diff --git a/fftools/Makefile b/fftools/Makefile
index 5234932ab0..384b340018 100644
--- a/fftools/Makefile
+++ b/fftools/Makefile
@@ -9,7 +9,7 @@ AVBASENAMES  = ffmpeg ffplay ffprobe
 ALLAVPROGS   = $(AVBASENAMES:%=%$(PROGSSUF)$(EXESUF))
 ALLAVPROGS_G = $(AVBASENAMES:%=%$(PROGSSUF)_g$(EXESUF))
 
-OBJS-ffmpeg                        += fftools/ffmpeg_opt.o fftools/ffmpeg_filter.o fftools/ffmpeg_hw.o
+OBJS-ffmpeg                        += fftools/ffmpeg_opt.o fftools/ffmpeg_filter.o fftools/ffmpeg_hw.o fftools/filterwriters.o
 ifndef CONFIG_VIDEOTOOLBOX
 OBJS-ffmpeg-$(CONFIG_VDA)          += fftools/ffmpeg_videotoolbox.o
 endif
diff --git a/fftools/ffmpeg.c b/fftools/ffmpeg.c
index b0ce7c7c32..7ffdc5250c 100644
--- a/fftools/ffmpeg.c
+++ b/fftools/ffmpeg.c
@@ -103,6 +103,7 @@
 
 #include "ffmpeg.h"
 #include "cmdutils.h"
+#include "filterwriters.h"
 
 #include "libavutil/avassert.h"
 
@@ -139,6 +140,7 @@ static int64_t decode_error_stat[2];
 static unsigned nb_output_dumped = 0;
 
 static int want_sdp = 1;
+static int filtergraphs_printed = 0;
 
 static BenchmarkTimeStamps current_time;
 AVIOContext *progress_avio = NULL;
@@ -512,10 +514,23 @@ static int decode_interrupt_cb(void *ctx)
 
 const AVIOInterruptCB int_cb = { decode_interrupt_cb, NULL };
 
+static void check_print_graphs(void)
+{
+    if (filtergraphs_printed)
+        return;
+
+    if (print_graphs || print_graphs_file)
+        print_filtergraphs(filtergraphs, nb_filtergraphs);
+
+    filtergraphs_printed = 1;
+}
+
 static void ffmpeg_cleanup(int ret)
 {
     int i, j;
 
+    check_print_graphs();
+
     if (do_benchmark) {
         int maxrss = getmaxrss() / 1024;
         av_log(NULL, AV_LOG_INFO, "bench: maxrss=%ikB\n", maxrss);
diff --git a/fftools/ffmpeg.h b/fftools/ffmpeg.h
index d2dd7ca092..1697f42028 100644
--- a/fftools/ffmpeg.h
+++ b/fftools/ffmpeg.h
@@ -636,6 +636,9 @@ extern char *videotoolbox_pixfmt;
 extern int 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;
diff --git a/fftools/ffmpeg_opt.c b/fftools/ffmpeg_opt.c
index 428934a3d8..6ffded5f9d 100644
--- a/fftools/ffmpeg_opt.c
+++ b/fftools/ffmpeg_opt.c
@@ -172,6 +172,9 @@ float max_error_rate  = 2.0/3;
 int filter_nbthreads = 0;
 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;
 
@@ -3634,6 +3637,12 @@ const OptionDef options[] = {
         "create a complex filtergraph", "graph_description" },
     { "filter_complex_script", HAS_ARG | OPT_EXPERT,                 { .func_arg = opt_filter_complex_script },
         "read complex filtergraph description from a file", "filename" },
+    { "print_graphs",   OPT_BOOL,                                    { &print_graphs },
+        "prints filtergraph details to stderr" },
+    { "print_graphs_file", HAS_ARG | OPT_STRING,                     { &print_graphs_file },
+        "writes graph details to a file", "filename" },
+    { "print_graphs_format", OPT_STRING | HAS_ARG,                   { &print_graphs_format },
+      "set the output printing format (available formats are: default, compact, csv, flat, ini, json, xml)", "format" },
     { "auto_conversion_filters", OPT_BOOL | OPT_EXPERT,              { &auto_conversion_filters },
         "enable automatic conversion filters globally" },
     { "stats",          OPT_BOOL,                                    { &print_stats },
diff --git a/fftools/filterwriters.c b/fftools/filterwriters.c
new file mode 100644
index 0000000000..11dfb54fa5
--- /dev/null
+++ b/fftools/filterwriters.c
@@ -0,0 +1,1559 @@
+/*
+ * Copyright (c) 2018 - 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
+ * output writers for filtergraph details
+ */
+
+#include "config.h"
+
+#include <string.h>
+
+#include "libavutil/avassert.h"
+#include "libavutil/avstring.h"
+#include "libavutil/mastering_display_metadata.h"
+#include "libavutil/opt.h"
+#include "libavutil/pixdesc.h"
+#include "libavutil/stereo3d.h"
+#include "libavutil/dict.h"
+#include "libavutil/intreadwrite.h"
+#include "libavutil/libm.h"
+#include "libavutil/common.h"
+#include "filterwriters.h"
+#include "libavfilter/avfilter.h"
+#include "libavfilter/internal.h"
+#include "libavutil/buffer.h"
+#include "libavutil/hwcontext.h"
+
+
+static const char *writer_get_name(void *p)
+{
+    WriterContext *wctx = p;
+    return wctx->writer->name;
+}
+
+#define OFFSET(x) offsetof(WriterContext, x)
+
+static const AVOption writer_options[] = {
+    { "string_validation", "set string validation mode",
+      OFFSET(string_validation), AV_OPT_TYPE_INT, {.i64=WRITER_STRING_VALIDATION_REPLACE}, 0, WRITER_STRING_VALIDATION_NB-1, .unit = "sv" },
+    { "sv", "set string validation mode",
+      OFFSET(string_validation), AV_OPT_TYPE_INT, {.i64=WRITER_STRING_VALIDATION_REPLACE}, 0, WRITER_STRING_VALIDATION_NB-1, .unit = "sv" },
+    { "ignore",  NULL, 0, AV_OPT_TYPE_CONST, {.i64 = WRITER_STRING_VALIDATION_IGNORE},  .unit = "sv" },
+    { "replace", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = WRITER_STRING_VALIDATION_REPLACE}, .unit = "sv" },
+    { "fail",    NULL, 0, AV_OPT_TYPE_CONST, {.i64 = WRITER_STRING_VALIDATION_FAIL},    .unit = "sv" },
+    { "string_validation_replacement", "set string validation replacement string", OFFSET(string_validation_replacement), AV_OPT_TYPE_STRING, {.str=""}},
+    { "svr", "set string validation replacement string", OFFSET(string_validation_replacement), AV_OPT_TYPE_STRING, {.str="\xEF\xBF\xBD"}},
+    { NULL }
+};
+
+static void *writer_child_next(void *obj, void *prev)
+{
+    WriterContext *ctx = obj;
+    if (!prev && ctx->writer && ctx->writer->priv_class && ctx->priv)
+        return ctx->priv;
+    return NULL;
+}
+
+static const AVClass writer_class = {
+    .class_name = "Writer",
+    .item_name  = writer_get_name,
+    .option     = writer_options,
+    .version    = LIBAVUTIL_VERSION_INT,
+    .child_next = writer_child_next,
+};
+
+void writer_close(WriterContext **wctx)
+{
+    int i;
+
+    if (!*wctx)
+        return;
+
+    if ((*wctx)->writer->uninit)
+        (*wctx)->writer->uninit(*wctx);
+    for (i = 0; i < SECTION_MAX_NB_LEVELS; i++)
+        av_bprint_finalize(&(*wctx)->section_pbuf[i], NULL);
+    av_bprint_finalize(&(*wctx)->bpBuf, NULL);
+    if ((*wctx)->writer->priv_class)
+        av_opt_free((*wctx)->priv);
+    av_freep(&((*wctx)->priv));
+    av_opt_free(*wctx);
+    av_freep(wctx);
+}
+
+static void bprint_bytes(AVBPrint *bp, const uint8_t *ubuf, size_t ubuf_size)
+{
+    int i;
+    av_bprintf(bp, "0X");
+    for (i = 0; i < ubuf_size; i++)
+        av_bprintf(bp, "%02X", ubuf[i]);
+}
+
+int writer_open(WriterContext **wctx, const Writer *writer, const char *args,
+                       const struct section *sections, int nb_sections)
+{
+    int i, ret = 0;
+
+    if (!(*wctx = av_mallocz(sizeof(WriterContext)))) {
+        ret = AVERROR(ENOMEM);
+        goto fail;
+    }
+
+    if (!((*wctx)->priv = av_mallocz(writer->priv_size))) {
+        ret = AVERROR(ENOMEM);
+        goto fail;
+    }
+
+    (*wctx)->class = &writer_class;
+    (*wctx)->writer = writer;
+    (*wctx)->level = -1;
+    (*wctx)->sections = sections;
+    (*wctx)->nb_sections = nb_sections;
+
+    av_opt_set_defaults(*wctx);
+
+    if (writer->priv_class) {
+        void *priv_ctx = (*wctx)->priv;
+        *((const AVClass **)priv_ctx) = writer->priv_class;
+        av_opt_set_defaults(priv_ctx);
+    }
+
+    /* convert options to dictionary */
+    if (args) {
+        AVDictionary *opts = NULL;
+        AVDictionaryEntry *opt = NULL;
+
+        if ((ret = av_dict_parse_string(&opts, args, "=", ":", 0)) < 0) {
+            av_log(*wctx, AV_LOG_ERROR, "Failed to parse option string '%s' provided to writer context\n", args);
+            av_dict_free(&opts);
+            goto fail;
+        }
+
+        while ((opt = av_dict_get(opts, "", opt, AV_DICT_IGNORE_SUFFIX))) {
+            if ((ret = av_opt_set(*wctx, opt->key, opt->value, AV_OPT_SEARCH_CHILDREN)) < 0) {
+                av_log(*wctx, AV_LOG_ERROR, "Failed to set option '%s' with value '%s' provided to writer context\n",
+                       opt->key, opt->value);
+                av_dict_free(&opts);
+                goto fail;
+            }
+        }
+
+        av_dict_free(&opts);
+    }
+
+    /* validate replace string */
+    {
+        const uint8_t *p = (*wctx)->string_validation_replacement;
+        const uint8_t *endp = p + strlen(p);
+        while (*p) {
+            const uint8_t *p0 = p;
+            int32_t code;
+            ret = av_utf8_decode(&code, &p, endp, (*wctx)->string_validation_utf8_flags);
+            if (ret < 0) {
+                AVBPrint bp;
+                av_bprint_init(&bp, 0, AV_BPRINT_SIZE_AUTOMATIC);
+                bprint_bytes(&bp, p0, p-p0),
+                    av_log(wctx, AV_LOG_ERROR,
+                           "Invalid UTF8 sequence %s found in string validation replace '%s'\n",
+                           bp.str, (*wctx)->string_validation_replacement);
+                return ret;
+            }
+        }
+    }
+
+    for (i = 0; i < SECTION_MAX_NB_LEVELS; i++)
+        av_bprint_init(&(*wctx)->section_pbuf[i], 1, AV_BPRINT_SIZE_UNLIMITED);
+
+    av_bprint_init(&(*wctx)->bpBuf, 500000, AV_BPRINT_SIZE_UNLIMITED);
+
+    if ((*wctx)->writer->init)
+        ret = (*wctx)->writer->init(*wctx);
+    if (ret < 0)
+        goto fail;
+
+    return 0;
+
+fail:
+    writer_close(wctx);
+    return ret;
+}
+
+void writer_print_section_header(WriterContext *wctx, int section_id)
+{
+    //int parent_section_id;
+    wctx->level++;
+    av_assert0(wctx->level < SECTION_MAX_NB_LEVELS);
+    //parent_section_id = wctx->level ?
+    //    (wctx->section[wctx->level-1])->id : SECTION_ID_NONE;
+
+    wctx->nb_item[wctx->level] = 0;
+    wctx->section[wctx->level] = &wctx->sections[section_id];
+
+    if (wctx->writer->print_section_header)
+        wctx->writer->print_section_header(wctx);
+}
+
+void writer_print_section_footer(WriterContext *wctx)
+{
+    //int section_id = wctx->section[wctx->level]->id;
+    int parent_section_id = wctx->level ?
+        wctx->section[wctx->level-1]->id : SECTION_ID_NONE;
+
+    if (parent_section_id != SECTION_ID_NONE)
+        wctx->nb_item[wctx->level-1]++;
+
+    if (wctx->writer->print_section_footer)
+        wctx->writer->print_section_footer(wctx);
+    wctx->level--;
+}
+
+static inline int validate_string(WriterContext *wctx, char **dstp, const char *src)
+{
+    const uint8_t *p, *endp;
+    AVBPrint dstbuf;
+    int invalid_chars_nb = 0, ret = 0;
+
+    av_bprint_init(&dstbuf, 0, AV_BPRINT_SIZE_UNLIMITED);
+
+    endp = src + strlen(src);
+    for (p = (uint8_t *)src; *p;) {
+        uint32_t code;
+        int invalid = 0;
+        const uint8_t *p0 = p;
+
+        if (av_utf8_decode(&code, &p, endp, wctx->string_validation_utf8_flags) < 0) {
+            AVBPrint bp;
+            av_bprint_init(&bp, 0, AV_BPRINT_SIZE_AUTOMATIC);
+            bprint_bytes(&bp, p0, p-p0);
+            av_log(wctx, AV_LOG_DEBUG,
+                   "Invalid UTF-8 sequence %s found in string '%s'\n", bp.str, src);
+            invalid = 1;
+        }
+
+        if (invalid) {
+            invalid_chars_nb++;
+
+            switch (wctx->string_validation) {
+            case WRITER_STRING_VALIDATION_FAIL:
+                av_log(wctx, AV_LOG_ERROR,
+                       "Invalid UTF-8 sequence found in string '%s'\n", src);
+                ret = AVERROR_INVALIDDATA;
+                goto end;
+
+            case WRITER_STRING_VALIDATION_REPLACE:
+                av_bprintf(&dstbuf, "%s", wctx->string_validation_replacement);
+                break;
+            }
+        }
+
+        if (!invalid || wctx->string_validation == WRITER_STRING_VALIDATION_IGNORE)
+            av_bprint_append_data(&dstbuf, p0, p-p0);
+    }
+
+    if (invalid_chars_nb && wctx->string_validation == WRITER_STRING_VALIDATION_REPLACE) {
+        av_log(wctx, AV_LOG_WARNING,
+               "%d invalid UTF-8 sequence(s) found in string '%s', replaced with '%s'\n",
+               invalid_chars_nb, src, wctx->string_validation_replacement);
+    }
+
+end:
+    av_bprint_finalize(&dstbuf, dstp);
+    return ret;
+}
+
+int writer_print_string(WriterContext *wctx, const char *key, const char *val, int flags)
+{
+    const struct section *section = wctx->section[wctx->level];
+    int ret = 0;
+
+    if ((flags & PRINT_STRING_OPT)
+        && !(wctx->writer->flags & WRITER_FLAG_DISPLAY_OPTIONAL_FIELDS))
+        return 0;
+
+    if (val == NULL)
+        return 0;
+
+    if (flags & PRINT_STRING_VALIDATE) {
+        char *key1 = NULL, *val1 = NULL;
+        ret = validate_string(wctx, &key1, key);
+        if (ret < 0) goto end;
+        ret = validate_string(wctx, &val1, val);
+        if (ret < 0) goto end;
+        wctx->writer->print_string(wctx, key1, val1);
+    end:
+        if (ret < 0) {
+            av_log(wctx, AV_LOG_ERROR,
+                    "Invalid key=value string combination %s=%s in section %s\n",
+                    key, val, section->unique_name);
+        }
+        av_free(key1);
+        av_free(val1);
+    } else {
+        wctx->writer->print_string(wctx, key, val);
+    }
+
+    wctx->nb_item[wctx->level]++;
+
+    return ret;
+}
+
+void writer_print_integer(WriterContext *wctx, const char *key, long long int val)
+{
+    //const struct section *section = wctx->section[wctx->level];
+
+    wctx->writer->print_integer(wctx, key, val);
+    wctx->nb_item[wctx->level]++;
+}
+
+void writer_print_rational(WriterContext *wctx, const char *key, AVRational q, char sep)
+{
+    AVBPrint buf;
+    av_bprint_init(&buf, 0, AV_BPRINT_SIZE_AUTOMATIC);
+    av_bprintf(&buf, "%d%c%d", q.num, sep, q.den);
+    writer_print_string(wctx, key, buf.str, 0);
+}
+
+static const Writer *registered_writers[MAX_REGISTERED_WRITERS_NB + 1];
+
+static int writer_register(const Writer *writer)
+{
+    static int next_registered_writer_idx = 0;
+
+    if (next_registered_writer_idx == MAX_REGISTERED_WRITERS_NB)
+        return AVERROR(ENOMEM);
+
+    registered_writers[next_registered_writer_idx++] = writer;
+    return 0;
+}
+
+const Writer *writer_get_by_name(const char *name)
+{
+    int i;
+
+    for (i = 0; registered_writers[i]; i++)
+        if (!strcmp(registered_writers[i]->name, name))
+            return registered_writers[i];
+
+    return NULL;
+}
+
+/* WRITERS */
+
+#define DEFINE_WRITER_CLASS(name)                   \
+static const char *name##_get_name(void *ctx)       \
+{                                                   \
+    return #name ;                                  \
+}                                                   \
+static const AVClass name##_class = {               \
+    .class_name = #name,                            \
+    .item_name  = name##_get_name,                  \
+    .option     = name##_options                    \
+}
+
+/* Default output */
+
+typedef struct DefaultContext {
+    const AVClass *class;
+    int nokey;
+    int noprint_wrappers;
+    int nested_section[SECTION_MAX_NB_LEVELS];
+} DefaultContext;
+
+#undef OFFSET
+#define OFFSET(x) offsetof(DefaultContext, x)
+
+static const AVOption default_options[] = {
+    { "noprint_wrappers", "do not print headers and footers", OFFSET(noprint_wrappers), AV_OPT_TYPE_BOOL, {.i64=0}, 0, 1 },
+    { "nw",               "do not print headers and footers", OFFSET(noprint_wrappers), AV_OPT_TYPE_BOOL, {.i64=0}, 0, 1 },
+    { "nokey",          "force no key printing",     OFFSET(nokey),          AV_OPT_TYPE_BOOL, {.i64=0}, 0, 1 },
+    { "nk",             "force no key printing",     OFFSET(nokey),          AV_OPT_TYPE_BOOL, {.i64=0}, 0, 1 },
+    {NULL},
+};
+
+DEFINE_WRITER_CLASS(default);
+
+/* lame uppercasing routine, assumes the string is lower case ASCII */
+static inline char *upcase_string(char *dst, size_t dst_size, const char *src)
+{
+    int i;
+    for (i = 0; src[i] && i < dst_size-1; i++)
+        dst[i] = av_toupper(src[i]);
+    dst[i] = 0;
+    return dst;
+}
+
+static void default_print_section_header(WriterContext *wctx)
+{
+    DefaultContext *def = wctx->priv;
+    char buf[32];
+    const struct section *section = wctx->section[wctx->level];
+    const struct section *parent_section = wctx->level ?
+        wctx->section[wctx->level-1] : NULL;
+
+    av_bprint_clear(&wctx->section_pbuf[wctx->level]);
+    if (parent_section &&
+        !(parent_section->flags & (SECTION_FLAG_IS_WRAPPER|SECTION_FLAG_IS_ARRAY))) {
+        def->nested_section[wctx->level] = 1;
+        av_bprintf(&wctx->section_pbuf[wctx->level], "%s%s:",
+                   wctx->section_pbuf[wctx->level-1].str,
+                   upcase_string(buf, sizeof(buf),
+                                 av_x_if_null(section->element_name, section->name)));
+    }
+
+    if (def->noprint_wrappers || def->nested_section[wctx->level])
+        return;
+
+    if (!(section->flags & (SECTION_FLAG_IS_WRAPPER|SECTION_FLAG_IS_ARRAY)))
+        av_bprintf(&wctx->bpBuf, "[%s]\n", upcase_string(buf, sizeof(buf), section->name));
+}
+
+static void default_print_section_footer(WriterContext *wctx)
+{
+    DefaultContext *def = wctx->priv;
+    const struct section *section = wctx->section[wctx->level];
+    char buf[32];
+
+    if (def->noprint_wrappers || def->nested_section[wctx->level])
+        return;
+
+    if (!(section->flags & (SECTION_FLAG_IS_WRAPPER|SECTION_FLAG_IS_ARRAY)))
+        av_bprintf(&wctx->bpBuf, "[/%s]\n", upcase_string(buf, sizeof(buf), section->name));
+}
+
+static void default_print_str(WriterContext *wctx, const char *key, const char *value)
+{
+    DefaultContext *def = wctx->priv;
+
+    if (!def->nokey)
+        av_bprintf(&wctx->bpBuf, "%s%s=", wctx->section_pbuf[wctx->level].str, key);
+    av_bprintf(&wctx->bpBuf, "%s\n", value);
+}
+
+static void default_print_int(WriterContext *wctx, const char *key, long long int value)
+{
+    DefaultContext *def = wctx->priv;
+
+    if (!def->nokey)
+        av_bprintf(&wctx->bpBuf, "%s%s=", wctx->section_pbuf[wctx->level].str, key);
+    av_bprintf(&wctx->bpBuf, "%lld\n", value);
+}
+
+static const Writer default_writer = {
+    .name                  = "default",
+    .priv_size             = sizeof(DefaultContext),
+    .print_section_header  = default_print_section_header,
+    .print_section_footer  = default_print_section_footer,
+    .print_integer         = default_print_int,
+    .print_string          = default_print_str,
+    .flags = WRITER_FLAG_DISPLAY_OPTIONAL_FIELDS,
+    .priv_class            = &default_class,
+};
+
+/* Compact output */
+
+/**
+ * Apply C-language-like string escaping.
+ */
+static const char *c_escape_str(AVBPrint *dst, const char *src, const char sep, void *log_ctx)
+{
+    const char *p;
+
+    for (p = src; *p; p++) {
+        switch (*p) {
+        case '\b': av_bprintf(dst, "%s", "\\b");  break;
+        case '\f': av_bprintf(dst, "%s", "\\f");  break;
+        case '\n': av_bprintf(dst, "%s", "\\n");  break;
+        case '\r': av_bprintf(dst, "%s", "\\r");  break;
+        case '\\': av_bprintf(dst, "%s", "\\\\"); break;
+        default:
+            if (*p == sep)
+                av_bprint_chars(dst, '\\', 1);
+            av_bprint_chars(dst, *p, 1);
+        }
+    }
+    return dst->str;
+}
+
+/**
+ * Quote fields containing special characters, check RFC4180.
+ */
+static const char *csv_escape_str(AVBPrint *dst, const char *src, const char sep, void *log_ctx)
+{
+    char meta_chars[] = { sep, '"', '\n', '\r', '\0' };
+    int needs_quoting = !!src[strcspn(src, meta_chars)];
+
+    if (needs_quoting)
+        av_bprint_chars(dst, '"', 1);
+
+    for (; *src; src++) {
+        if (*src == '"')
+            av_bprint_chars(dst, '"', 1);
+        av_bprint_chars(dst, *src, 1);
+    }
+    if (needs_quoting)
+        av_bprint_chars(dst, '"', 1);
+    return dst->str;
+}
+
+static const char *none_escape_str(AVBPrint *dst, const char *src, const char sep, void *log_ctx)
+{
+    return src;
+}
+
+typedef struct CompactContext {
+    const AVClass *class;
+    char *item_sep_str;
+    char item_sep;
+    int nokey;
+    int print_section;
+    char *escape_mode_str;
+    const char * (*escape_str)(AVBPrint *dst, const char *src, const char sep, void *log_ctx);
+    int nested_section[SECTION_MAX_NB_LEVELS];
+    int has_nested_elems[SECTION_MAX_NB_LEVELS];
+    int terminate_line[SECTION_MAX_NB_LEVELS];
+} CompactContext;
+
+#undef OFFSET
+#define OFFSET(x) offsetof(CompactContext, x)
+
+static const AVOption compact_options[]= {
+    {"item_sep", "set item separator",    OFFSET(item_sep_str),    AV_OPT_TYPE_STRING, {.str="|"},  0, 0 },
+    {"s",        "set item separator",    OFFSET(item_sep_str),    AV_OPT_TYPE_STRING, {.str="|"},  0, 0 },
+    {"nokey",    "force no key printing", OFFSET(nokey),           AV_OPT_TYPE_BOOL,   {.i64=0},    0,        1        },
+    {"nk",       "force no key printing", OFFSET(nokey),           AV_OPT_TYPE_BOOL,   {.i64=0},    0,        1        },
+    {"escape",   "set escape mode",       OFFSET(escape_mode_str), AV_OPT_TYPE_STRING, {.str="c"},  0, 0 },
+    {"e",        "set escape mode",       OFFSET(escape_mode_str), AV_OPT_TYPE_STRING, {.str="c"},  0, 0 },
+    {"print_section", "print section name", OFFSET(print_section), AV_OPT_TYPE_BOOL,   {.i64=1},    0,        1        },
+    {"p",             "print section name", OFFSET(print_section), AV_OPT_TYPE_BOOL,   {.i64=1},    0,        1        },
+    {NULL},
+};
+
+DEFINE_WRITER_CLASS(compact);
+
+static av_cold int compact_init(WriterContext *wctx)
+{
+    CompactContext *compact = wctx->priv;
+
+    if (strlen(compact->item_sep_str) != 1) {
+        av_log(wctx, AV_LOG_ERROR, "Item separator '%s' specified, but must contain a single character\n",
+               compact->item_sep_str);
+        return AVERROR(EINVAL);
+    }
+    compact->item_sep = compact->item_sep_str[0];
+
+    if      (!strcmp(compact->escape_mode_str, "none")) compact->escape_str = none_escape_str;
+    else if (!strcmp(compact->escape_mode_str, "c"   )) compact->escape_str = c_escape_str;
+    else if (!strcmp(compact->escape_mode_str, "csv" )) compact->escape_str = csv_escape_str;
+    else {
+        av_log(wctx, AV_LOG_ERROR, "Unknown escape mode '%s'\n", compact->escape_mode_str);
+        return AVERROR(EINVAL);
+    }
+
+    return 0;
+}
+
+static void compact_print_section_header(WriterContext *wctx)
+{
+    CompactContext *compact = wctx->priv;
+    const struct section *section = wctx->section[wctx->level];
+    const struct section *parent_section = wctx->level ?
+        wctx->section[wctx->level-1] : NULL;
+    compact->terminate_line[wctx->level] = 1;
+    compact->has_nested_elems[wctx->level] = 0;
+
+    av_bprint_clear(&wctx->section_pbuf[wctx->level]);
+    if (!(section->flags & SECTION_FLAG_IS_ARRAY) && parent_section &&
+        !(parent_section->flags & (SECTION_FLAG_IS_WRAPPER|SECTION_FLAG_IS_ARRAY))) {
+        compact->nested_section[wctx->level] = 1;
+        compact->has_nested_elems[wctx->level-1] = 1;
+        av_bprintf(&wctx->section_pbuf[wctx->level], "%s%s:",
+                   wctx->section_pbuf[wctx->level-1].str,
+                   (char *)av_x_if_null(section->element_name, section->name));
+        wctx->nb_item[wctx->level] = wctx->nb_item[wctx->level-1];
+    } else {
+        if (parent_section && compact->has_nested_elems[wctx->level-1] &&
+            (section->flags & SECTION_FLAG_IS_ARRAY)) {
+            compact->terminate_line[wctx->level-1] = 0;
+            printf("\n");
+        }
+        if (compact->print_section &&
+            !(section->flags & (SECTION_FLAG_IS_WRAPPER|SECTION_FLAG_IS_ARRAY)))
+            printf("%s%c", section->name, compact->item_sep);
+    }
+}
+
+static void compact_print_section_footer(WriterContext *wctx)
+{
+    CompactContext *compact = wctx->priv;
+
+    if (!compact->nested_section[wctx->level] &&
+        compact->terminate_line[wctx->level] &&
+        !(wctx->section[wctx->level]->flags & (SECTION_FLAG_IS_WRAPPER|SECTION_FLAG_IS_ARRAY)))
+        printf("\n");
+}
+
+static void compact_print_str(WriterContext *wctx, const char *key, const char *value)
+{
+    CompactContext *compact = wctx->priv;
+    AVBPrint buf;
+
+    if (wctx->nb_item[wctx->level]) printf("%c", compact->item_sep);
+    if (!compact->nokey)
+        printf("%s%s=", wctx->section_pbuf[wctx->level].str, key);
+    av_bprint_init(&buf, 1, AV_BPRINT_SIZE_UNLIMITED);
+    printf("%s", compact->escape_str(&buf, value, compact->item_sep, wctx));
+    av_bprint_finalize(&buf, NULL);
+}
+
+static void compact_print_int(WriterContext *wctx, const char *key, long long int value)
+{
+    CompactContext *compact = wctx->priv;
+
+    if (wctx->nb_item[wctx->level]) printf("%c", compact->item_sep);
+    if (!compact->nokey)
+        printf("%s%s=", wctx->section_pbuf[wctx->level].str, key);
+    printf("%lld", value);
+}
+
+static const Writer compact_writer = {
+    .name                 = "compact",
+    .priv_size            = sizeof(CompactContext),
+    .init                 = compact_init,
+    .print_section_header = compact_print_section_header,
+    .print_section_footer = compact_print_section_footer,
+    .print_integer        = compact_print_int,
+    .print_string         = compact_print_str,
+    .flags = WRITER_FLAG_DISPLAY_OPTIONAL_FIELDS,
+    .priv_class           = &compact_class,
+};
+
+/* CSV output */
+
+#undef OFFSET
+#define OFFSET(x) offsetof(CompactContext, x)
+
+static const AVOption csv_options[] = {
+    {"item_sep", "set item separator",    OFFSET(item_sep_str),    AV_OPT_TYPE_STRING, {.str=","},  0, 0 },
+    {"s",        "set item separator",    OFFSET(item_sep_str),    AV_OPT_TYPE_STRING, {.str=","},  0, 0 },
+    {"nokey",    "force no key printing", OFFSET(nokey),           AV_OPT_TYPE_BOOL,   {.i64=1},    0,        1        },
+    {"nk",       "force no key printing", OFFSET(nokey),           AV_OPT_TYPE_BOOL,   {.i64=1},    0,        1        },
+    {"escape",   "set escape mode",       OFFSET(escape_mode_str), AV_OPT_TYPE_STRING, {.str="csv"}, 0, 0 },
+    {"e",        "set escape mode",       OFFSET(escape_mode_str), AV_OPT_TYPE_STRING, {.str="csv"}, 0, 0 },
+    {"print_section", "print section name", OFFSET(print_section), AV_OPT_TYPE_BOOL,   {.i64=1},    0,        1        },
+    {"p",             "print section name", OFFSET(print_section), AV_OPT_TYPE_BOOL,   {.i64=1},    0,        1        },
+    {NULL},
+};
+
+DEFINE_WRITER_CLASS(csv);
+
+static const Writer csv_writer = {
+    .name                 = "csv",
+    .priv_size            = sizeof(CompactContext),
+    .init                 = compact_init,
+    .print_section_header = compact_print_section_header,
+    .print_section_footer = compact_print_section_footer,
+    .print_integer        = compact_print_int,
+    .print_string         = compact_print_str,
+    .flags = WRITER_FLAG_DISPLAY_OPTIONAL_FIELDS,
+    .priv_class           = &csv_class,
+};
+
+/* Flat output */
+
+typedef struct FlatContext {
+    const AVClass *class;
+    const char *sep_str;
+    char sep;
+    int hierarchical;
+} FlatContext;
+
+#undef OFFSET
+#define OFFSET(x) offsetof(FlatContext, x)
+
+static const AVOption flat_options[]= {
+    {"sep_char", "set separator",    OFFSET(sep_str),    AV_OPT_TYPE_STRING, {.str="."},  0, 0 },
+    {"s",        "set separator",    OFFSET(sep_str),    AV_OPT_TYPE_STRING, {.str="."},  0, 0 },
+    {"hierarchical", "specify if the section specification should be hierarchical", OFFSET(hierarchical), AV_OPT_TYPE_BOOL, {.i64=1}, 0, 1 },
+    {"h",            "specify if the section specification should be hierarchical", OFFSET(hierarchical), AV_OPT_TYPE_BOOL, {.i64=1}, 0, 1 },
+    {NULL},
+};
+
+DEFINE_WRITER_CLASS(flat);
+
+static av_cold int flat_init(WriterContext *wctx)
+{
+    FlatContext *flat = wctx->priv;
+
+    if (strlen(flat->sep_str) != 1) {
+        av_log(wctx, AV_LOG_ERROR, "Item separator '%s' specified, but must contain a single character\n",
+               flat->sep_str);
+        return AVERROR(EINVAL);
+    }
+    flat->sep = flat->sep_str[0];
+
+    return 0;
+}
+
+static const char *flat_escape_key_str(AVBPrint *dst, const char *src, const char sep)
+{
+    const char *p;
+
+    for (p = src; *p; p++) {
+        if (!((*p >= '0' && *p <= '9') ||
+              (*p >= 'a' && *p <= 'z') ||
+              (*p >= 'A' && *p <= 'Z')))
+            av_bprint_chars(dst, '_', 1);
+        else
+            av_bprint_chars(dst, *p, 1);
+    }
+    return dst->str;
+}
+
+static const char *flat_escape_value_str(AVBPrint *dst, const char *src)
+{
+    const char *p;
+
+    for (p = src; *p; p++) {
+        switch (*p) {
+        case '\n': av_bprintf(dst, "%s", "\\n");  break;
+        case '\r': av_bprintf(dst, "%s", "\\r");  break;
+        case '\\': av_bprintf(dst, "%s", "\\\\"); break;
+        case '"':  av_bprintf(dst, "%s", "\\\""); break;
+        case '`':  av_bprintf(dst, "%s", "\\`");  break;
+        case '$':  av_bprintf(dst, "%s", "\\$");  break;
+        default:   av_bprint_chars(dst, *p, 1);   break;
+        }
+    }
+    return dst->str;
+}
+
+static void flat_print_section_header(WriterContext *wctx)
+{
+    FlatContext *flat = wctx->priv;
+    AVBPrint *buf = &wctx->section_pbuf[wctx->level];
+    const struct section *section = wctx->section[wctx->level];
+    const struct section *parent_section = wctx->level ?
+        wctx->section[wctx->level-1] : NULL;
+
+    /* build section header */
+    av_bprint_clear(buf);
+    if (!parent_section)
+        return;
+    av_bprintf(buf, "%s", wctx->section_pbuf[wctx->level-1].str);
+
+    if (flat->hierarchical ||
+        !(section->flags & (SECTION_FLAG_IS_ARRAY|SECTION_FLAG_IS_WRAPPER))) {
+        av_bprintf(buf, "%s%s", wctx->section[wctx->level]->name, flat->sep_str);
+    }
+}
+
+static void flat_print_int(WriterContext *wctx, const char *key, long long int value)
+{
+    printf("%s%s=%lld\n", wctx->section_pbuf[wctx->level].str, key, value);
+}
+
+static void flat_print_str(WriterContext *wctx, const char *key, const char *value)
+{
+    FlatContext *flat = wctx->priv;
+    AVBPrint buf;
+
+    printf("%s", wctx->section_pbuf[wctx->level].str);
+    av_bprint_init(&buf, 1, AV_BPRINT_SIZE_UNLIMITED);
+    printf("%s=", flat_escape_key_str(&buf, key, flat->sep));
+    av_bprint_clear(&buf);
+    printf("\"%s\"\n", flat_escape_value_str(&buf, value));
+    av_bprint_finalize(&buf, NULL);
+}
+
+static const Writer flat_writer = {
+    .name                  = "flat",
+    .priv_size             = sizeof(FlatContext),
+    .init                  = flat_init,
+    .print_section_header  = flat_print_section_header,
+    .print_integer         = flat_print_int,
+    .print_string          = flat_print_str,
+    .flags = WRITER_FLAG_DISPLAY_OPTIONAL_FIELDS|WRITER_FLAG_PUT_PACKETS_AND_FRAMES_IN_SAME_CHAPTER,
+    .priv_class            = &flat_class,
+};
+
+/* INI format output */
+
+typedef struct INIContext {
+    const AVClass *class;
+    int hierarchical;
+} INIContext;
+
+#undef OFFSET
+#define OFFSET(x) offsetof(INIContext, x)
+
+static const AVOption ini_options[] = {
+    {"hierarchical", "specify if the section specification should be hierarchical", OFFSET(hierarchical), AV_OPT_TYPE_BOOL, {.i64=1}, 0, 1 },
+    {"h",            "specify if the section specification should be hierarchical", OFFSET(hierarchical), AV_OPT_TYPE_BOOL, {.i64=1}, 0, 1 },
+    {NULL},
+};
+
+DEFINE_WRITER_CLASS(ini);
+
+static char *ini_escape_str(AVBPrint *dst, const char *src)
+{
+    int i = 0;
+    char c = 0;
+
+    while (c = src[i++]) {
+        switch (c) {
+        case '\b': av_bprintf(dst, "%s", "\\b"); break;
+        case '\f': av_bprintf(dst, "%s", "\\f"); break;
+        case '\n': av_bprintf(dst, "%s", "\\n"); break;
+        case '\r': av_bprintf(dst, "%s", "\\r"); break;
+        case '\t': av_bprintf(dst, "%s", "\\t"); break;
+        case '\\':
+        case '#' :
+        case '=' :
+        case ':' : av_bprint_chars(dst, '\\', 1);
+        default:
+            if ((unsigned char)c < 32)
+                av_bprintf(dst, "\\x00%02x", c & 0xff);
+            else
+                av_bprint_chars(dst, c, 1);
+            break;
+        }
+    }
+    return dst->str;
+}
+
+static void ini_print_section_header(WriterContext *wctx)
+{
+    INIContext *ini = wctx->priv;
+    AVBPrint *buf = &wctx->section_pbuf[wctx->level];
+    const struct section *section = wctx->section[wctx->level];
+    const struct section *parent_section = wctx->level ?
+        wctx->section[wctx->level-1] : NULL;
+
+    av_bprint_clear(buf);
+    if (!parent_section) {
+        printf("# ffprobe output\n\n");
+        return;
+    }
+
+    if (wctx->nb_item[wctx->level-1])
+        printf("\n");
+
+    av_bprintf(buf, "%s", wctx->section_pbuf[wctx->level-1].str);
+    if (ini->hierarchical ||
+        !(section->flags & (SECTION_FLAG_IS_ARRAY|SECTION_FLAG_IS_WRAPPER))) {
+        av_bprintf(buf, "%s%s", buf->str[0] ? "." : "", wctx->section[wctx->level]->name);
+    }
+
+    if (!(section->flags & (SECTION_FLAG_IS_ARRAY|SECTION_FLAG_IS_WRAPPER)))
+        printf("[%s]\n", buf->str);
+}
+
+static void ini_print_str(WriterContext *wctx, const char *key, const char *value)
+{
+    AVBPrint buf;
+
+    av_bprint_init(&buf, 1, AV_BPRINT_SIZE_UNLIMITED);
+    printf("%s=", ini_escape_str(&buf, key));
+    av_bprint_clear(&buf);
+    printf("%s\n", ini_escape_str(&buf, value));
+    av_bprint_finalize(&buf, NULL);
+}
+
+static void ini_print_int(WriterContext *wctx, const char *key, long long int value)
+{
+    printf("%s=%lld\n", key, value);
+}
+
+static const Writer ini_writer = {
+    .name                  = "ini",
+    .priv_size             = sizeof(INIContext),
+    .print_section_header  = ini_print_section_header,
+    .print_integer         = ini_print_int,
+    .print_string          = ini_print_str,
+    .flags = WRITER_FLAG_DISPLAY_OPTIONAL_FIELDS|WRITER_FLAG_PUT_PACKETS_AND_FRAMES_IN_SAME_CHAPTER,
+    .priv_class            = &ini_class,
+};
+
+/* JSON output */
+
+typedef struct JSONContext {
+    const AVClass *class;
+    int indent_level;
+    int compact;
+    const char *item_sep, *item_start_end;
+} JSONContext;
+
+#undef OFFSET
+#define OFFSET(x) offsetof(JSONContext, x)
+
+static const AVOption json_options[]= {
+    { "compact", "enable compact output", OFFSET(compact), AV_OPT_TYPE_BOOL, {.i64=0}, 0, 1 },
+    { "c",       "enable compact output", OFFSET(compact), AV_OPT_TYPE_BOOL, {.i64=0}, 0, 1 },
+    { NULL }
+};
+
+DEFINE_WRITER_CLASS(json);
+
+static av_cold int json_init(WriterContext *wctx)
+{
+    JSONContext *json = wctx->priv;
+
+    json->item_sep       = json->compact ? ", " : ",\n";
+    json->item_start_end = json->compact ? " "  : "\n";
+
+    return 0;
+}
+
+static const char *json_escape_str(AVBPrint *dst, const char *src, void *log_ctx)
+{
+    static const char json_escape[] = {'"', '\\', '\b', '\f', '\n', '\r', '\t', 0};
+    static const char json_subst[]  = {'"', '\\',  'b',  'f',  'n',  'r',  't', 0};
+    const char *p;
+
+    for (p = src; *p; p++) {
+        char *s = strchr(json_escape, *p);
+        if (s) {
+            av_bprint_chars(dst, '\\', 1);
+            av_bprint_chars(dst, json_subst[s - json_escape], 1);
+        } else if ((unsigned char)*p < 32) {
+            av_bprintf(dst, "\\u00%02x", *p & 0xff);
+        } else {
+            av_bprint_chars(dst, *p, 1);
+        }
+    }
+    return dst->str;
+}
+
+#define JSON_INDENT() av_bprintf(&wctx->bpBuf, "%*c", json->indent_level * 4, ' ')
+
+static void json_print_section_header(WriterContext *wctx)
+{
+    JSONContext *json = wctx->priv;
+    AVBPrint buf;
+    const struct section *section = wctx->section[wctx->level];
+    const struct section *parent_section = wctx->level ?
+        wctx->section[wctx->level-1] : NULL;
+
+    if (wctx->level && wctx->nb_item[wctx->level-1])
+        av_bprintf(&wctx->bpBuf, ",\n");
+
+    if (section->flags & SECTION_FLAG_IS_WRAPPER) {
+        av_bprintf(&wctx->bpBuf, "{\n");
+        json->indent_level++;
+    } else {
+        av_bprint_init(&buf, 1, AV_BPRINT_SIZE_UNLIMITED);
+        json_escape_str(&buf, section->name, wctx);
+        JSON_INDENT();
+
+        json->indent_level++;
+        if (section->flags & SECTION_FLAG_IS_ARRAY) {
+            av_bprintf(&wctx->bpBuf, "\"%s\": [\n", buf.str);
+        } else if (parent_section && !(parent_section->flags & SECTION_FLAG_IS_ARRAY)) {
+            av_bprintf(&wctx->bpBuf, "\"%s\": {%s", buf.str, json->item_start_end);
+        } else {
+            av_bprintf(&wctx->bpBuf, "{%s", json->item_start_end);
+        }
+        av_bprint_finalize(&buf, NULL);
+    }
+}
+
+static void json_print_section_footer(WriterContext *wctx)
+{
+    JSONContext *json = wctx->priv;
+    const struct section *section = wctx->section[wctx->level];
+
+    if (wctx->level == 0) {
+        json->indent_level--;
+        av_bprintf(&wctx->bpBuf, "\n}\n");
+    } else if (section->flags & SECTION_FLAG_IS_ARRAY) {
+        av_bprintf(&wctx->bpBuf, "\n");
+        json->indent_level--;
+        JSON_INDENT();
+        av_bprintf(&wctx->bpBuf, "]");
+    } else {
+        av_bprintf(&wctx->bpBuf, "%s", json->item_start_end);
+        json->indent_level--;
+        if (!json->compact)
+            JSON_INDENT();
+        av_bprintf(&wctx->bpBuf, "}");
+    }
+}
+
+static inline void json_print_item_str(WriterContext *wctx,
+                                       const char *key, const char *value)
+{
+    AVBPrint buf;
+
+    av_bprint_init(&buf, 1, AV_BPRINT_SIZE_UNLIMITED);
+    av_bprintf(&wctx->bpBuf, "\"%s\":", json_escape_str(&buf, key,   wctx));
+    av_bprint_clear(&buf);
+    av_bprintf(&wctx->bpBuf, " \"%s\"", json_escape_str(&buf, value, wctx));
+    av_bprint_finalize(&buf, NULL);
+}
+
+static void json_print_str(WriterContext *wctx, const char *key, const char *value)
+{
+    JSONContext *json = wctx->priv;
+
+    if (wctx->nb_item[wctx->level])
+        av_bprintf(&wctx->bpBuf, "%s", json->item_sep);
+    if (!json->compact)
+        JSON_INDENT();
+    json_print_item_str(wctx, key, value);
+}
+
+static void json_print_int(WriterContext *wctx, const char *key, long long int value)
+{
+    JSONContext *json = wctx->priv;
+    AVBPrint buf;
+
+    if (wctx->nb_item[wctx->level])
+        av_bprintf(&wctx->bpBuf, "%s", json->item_sep);
+    if (!json->compact)
+        JSON_INDENT();
+
+    av_bprint_init(&buf, 1, AV_BPRINT_SIZE_UNLIMITED);
+    av_bprintf(&wctx->bpBuf, "\"%s\": %lld", json_escape_str(&buf, key, wctx), value);
+    av_bprint_finalize(&buf, NULL);
+}
+
+static const Writer json_writer = {
+    .name                 = "json",
+    .priv_size            = sizeof(JSONContext),
+    .init                 = json_init,
+    .print_section_header = json_print_section_header,
+    .print_section_footer = json_print_section_footer,
+    .print_integer        = json_print_int,
+    .print_string         = json_print_str,
+    .flags = WRITER_FLAG_PUT_PACKETS_AND_FRAMES_IN_SAME_CHAPTER,
+    .priv_class           = &json_class,
+};
+
+
+/* XML output */
+
+typedef struct XMLContext {
+    const AVClass *class;
+    int within_tag;
+    int indent_level;
+    int fully_qualified;
+    int xsd_strict;
+} XMLContext;
+
+#undef OFFSET
+#define OFFSET(x) offsetof(XMLContext, x)
+
+static const AVOption xml_options[] = {
+    {"fully_qualified", "specify if the output should be fully qualified", OFFSET(fully_qualified), AV_OPT_TYPE_BOOL, {.i64=0},  0, 1 },
+    {"q",               "specify if the output should be fully qualified", OFFSET(fully_qualified), AV_OPT_TYPE_BOOL, {.i64=0},  0, 1 },
+    {"xsd_strict",      "ensure that the output is XSD compliant",         OFFSET(xsd_strict),      AV_OPT_TYPE_BOOL, {.i64=0},  0, 1 },
+    {"x",               "ensure that the output is XSD compliant",         OFFSET(xsd_strict),      AV_OPT_TYPE_BOOL, {.i64=0},  0, 1 },
+    {NULL},
+};
+
+DEFINE_WRITER_CLASS(xml);
+
+static av_cold int xml_init(WriterContext *wctx)
+{
+    XMLContext *xml = wctx->priv;
+
+    if (xml->xsd_strict) {
+        xml->fully_qualified = 1;
+    }
+
+    return 0;
+}
+
+#define XML_INDENT() printf("%*c", xml->indent_level * 4, ' ')
+
+static void xml_print_section_header(WriterContext *wctx)
+{
+    XMLContext *xml = wctx->priv;
+    const struct section *section = wctx->section[wctx->level];
+    const struct section *parent_section = wctx->level ?
+        wctx->section[wctx->level-1] : NULL;
+
+    if (wctx->level == 0) {
+        const char *qual = " xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\" "
+            "xmlns:ffprobe=\"http://www.ffmpeg.org/schema/ffprobe\" "
+            "xsi:schemaLocation=\"http://www.ffmpeg.org/schema/ffprobe ffprobe.xsd\"";
+
+        printf("<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n");
+        printf("<%sffprobe%s>\n",
+               xml->fully_qualified ? "ffprobe:" : "",
+               xml->fully_qualified ? qual : "");
+        return;
+    }
+
+    if (xml->within_tag) {
+        xml->within_tag = 0;
+        printf(">\n");
+    }
+    if (section->flags & SECTION_FLAG_HAS_VARIABLE_FIELDS) {
+        xml->indent_level++;
+    } else {
+        if (parent_section && (parent_section->flags & SECTION_FLAG_IS_WRAPPER) &&
+            wctx->level && wctx->nb_item[wctx->level-1])
+            printf("\n");
+        xml->indent_level++;
+
+        if (section->flags & SECTION_FLAG_IS_ARRAY) {
+            XML_INDENT(); printf("<%s>\n", section->name);
+        } else {
+            XML_INDENT(); printf("<%s ", section->name);
+            xml->within_tag = 1;
+        }
+    }
+}
+
+static void xml_print_section_footer(WriterContext *wctx)
+{
+    XMLContext *xml = wctx->priv;
+    const struct section *section = wctx->section[wctx->level];
+
+    if (wctx->level == 0) {
+        printf("</%sffprobe>\n", xml->fully_qualified ? "ffprobe:" : "");
+    } else if (xml->within_tag) {
+        xml->within_tag = 0;
+        printf("/>\n");
+        xml->indent_level--;
+    } else if (section->flags & SECTION_FLAG_HAS_VARIABLE_FIELDS) {
+        xml->indent_level--;
+    } else {
+        XML_INDENT(); printf("</%s>\n", section->name);
+        xml->indent_level--;
+    }
+}
+
+static void xml_print_str(WriterContext *wctx, const char *key, const char *value)
+{
+    AVBPrint buf;
+    XMLContext *xml = wctx->priv;
+    const struct section *section = wctx->section[wctx->level];
+
+    av_bprint_init(&buf, 1, AV_BPRINT_SIZE_UNLIMITED);
+
+    if (section->flags & SECTION_FLAG_HAS_VARIABLE_FIELDS) {
+        XML_INDENT();
+        av_bprint_escape(&buf, key, NULL,
+                         AV_ESCAPE_MODE_XML, AV_ESCAPE_FLAG_XML_DOUBLE_QUOTES);
+        printf("<%s key=\"%s\"",
+               section->element_name, buf.str);
+        av_bprint_clear(&buf);
+
+        av_bprint_escape(&buf, value, NULL,
+                         AV_ESCAPE_MODE_XML, AV_ESCAPE_FLAG_XML_DOUBLE_QUOTES);
+        printf(" value=\"%s\"/>\n", buf.str);
+    } else {
+        if (wctx->nb_item[wctx->level])
+            printf(" ");
+
+        av_bprint_escape(&buf, value, NULL,
+                         AV_ESCAPE_MODE_XML, AV_ESCAPE_FLAG_XML_DOUBLE_QUOTES);
+        printf("%s=\"%s\"", key, buf.str);
+    }
+
+    av_bprint_finalize(&buf, NULL);
+}
+
+static void xml_print_int(WriterContext *wctx, const char *key, long long int value)
+{
+    if (wctx->nb_item[wctx->level])
+        printf(" ");
+    printf("%s=\"%lld\"", key, value);
+}
+
+static Writer xml_writer = {
+    .name                 = "xml",
+    .priv_size            = sizeof(XMLContext),
+    .init                 = xml_init,
+    .print_section_header = xml_print_section_header,
+    .print_section_footer = xml_print_section_footer,
+    .print_integer        = xml_print_int,
+    .print_string         = xml_print_str,
+    .flags = WRITER_FLAG_PUT_PACKETS_AND_FRAMES_IN_SAME_CHAPTER,
+    .priv_class           = &xml_class,
+};
+
+static void print_hwdevicecontext(WriterContext *w, AVHWDeviceContext *hw_device_context)
+{
+    writer_print_section_header(w, SECTION_ID_HWDEViCECONTEXT);
+
+    print_int("HasHwDeviceContext", 1);
+    print_str("DeviceType", av_hwdevice_get_type_name(hw_device_context->type));
+
+    writer_print_section_footer(w); // SECTION_ID_HWDEViCECONTEXT
+}
+
+static void print_hwframescontext(WriterContext *w, AVHWFramesContext *hw_frames_context)
+{
+    const AVPixFmtDescriptor* pixdescHw = NULL;
+    const AVPixFmtDescriptor* pixdescSw = NULL;
+
+    writer_print_section_header(w, SECTION_ID_HWFRAMESCONTEXT);
+
+    print_int("HasHwFramesContext", 1);
+    print_str("HardwareFormat", av_hwdevice_get_type_name(hw_frames_context->format));
+    print_str("SoftwareFormat", av_hwdevice_get_type_name(hw_frames_context->sw_format));
+
+    pixdescHw = av_pix_fmt_desc_get(hw_frames_context->format);
+    if (pixdescHw != NULL) {
+        print_str("HwPixelFormat", pixdescHw->name);
+        print_str("HwPixelFormatAlias", pixdescHw->alias);
+    }
+    
+    pixdescSw = av_pix_fmt_desc_get(hw_frames_context->sw_format);
+    if (pixdescSw != NULL) {
+        print_str("SwPixelFormat", pixdescSw->name);
+        print_str("SwPixelFormatAlias", pixdescSw->alias);
+    }
+    
+    print_int("Width", hw_frames_context->width);
+    print_int("Height", hw_frames_context->height);
+
+    print_hwdevicecontext(w, hw_frames_context->device_ctx);
+    
+    writer_print_section_footer(w); // SECTION_ID_HWFRAMESCONTEXT
+}
+
+static void print_link(WriterContext *w, AVFilterLink *link)
+{
+    char layoutString[64];
+
+    switch (link->type) {
+        case AVMEDIA_TYPE_VIDEO:
+            print_str("Format",  av_x_if_null(av_get_pix_fmt_name(link->format), "?"));
+            print_int("Width", link->w);
+            print_int("Height", link->h);
+            print_q("SAR", link->sample_aspect_ratio, ':');
+            break;
+
+        case AVMEDIA_TYPE_AUDIO:
+            av_get_channel_layout_string(layoutString, sizeof(layoutString), link->channels, link->channel_layout);
+            print_str("ChannelString", layoutString);
+            print_int("Channels", link->channels);
+            print_int("ChannelLayout", link->channel_layout);
+            print_int("SampleRate", link->sample_rate);
+            break;
+    }
+
+    if (link->hw_frames_ctx != NULL && link->hw_frames_ctx->buffer != NULL)
+        print_hwframescontext(w, (AVHWFramesContext*)link->hw_frames_ctx->data);
+}
+
+static void print_filter(WriterContext *w, AVFilterContext* filter)
+{
+    writer_print_section_header(w, SECTION_ID_FILTER);
+
+    print_str("Name", filter->name);
+
+    if (filter->filter != NULL) {
+        print_str("Name2", filter->filter->name);
+        print_str("Description", filter->filter->description);
+    }
+
+    if (filter->hw_device_ctx != NULL) {
+        AVHWDeviceContext* decCtx = (AVHWDeviceContext*)filter->hw_device_ctx->data;
+        print_hwdevicecontext(w, decCtx);
+    }
+
+    writer_print_section_header(w, SECTION_ID_INPUTS);
+
+    for (int i = 0; i < filter->nb_inputs; i++) {
+        AVFilterLink *link = filter->inputs[i];
+        writer_print_section_header(w, SECTION_ID_INPUT);
+
+        print_str("SourceName", link->src->name);
+        print_str("SourcePadName", link->srcpad->name);
+        print_str("DestPadName", link->dstpad->name);
+
+        print_link(w, link);
+
+        writer_print_section_footer(w); // SECTION_ID_INPUT
+    }
+
+    writer_print_section_footer(w); // SECTION_ID_INPUTS
+
+    // --------------------------------------------------
+    
+    writer_print_section_header(w, SECTION_ID_OUTPUTS);
+
+    for (int i = 0; i < filter->nb_outputs; i++) {
+        AVFilterLink *link = filter->outputs[i];
+        writer_print_section_header(w, SECTION_ID_OUTPUT);
+
+        print_str("DestName", link->dst->name);
+        print_str("DestPadName", link->dstpad->name);
+        print_str("SourceName", link->src->name);
+
+        print_link(w, link);
+
+        writer_print_section_footer(w); // SECTION_ID_OUTPUT
+    }
+
+    writer_print_section_footer(w); // SECTION_ID_OUTPUTS
+
+    writer_print_section_footer(w); // SECTION_ID_FILTER
+}
+
+static void print_filtergraph_single(WriterContext *w, FilterGraph* fg)
+{
+    char layoutString[64];
+
+    writer_print_section_header(w, SECTION_ID_FILTERGRAPH);
+
+    print_int("GraphIndex", fg->index);
+    print_str("Description", fg->graph_desc);
+
+    writer_print_section_header(w, SECTION_ID_INPUTS);
+
+    for (int i = 0; i < fg->nb_inputs; i++) {
+        enum AVMediaType mediaType = AVMEDIA_TYPE_UNKNOWN;
+        InputFilter *ifilter = fg->inputs[i];
+
+        writer_print_section_header(w, SECTION_ID_INPUT);
+
+        print_str("Name1", ifilter->name);
+
+        if (ifilter->filter != NULL) {
+            print_str("Name2", ifilter->filter->name);
+            print_str("Name3", ifilter->filter->filter->name);
+            print_str("Description", ifilter->filter->filter->description);
+
+            if (ifilter->filter->nb_outputs > 0)
+                mediaType = ifilter->filter->outputs[0]->type;
+        }
+
+        print_str("MediaType", av_get_media_type_string(mediaType));
+        print_int("MediaTypeId", mediaType);
+
+        switch (ifilter->type) {
+        case AVMEDIA_TYPE_VIDEO:
+        case AVMEDIA_TYPE_SUBTITLE:
+            print_str("Format",  av_x_if_null(av_get_pix_fmt_name(ifilter->format), "?"));
+            print_int("Width", ifilter->width);
+            print_int("Height", ifilter->height);
+            print_q("SAR", ifilter->sample_aspect_ratio, ':');
+            break;
+        case AVMEDIA_TYPE_AUDIO:
+
+            av_get_channel_layout_string(layoutString, sizeof(layoutString), ifilter->channels, ifilter->channel_layout);
+            print_str("ChannelString", layoutString);
+            print_int("Channels", ifilter->channels);
+            print_int("ChannelLayout", ifilter->channel_layout);
+            print_int("SampleRate", ifilter->sample_rate);
+            break;
+        case AVMEDIA_TYPE_ATTACHMENT:
+        case AVMEDIA_TYPE_DATA:
+            break;
+        }
+
+        if (ifilter->hw_frames_ctx != NULL)
+            print_hwframescontext(w, (AVHWFramesContext*)ifilter->hw_frames_ctx->data);
+        else if (ifilter->filter != NULL && ifilter->filter->hw_device_ctx != NULL) {
+            AVHWDeviceContext* devCtx = (AVHWDeviceContext*)ifilter->filter->hw_device_ctx->data;
+            print_hwdevicecontext(w, devCtx);
+        }
+
+        writer_print_section_footer(w); // SECTION_ID_INPUT
+    }
+
+    writer_print_section_footer(w); // SECTION_ID_INPUTS
+
+
+    writer_print_section_header(w, SECTION_ID_OUTPUTS);
+
+    for (int i = 0; i < fg->nb_outputs; i++) {
+        OutputFilter *ofilter = fg->outputs[i];
+        enum AVMediaType mediaType = AVMEDIA_TYPE_UNKNOWN;
+
+        writer_print_section_header(w, SECTION_ID_OUTPUT);
+        print_str("Name1", ofilter->name);
+
+        if (ofilter->filter != NULL) {
+            print_str("Name2", ofilter->filter->name);
+            print_str("Name3", ofilter->filter->filter->name);
+            print_str("Description", ofilter->filter->filter->description);
+
+            if (ofilter->filter->nb_inputs > 0)
+                mediaType = ofilter->filter->inputs[0]->type;
+        }
+
+        print_str("MediaType", av_get_media_type_string(mediaType));
+        print_int("MediaTypeId", mediaType);
+
+        switch (ofilter->type) {
+        case AVMEDIA_TYPE_VIDEO:
+        case AVMEDIA_TYPE_SUBTITLE:
+            print_str("Format",  av_x_if_null(av_get_pix_fmt_name(ofilter->format), "?"));
+            print_int("Width", ofilter->width);
+            print_int("Height", ofilter->height);
+            break;
+        case AVMEDIA_TYPE_AUDIO:
+
+            ////av_get_channel_layout_string(layoutString, sizeof(layoutString), ofilter->ost->, ofilter->channel_layout);
+            ////print_str("ChannelString", layoutString);
+            ////print_int("Channels", ofilter->channels);
+            print_int("ChannelLayout", ofilter->channel_layout);
+            print_int("SampleRate", ofilter->sample_rate);
+            break;
+        case AVMEDIA_TYPE_ATTACHMENT:
+        case AVMEDIA_TYPE_DATA:
+            break;
+        }
+
+        if (ofilter->filter != NULL && ofilter->filter->hw_device_ctx != NULL) {
+            AVHWDeviceContext* devCtx = (AVHWDeviceContext*)ofilter->filter->hw_device_ctx->data;
+            print_hwdevicecontext(w, devCtx);
+        }
+
+        writer_print_section_footer(w); // SECTION_ID_OUTPUT
+    }
+
+    writer_print_section_footer(w); // SECTION_ID_OUTPUTS
+
+
+    writer_print_section_header(w, SECTION_ID_FILTERS);
+
+    if (fg->graph != NULL) {
+        for (int i = 0; i < fg->graph->nb_filters; i++) {
+            AVFilterContext *filter = fg->graph->filters[i];
+            writer_print_section_header(w, SECTION_ID_FILTER);
+
+            print_filter(w, filter);
+
+            writer_print_section_footer(w); // SECTION_ID_FILTER
+        }
+    }
+
+    writer_print_section_footer(w); // SECTION_ID_FILTERS
+
+
+    writer_print_section_footer(w); // SECTION_ID_FILTERGRAPH
+}
+
+int print_filtergraphs(FilterGraph **graphs, int nb_graphs)
+{
+    const Writer *writer;
+    WriterContext *w;
+    char *buf;
+    char *w_name, *w_args;
+    int ret;
+
+    writer_register_all();
+
+    if (!print_graphs_format)
+        print_graphs_format = av_strdup("default");
+    if (!print_graphs_format) {
+        return AVERROR(ENOMEM);
+    }
+
+    w_name = av_strtok(print_graphs_format, "=", &buf);
+    if (!w_name) {
+        av_log(NULL, AV_LOG_ERROR, "No name specified for the filter graph output format\n");
+        return AVERROR(EINVAL);
+    }
+    w_args = buf;
+
+    writer = writer_get_by_name(w_name);
+    if (writer == NULL) {
+        av_log(NULL, AV_LOG_ERROR, "Unknown filter graph  output format with name '%s'\n", w_name);
+        return AVERROR(EINVAL);
+    }
+
+    ////if (print_graphs_file) {
+
+    ////    graph_file = freopen(print_graphs_file, "w", stdout);
+    ////    if (!graph_file) {
+    ////        int ret = AVERROR(errno);
+
+    ////        av_log(NULL, AV_LOG_ERROR, "Failed to open graph output file \"%s\": %s\n",
+    ////               print_graphs_file, strerror(errno));
+
+    ////        return ret;
+    ////    }
+    ////}
+
+    if ((ret = writer_open(&w, writer, w_args, sections, FF_ARRAY_ELEMS(sections))) >= 0) {
+        writer_print_section_header(w, SECTION_ID_ROOT);
+
+        writer_print_section_header(w, SECTION_ID_FILTERGRAPHS);
+
+        for (int i = 0; i < nb_graphs; i++)
+            print_filtergraph_single(w, graphs[i]);
+
+        writer_print_section_footer(w); // SECTION_ID_FILTERGRAPHS
+
+        writer_print_section_footer(w); // SECTION_ID_ROOT
+
+        if (print_graphs_file) {
+
+            AVIOContext *avio = NULL;
+
+            ret = avio_open2(&avio, print_graphs_file, AVIO_FLAG_WRITE, NULL, NULL);
+            if (ret < 0) {
+                av_log(NULL, AV_LOG_ERROR, "Failed to open graph output file, \"%s\": %s\n",
+                       print_graphs_file, av_err2str(ret));
+                return ret;
+            }
+
+            avio_write(avio, w->bpBuf.str, FFMIN(w->bpBuf.len, w->bpBuf.size - 1));
+            avio_flush(avio);
+
+            if ((ret = avio_closep(&avio)) < 0)
+                av_log(NULL, AV_LOG_ERROR, "Error closing graph output file, loss of information possible: %s\n", av_err2str(ret));
+        }
+
+        if (print_graphs)
+            av_log(NULL, AV_LOG_INFO, "%s    %c", w->bpBuf.str, '\n');
+
+        writer_close(&w);
+    }
+
+    ////if (graph_file) {
+
+    ////    if (fclose(graph_file))
+    ////        av_log(NULL, AV_LOG_ERROR,
+    ////            "Error closing filter report file, loss of information possible: %s\n",
+    ////            av_err2str(AVERROR(errno)));
+    ////    graph_file = NULL;
+    ////}
+
+    return 0;
+}
+
+void writer_register_all(void)
+{
+    static int initialized;
+
+    if (initialized)
+        return;
+    initialized = 1;
+
+    writer_register(&default_writer);
+    writer_register(&compact_writer);
+    writer_register(&csv_writer);
+    writer_register(&flat_writer);
+    writer_register(&ini_writer);
+    writer_register(&json_writer);
+    writer_register(&xml_writer);
+}
diff --git a/fftools/filterwriters.h b/fftools/filterwriters.h
new file mode 100644
index 0000000000..e7b58f2c13
--- /dev/null
+++ b/fftools/filterwriters.h
@@ -0,0 +1,205 @@
+/*
+ * Copyright (c) 2018 - 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_FILTERWRITERS_H
+#define FFTOOLS_FILTERWRITERS_H
+
+#include <stdint.h>
+
+#include "config.h"
+#include "ffmpeg.h"
+#include "libavutil/avutil.h"
+#include "libavutil/bprint.h"
+
+#define SECTION_MAX_NB_CHILDREN 11
+#define PRINT_STRING_OPT      1
+#define PRINT_STRING_VALIDATE 2
+#define MAX_REGISTERED_WRITERS_NB 64
+
+struct section {
+    int id;             ///< unique id identifying a section
+    const char *name;
+
+#define SECTION_FLAG_IS_WRAPPER      1 ///< the section only contains other sections, but has no data at its own level
+#define SECTION_FLAG_IS_ARRAY        2 ///< the section contains an array of elements of the same type
+#define SECTION_FLAG_HAS_VARIABLE_FIELDS 4 ///< the section may contain a variable number of fields with variable keys.
+                                           ///  For these sections the element_name field is mandatory.
+    int flags;
+    int children_ids[SECTION_MAX_NB_CHILDREN+1]; ///< list of children section IDS, terminated by -1
+    const char *element_name; ///< name of the contained element, if provided
+    const char *unique_name;  ///< unique section name, in case the name is ambiguous
+};
+
+typedef enum {
+    SECTION_ID_NONE = -1,
+    SECTION_ID_ROOT,
+    SECTION_ID_PROGRAM_VERSION,
+    SECTION_ID_FILTERGRAPHS,
+    SECTION_ID_FILTERGRAPH,
+    SECTION_ID_INPUTS,
+    SECTION_ID_INPUT,
+    SECTION_ID_OUTPUTS,
+    SECTION_ID_OUTPUT,
+    SECTION_ID_FILTERS,
+    SECTION_ID_FILTER,
+    SECTION_ID_HWDEViCECONTEXT,
+    SECTION_ID_HWFRAMESCONTEXT,
+    SECTION_ID_ERROR,
+    SECTION_ID_LOG,
+    SECTION_ID_LOGS,
+
+} SectionID;
+
+static const struct section sections[] = {
+    [SECTION_ID_ROOT] =               { SECTION_ID_ROOT, "GraphDescription", SECTION_FLAG_IS_WRAPPER,
+                                      { SECTION_ID_ERROR, SECTION_ID_PROGRAM_VERSION, SECTION_ID_FILTERGRAPHS, SECTION_ID_LOGS, -1} },
+    [SECTION_ID_PROGRAM_VERSION] =    { SECTION_ID_PROGRAM_VERSION, "ProgramVersion", 0, { -1 } },
+
+    [SECTION_ID_FILTERGRAPHS] =       { SECTION_ID_FILTERGRAPHS, "Graphs", SECTION_FLAG_IS_ARRAY, { SECTION_ID_FILTERGRAPH, -1 } },
+    [SECTION_ID_FILTERGRAPH] =        { SECTION_ID_FILTERGRAPH, "Graph", 0, { SECTION_ID_INPUTS, SECTION_ID_OUTPUTS, SECTION_ID_FILTERS, -1 },  },
+
+    [SECTION_ID_INPUTS] =             { SECTION_ID_INPUTS, "Inputs", SECTION_FLAG_IS_ARRAY, { SECTION_ID_INPUT, SECTION_ID_ERROR, -1 } },
+    [SECTION_ID_INPUT] =              { SECTION_ID_INPUT, "Input", 0, { SECTION_ID_HWFRAMESCONTEXT, SECTION_ID_ERROR, -1 },  },
+
+    [SECTION_ID_OUTPUTS] =            { SECTION_ID_OUTPUTS, "Outputs", SECTION_FLAG_IS_ARRAY, { SECTION_ID_OUTPUT, SECTION_ID_ERROR, -1 } },
+    [SECTION_ID_OUTPUT] =             { SECTION_ID_OUTPUT, "Output", 0, { SECTION_ID_HWFRAMESCONTEXT, SECTION_ID_ERROR, -1 },  },
+
+    [SECTION_ID_FILTERS] =            { SECTION_ID_FILTERS, "Filters", SECTION_FLAG_IS_ARRAY, { SECTION_ID_FILTER, SECTION_ID_ERROR, -1 } },
+    [SECTION_ID_FILTER] =             { SECTION_ID_FILTER, "Filter", 0, { SECTION_ID_HWDEViCECONTEXT, SECTION_ID_ERROR, -1 },  },
+
+    [SECTION_ID_HWDEViCECONTEXT] =    { SECTION_ID_HWDEViCECONTEXT, "HwDeviceContext", 0, { SECTION_ID_ERROR, -1 },  },
+    [SECTION_ID_HWFRAMESCONTEXT] =    { SECTION_ID_HWFRAMESCONTEXT, "HwFramesContext", 0, { SECTION_ID_ERROR, -1 },  },
+
+    [SECTION_ID_ERROR] =              { SECTION_ID_ERROR, "Error", 0, { -1 } },
+    [SECTION_ID_LOGS] =               { SECTION_ID_LOGS, "Log", SECTION_FLAG_IS_ARRAY, { SECTION_ID_LOG, -1 } },
+    [SECTION_ID_LOG] =                { SECTION_ID_LOG, "LogEntry", 0, { -1 },  },
+};
+
+struct unit_value {
+    union { double d; long long int i; } val;
+    const char *unit;
+};
+
+static const char unit_second_str[]         = "s"    ;
+static const char unit_hertz_str[]          = "Hz"   ;
+static const char unit_byte_str[]           = "byte" ;
+static const char unit_bit_per_second_str[] = "bit/s";
+
+/* WRITERS API */
+
+typedef struct WriterContext WriterContext;
+
+#define WRITER_FLAG_DISPLAY_OPTIONAL_FIELDS 1
+#define WRITER_FLAG_PUT_PACKETS_AND_FRAMES_IN_SAME_CHAPTER 2
+
+typedef enum {
+    WRITER_STRING_VALIDATION_FAIL,
+    WRITER_STRING_VALIDATION_REPLACE,
+    WRITER_STRING_VALIDATION_IGNORE,
+    WRITER_STRING_VALIDATION_NB
+} StringValidation;
+
+typedef struct Writer {
+    const AVClass *priv_class;      ///< private class of the writer, if any
+    int priv_size;                  ///< private size for the writer context
+    const char *name;
+
+    int  (*init)  (WriterContext *wctx);
+    void (*uninit)(WriterContext *wctx);
+
+    void (*print_section_header)(WriterContext *wctx);
+    void (*print_section_footer)(WriterContext *wctx);
+    void (*print_integer)       (WriterContext *wctx, const char *, long long int);
+    void (*print_rational)      (WriterContext *wctx, AVRational *q, char *sep);
+    void (*print_string)        (WriterContext *wctx, const char *, const char *);
+    int flags;                  ///< a combination or WRITER_FLAG_*
+} Writer;
+
+#define SECTION_MAX_NB_LEVELS 10
+
+struct WriterContext {
+    const AVClass *class;           ///< class of the writer
+    const Writer *writer;           ///< the Writer of which this is an instance
+    char *name;                     ///< name of this writer instance
+    void *priv;                     ///< private data for use by the filter
+
+    const struct section *sections; ///< array containing all sections
+    int nb_sections;                ///< number of sections
+
+    int level;                      ///< current level, starting from 0
+
+    /** number of the item printed in the given section, starting from 0 */
+    unsigned int nb_item[SECTION_MAX_NB_LEVELS];
+
+    /** section per each level */
+    const struct section *section[SECTION_MAX_NB_LEVELS];
+    AVBPrint section_pbuf[SECTION_MAX_NB_LEVELS]; ///< generic print buffer dedicated to each section,
+                                                  ///  used by various writers
+    AVBPrint bpBuf;
+    unsigned int nb_section_packet; ///< number of the packet section in case we are in "packets_and_frames" section
+    unsigned int nb_section_frame;  ///< number of the frame  section in case we are in "packets_and_frames" section
+    unsigned int nb_section_packet_frame; ///< nb_section_packet or nb_section_frame according if is_packets_and_frames
+
+    int string_validation;
+    char *string_validation_replacement;
+    unsigned int string_validation_utf8_flags;
+};
+
+#define print_fmt(k, f, ...) do {              \
+    av_bprint_clear(&pbuf);                    \
+    av_bprintf(&pbuf, f, __VA_ARGS__);         \
+    writer_print_string(w, k, pbuf.str, 0);    \
+} while (0)
+
+#define print_int(k, v)         writer_print_integer(w, k, v)
+#define print_q(k, v, s)        writer_print_rational(w, k, v, s)
+#define print_guid(k, v)        writer_print_guid(w, k, v)
+#define print_str(k, v)         writer_print_string(w, k, v, 0)
+#define print_str_opt(k, v)     writer_print_string(w, k, v, PRINT_STRING_OPT)
+#define print_str_validate(k, v) writer_print_string(w, k, v, PRINT_STRING_VALIDATE)
+#define print_time(k, v, tb)    writer_print_time(w, k, v, tb, 0)
+#define print_ts(k, v)          writer_print_ts(w, k, v, 0)
+#define print_duration_time(k, v, tb) writer_print_time(w, k, v, tb, 1)
+#define print_duration_ts(k, v)       writer_print_ts(w, k, v, 1)
+#define print_val(k, v, u) do {                                     \
+    struct unit_value uv;                                           \
+    uv.val.i = v;                                                   \
+    uv.unit = u;                                                    \
+    writer_print_string(w, k, value_string(val_str, sizeof(val_str), uv), 0); \
+} while (0)
+
+void writer_register_all(void);
+int print_filtergraphs(FilterGraph **filtergraphs, int nb_filtergraphs);
+
+const Writer *writer_get_by_name(const char *name);
+
+int writer_open(WriterContext **wctx, const Writer *writer, const char *args,
+                       const struct section *sections, int nb_sections);
+
+void writer_print_section_header(WriterContext *wctx, int section_id);
+void writer_print_section_footer(WriterContext *wctx);
+
+int writer_print_string(WriterContext *wctx, const char *key, const char *val, int flags);
+void writer_print_integer(WriterContext *wctx, const char *key, long long int val);
+void writer_print_rational(WriterContext *wctx, const char *key, AVRational q, char sep);
+
+void writer_close(WriterContext **wctx);
+
+#endif /* FFTOOLS_FILTERWRITERS_H */
