fftools/graphprint: Add execution graph printing

The key benefits are:

- Different to other graph printing methods, this is outputting:
  - all graphs with runtime state
    (including auto-inserted filters)
  - each graph with its inputs and outputs
  - all filters with their in- and output pads
  - all connections between all input- and output pads
  - for each connection:
    - the runtime-negotiated format and media type
    - the hw context
    - if video hw context, both: hw pixfmt + sw pixfmt
- Output can either be printed to stdout or written to specified file
- Output is machine-readable
- Use the same output implementation as ffprobe, supporting multiple
  formats

Signed-off-by: softworkz <softworkz@hotmail.com>

doc/ffmpeg.texi

@@ -1394,6 +1394,16 @@ It is on by default, to explicitly disable it you need to specify @code{-nostats
 @item -stats_period @var{time} (@emph{global})
 Set period at which encoding progress/statistics are updated. Default is 0.5 seconds.
 
+@item -print_graphs (@emph{global})
+Prints execution graph details to stderr in the format set via -print_graphs_format.
+
+@item -print_graphs_file @var{filename} (@emph{global})
+Writes execution graph details to the specified file in the format set via -print_graphs_format.
+
+@item -print_graphs_format @var{format} (@emph{global})
+Sets the output format (available formats are: default, compact, csv, flat, ini, json, xml, mermaid, mermaidhtml)
+The default format is json.
+
 @item -progress @var{url} (@emph{global})
 Send program-friendly progress information to @var{url}.
 

fftools/Makefile

@@ -9,6 +9,8 @@ AVBASENAMES  = ffmpeg ffplay ffprobe
 ALLAVPROGS   = $(AVBASENAMES:%=%$(PROGSSUF)$(EXESUF))
 ALLAVPROGS_G = $(AVBASENAMES:%=%$(PROGSSUF)_g$(EXESUF))
 
+include $(SRC_PATH)/fftools/resources/Makefile
+
 OBJS-ffmpeg +=                  \
     fftools/ffmpeg_dec.o        \
     fftools/ffmpeg_demux.o      \
@@ -19,8 +21,21 @@ OBJS-ffmpeg +=                  \
     fftools/ffmpeg_mux_init.o   \
     fftools/ffmpeg_opt.o        \
     fftools/ffmpeg_sched.o      \
+    fftools/graph/graphprint.o        \
     fftools/sync_queue.o        \
     fftools/thread_queue.o      \
+    fftools/textformat/avtextformat.o \
+    fftools/textformat/tf_compact.o   \
+    fftools/textformat/tf_default.o   \
+    fftools/textformat/tf_flat.o      \
+    fftools/textformat/tf_ini.o       \
+    fftools/textformat/tf_json.o      \
+    fftools/textformat/tf_mermaid.o   \
+    fftools/textformat/tf_xml.o       \
+    fftools/textformat/tw_avio.o      \
+    fftools/textformat/tw_buffer.o    \
+    fftools/textformat/tw_stdout.o    \
+    $(OBJS-resman)                    \
 
 OBJS-ffprobe +=                       \
     fftools/textformat/avtextformat.o \
@@ -29,10 +44,12 @@ OBJS-ffprobe +=                       \
     fftools/textformat/tf_flat.o      \
     fftools/textformat/tf_ini.o       \
     fftools/textformat/tf_json.o      \
+    fftools/textformat/tf_mermaid.o   \
     fftools/textformat/tf_xml.o       \
     fftools/textformat/tw_avio.o      \
     fftools/textformat/tw_buffer.o    \
     fftools/textformat/tw_stdout.o    \
+    $(OBJS-resman)                    \
 
 OBJS-ffplay += fftools/ffplay_renderer.o
 
@@ -42,7 +59,7 @@ ifdef HAVE_GNU_WINDRES
 OBJS-$(1) += fftools/fftoolsres.o
 endif
 $(1)$(PROGSSUF)_g$(EXESUF): $$(OBJS-$(1))
-$$(OBJS-$(1)): | fftools fftools/textformat fftools/resources
+$$(OBJS-$(1)): | fftools fftools/textformat fftools/resources fftools/graph
 $$(OBJS-$(1)): CFLAGS  += $(CFLAGS-$(1))
 $(1)$(PROGSSUF)_g$(EXESUF): LDFLAGS += $(LDFLAGS-$(1))
 $(1)$(PROGSSUF)_g$(EXESUF): FF_EXTRALIBS += $(EXTRALIBS-$(1))
@@ -57,6 +74,7 @@ fftools/ffprobe.o fftools/cmdutils.o: libavutil/ffversion.h | fftools
 OUTDIRS += fftools
 OUTDIRS += fftools/textformat
 OUTDIRS += fftools/resources
+OUTDIRS += fftools/graph
 
 ifdef AVPROGS
 install: install-progs install-data

fftools/ffmpeg.c

@@ -81,6 +81,7 @@
 #include "ffmpeg.h"
 #include "ffmpeg_sched.h"
 #include "ffmpeg_utils.h"
+#include "graph/graphprint.h"
 
 const char program_name[] = "ffmpeg";
 const int program_birth_year = 2000;
@@ -308,6 +309,9 @@ const AVIOInterruptCB int_cb = { decode_interrupt_cb, NULL };
 
 static void ffmpeg_cleanup(int ret)
 {
+    if (print_graphs || print_graphs_file)
+        print_filtergraphs(filtergraphs, nb_filtergraphs, input_files, nb_input_files, output_files, nb_output_files);
+
     if (do_benchmark) {
         int64_t maxrss = getmaxrss() / 1024;
         av_log(NULL, AV_LOG_INFO, "bench: maxrss=%"PRId64"KiB\n", maxrss);

fftools/ffmpeg.h

@@ -717,6 +717,9 @@ extern float max_error_rate;
 extern char *filter_nbthreads;
 extern int filter_complex_nbthreads;
 extern int vstats_version;
+extern int print_graphs;
+extern char *print_graphs_file;
+extern char *print_graphs_format;
 extern int auto_conversion_filters;
 
 extern const AVIOInterruptCB int_cb;

fftools/ffmpeg_filter.c

@@ -22,6 +22,7 @@
 
 #include "ffmpeg.h"
 #include "ffmpeg_filter.h"
+#include "graph/graphprint.h"
 
 #include "libavfilter/avfilter.h"
 #include "libavfilter/buffersink.h"
@@ -2983,6 +2984,10 @@ read_frames:
     }
 
 finish:
+
+    if (print_graphs || print_graphs_file)
+        print_filtergraph(fg, fgt.graph);
+
     // EOF is normal termination
     if (ret == AVERROR_EOF)
         ret = 0;

fftools/ffmpeg_opt.c

@@ -47,6 +47,7 @@
 #include "libavutil/opt.h"
 #include "libavutil/parseutils.h"
 #include "libavutil/stereo3d.h"
+#include "graph/graphprint.h"
 
 HWDevice *filter_hw_device;
 
@@ -75,6 +76,9 @@ float max_error_rate  = 2.0/3;
 char *filter_nbthreads;
 int filter_complex_nbthreads = 0;
 int vstats_version = 2;
+int print_graphs = 0;
+char *print_graphs_file = NULL;
+char *print_graphs_format = NULL;
 int auto_conversion_filters = 1;
 int64_t stats_period = 500000;
 
@@ -1735,6 +1739,15 @@ const OptionDef options[] = {
         { .func_arg = opt_filter_complex_script },
         "deprecated, use -/filter_complex instead", "filename" },
 #endif
+    { "print_graphs",   OPT_TYPE_BOOL, 0,
+        { &print_graphs },
+        "print execution graph data to stderr" },
+    { "print_graphs_file", OPT_TYPE_STRING, 0,
+        { &print_graphs_file },
+        "write execution graph data to the specified file", "filename" },
+    { "print_graphs_format", OPT_TYPE_STRING, 0,
+        { &print_graphs_format },
+      "set the output printing format (available formats are: default, compact, csv, flat, ini, json, xml, mermaid, mermaidhtml)", "format" },
     { "auto_conversion_filters", OPT_TYPE_BOOL, OPT_EXPERT,
         { &auto_conversion_filters },
         "enable automatic conversion filters globally" },

fftools/graph/graphprint.h

@@ -0,0 +1,30 @@
+/*
+ * Copyright (c) 2018-2025 - 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
+ */
+
+#ifndef FFTOOLS_GRAPH_GRAPHPRINT_H
+#define FFTOOLS_GRAPH_GRAPHPRINT_H
+
+#include "fftools/ffmpeg.h"
+
+int print_filtergraphs(FilterGraph **graphs, int nb_graphs, InputFile **ifiles, int nb_ifiles, OutputFile **ofiles, int nb_ofiles);
+
+int print_filtergraph(FilterGraph *fg, AVFilterGraph *graph);
+
+#endif /* FFTOOLS_GRAPH_GRAPHPRINT_H */

fftools/textformat/avtextformat.c

@@ -677,7 +677,7 @@ fail:
     return ret;
 }
 
-static const AVTextFormatter *registered_formatters[7 + 1];
+static const AVTextFormatter *registered_formatters[9 + 1];
 
 static void formatters_register_all(void)
 {
@@ -694,6 +694,8 @@ static void formatters_register_all(void)
     registered_formatters[4] = &avtextformatter_ini;
     registered_formatters[5] = &avtextformatter_json;
     registered_formatters[6] = &avtextformatter_xml;
+    registered_formatters[7] = &avtextformatter_mermaid;
+    registered_formatters[8] = &avtextformatter_mermaidhtml;
 }
 
 const AVTextFormatter *avtext_get_formatter_by_name(const char *name)

fftools/textformat/avtextformat.h

@@ -31,6 +31,12 @@
 
 #define SECTION_MAX_NB_CHILDREN 11
 
+typedef struct AVTextFormatSectionContext {
+    char *context_id;
+    const char *context_type;
+    int context_flags;
+} AVTextFormatSectionContext;
+
 
 typedef struct AVTextFormatSection {
     int id;             ///< unique id identifying a section
@@ -42,6 +48,10 @@ typedef struct AVTextFormatSection {
                                            ///  For these sections the element_name field is mandatory.
 #define AV_TEXTFORMAT_SECTION_FLAG_HAS_TYPE        8 ///< the section contains a type to distinguish multiple nested elements
 #define AV_TEXTFORMAT_SECTION_FLAG_NUMBERING_BY_TYPE 16 ///< the items in this array section should be numbered individually by type
+#define AV_TEXTFORMAT_SECTION_FLAG_IS_SHAPE       32 ///< ...
+#define AV_TEXTFORMAT_SECTION_FLAG_HAS_LINKS      64 ///< ...
+#define AV_TEXTFORMAT_SECTION_PRINT_TAGS         128 ///< ...
+#define AV_TEXTFORMAT_SECTION_FLAG_IS_SUBGRAPH   256 ///< ...
 
     int flags;
     const int children_ids[SECTION_MAX_NB_CHILDREN + 1]; ///< list of children section IDS, terminated by -1
@@ -50,12 +60,17 @@ typedef struct AVTextFormatSection {
     AVDictionary *entries_to_show;
     const char *(*get_type)(const void *data); ///< function returning a type if defined, must be defined when SECTION_FLAG_HAS_TYPE is defined
     int show_all_entries;
+    const char *id_key;          ///< name of the key to be used as the id
+    const char *src_id_key;     ///< name of the key to be used as the source id for diagram connections
+    const char *dest_id_key;   ///< name of the key to be used as the target id for diagram connections
+    const char *linktype_key; ///< name of the key to be used as the link type for diagram connections (AVTextFormatLinkType)
 } AVTextFormatSection;
 
 typedef struct AVTextFormatContext AVTextFormatContext;
 
 #define AV_TEXTFORMAT_FLAG_SUPPORTS_OPTIONAL_FIELDS 1
 #define AV_TEXTFORMAT_FLAG_SUPPORTS_MIXED_ARRAY_CONTENT 2
+#define AV_TEXTFORMAT_FLAG_IS_DIAGRAM_FORMATTER         4
 
 typedef enum {
     AV_TEXTFORMAT_STRING_VALIDATION_FAIL,
@@ -64,6 +79,18 @@ typedef enum {
     AV_TEXTFORMAT_STRING_VALIDATION_NB
 } StringValidation;
 
+typedef enum {
+    AV_TEXTFORMAT_LINKTYPE_SRCDEST,
+    AV_TEXTFORMAT_LINKTYPE_DESTSRC,
+    AV_TEXTFORMAT_LINKTYPE_BIDIR,
+    AV_TEXTFORMAT_LINKTYPE_NONDIR,
+    AV_TEXTFORMAT_LINKTYPE_HIDDEN,
+    AV_TEXTFORMAT_LINKTYPE_ONETOMANY = AV_TEXTFORMAT_LINKTYPE_SRCDEST,
+    AV_TEXTFORMAT_LINKTYPE_MANYTOONE = AV_TEXTFORMAT_LINKTYPE_DESTSRC,
+    AV_TEXTFORMAT_LINKTYPE_ONETOONE = AV_TEXTFORMAT_LINKTYPE_BIDIR,
+    AV_TEXTFORMAT_LINKTYPE_MANYTOMANY = AV_TEXTFORMAT_LINKTYPE_NONDIR,
+} AVTextFormatLinkType;
+
 typedef struct AVTextFormatter {
     const AVClass *priv_class;      ///< private class of the formatter, if any
     int priv_size;                  ///< private size for the formatter context
@@ -166,5 +193,7 @@ extern const AVTextFormatter avtextformatter_flat;
 extern const AVTextFormatter avtextformatter_ini;
 extern const AVTextFormatter avtextformatter_json;
 extern const AVTextFormatter avtextformatter_xml;
+extern const AVTextFormatter avtextformatter_mermaid;
+extern const AVTextFormatter avtextformatter_mermaidhtml;
 
 #endif /* FFTOOLS_TEXTFORMAT_AVTEXTFORMAT_H */

fftools/textformat/tf_mermaid.c

@@ -0,0 +1,658 @@
+/*
+ * Copyright (c) The FFmpeg developers
+ *
+ * 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
+ */
+
+#include <limits.h>
+#include <stdarg.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <string.h>
+
+#include "avtextformat.h"
+#include "tf_internal.h"
+#include "tf_mermaid.h"
+#include <libavutil/mem.h>
+#include <libavutil/avassert.h>
+#include <libavutil/bprint.h>
+#include <libavutil/opt.h>
+
+
+static const char *init_directive = ""
+    "%%{init: {"
+        "\"theme\": \"base\","
+        "\"curve\": \"monotoneX\","
+        "\"rankSpacing\": 10,"
+        "\"nodeSpacing\": 10,"
+        "\"themeCSS\": \"__###__\","
+        "\"fontFamily\": \"Roboto,Segoe UI,sans-serif\","
+        "\"themeVariables\": { "
+            "\"clusterBkg\": \"white\", "
+            "\"primaryBorderColor\": \"gray\", "
+            "\"lineColor\": \"gray\", "
+            "\"secondaryTextColor\": \"gray\", "
+            "\"tertiaryBorderColor\": \"gray\", "
+            "\"primaryTextColor\": \"#666\", "
+            "\"secondaryTextColor\": \"red\" "
+        "},"
+        "\"flowchart\": { "
+            "\"subGraphTitleMargin\": { \"top\": -15, \"bottom\": 20 }, "
+            "\"diagramPadding\": 20, "
+            "\"curve\": \"monotoneX\" "
+        "}"
+    " }}%%\n\n";
+
+static const char* init_directive_er = ""
+    "%%{init: {"
+        "\"theme\": \"base\","
+        "\"layout\": \"elk\","
+        "\"curve\": \"monotoneX\","
+        "\"rankSpacing\": 65,"
+        "\"nodeSpacing\": 60,"
+        "\"themeCSS\": \"__###__\","
+        "\"fontFamily\": \"Roboto,Segoe UI,sans-serif\","
+        "\"themeVariables\": { "
+            "\"clusterBkg\": \"white\", "
+            "\"primaryBorderColor\": \"gray\", "
+            "\"lineColor\": \"gray\", "
+            "\"secondaryTextColor\": \"gray\", "
+            "\"tertiaryBorderColor\": \"gray\", "
+            "\"primaryTextColor\": \"#666\", "
+            "\"secondaryTextColor\": \"red\" "
+        "},"
+        "\"er\": { "
+            "\"diagramPadding\": 12, "
+            "\"entityPadding\": 4, "
+            "\"minEntityWidth\": 150, "
+            "\"minEntityHeight\": 20, "
+            "\"curve\": \"monotoneX\" "
+        "}"
+    " }}%%\n\n";
+
+static const char *theme_css_er = ""
+
+    // Variables
+            ".root { "
+                "--ff-colvideo: #6eaa7b; "
+                "--ff-colaudio: #477fb3; "
+                "--ff-colsubtitle: #ad76ab; "
+                "--ff-coltext: #666; "
+            "} "
+            " g.nodes g.node.default rect.basic.label-container, "
+            " g.nodes g.node.default path { "
+            "     rx: 1; "
+            "     ry: 1; "
+            "     stroke-width: 1px !important; "
+            "     stroke: #e9e9e9 !important; "
+            "     fill: url(#ff-filtergradient) !important; "
+            "     filter: drop-shadow(0px 0px 5.5px rgba(0, 0, 0, 0.05)); "
+            "     fill: white !important; "
+            " } "
+            "  "
+            " .relationshipLine { "
+            "     stroke: gray; "
+            "     stroke-width: 1; "
+            "     fill: none; "
+            "     filter: drop-shadow(0px 0px 3px rgba(0, 0, 0, 0.2)); "
+            " } "
+            "  "
+            " g.node.default g.label.name  foreignObject > div > span > p, "
+            " g.nodes g.node.default g.label:not(.attribute-name, .attribute-keys, .attribute-type, .attribute-comment) foreignObject > div > span > p { "
+            "     font-size: 0.95rem; "
+            "     font-weight: 500; "
+            "     text-transform: uppercase; "
+            "     min-width: 5.5rem; "
+            "     margin-bottom: 0.5rem; "
+            "      "
+            " } "
+            "  "
+            " .edgePaths path { "
+            "     marker-end: none; "
+            "     marker-start: none; "
+            "  "
+            "} ";
+
+
+/* Mermaid Graph output */
+
+typedef struct MermaidContext {
+    const AVClass *class;
+    AVDiagramConfig *diagram_config;
+    int subgraph_count;
+    int within_tag;
+    int indent_level;
+    int create_html;
+
+    // Options
+    int enable_link_colors; // Requires Mermaid 11.5
+
+    struct section_data {
+        const char *section_id;
+        const char *section_type;
+        const char *src_id;
+        const char *dest_id;
+        AVTextFormatLinkType link_type;
+        int current_is_textblock;
+        int current_is_stadium;
+        int subgraph_start_incomplete;
+    }  section_data[SECTION_MAX_NB_LEVELS];
+
+    unsigned nb_link_captions[SECTION_MAX_NB_LEVELS]; ///< generic print buffer dedicated to each section,
+    AVBPrint section_pbuf[SECTION_MAX_NB_LEVELS]; ///< generic print buffer dedicated to each section,
+    AVBPrint link_buf; ///< print buffer for writing diagram links
+    AVDictionary *link_dict;
+} MermaidContext;
+
+#undef OFFSET
+#define OFFSET(x) offsetof(MermaidContext, x)
+
+static const AVOption mermaid_options[] = {
+    { "link_coloring",    "enable colored links (requires Mermaid >= 11.5)",  OFFSET(enable_link_colors), AV_OPT_TYPE_BOOL,   { .i64 = 1 },  0, 1 },
+    ////{"diagram_css",      "CSS for the diagram",                              OFFSET(diagram_css),        AV_OPT_TYPE_STRING, {.i64=0},  0, 1 },
+    ////{"html_template",    "Template HTML",                                    OFFSET(html_template),      AV_OPT_TYPE_STRING, {.i64=0},  0, 1 },
+    { NULL },
+};
+
+DEFINE_FORMATTER_CLASS(mermaid);
+
+void av_diagram_init(AVTextFormatContext *tfc, AVDiagramConfig *diagram_config)
+{
+    MermaidContext *mmc = tfc->priv;
+    mmc->diagram_config = diagram_config;
+}
+
+static av_cold int has_link_pair(const AVTextFormatContext *tfc, const char *src, const char *dest)
+{
+    MermaidContext *mmc = tfc->priv;
+    AVBPrint buf;
+
+    av_bprint_init(&buf, 0, AV_BPRINT_SIZE_UNLIMITED);
+    av_bprintf(&buf, "%s--%s", src, dest);
+
+    if (mmc->link_dict && av_dict_get(mmc->link_dict, buf.str, NULL, 0))
+        return 1;
+
+    av_dict_set(&mmc->link_dict, buf.str, buf.str, 0);
+
+    return 0;
+}
+
+static av_cold int mermaid_init(AVTextFormatContext *tfc)
+{
+    MermaidContext *mmc = tfc->priv;
+
+    av_bprint_init(&mmc->link_buf, 0, AV_BPRINT_SIZE_UNLIMITED);
+
+    ////mmc->enable_link_colors = 1; // Requires Mermaid 11.5
+    return 0;
+}
+
+static av_cold int mermaid_init_html(AVTextFormatContext *tfc)
+{
+    MermaidContext *mmc = tfc->priv;
+
+    int ret = mermaid_init(tfc);
+
+    if (ret < 0)
+        return ret;
+
+    mmc->create_html = 1;
+
+    return 0;
+}
+
+#define MM_INDENT() writer_printf(tfc, "%*c", mmc->indent_level * 2, ' ')
+
+static void mermaid_print_section_header(AVTextFormatContext *tfc, const void *data)
+{
+    const AVTextFormatSection *section = tf_get_section(tfc, tfc->level);
+    const AVTextFormatSection *parent_section = tf_get_parent_section(tfc, tfc->level);
+
+    if (!section)
+        return;
+    AVBPrint *buf = &tfc->section_pbuf[tfc->level];
+    MermaidContext *mmc = tfc->priv;
+    const AVTextFormatSectionContext *sec_ctx = data;
+
+    if (tfc->level == 0) {
+        char *directive;
+        AVBPrint css_buf;
+        const char *diag_directive = mmc->diagram_config->diagram_type == AV_DIAGRAMTYPE_ENTITYRELATIONSHIP ? init_directive_er : init_directive;
+        char *single_line_css = av_strireplace(mmc->diagram_config->diagram_css, "\n", " ");
+        (void)theme_css_er;
+        ////char *single_line_css = av_strireplace(theme_css_er, "\n", " ");
+        av_bprint_init(&css_buf, 0, AV_BPRINT_SIZE_UNLIMITED);
+        av_bprint_escape(&css_buf, single_line_css, "'\\", AV_ESCAPE_MODE_BACKSLASH, AV_ESCAPE_FLAG_STRICT);
+        av_freep(&single_line_css);
+
+        directive = av_strireplace(diag_directive, "__###__", css_buf.str);
+        if (mmc->create_html) {
+            uint64_t length;
+            char *token_pos = av_stristr(mmc->diagram_config->html_template, "__###__");
+            if (!token_pos) {
+                av_log(tfc, AV_LOG_ERROR, "Unable to locate the required token (__###__) in the html template.");
+                return;
+            }
+
+            length = token_pos - mmc->diagram_config->html_template;
+            for (uint64_t i = 0; i < length; i++)
+                writer_w8(tfc, mmc->diagram_config->html_template[i]);
+        }
+
+        writer_put_str(tfc, directive);
+        switch (mmc->diagram_config->diagram_type) {
+        case AV_DIAGRAMTYPE_GRAPH:
+            writer_put_str(tfc, "flowchart LR\n");
+        ////writer_put_str(tfc, "  gradient_def@{ shape: text, label: \"<svg xmlns=\"http://www.w3.org/2000/svg\" width=\"1\" height=\"1\"><defs><linearGradient id=\"ff-filtergradient\" x1=\"0%\" y1=\"0%\" x2=\"0%\" y2=\"100%\"><stop offset=\"0%\" style=\"stop-color:hsla(0, 0%, 30%, 0.02);\"/><stop offset=\"50%\" style=\"stop-color:hsla(0, 0%, 30%, 0);\"/><stop offset=\"100%\" style=\"stop-color:hsla(0, 0%, 30%, 0.05);\"/></linearGradient></defs></svg>\" }\n");
+            writer_put_str(tfc, "  gradient_def@{ shape: text, label: \"<svg xmlns=\"http://www.w3.org/2000/svg\" width=\"1\" height=\"1\"><defs><linearGradient id=\"ff-filtergradient\" x1=\"0%\" y1=\"0%\" x2=\"0%\" y2=\"100%\"><stop offset=\"0%\" style=\"stop-color:hsl(0, 0%, 98.6%);     \"/><stop offset=\"50%\" style=\"stop-color:hsl(0, 0%, 100%);   \"/><stop offset=\"100%\" style=\"stop-color:hsl(0, 0%, 96.5%);     \"/></linearGradient><radialGradient id=\"ff-radgradient\" cx=\"50%\" cy=\"50%\" r=\"100%\" fx=\"45%\" fy=\"40%\"><stop offset=\"25%\" stop-color=\"hsl(0, 0%, 100%)\" /><stop offset=\"100%\" stop-color=\"hsl(0, 0%, 96%)\" /></radialGradient></defs></svg>\" }\n");
+            break;
+        case AV_DIAGRAMTYPE_ENTITYRELATIONSHIP:
+            writer_put_str(tfc, "erDiagram\n");
+            break;
+        }
+
+        return;
+    }
+
+    if (parent_section && parent_section->flags & AV_TEXTFORMAT_SECTION_FLAG_IS_SUBGRAPH) {
+
+        struct section_data parent_sec_data = mmc->section_data[tfc->level - 1];
+        AVBPrint *parent_buf = &tfc->section_pbuf[tfc->level - 1];
+
+        if (parent_sec_data.subgraph_start_incomplete) {
+
+            if (parent_buf->len > 0)
+                writer_printf(tfc, "%s", parent_buf->str);
+
+            writer_put_str(tfc, "</div>\"]\n");
+
+            mmc->section_data[tfc->level - 1].subgraph_start_incomplete = 0;
+        }
+    }
+
+    av_freep(&mmc->section_data[tfc->level].section_id);
+    av_freep(&mmc->section_data[tfc->level].section_type);
+    av_freep(&mmc->section_data[tfc->level].src_id);
+    av_freep(&mmc->section_data[tfc->level].dest_id);
+    mmc->section_data[tfc->level].current_is_textblock = 0;
+    mmc->section_data[tfc->level].current_is_stadium = 0;
+    mmc->section_data[tfc->level].subgraph_start_incomplete = 0;
+    mmc->section_data[tfc->level].link_type = AV_TEXTFORMAT_LINKTYPE_SRCDEST;
+
+    // NOTE: av_strdup() allocations aren't checked
+    if (section->flags & AV_TEXTFORMAT_SECTION_FLAG_IS_SUBGRAPH) {
+
+        av_bprint_clear(buf);
+        writer_put_str(tfc, "\n");
+
+        mmc->indent_level++;
+
+        if (sec_ctx->context_id) {
+            MM_INDENT();
+            writer_printf(tfc, "subgraph %s[\"<div class=\"ff-%s\">", sec_ctx->context_id, section->name);
+        } else {
+            av_log(tfc, AV_LOG_ERROR, "Unable to write subgraph start. Missing id field. Section: %s", section->name);
+        }
+
+        mmc->section_data[tfc->level].subgraph_start_incomplete = 1;
+        mmc->section_data[tfc->level].section_id = av_strdup(sec_ctx->context_id);
+    }
+
+    if (section->flags & AV_TEXTFORMAT_SECTION_FLAG_IS_SHAPE) {
+
+        av_bprint_clear(buf);
+        writer_put_str(tfc, "\n");
+
+        mmc->indent_level++;
+
+        if (sec_ctx->context_id) {
+
+            mmc->section_data[tfc->level].section_id = av_strdup(sec_ctx->context_id);
+
+            switch (mmc->diagram_config->diagram_type) {
+            case AV_DIAGRAMTYPE_GRAPH:
+                if (sec_ctx->context_flags & 1) {
+
+                    MM_INDENT();
+                    writer_printf(tfc, "%s@{ shape: text, label: \"", sec_ctx->context_id);
+                    mmc->section_data[tfc->level].current_is_textblock = 1;
+                } else if (sec_ctx->context_flags & 2) {
+
+                    MM_INDENT();
+                    writer_printf(tfc, "%s([\"", sec_ctx->context_id);
+                    mmc->section_data[tfc->level].current_is_stadium = 1;
+                } else {
+                    MM_INDENT();
+                    writer_printf(tfc, "%s(\"", sec_ctx->context_id);
+                }
+
+                break;
+            case AV_DIAGRAMTYPE_ENTITYRELATIONSHIP:
+                MM_INDENT();
+                writer_printf(tfc, "%s {\n", sec_ctx->context_id);
+                break;
+            }
+
+        } else {
+            av_log(tfc, AV_LOG_ERROR, "Unable to write shape start. Missing id field. Section: %s", section->name);
+        }
+
+        mmc->section_data[tfc->level].section_id = av_strdup(sec_ctx->context_id);
+    }
+
+
+    if (section->flags & AV_TEXTFORMAT_SECTION_PRINT_TAGS) {
+
+        if (sec_ctx && sec_ctx->context_type)
+            writer_printf(tfc, "<div class=\"ff-%s %s\">", section->name, sec_ctx->context_type);
+        else
+            writer_printf(tfc, "<div class=\"ff-%s\">", section->name);
+    }
+
+
+    if (section->flags & AV_TEXTFORMAT_SECTION_FLAG_HAS_LINKS) {
+
+        av_bprint_clear(buf);
+        mmc->nb_link_captions[tfc->level] = 0;
+
+        if (sec_ctx && sec_ctx->context_type)
+            mmc->section_data[tfc->level].section_type = av_strdup(sec_ctx->context_type);
+
+        ////if (section->flags & AV_TEXTFORMAT_SECTION_FLAG_HAS_TYPE) {
+        ////    AVBPrint buf;
+        ////    av_bprint_init(&buf, 1, AV_BPRINT_SIZE_UNLIMITED);
+        ////    av_bprint_escape(&buf, section->get_type(data), NULL,
+        ////                     AV_ESCAPE_MODE_XML, AV_ESCAPE_FLAG_XML_DOUBLE_QUOTES);
+        ////    writer_printf(tfc, " type=\"%s\"", buf.str);
+    }
+}
+
+static void mermaid_print_section_footer(AVTextFormatContext *tfc)
+{
+    MermaidContext *mmc = tfc->priv;
+    const AVTextFormatSection *section = tf_get_section(tfc, tfc->level);
+
+    if (!section)
+        return;
+    AVBPrint *buf = &tfc->section_pbuf[tfc->level];
+    struct section_data sec_data = mmc->section_data[tfc->level];
+
+    if (section->flags & AV_TEXTFORMAT_SECTION_PRINT_TAGS)
+        writer_put_str(tfc, "</div>");
+
+    if (section->flags & AV_TEXTFORMAT_SECTION_FLAG_IS_SHAPE) {
+
+        switch (mmc->diagram_config->diagram_type) {
+        case AV_DIAGRAMTYPE_GRAPH:
+
+            if (sec_data.current_is_textblock) {
+                writer_printf(tfc, "\"}\n", section->name);
+
+                if (sec_data.section_id) {
+                    MM_INDENT();
+                    writer_put_str(tfc, "class ");
+                    writer_put_str(tfc, sec_data.section_id);
+                    writer_put_str(tfc, " ff-");
+                    writer_put_str(tfc, section->name);
+                    writer_put_str(tfc, "\n");
+                }
+            } else if (sec_data.current_is_stadium) {
+                writer_printf(tfc, "\"]):::ff-%s\n", section->name);
+            } else {
+                writer_printf(tfc, "\"):::ff-%s\n", section->name);
+            }
+
+            break;
+        case AV_DIAGRAMTYPE_ENTITYRELATIONSHIP:
+            MM_INDENT();
+            writer_put_str(tfc, "}\n\n");
+            break;
+        }
+
+        mmc->indent_level--;
+
+    } else if ((section->flags & AV_TEXTFORMAT_SECTION_FLAG_IS_SUBGRAPH)) {
+
+        MM_INDENT();
+        writer_put_str(tfc, "end\n");
+
+        if (sec_data.section_id) {
+            MM_INDENT();
+            writer_put_str(tfc, "class ");
+            writer_put_str(tfc, sec_data.section_id);
+            writer_put_str(tfc, " ff-");
+            writer_put_str(tfc, section->name);
+            writer_put_str(tfc, "\n");
+        }
+
+        mmc->indent_level--;
+    }
+
+    if ((section->flags & AV_TEXTFORMAT_SECTION_FLAG_HAS_LINKS))
+        if (sec_data.src_id && sec_data.dest_id
+            && !has_link_pair(tfc, sec_data.src_id, sec_data.dest_id))
+            switch (mmc->diagram_config->diagram_type) {
+            case AV_DIAGRAMTYPE_GRAPH:
+
+                if (sec_data.section_type && mmc->enable_link_colors)
+                    av_bprintf(&mmc->link_buf, "\n  %s %s-%s-%s@==", sec_data.src_id, sec_data.section_type, sec_data.src_id, sec_data.dest_id);
+                else
+                    av_bprintf(&mmc->link_buf, "\n  %s ==", sec_data.src_id);
+
+                if (buf->len > 0) {
+                    av_bprintf(&mmc->link_buf, " \"%s", buf->str);
+
+                    for (unsigned i = 0; i < mmc->nb_link_captions[tfc->level]; i++)
+                        av_bprintf(&mmc->link_buf, "<br>&nbsp;");
+
+                    av_bprintf(&mmc->link_buf, "\" ==");
+                }
+
+                av_bprintf(&mmc->link_buf, "> %s", sec_data.dest_id);
+
+                break;
+            case AV_DIAGRAMTYPE_ENTITYRELATIONSHIP:
+
+
+                av_bprintf(&mmc->link_buf, "\n  %s", sec_data.src_id);
+
+                switch (sec_data.link_type) {
+                case AV_TEXTFORMAT_LINKTYPE_ONETOMANY:
+                    av_bprintf(&mmc->link_buf, "%s", " ||--o{ ");
+                    break;
+                case AV_TEXTFORMAT_LINKTYPE_MANYTOONE:
+                    av_bprintf(&mmc->link_buf, "%s", " }o--|| ");
+                    break;
+                case AV_TEXTFORMAT_LINKTYPE_ONETOONE:
+                    av_bprintf(&mmc->link_buf, "%s", " ||--|| ");
+                    break;
+                case AV_TEXTFORMAT_LINKTYPE_MANYTOMANY:
+                    av_bprintf(&mmc->link_buf, "%s", " }o--o{ ");
+                    break;
+                default:
+                    av_bprintf(&mmc->link_buf, "%s", " ||--|| ");
+                    break;
+                }
+
+                av_bprintf(&mmc->link_buf, "%s : \"\"", sec_data.dest_id);
+
+                break;
+            }
+
+    if (tfc->level == 0) {
+
+        writer_put_str(tfc, "\n");
+        if (mmc->create_html) {
+            char *token_pos = av_stristr(mmc->diagram_config->html_template, "__###__");
+            if (!token_pos) {
+                av_log(tfc, AV_LOG_ERROR, "Unable to locate the required token (__###__) in the html template.");
+                return;
+            }
+            token_pos += strlen("__###__");
+            writer_put_str(tfc, token_pos);
+        }
+    }
+
+    if (tfc->level == 1) {
+
+        if (mmc->link_buf.len > 0) {
+            writer_put_str(tfc, mmc->link_buf.str);
+            av_bprint_clear(&mmc->link_buf);
+        }
+
+        writer_put_str(tfc, "\n");
+    }
+}
+
+static void mermaid_print_value(AVTextFormatContext *tfc, const char *key,
+                                const char *str, int64_t num, const int is_int)
+{
+    MermaidContext *mmc = tfc->priv;
+    const AVTextFormatSection *section = tf_get_section(tfc, tfc->level);
+
+    if (!section)
+        return;
+
+    AVBPrint *buf = &tfc->section_pbuf[tfc->level];
+    struct section_data sec_data = mmc->section_data[tfc->level];
+    int exit = 0;
+
+    if (section->id_key && !strcmp(section->id_key, key)) {
+        mmc->section_data[tfc->level].section_id = av_strdup(str);
+        exit = 1;
+    }
+
+    if (section->dest_id_key && !strcmp(section->dest_id_key, key)) {
+        mmc->section_data[tfc->level].dest_id = av_strdup(str);
+        exit = 1;
+    }
+
+    if (section->src_id_key && !strcmp(section->src_id_key, key)) {
+        mmc->section_data[tfc->level].src_id = av_strdup(str);
+        exit = 1;
+    }
+
+    if (section->linktype_key && !strcmp(section->linktype_key, key)) {
+        mmc->section_data[tfc->level].link_type = (AVTextFormatLinkType)num;;
+        exit = 1;
+    }
+
+    //if (exit)
+    //    return;
+
+    if ((section->flags & (AV_TEXTFORMAT_SECTION_FLAG_IS_SHAPE | AV_TEXTFORMAT_SECTION_PRINT_TAGS))
+        || (section->flags & AV_TEXTFORMAT_SECTION_FLAG_IS_SUBGRAPH && sec_data.subgraph_start_incomplete)) {
+
+        if (exit)
+            return;
+
+        switch (mmc->diagram_config->diagram_type) {
+        case AV_DIAGRAMTYPE_GRAPH:
+
+            if (is_int) {
+                writer_printf(tfc, "<span class=\"%s\">%s: %"PRId64"</span>", key, key, num);
+            } else {
+                ////AVBPrint b;
+                ////av_bprint_init(&b, 0, AV_BPRINT_SIZE_UNLIMITED);
+                const char *tmp = av_strireplace(str, "\"", "'");
+                ////av_bprint_escape(&b, str, NULL, AV_ESCAPE_MODE_AUTO, AV_ESCAPE_FLAG_STRICT);
+                writer_printf(tfc, "<span class=\"%s\">%s</span>", key, tmp);
+                av_freep(&tmp);
+            }
+
+            break;
+        case AV_DIAGRAMTYPE_ENTITYRELATIONSHIP:
+
+            if (!is_int && str)
+            {
+                const char *col_type;
+
+                if (key[0] == '_')
+                    return;
+
+                if (sec_data.section_id && !strcmp(str, sec_data.section_id))
+                    col_type = "PK";
+                else if (sec_data.dest_id && !strcmp(str, sec_data.dest_id))
+                    col_type = "FK";
+                else if (sec_data.src_id && !strcmp(str, sec_data.src_id))
+                    col_type = "FK";
+                else
+                    col_type = "";
+
+                MM_INDENT();
+
+                if (is_int)
+                    writer_printf(tfc, "    %s %"PRId64" %s\n", key, num, col_type);
+                else
+                    writer_printf(tfc, "    %s %s %s\n", key, str, col_type);
+            }
+            break;
+        }
+
+    } else if (section->flags & AV_TEXTFORMAT_SECTION_FLAG_HAS_LINKS) {
+
+        if (exit)
+            return;
+
+        if (buf->len > 0)
+            av_bprintf(buf, "%s", "<br>");
+
+        av_bprintf(buf, "");
+        if (is_int)
+            av_bprintf(buf, "<span>%s: %"PRId64"</span>", key, num);
+        else
+            av_bprintf(buf, "<span>%s</span>", str);
+
+        mmc->nb_link_captions[tfc->level]++;
+    }
+}
+
+static inline void mermaid_print_str(AVTextFormatContext *tfc, const char *key, const char *value)
+{
+    mermaid_print_value(tfc, key, value, 0, 0);
+}
+
+static void mermaid_print_int(AVTextFormatContext *tfc, const char *key, int64_t value)
+{
+    mermaid_print_value(tfc, key, NULL, value, 1);
+}
+
+const AVTextFormatter avtextformatter_mermaid = {
+    .name                 = "mermaid",
+    .priv_size            = sizeof(MermaidContext),
+    .init                 = mermaid_init,
+    .print_section_header = mermaid_print_section_header,
+    .print_section_footer = mermaid_print_section_footer,
+    .print_integer        = mermaid_print_int,
+    .print_string         = mermaid_print_str,
+    .flags = AV_TEXTFORMAT_FLAG_IS_DIAGRAM_FORMATTER,
+    .priv_class           = &mermaid_class,
+};
+
+
+const AVTextFormatter avtextformatter_mermaidhtml = {
+    .name                 = "mermaidhtml",
+    .priv_size            = sizeof(MermaidContext),
+    .init                 = mermaid_init_html,
+    .print_section_header = mermaid_print_section_header,
+    .print_section_footer = mermaid_print_section_footer,
+    .print_integer        = mermaid_print_int,
+    .print_string         = mermaid_print_str,
+    .flags = AV_TEXTFORMAT_FLAG_IS_DIAGRAM_FORMATTER,
+    .priv_class           = &mermaid_class,
+};

fftools/textformat/tf_mermaid.h

@@ -0,0 +1,41 @@
+/*
+ * Copyright (c) The FFmpeg developers
+ *
+ * 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
+ */
+
+#ifndef FFTOOLS_TEXTFORMAT_TF_MERMAID_H
+#define FFTOOLS_TEXTFORMAT_TF_MERMAID_H
+
+typedef enum {
+    AV_DIAGRAMTYPE_GRAPH,
+    AV_DIAGRAMTYPE_ENTITYRELATIONSHIP,
+} AVDiagramType;
+
+typedef struct AVDiagramConfig {
+    AVDiagramType diagram_type;
+    const char *diagram_css;
+    const char *html_template;
+} AVDiagramConfig;
+
+
+void av_diagram_init(AVTextFormatContext *tfc, AVDiagramConfig *diagram_config);
+
+void av_mermaid_set_html_template(AVTextFormatContext *tfc, const char *html_template);
+
+
+#endif /* FFTOOLS_TEXTFORMAT_TF_MERMAID_H */