[FFmpeg-devel] [PATCH v3 15/18] avfilter/textmod: Add textmod filter
Soft Works
softworkz at hotmail.com
Sat Sep 11 09:03:09 EEST 2021
Signed-off-by: softworkz <softworkz at hotmail.com>
---
libavfilter/Makefile | 3 +
libavfilter/allfilters.c | 1 +
libavfilter/sf_textmod.c | 409 +++++++++++++++++++++++++++++++++++++++
3 files changed, 413 insertions(+)
create mode 100644 libavfilter/sf_textmod.c
diff --git a/libavfilter/Makefile b/libavfilter/Makefile
index 0e752c5bf9..5a5a4be47e 100644
--- a/libavfilter/Makefile
+++ b/libavfilter/Makefile
@@ -534,6 +534,9 @@ OBJS-$(CONFIG_YUVTESTSRC_FILTER) += vsrc_testsrc.o
OBJS-$(CONFIG_NULLSINK_FILTER) += vsink_nullsink.o
+# subtitle filters
+OBJS-$(CONFIG_TEXTMOD_FILTER) += sf_textmod.o
+
# multimedia filters
OBJS-$(CONFIG_ABITSCOPE_FILTER) += avf_abitscope.o
OBJS-$(CONFIG_ADRAWGRAPH_FILTER) += f_drawgraph.o
diff --git a/libavfilter/allfilters.c b/libavfilter/allfilters.c
index 77463aa4c8..6d7a535ee8 100644
--- a/libavfilter/allfilters.c
+++ b/libavfilter/allfilters.c
@@ -524,6 +524,7 @@ extern const AVFilter ff_avf_showvolume;
extern const AVFilter ff_avf_showwaves;
extern const AVFilter ff_avf_showwavespic;
extern const AVFilter ff_vaf_spectrumsynth;
+extern const AVFilter ff_sf_textmod;
extern const AVFilter ff_svf_graphicsub2video;
extern const AVFilter ff_svf_textsub2video;
diff --git a/libavfilter/sf_textmod.c b/libavfilter/sf_textmod.c
new file mode 100644
index 0000000000..fca47d68da
--- /dev/null
+++ b/libavfilter/sf_textmod.c
@@ -0,0 +1,409 @@
+/*
+ * Copyright (c) 2021 softworkz
+ *
+ * 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
+ * text subtitle filter which allows to modify subtitle text in several ways
+ */
+
+#include <libavcodec/ass.h>
+
+#include "libavutil/avassert.h"
+#include "libavutil/avstring.h"
+#include "libavutil/opt.h"
+#include "avfilter.h"
+#include "internal.h"
+#include "libavcodec/avcodec.h"
+#include "libavcodec/ass_split.h"
+
+static const char* leet_src = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
+static const char* leet_dst = "abcd3f6#1jklmn0pq257uvwxyzAB(D3F6#1JKLMN0PQ257UVWXYZ";
+
+enum TextModOperation {
+ OP_LEET,
+ OP_TO_UPPER,
+ OP_TO_LOWER,
+ OP_REPLACE_CHARS,
+ OP_REMOVE_CHARS,
+ OP_REPLACE_WORDS,
+ OP_REMOVE_WORDS,
+ NB_OPS,
+};
+
+typedef struct TextModContext {
+ const AVClass *class;
+ enum AVSubtitleType format;
+ enum TextModOperation operation;
+ char *find;
+ char *replace;
+ char *separator;
+ char **find_list;
+ int nb_find_list;
+ char **replace_list;
+ int nb_replace_list;
+} TextModContext;
+
+static char **split_string(char *source, int *nb_elems, char delim)
+{
+ char **list = NULL;
+ char *temp = NULL;
+ char *ptr = av_strtok(source, &delim, &temp);
+
+ while (ptr) {
+ av_dynarray_add(&list, nb_elems, ptr);
+ if (!list)
+ return NULL;
+
+ ptr = av_strtok(NULL, &delim, &temp);
+ }
+
+ av_dynarray_add(&list, nb_elems, NULL);
+
+ return list;
+}
+
+static int init(AVFilterContext *ctx)
+{
+ TextModContext *s = ctx->priv;
+
+ switch (s->operation) {
+ case OP_REPLACE_CHARS:
+ case OP_REMOVE_CHARS:
+ case OP_REPLACE_WORDS:
+ case OP_REMOVE_WORDS:
+ if (!s->find || !strlen(s->find)) {
+ av_log(ctx, AV_LOG_ERROR, "Selected mode requires the 'find' parameter to be specified");
+ return AVERROR(EINVAL);
+ }
+ break;
+ }
+
+ switch (s->operation) {
+ case OP_REPLACE_CHARS:
+ case OP_REPLACE_WORDS:
+ if (!s->replace || !strlen(s->replace)) {
+ av_log(ctx, AV_LOG_ERROR, "Selected mode requires the 'replace' parameter to be specified");
+ return AVERROR(EINVAL);
+ }
+ break;
+ }
+
+ if (s->operation == OP_REPLACE_CHARS && strlen(s->find) != strlen(s->replace)) {
+ av_log(ctx, AV_LOG_ERROR, "Selected mode requires the 'find' and 'replace' parameters to have the same length");
+ return AVERROR(EINVAL);
+ }
+
+ if (s->operation == OP_REPLACE_WORDS || s->operation == OP_REMOVE_WORDS) {
+ if (!s->separator || strlen(s->separator) != 1) {
+ av_log(ctx, AV_LOG_ERROR, "Selected mode requires a single separator char to be specified");
+ return AVERROR(EINVAL);
+ }
+
+ s->find_list = split_string(s->find, &s->nb_find_list, *s->separator);
+ if (!s->find_list)
+ return AVERROR(ENOMEM);
+
+ if (s->operation == OP_REPLACE_WORDS) {
+
+ s->replace_list = split_string(s->replace, &s->nb_replace_list, *s->separator);
+ if (!s->replace_list)
+ return AVERROR(ENOMEM);
+
+ if (s->nb_find_list != s->nb_replace_list) {
+ av_log(ctx, AV_LOG_ERROR, "The number of words in 'find' and 'replace' needs to be equal");
+ return AVERROR(EINVAL);
+ }
+ }
+ }
+
+ return 0;
+}
+
+static void uninit(AVFilterContext *ctx)
+{
+ TextModContext *s = ctx->priv;
+ int i;
+
+ for (i = 0; i < s->nb_find_list; i++) {
+ av_free(&s->find_list[i]);
+ }
+ s->nb_find_list = 0;
+ av_freep(&s->find_list);
+
+ for (i = 0; i < s->nb_replace_list; i++) {
+ av_free(&s->replace_list[i]);
+ }
+ s->nb_replace_list = 0;
+ av_freep(&s->replace_list);
+}
+
+static int query_formats(AVFilterContext *ctx)
+{
+ AVFilterFormats *formats;
+ AVFilterLink *inlink = ctx->inputs[0];
+ AVFilterLink *outlink = ctx->outputs[0];
+ static const enum AVSubtitleType subtitle_fmts[] = { AV_SUBTITLE_FMT_ASS, AV_SUBTITLE_FMT_NONE };
+ int ret;
+
+ /* set input subtitle format */
+ formats = ff_make_format_list(subtitle_fmts);
+ if ((ret = ff_formats_ref(formats, &inlink->outcfg.formats)) < 0)
+ return ret;
+
+ /* set output video format */
+ if ((ret = ff_formats_ref(formats, &outlink->incfg.formats)) < 0)
+ return ret;
+
+ return 0;
+}
+
+static char *process_text(TextModContext *s, char *text)
+{
+ const char *char_src = s->find;
+ const char *char_dst = s->replace;
+ char *result = NULL;
+ int escape_level = 0, k = 0;
+
+ switch (s->operation) {
+ case OP_LEET:
+ case OP_REPLACE_CHARS:
+
+ if (s->operation == OP_LEET) {
+ char_src = leet_src;
+ char_dst = leet_dst;
+ }
+
+ result = av_strdup(text);
+ if (!result)
+ return NULL;
+
+ for (size_t n = 0; n < strlen(result); n++) {
+ if (result[n] == '{')
+ escape_level++;
+
+ if (!escape_level) {
+ for (size_t t = 0; t < FF_ARRAY_ELEMS(char_src); t++) {
+ if (result[n] == char_src[t]) {
+ result[n] = char_dst[t];
+ break;
+ }
+ }
+ }
+
+ if (result[n] == '}')
+ escape_level--;
+ }
+
+ break;
+ case OP_TO_UPPER:
+ case OP_TO_LOWER:
+
+ result = av_strdup(text);
+ if (!result)
+ return NULL;
+
+ for (size_t n = 0; n < strlen(result); n++) {
+ if (result[n] == '{')
+ escape_level++;
+ if (!escape_level)
+ result[n] = s->operation == OP_TO_LOWER ? av_tolower(result[n]) : av_toupper(result[n]);
+ if (result[n] == '}')
+ escape_level--;
+ }
+
+ break;
+ case OP_REMOVE_CHARS:
+
+ result = av_strdup(text);
+ if (!result)
+ return NULL;
+
+ for (size_t n = 0; n < strlen(result); n++) {
+ int skip_char = 0;
+
+ if (result[n] == '{')
+ escape_level++;
+
+ if (!escape_level) {
+ for (size_t t = 0; t < FF_ARRAY_ELEMS(char_src); t++) {
+ if (result[n] == char_src[t]) {
+ skip_char = 1;
+ break;
+ }
+ }
+ }
+
+ if (!skip_char)
+ result[k++] = result[n];
+
+ if (result[n] == '}')
+ escape_level--;
+ }
+
+ result[k] = 0;
+
+ break;
+ case OP_REPLACE_WORDS:
+ case OP_REMOVE_WORDS:
+
+ result = av_strdup(text);
+ if (!result)
+ return NULL;
+
+ for (int n = 0; n < s->nb_find_list; n++) {
+ char *tmp = result;
+ const char *replace = (s->operation == OP_REPLACE_WORDS) ? s->replace_list[n] : "";
+
+ result = av_strireplace(result, s->find_list[n], replace);
+ if (!result)
+ return NULL;
+
+ av_free(tmp);
+ }
+
+ break;
+ }
+
+ return result;
+}
+
+static char *process_dialog(TextModContext *s, char *ass_line)
+{
+ ASSDialog *dialog = ff_ass_split_dialog(NULL, ass_line);
+ char *result, *text;
+
+ if (!dialog)
+ return NULL;
+
+ text = process_text(s, dialog->text);
+ if (!text)
+ return NULL;
+
+ result = ff_ass_get_dialog(dialog->readorder, dialog->layer, dialog->style, dialog->name, text);
+
+ av_free(text);
+ ff_ass_free_dialog(&dialog);
+ return result;
+}
+
+static int filter_frame(AVFilterLink *inlink, AVFrame *src_frame)
+{
+ TextModContext *s = inlink->dst->priv;
+ AVFilterLink *outlink = inlink->dst->outputs[0];
+ AVSubtitle *sub;
+ int ret;
+ AVFrame *out;
+
+ outlink->format = inlink->format;
+
+ out = av_frame_alloc();
+ if (!out) {
+ av_frame_free(&src_frame);
+ return AVERROR(ENOMEM);
+ }
+
+ out->format = outlink->format;
+
+ if ((ret = av_frame_get_buffer2(out, AVMEDIA_TYPE_SUBTITLE, 0)) < 0)
+ return ret;
+
+ out->pts = src_frame->pts;
+ out->pkt_dts = src_frame->pkt_dts;
+ out->pkt_duration = src_frame->pkt_duration;
+ out->best_effort_timestamp = src_frame->best_effort_timestamp;
+
+ sub = (AVSubtitle *)src_frame->data[0];
+
+ if (sub) {
+ AVSubtitle *out_sub = av_memdup(sub, sizeof(*out_sub));
+ if (!out_sub)
+ return AVERROR(ENOMEM);
+
+ out->buf[0] = av_buffer_create((uint8_t*)out_sub, sizeof(*out_sub), avsubtitle_free_ref, NULL, AV_BUFFER_FLAG_READONLY);
+ out->data[0] = (uint8_t*)out_sub;
+
+ if (sub->num_rects) {
+ out_sub->rects = av_malloc_array(sub->num_rects, sizeof(AVSubtitleRect *));
+ }
+
+ for (unsigned i = 0; i < sub->num_rects; i++) {
+
+ const AVSubtitleRect *src_rect = sub->rects[i];
+ AVSubtitleRect *dst_rect = av_memdup(src_rect, sizeof(*dst_rect));
+ out_sub->rects[i] = dst_rect;
+
+ if (src_rect->ass) {
+ dst_rect->ass = process_dialog(s, src_rect->ass);
+ if (!dst_rect->ass)
+ return AVERROR(ENOMEM);
+ }
+ }
+ }
+
+ av_frame_free(&src_frame);
+ return ff_filter_frame(outlink, out);
+}
+
+#define OFFSET(x) offsetof(TextModContext, x)
+#define FLAGS (AV_OPT_FLAG_SUBTITLE_PARAM | AV_OPT_FLAG_FILTERING_PARAM)
+
+static const AVOption textmod_options[] = {
+ { "mode", "set operation mode", OFFSET(operation), AV_OPT_TYPE_INT, {.i64=OP_LEET}, OP_LEET, NB_OPS-1, FLAGS, "mode" },
+ { "leet", "convert text to 'leet speak'", 0, AV_OPT_TYPE_CONST, {.i64=OP_LEET}, 0, 0, FLAGS, "mode" },
+ { "to_upper", "change to upper case", 0, AV_OPT_TYPE_CONST, {.i64=OP_TO_UPPER}, 0, 0, FLAGS, "mode" },
+ { "to_lower", "change to lower case", 0, AV_OPT_TYPE_CONST, {.i64=OP_TO_LOWER}, 0, 0, FLAGS, "mode" },
+ { "replace_chars", "replace characters", 0, AV_OPT_TYPE_CONST, {.i64=OP_REPLACE_CHARS}, 0, 0, FLAGS, "mode" },
+ { "remove_chars", "remove characters", 0, AV_OPT_TYPE_CONST, {.i64=OP_REMOVE_CHARS}, 0, 0, FLAGS, "mode" },
+ { "replace_words", "replace words", 0, AV_OPT_TYPE_CONST, {.i64=OP_REPLACE_WORDS}, 0, 0, FLAGS, "mode" },
+ { "remove_words", "remove words", 0, AV_OPT_TYPE_CONST, {.i64=OP_REMOVE_WORDS}, 0, 0, FLAGS, "mode" },
+ { "find", "chars/words to find or remove", OFFSET(find), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, FLAGS, NULL },
+ { "replace", "chars/words to replace", OFFSET(replace), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, FLAGS, NULL },
+ { "separator", "word separator (default: ',')", OFFSET(separator), AV_OPT_TYPE_STRING, {.str = ","}, 0, 0, FLAGS, NULL },
+ { NULL },
+};
+
+AVFILTER_DEFINE_CLASS(textmod);
+
+static const AVFilterPad inputs[] = {
+ {
+ .name = "default",
+ .type = AVMEDIA_TYPE_SUBTITLE,
+ .filter_frame = filter_frame,
+ },
+};
+
+static const AVFilterPad outputs[] = {
+ {
+ .name = "default",
+ .type = AVMEDIA_TYPE_SUBTITLE,
+ },
+};
+
+const AVFilter ff_sf_textmod = {
+ .name = "textmod",
+ .description = NULL_IF_CONFIG_SMALL("Modify subtitle text in several ways"),
+ .init = init,
+ .uninit = uninit,
+ .query_formats = query_formats,
+ .priv_size = sizeof(TextModContext),
+ .priv_class = &textmod_class,
+ FILTER_INPUTS(inputs),
+ FILTER_OUTPUTS(outputs),
+};
--
2.30.2.windows.1
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