_idx;
+ struct ELBGContext *elbg;
+ AVLFG lfg;
+} PalettizeContext;
+
+typedef struct Text2GraphicSubContext {
+ const AVClass *class;
+ ASS_Library *library;
+ ASS_Renderer *renderer;
+ ASS_Track *track;
+ PalettizeContext *palettize_context;
+ FFDrawContext draw_context;
+ struct { int width; int height; } size;
+ int num_colors, stripstyles;
+ char *filename, *fontsdir, *force_style;
+ int got_header;
+} Text2GraphicSubContext;
+
+typedef struct DialogContext {
+ int is_animated;
+ int has_text;
+} DialogContext;
+
+static void dialog_text_cb(void *priv, const char *text, int len)
+{
+ DialogContext *s = priv;
+ if (!s->is_animated )
+ s->has_text = 1;
+}
+
+static void dialog_drawing_mode_cb(void *priv, int scale)
+{
+ DialogContext *s = priv;
+ s->is_animated = 1;
+}
+
+static void dialog_animate_cb(void *priv, int t1, int t2, int accel, char *style)
+{
+ DialogContext *s = priv;
+ s->is_animated = 1;
+}
+
+static void dialog_move_cb(void *priv, int x1, int y1, int x2, int y2, int t1, int t2)
+{
+ DialogContext *s = priv;
+ if (t1 >= 0 || t2 >= 0)
+ s->is_animated = 1;
+}
+
+static const ASSCodesCallbacks dialog_callbacks = {
+ .text = dialog_text_cb,
+ .drawing_mode = dialog_drawing_mode_cb,
+ .animate = dialog_animate_cb,
+ .move = dialog_move_cb,
+};
+
+static char *process_dialog(const char *ass_line)
+{
+ DialogContext dlg_ctx = { 0 };
+ ASSDialog *dialog = avpriv_ass_split_dialog(NULL, ass_line);
+ AVBPrint buffer;
+ char *result = NULL;
+
+ if (!dialog)
+ return NULL;
+
+ av_bprint_init(&buffer, 512, AV_BPRINT_SIZE_UNLIMITED);
+
+ avpriv_ass_filter_override_codes(&dialog_callbacks, &dlg_ctx, dialog->text, &buffer, ASS_SPLIT_BASIC);
+
+ if (av_bprint_is_complete(&buffer) && buffer.len > 0 && dlg_ctx.has_text > 0)
+ result = avpriv_ass_get_dialog_ex(dialog->readorder, dialog->layer, dialog->style, dialog->name, dialog->margin_l, dialog->margin_r, dialog->margin_v, dialog->effect, buffer.str);
+
+ av_bprint_finalize(&buffer, NULL);
+ avpriv_ass_free_dialog(&dialog);
+
+ return result;
+}
+
+static void palettize_image(PalettizeContext *const s,
+ const int w, const int h,
+ uint8_t *src_data, const int src_linesize,
+ uint8_t *dst_data, const int dst_linesize,
+ uint32_t *dst_pal, const int num_colors)
+{
+ const int codeword_length = w * h;
+
+ /* Re-Initialize */
+ s->codeword = av_realloc_f(s->codeword, codeword_length, 4 * sizeof(*s->codeword));
+ s->codeword_closest_codebook_idxs = av_realloc_f(
+ s->codeword_closest_codebook_idxs, codeword_length,
+ sizeof(*s->codeword_closest_codebook_idxs));
+ s->codebook = av_realloc_f(s->codebook, num_colors, 4 * sizeof(*s->codebook));
+
+ /* build the codeword */
+ for (int k = 0, i = 0; i < h; i++)
+ for (int j = 0; j < w; j++) {
+ s->codeword[k++] = src_data[i * src_linesize + j * 4 + s->b_idx];
+ s->codeword[k++] = src_data[i * src_linesize + j * 4 + s->g_idx];
+ s->codeword[k++] = src_data[i * src_linesize + j * 4 + s->r_idx];
+ s->codeword[k++] = src_data[i * src_linesize + j * 4 + s->a_idx];
+ }
+
+ /* compute the codebook */
+ avpriv_elbg_do(&s->elbg, s->codeword, 4,
+ codeword_length, s->codebook, num_colors, 1,
+ s->codeword_closest_codebook_idxs, &s->lfg, 0);
+
+ /* Write Palette */
+ for (int i = 0; i < num_colors; i++)
+ dst_pal[i] = (s->codebook[i*4+3] << 24) |
+ (s->codebook[i*4+2] << 16) |
+ (s->codebook[i*4+1] << 8) |
+ (s->codebook[i*4+0] << 0);
+
+ /* Write Image */
+ for (int k = 0, i = 0; i < h; i++)
+ for (int j = 0; j < w; j++)
+ dst_data[i * dst_linesize + j] =
+ s->codeword_closest_codebook_idxs[k++];
+}
+
+static void init_palettizecontext(PalettizeContext **palettizecontext)
+{
+ uint8_t rgba_map[4];
+ PalettizeContext *context = (PalettizeContext *)av_malloc(sizeof(PalettizeContext));
+ context->codebook = NULL;
+ context->codeword = NULL;
+ context->codeword_closest_codebook_idxs = NULL;
+ context->elbg = NULL;
+ av_lfg_init(&context->lfg, 0xACBADF);
+ ff_fill_rgba_map(&rgba_map[0], AV_PIX_FMT_RGB32);
+ context->r_idx = rgba_map[0]; // R
+ context->g_idx = rgba_map[1]; // G
+ context->b_idx = rgba_map[2]; // B
+ context->a_idx = rgba_map[3]; // A
+ *palettizecontext = context;
+}
+
+static void free_palettizecontext(PalettizeContext **palettizecontext)
+{
+ PalettizeContext *context = *palettizecontext;
+ if (context) {
+ av_freep(&context->codebook);
+ av_freep(&context->codeword);
+ av_freep(&context->codeword_closest_codebook_idxs);
+ avpriv_elbg_free(&context->elbg);
+ av_free(context);
+ *palettizecontext = NULL;
+ }
+}
+
+/* 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 const char * const font_mimetypes[] = {
+ "font/ttf",
+ "font/otf",
+ "font/sfnt",
+ "font/woff",
+ "font/woff2",
+ "application/font-sfnt",
+ "application/font-woff",
+ "application/x-truetype-font",
+ "application/vnd.ms-opentype",
+ "application/x-font-ttf",
+ NULL
+};
+
+static int stream_is_font(AVStream* st)
+{
+ const AVDictionaryEntry *tag = NULL;
+
+ if (st->codecpar->codec_type != AVMEDIA_TYPE_ATTACHMENT)
+ return 0;
+
+ tag = av_dict_get(st->metadata, "mimetype", NULL, AV_DICT_MATCH_CASE);
+ if (!tag) return 0;
+ for (int i = 0; font_mimetypes[i]; i++)
+ if (av_strcasecmp(font_mimetypes[i], tag->value) == 0)
+ return 1;
+ return 0;
+}
+
+#define AR(c) (((c)>>24)&0xFF)
+#define AG(c) (((c)>>16)&0xFF)
+#define AB(c) (((c)>> 8)&0xFF)
+#define AA(c) ((0xFF-(c))&0xFF)
+
+static void set_area_bounds(ASS_Image *image, AVSubtitleArea *area)
+{
+ int x_min = INT_MAX, y_min = INT_MAX;
+ int x_max = 0, y_max = 0;
+ int stride_max = 0;
+
+ for (ASS_Image *img = image; img != NULL; img = img->next)
+ {
+ x_min = FFMIN(x_min, img->dst_x);
+ y_min = FFMIN(y_min, img->dst_y);
+ x_max = FFMAX(x_max, img->dst_x + img->w);
+ y_max = FFMAX(y_max, img->dst_y + img->h);
+ stride_max = FFMAX(stride_max, img->dst_x + img->stride);
+ }
+
+ area->x = x_min;
+ area->y = y_min;
+ area->w = FFALIGN(x_max - x_min, 2);
+ area->h = FFALIGN(y_max - y_min, 2);
+ area->linesize[0] = area->w; //stride_max - x_min;
+}
+
+static void ass_image_to_area_palletization(Text2GraphicSubContext *context, ASS_Image *image, AVSubtitleArea *area)
+{
+ size_t image_rgba_size;
+ uint8_t *image_rgba;
+
+ set_area_bounds(image, area);
+ av_log(context, AV_LOG_VERBOSE, "set_area_bounds %d,%d %dx%d\n", area->x, area->y, area->w, area->h);
+
+ // Create rgba image
+ image_rgba_size = (area->linesize[0] * area->h) * 4 * sizeof(uint8_t);
+ image_rgba = (uint8_t *)av_mallocz(image_rgba_size);
+ for (; image != NULL; image = image->next)
+ {
+ uint8_t rgba_color[] = {AR(image->color), AG(image->color), AB(image->color), AA(image->color)};
+ int linesize = area->linesize[0] * 4;
+ FFDrawColor color;
+ ff_draw_color(&context->draw_context, &color, rgba_color);
+ ff_blend_mask(&context->draw_context, &color,
+ &image_rgba, &linesize, area->w, area->h,
+ image->bitmap, image->stride, image->w, image->h,
+ 3, 0, image->dst_x - area->x, image->dst_y - area->y);
+ }
+
+ area->nb_colors = context->num_colors;
+ area->buf[0] = av_buffer_alloc(image_rgba_size / 4);
+
+ palettize_image(context->palettize_context,
+ area->w, area->h,
+ image_rgba, area->linesize[0] * 4,
+ area->buf[0]->data, area->linesize[0],
+ &area->pal[0], context->num_colors);
+
+ // Clean up
+ av_free(image_rgba);
+}
+
+static void process_header(const AVFilterContext *link, const AVFrame *frame)
+{
+ Text2GraphicSubContext *s = link->priv;
+ ASS_Track *track = s->track;
+ ASS_Style *style;
+ int sid = 0;
+
+ if (!track)
+ return;
+
+ if (frame && frame->subtitle_header) {
+ char *subtitle_header = (char *)frame->subtitle_header->data;
+ ass_process_codec_private(s->track, subtitle_header, strlen(subtitle_header));
+ }
+ else {
+ char* subtitle_header = avpriv_ass_get_subtitle_header_default(0);
+ if (!subtitle_header)
+ return;
+
+ ass_process_codec_private(s->track, subtitle_header, strlen(subtitle_header));
+ av_free(subtitle_header);
+ }
+
+ if (!s->track->event_format) {
+ s->track->event_format = av_strdup("ReadOrder, Layer, Style, Name, MarginL, MarginR, MarginV, Effect, Text");
+ }
+
+ if (s->track->n_styles == 0) {
+ sid = ass_alloc_style(track);
+ style = &s->track->styles[sid];
+ style->Name = av_strdup("Default");
+ style->PrimaryColour = 0xffffff00;
+ style->SecondaryColour = 0x00ffff00;
+ style->OutlineColour = 0x00000000;
+ style->BackColour = 0x00000080;
+ style->Bold = 200;
+ style->ScaleX = 1.0;
+ style->ScaleY = 1.0;
+ style->Spacing = 0;
+ style->BorderStyle = 1;
+ style->Outline = 2;
+ style->Shadow = 3;
+ style->Alignment = 2;
+ track->default_style = sid;
+ }
+
+ s->got_header = 1;
+}
+
+// Main interface functions
+
+static av_cold int init(AVFilterContext *ctx)
+{
+ Text2GraphicSubContext *context = ctx->priv;
+
+ context->library = ass_library_init();
+ ass_set_message_cb(context->library, ass_log, context);
+ ass_set_fonts_dir(context->library, context->fontsdir);
+ ass_set_extract_fonts(context->library, 1);
+
+ if (context->filename) {
+ AVFormatContext *video = NULL;
+ int ret = avformat_open_input(&video, context->filename, NULL, NULL);
+ if (ret < 0) {
+ av_log(ctx, AV_LOG_ERROR, "Unable to open %s\n", context->filename);
+ return ret;
+ }
+ for (int i = 0; i < video->nb_streams; i++) {
+ const AVDictionaryEntry *tag;
+ AVStream *st = video->streams[i];
+ if (!stream_is_font(st)) continue;
+ tag = av_dict_get(st->metadata, "filename", NULL, AV_DICT_MATCH_CASE);
+ if (!tag) continue;
+ av_log(NULL, AV_LOG_DEBUG, "Loading attached font: %s\n", tag->value);
+ ass_add_font(context->library, tag->value,
+ (char *)st->codecpar->extradata,
+ st->codecpar->extradata_size);
+ }
+ avformat_close_input(&video);
+ }
+
+ context->renderer = ass_renderer_init(context->library);
+ ass_set_pixel_aspect(context->renderer, 1);
+ ass_set_shaper(context->renderer, 0);
+ ass_set_fonts(context->renderer, NULL, NULL, 1, NULL, 1);
+
+ context->track = ass_new_track(context->library);
+ if (!context->track) {
+ av_log(ctx, AV_LOG_ERROR, "ass_new_track() failed!\n");
+ return AVERROR(EINVAL);
+ }
+
+ ass_set_check_readorder(context->track, 0);
+
+ if (context->force_style) {
+ char **list = NULL;
+ char *temp = NULL;
+ char *ptr = av_strtok(context->force_style, ",", &temp);
+ int i = 0;
+ while (ptr) {
+ av_dynarray_add(&list, &i, ptr);
+ if (!list) {
+ return AVERROR(ENOMEM);
+ }
+ ptr = av_strtok(NULL, ",", &temp);
+ }
+ av_dynarray_add(&list, &i, NULL);
+ if (!list) {
+ return AVERROR(ENOMEM);
+ }
+ ass_set_style_overrides(context->library, list);
+ av_free(list);
+ }
+
+ init_palettizecontext(&context->palettize_context);
+
+ ff_draw_init(&context->draw_context, AV_PIX_FMT_BGRA, FF_DRAW_PROCESS_ALPHA);
+
+ return 0;
+}
+
+static int config_input(AVFilterLink *inlink)
+{
+ const AVFilterContext *ctx = inlink->dst;
+ Text2GraphicSubContext *context = ctx->priv;
+ if (!context->size.width) context->size.width = inlink->w;
+ if (!context->size.height) context->size.height = inlink->h;
+ if (!context->size.height || !context->size.width) {
+ av_log(NULL, AV_LOG_ERROR, "A positive height and width are required to render subtitles\n");
+ return AVERROR_EXIT;
+ }
+ ass_set_frame_size(context->renderer, context->size.width, context->size.height);
+ ass_set_storage_size(context->renderer, inlink->w, inlink->h);
+
+ return 0;
+}
+
+static int config_output(AVFilterLink *outlink)
+{
+ AVFilterContext *ctx = outlink->src;
+ Text2GraphicSubContext *context = ctx->priv;
+
+ outlink->time_base = AV_TIME_BASE_Q;
+ outlink->format = AV_SUBTITLE_FMT_BITMAP;
+ outlink->w = context->size.width;
+ outlink->h = context->size.height;
+
+ return 0;
+}
+
+static int filter_frame(AVFilterLink *inlink, AVFrame *frame)
+{
+ const AVFilterContext *ctx = inlink->dst;
+ Text2GraphicSubContext *context = ctx->priv;
+ AVFilterLink *outlink = ctx->outputs[0];
+ AVSubtitleArea *area;
+ int ret;
+ unsigned processed_area_cnt = 0;
+ const int64_t start_time = av_rescale_q(frame->subtitle_timing.start_pts, AV_TIME_BASE_Q, av_make_q(1, 1000));
+ const int64_t duration = av_rescale_q(frame->subtitle_timing.duration, AV_TIME_BASE_Q, av_make_q(1, 1000));
+ ASS_Image *image;
+
+ // Postpone header processing until we receive a frame with content
+ if (!context->got_header && frame->num_subtitle_areas > 0)
+ process_header(ctx, frame);
+
+ if (frame->repeat_sub || frame->num_subtitle_areas == 0) {
+ av_frame_free(&frame);
+ return 0;
+ }
+
+ ret = av_frame_make_writable(frame);
+ if (ret < 0)
+ return ret;
+
+ if (context->stripstyles) {
+ for (unsigned r = 0; r < frame->num_subtitle_areas; r++) {
+
+ area = frame->subtitle_areas[r];
+
+ if (area->ass) {
+ char *tmp = area->ass;
+ area->ass = process_dialog(area->ass);
+
+ if (area->ass) {
+ av_log(inlink->dst, AV_LOG_DEBUG, "original: %d %s\n", r, tmp);
+ av_log(inlink->dst, AV_LOG_DEBUG, "stripped: %d %s\n", r, area->ass);
+ }
+
+ av_free(tmp);
+ }
+ }
+ }
+
+ for (unsigned r = 0; r < frame->num_subtitle_areas; r++)
+ {
+ area = frame->subtitle_areas[r];
+ if (area->type != AV_SUBTITLE_FMT_ASS || area->ass == NULL)
+ continue;
+
+ ass_process_chunk(context->track, area->ass, strlen(area->ass), start_time, duration);
+ processed_area_cnt++;
+
+ }
+
+ if (processed_area_cnt == 0) {
+ av_frame_free(&frame);
+ return 0;
+ }
+
+ for (unsigned r = 1; r < frame->num_subtitle_areas; r++)
+ av_free(frame->subtitle_areas[r]);
+
+ frame->num_subtitle_areas = 1;
+ area = frame->subtitle_areas[0];
+
+ image = ass_render_frame(context->renderer, context->track, start_time + duration / 2, NULL);
+ if (image == NULL) {
+ av_log(NULL, AV_LOG_WARNING, "failed to render ass: %s\n", area->ass);
+ return 0;
+ }
+
+ // TODO: Split into multiple bitmaps
+
+ ass_image_to_area_palletization(context, image, area);
+ area->type = AV_SUBTITLE_FMT_BITMAP;
+
+ av_log(NULL, AV_LOG_DEBUG, "successfully rendered ass: %s\n", area->ass);
+
+ frame->width = context->size.width;
+ frame->height = context->size.height;
+ frame->format = AV_SUBTITLE_FMT_BITMAP;
+ return ff_filter_frame(outlink, frame);
+}
+
+static av_cold void uninit(AVFilterContext *ctx)
+{
+ Text2GraphicSubContext *context = ctx->priv;
+ free_palettizecontext(&context->palettize_context);
+ if (context->track) ass_free_track(context->track);
+ if (context->renderer) ass_renderer_done(context->renderer);
+ if (context->library) ass_library_done(context->library);
+ context->track = NULL;
+ context->renderer = NULL;
+ context->library = NULL;
+}
+
+// Copied from sf_graphicsub2text, with formats swapped
+static int query_formats(AVFilterContext *ctx)
+{
+ AVFilterFormats *formats, *formats2;
+ AVFilterLink *inlink = ctx->inputs[0];
+ AVFilterLink *outlink = ctx->outputs[0];
+ static const enum AVSubtitleType in_fmts[] = { AV_SUBTITLE_FMT_ASS, AV_SUBTITLE_FMT_NONE };
+ static const enum AVSubtitleType out_fmts[] = { AV_SUBTITLE_FMT_BITMAP, AV_SUBTITLE_FMT_NONE };
+ int ret;
+
+ /* set input format */
+ formats = ff_make_format_list(in_fmts);
+ if ((ret = ff_formats_ref(formats, &inlink->outcfg.formats)) < 0)
+ return ret;
+
+ /* set output format */
+ formats2 = ff_make_format_list(out_fmts);
+ if ((ret = ff_formats_ref(formats2, &outlink->incfg.formats)) < 0)
+ return ret;
+
+ return 0;
+}
+
+// Filter structures
+
+#define OFFSET(x) offsetof(Text2GraphicSubContext, x)
+#define FLAGS (AV_OPT_FLAG_SUBTITLE_PARAM|AV_OPT_FLAG_FILTERING_PARAM)
+
+static const AVOption text2graphicsub_options[] = {
+ { "s", "output size", OFFSET(size), AV_OPT_TYPE_IMAGE_SIZE, .default_val.str = NULL, .flags = FLAGS },
+ { "size", "output size", OFFSET(size), AV_OPT_TYPE_IMAGE_SIZE, .default_val.str = NULL, .flags = FLAGS },
+ { "n", "number of output colors", OFFSET(num_colors), AV_OPT_TYPE_INT, .min = 2, .max = 256, .default_val.i64 = 16, .flags = FLAGS },
+ { "num_colors", "number of output colors", OFFSET(num_colors), AV_OPT_TYPE_INT, .min = 2, .max = 256, .default_val.i64 = 16, .flags = FLAGS },
+ { "ss", "strip animations and blur styles", OFFSET(stripstyles), AV_OPT_TYPE_BOOL, .min = 0, .max = 1, .default_val.i64 = 1, .flags = FLAGS },
+ { "stripstyles", "strip animations and blur styles", OFFSET(stripstyles), AV_OPT_TYPE_BOOL, .min = 0, .max = 1, .default_val.i64 = 1, .flags = FLAGS },
+ { "force_style", "enforce subtitle styles", OFFSET(force_style), AV_OPT_TYPE_STRING, .default_val.str = NULL, .flags = FLAGS },
+ { "f", "media file from which to load fonts", OFFSET(filename), AV_OPT_TYPE_STRING, .default_val.str = NULL, .flags = FLAGS },
+ { "filename", "media file from which to load fonts", OFFSET(filename), AV_OPT_TYPE_STRING, .default_val.str = NULL, .flags = FLAGS },
+ { "fd", "fonts directory", OFFSET(fontsdir), AV_OPT_TYPE_STRING, .default_val.str = NULL, .flags = FLAGS },
+ { "fontsdir", "fonts directory", OFFSET(fontsdir), AV_OPT_TYPE_STRING, .default_val.str = NULL, .flags = FLAGS },
+ { .name = NULL }
+};
+
+static const AVClass text2graphicsub_class = {
+ .class_name = "text2graphicsub",
+ .item_name = av_default_item_name,
+ .option = text2graphicsub_options,
+ .version = LIBAVUTIL_VERSION_INT,
+ .category = AV_CLASS_CATEGORY_FILTER,
+};
+
+static const AVFilterPad inputs[] = {
+ {
+ .name = "default",
+ .type = AVMEDIA_TYPE_SUBTITLE,
+ .filter_frame = filter_frame,
+ .config_props = config_input,
+ },
+};
+
+static const AVFilterPad outputs[] = {
+ {
+ .name = "default",
+ .type = AVMEDIA_TYPE_SUBTITLE,
+ .config_props = config_output,
+ },
+};
+
+const AVFilter ff_sf_text2graphicsub = {
+ .name = "text2graphicsub",
+ .description = NULL_IF_CONFIG_SMALL("Convert text subtitles to bitmap subtitles."),
+ .init = init,
+ .uninit = uninit,
+ .priv_size = sizeof(Text2GraphicSubContext),
+ .priv_class = &text2graphicsub_class,
+ FILTER_INPUTS(inputs),
+ FILTER_OUTPUTS(outputs),
+ FILTER_QUERY_FUNC(query_formats)
+};
--
ffmpeg-codebot
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