[FFmpeg-devel] [PATCH 01/12] Implemented text to bitmap subtitles!
Traian Coza
traian.coza at gmail.com
Tue May 3 19:13:17 EEST 2022
---
fftools/ffmpeg.c | 47 ++++++++++++++-
libavfilter/vf_subtitles.c | 117 +++++++++++++++++++++++++++++++++++++
2 files changed, 163 insertions(+), 1 deletion(-)
diff --git a/fftools/ffmpeg.c b/fftools/ffmpeg.c
index a85ed18b08..53717d3ebb 100644
--- a/fftools/ffmpeg.c
+++ b/fftools/ffmpeg.c
@@ -2325,6 +2325,45 @@ fail:
return err < 0 ? err : ret;
}
+void render_avsub_ass(InputStream *, AVSubtitle *);
+
+static void print_subtitle(AVSubtitle sub)
+{
+ printf("sub.format: %u\n", sub.format);
+ printf("sub.start_display_time: %u\n", sub.start_display_time);
+ printf("sub.end_display_time: %u\n", sub.end_display_time);
+ printf("sub.num_rects: %u\n", sub.num_rects);
+ printf("sub.pts: %ld\n", sub.pts);
+ for (int i = 0; i < sub.num_rects; i++)
+ {
+ printf("sub.rects[%d]->type: %d\n", i, sub.rects[i]->type);
+ printf("sub.rects[%d]->nb_colors: %d\n", i, sub.rects[i]->nb_colors);
+ printf("sub.rects[%d]->(x,y,w,h): (%d,%d,%d,%d)\n", i, sub.rects[i]->x, sub.rects[i]->y, sub.rects[i]->w, sub.rects[i]->h);
+ printf("sub.rects[%d]->linesize: [%d,%d,%d,%d]\n", i, sub.rects[i]->linesize[0], sub.rects[i]->linesize[1], sub.rects[i]->linesize[1], sub.rects[i]->linesize[1]);
+ switch (sub.rects[i]->type)
+ {
+ case SUBTITLE_TEXT:
+ printf("sub.rects[%d]->text: %s\n", i, sub.rects[i]->text);
+ break;
+ case SUBTITLE_ASS:
+ printf("sub.rects[%d]->ass: %s\n", i, sub.rects[i]->ass);
+ break;
+ case SUBTITLE_BITMAP:
+ for (int c = 0; c < sub.rects[i]->nb_colors; c++)
+ printf("color %d: [%u,%u,%u,%u]\n", c,
+ sub.rects[i]->data[1][c * 4 + 0],
+ sub.rects[i]->data[1][c * 4 + 1],
+ sub.rects[i]->data[1][c * 4 + 2],
+ sub.rects[i]->data[1][c * 4 + 3]);
+ for (int y = 0; y < sub.rects[i]->h; y++, printf("\n"))
+ for (int x = 0; x < sub.rects[i]->w; x++)
+ printf("%d", sub.rects[i]->data[0][y * sub.rects[i]->w + x]);
+ break;
+ }
+ }
+ printf("\n");
+}
+
static int transcode_subtitles(InputStream *ist, AVPacket *pkt, int *got_output,
int *decode_failed)
{
@@ -2383,6 +2422,8 @@ static int transcode_subtitles(InputStream *ist, AVPacket *pkt, int *got_output,
goto out;
ist->frames_decoded++;
+
+ render_avsub_ass(ist, &subtitle);
for (i = 0; i < nb_output_streams; i++) {
OutputStream *ost = output_streams[i];
@@ -3213,11 +3254,15 @@ static int init_output_stream(OutputStream *ost, AVFrame *frame,
input_props = input_descriptor->props & (AV_CODEC_PROP_TEXT_SUB | AV_CODEC_PROP_BITMAP_SUB);
if (output_descriptor)
output_props = output_descriptor->props & (AV_CODEC_PROP_TEXT_SUB | AV_CODEC_PROP_BITMAP_SUB);
- if (input_props && output_props && input_props != output_props) {
+ /*if (input_props && output_props && input_props != output_props) {
snprintf(error, error_len,
"Subtitle encoding currently only possible from text to text "
"or bitmap to bitmap");
return AVERROR_INVALIDDATA;
+ }*/
+ if (input_props == AV_CODEC_PROP_BITMAP_SUB && output_props == AV_CODEC_PROP_TEXT_SUB) {
+ snprintf(error, error_len, "Subtitle encoding from bitmap to text currently not possible");
+ return AVERROR_INVALIDDATA;
}
}
diff --git a/libavfilter/vf_subtitles.c b/libavfilter/vf_subtitles.c
index 82e140e986..f751786033 100644
--- a/libavfilter/vf_subtitles.c
+++ b/libavfilter/vf_subtitles.c
@@ -181,6 +181,24 @@ static void overlay_ass_image(AssContext *ass, AVFrame *picref,
}
}
+static void print_ass_image(const ASS_Image *image)
+{
+ int index = 0;
+ for (; image != NULL; image = image->next, index++)
+ {
+ printf("index: %d\n", index);
+ printf("image->(dst_x,dst_y): (%d,%d)\n", image->dst_x, image->dst_y);
+ printf("image->(w,h): (%d,%d)\n", image->w, image->h);
+ printf("image->stride: %d\n", image->stride);
+ printf("image->type: %d\n", image->type);
+ printf("image->color: [%u,%u,%u,%u]\n", AR(image->color), AG(image->color), AB(image->color), AA(image->color));
+ for (int y = 0; y < image->h; y++, printf("\n"))
+ for (int x = 0; x < image->w; x++)
+ printf("%02X", image->bitmap[y * image->stride + x]);
+ printf("\n");
+ }
+}
+
static int filter_frame(AVFilterLink *inlink, AVFrame *picref)
{
AVFilterContext *ctx = inlink->dst;
@@ -199,6 +217,105 @@ static int filter_frame(AVFilterLink *inlink, AVFrame *picref)
return ff_filter_frame(outlink, picref);
}
+#include "../fftools/ffmpeg.h"
+#include "libavcodec/avcodec.h"
+#include "../libavcodec/ass_split.h"
+
+#define ALPHA_THRESHOLD 0b10000000
+
+void render_avsub_ass(InputStream *, AVSubtitle *);
+void render_avsub_ass(InputStream *ist, AVSubtitle *sub)
+{
+ ASS_Library *library = ass_library_init();
+ ass_set_extract_fonts(library, 1);
+ ASS_Renderer *renderer = ass_renderer_init(library);
+ int w = 1920, h = 1080;
+ ass_set_frame_size(renderer, w, h);
+ ass_set_pixel_aspect(renderer, 1);
+ ass_set_storage_size(renderer, w, h);
+ ass_set_shaper(renderer, 0);
+ ass_set_fonts(renderer, NULL, NULL, 1, NULL, 1);
+
+ for (int r = 0; r < sub->num_rects; r++)
+ {
+ AVSubtitleRect *rect = sub->rects[r];
+ if (rect->data[0]) continue;
+
+ ASSSplitContext *ass_context = ff_ass_split((char *)ist->dec_ctx->subtitle_header);
+ ASSDialog *dialog = ff_ass_split_dialog(ass_context, rect->ass);
+
+ ASS_Track *track = ass_read_memory(library, (char *)ist->dec_ctx->subtitle_header, ist->dec_ctx->subtitle_header_size, NULL);
+ track->n_events = track->max_events = 1;
+ track->events = (ASS_Event *)malloc(sizeof(ASS_Event));
+ track->events[0].Start = sub->start_display_time + sub->pts / (AV_TIME_BASE / 1000);
+ track->events[0].Duration = sub->end_display_time - sub->start_display_time;
+ track->events[0].Effect = strdup(dialog->effect);
+ track->events[0].Layer = dialog->layer;
+ track->events[0].MarginL = dialog->margin_l;
+ track->events[0].MarginR = dialog->margin_r;
+ track->events[0].MarginV = dialog->margin_v;
+ track->events[0].Name = strdup(dialog->name);
+ track->events[0].Text = strdup(dialog->text);
+ track->events[0].ReadOrder = dialog->readorder;
+ track->events[0].Style = 0;
+ for (int style = 0; style < track->n_styles; style++)
+ if (!strcmp(track->styles[style].Name, dialog->style))
+ track->events[0].Style = style;
+ track->events[0].render_priv = NULL;
+ ff_ass_free_dialog(&dialog);
+ ff_ass_split_free(ass_context);
+
+ int change;
+ ASS_Image *image = ass_render_frame(renderer, track, track->events[0].Start + 1, &change); // Don't have to free it for some reason
+ printf("image: %p\n", image);
+
+ rect->x = image->dst_x; rect->w = 0;
+ rect->y = image->dst_y; rect->h = 0;
+ rect->nb_colors = 1; // Transparent background counts as a color
+ for (ASS_Image *img = image; img != NULL; img = img->next)
+ {
+ // Set image bounds to encompass all images
+ if (img->dst_x < rect->x) rect->x = img->dst_x;
+ if (img->dst_y < rect->y) rect->y = img->dst_y;
+ if (img->dst_x + img->w > rect->x + rect->w)
+ rect->w = img->dst_x + img->w - rect->x;
+ if (img->dst_y + img->h > rect->y + rect->h)
+ rect->h = img->dst_y + img->h - rect->y;
+ rect->nb_colors++;
+ }
+ rect->linesize[0] = rect->w;
+ rect->data[0] = (uint8_t *)malloc(rect->w * rect->h * sizeof(uint8_t));
+ rect->data[1] = (uint8_t *)malloc(4 * rect->nb_colors * sizeof(uint8_t));
+ memset(rect->data[0], 0, rect->w * rect->h); // Set all to transparent
+ memset(rect->data[1], 0, 4); // Set transparent color
+ memset(&rect->linesize[1], 0, 3 * sizeof(int));
+ rect->data[2] = rect->data[3] = NULL;
+ for (int color = 1; image != NULL; image = image->next, color++)
+ {
+ // Set color
+ rect->data[1][4 * color + 0] = AR(image->color);
+ rect->data[1][4 * color + 1] = AG(image->color);
+ rect->data[1][4 * color + 2] = AB(image->color);
+ rect->data[1][4 * color + 3] = AA(image->color);
+ // Set pixels
+ for (int y = 0; y < image->h; y++)
+ for (int x = 0; x < image->w; x++)
+ if (image->bitmap[y * image->stride + x] >= ALPHA_THRESHOLD)
+ {
+ int x_rect = image->dst_x + x - rect->x;
+ int y_rect = image->dst_y + y - rect->y;
+ rect->data[0][y_rect * rect->w + x_rect] = color;
+ }
+ }
+ rect->type = SUBTITLE_BITMAP;
+
+ ass_free_track(track);
+ }
+
+ ass_renderer_done(renderer);
+ ass_library_done(library);
+}
+
static const AVFilterPad ass_inputs[] = {
{
.name = "default",
--
2.34.1
More information about the ffmpeg-devel
mailing list