[FFmpeg-devel] [PATCH v7 1/3] avfilter/graphdump: support for the graph2dot function

Nicolas George george at nsup.org
Fri Jun 5 18:06:53 EEST 2020


lance.lmwang at gmail.com (12020-05-25):
> From: Limin Wang <lance.lmwang at gmail.com>
> 
> Signed-off-by: Limin Wang <lance.lmwang at gmail.com>
> ---
>  libavfilter/Makefile    |   1 -
>  libavfilter/graphdump.c |  89 +++++++++++++++++++++
>  tools/graph2dot.c       | 204 ------------------------------------------------
>  3 files changed, 89 insertions(+), 205 deletions(-)
>  delete mode 100644 tools/graph2dot.c

I think the parsing of the options string should go in a separate first
patch. Then another separate patch to add file output. Then this patch.

> 
> diff --git a/libavfilter/Makefile b/libavfilter/Makefile
> index 4d07bb6..291126e 100644
> --- a/libavfilter/Makefile
> +++ b/libavfilter/Makefile
> @@ -526,7 +526,6 @@ SKIPHEADERS-$(CONFIG_VULKAN)                 += vulkan.h
>  
>  OBJS-$(CONFIG_LIBGLSLANG)                    += glslang.o
>  
> -TOOLS     = graph2dot
>  TESTPROGS = drawutils filtfmts formats integral
>  
>  TOOLS-$(CONFIG_LIBZMQ) += zmqsend
> diff --git a/libavfilter/graphdump.c b/libavfilter/graphdump.c
> index 79ef1a7..97d4f39 100644
> --- a/libavfilter/graphdump.c
> +++ b/libavfilter/graphdump.c
> @@ -151,15 +151,104 @@ static void avfilter_graph_dump_to_buf(AVBPrint *buf, AVFilterGraph *graph)
>      }
>  }
>  
> +static void avfilter_graph2dot_to_buf(AVBPrint *buf, AVFilterGraph *graph)
> +{
> +    int i, j;
> +
> +    av_bprintf(buf, "digraph G {\n");
> +    av_bprintf(buf, "node [shape=box]\n");
> +    av_bprintf(buf, "rankdir=LR\n");
> +
> +    for (i = 0; i < graph->nb_filters; i++) {

> +        char filter_ctx_label[128];
> +        const AVFilterContext *filter_ctx = graph->filters[i];
> +
> +        snprintf(filter_ctx_label, sizeof(filter_ctx_label), "%s\\n(%s)",
> +                 filter_ctx->name,
> +                 filter_ctx->filter->name);

Do not use a temporary buffer when the target is AVBprint. Same below.

> +
> +        for (j = 0; j < filter_ctx->nb_outputs; j++) {
> +            AVFilterLink *link = filter_ctx->outputs[j];
> +            if (link) {
> +                char dst_filter_ctx_label[128];
> +                const AVFilterContext *dst_filter_ctx = link->dst;
> +
> +                snprintf(dst_filter_ctx_label, sizeof(dst_filter_ctx_label),
> +                         "%s\\n(%s)",
> +                         dst_filter_ctx->name,
> +                         dst_filter_ctx->filter->name);
> +

> +                av_bprintf(buf, "\"%s\" -> \"%s\" [ label= \"inpad:%s -> outpad:%s\\n",
> +                        filter_ctx_label, dst_filter_ctx_label,
> +                        avfilter_pad_get_name(link->srcpad, 0),
> +                        avfilter_pad_get_name(link->dstpad, 0));

Indentation is off. Same below.

> +
> +                if (link->type == AVMEDIA_TYPE_VIDEO) {
> +                    const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(link->format);
> +                    av_bprintf(buf,
> +                            "fmt:%s w:%d h:%d tb:%d/%d",
> +                            desc->name,
> +                            link->w, link->h,
> +                            link->time_base.num, link->time_base.den);
> +                } else if (link->type == AVMEDIA_TYPE_AUDIO) {
> +                    char audio_buf[255];
> +                    av_get_channel_layout_string(audio_buf, sizeof(audio_buf), -1,
> +                                                 link->channel_layout);
> +                    av_bprintf(buf,
> +                            "fmt:%s sr:%d cl:%s tb:%d/%d",
> +                            av_get_sample_fmt_name(link->format),
> +                            link->sample_rate, audio_buf,
> +                            link->time_base.num, link->time_base.den);
> +                }
> +                av_bprintf(buf, "\" ];\n");
> +            }
> +        }
> +    }
> +    av_bprintf(buf, "}\n");
> +}

I did not check the logic itself, I assume it is identical to graph2dot.

> +
>  char *avfilter_graph_dump(AVFilterGraph *graph, const char *options)
>  {
>      AVBPrint buf;
>      char *dump = NULL;
> +    int ret;
> +    AVDictionary *dict = NULL;
> +    AVDictionaryEntry *format = NULL;
> +    AVDictionaryEntry *filename = NULL;
> +
> +    ret = av_dict_parse_string(&dict, options, "=", ":", 0);
> +    if (ret < 0) {
> +        av_dict_free(&dict);
> +        return NULL;
> +    }
> +    format = av_dict_get(dict, "fmt", NULL, 0);
>  
> +    if (format && !av_strcasecmp(format->value, "DOT")) {
> +    av_bprint_init(&buf, 0, AV_BPRINT_SIZE_UNLIMITED);
> +    avfilter_graph2dot_to_buf(&buf, graph);

> +    av_bprint_finalize(&buf, &dump);

Missing error check. (Yes, the error check is also missing in the
existing code.)

> +    } else {

Invalid format selections should be reported to users.

>      av_bprint_init(&buf, 0, AV_BPRINT_SIZE_COUNT_ONLY);
>      avfilter_graph_dump_to_buf(&buf, graph);
>      av_bprint_init(&buf, buf.len + 1, buf.len + 1);
>      avfilter_graph_dump_to_buf(&buf, graph);
>      av_bprint_finalize(&buf, &dump);
> +    }
> +
> +    if (filename = av_dict_get(dict, "filename", NULL, 0)) {

> +        FILE* file = fopen(filename->value, "w");

Nit: Pointer marks belong with the variable, not the type.

> +        if (!file) {
> +            av_log(graph, AV_LOG_ERROR, "failed to open: %s \n", filename->value);
> +            av_freep(&dump);
> +            return NULL;
> +        }

> +        if (dump) {

Urgh. If something failed, the code should have stopped long ago.

> +            fputs(dump, file);
> +            fflush(file);
> +        }
> +        fclose(file);
> +    }
> +

> +    av_dict_free(&dict);

Unused options should be reported to users, possibly cause an error.

>      return dump;
>  }
> diff --git a/tools/graph2dot.c b/tools/graph2dot.c
> deleted file mode 100644
> index d5c1e4e..0000000
> --- a/tools/graph2dot.c
> +++ /dev/null
> @@ -1,204 +0,0 @@
> -/*

> - * Copyright (c) 2008-2010 Stefano Sabatini

Please make sure Stefano's copyright is not lost.

> - *
> - * 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 "config.h"
> -#if HAVE_UNISTD_H
> -#include <unistd.h>             /* getopt */
> -#endif
> -#include <stdio.h>
> -#include <string.h>
> -
> -#include "libavutil/channel_layout.h"
> -#include "libavutil/mem.h"
> -#include "libavutil/pixdesc.h"
> -#include "libavfilter/avfilter.h"
> -
> -#if !HAVE_GETOPT
> -#include "compat/getopt.c"
> -#endif
> -
> -static void usage(void)
> -{
> -    printf("Convert a libavfilter graph to a dot file.\n");
> -    printf("Usage: graph2dot [OPTIONS]\n");
> -    printf("\n"
> -           "Options:\n"
> -           "-i INFILE         set INFILE as input file, stdin if omitted\n"
> -           "-o OUTFILE        set OUTFILE as output file, stdout if omitted\n"
> -           "-h                print this help\n");
> -}
> -
> -struct line {
> -    char data[256];
> -    struct line *next;
> -};
> -
> -static void print_digraph(FILE *outfile, AVFilterGraph *graph)
> -{
> -    int i, j;
> -
> -    fprintf(outfile, "digraph G {\n");
> -    fprintf(outfile, "node [shape=box]\n");
> -    fprintf(outfile, "rankdir=LR\n");
> -
> -    for (i = 0; i < graph->nb_filters; i++) {
> -        char filter_ctx_label[128];
> -        const AVFilterContext *filter_ctx = graph->filters[i];
> -
> -        snprintf(filter_ctx_label, sizeof(filter_ctx_label), "%s\\n(%s)",
> -                 filter_ctx->name,
> -                 filter_ctx->filter->name);
> -
> -        for (j = 0; j < filter_ctx->nb_outputs; j++) {
> -            AVFilterLink *link = filter_ctx->outputs[j];
> -            if (link) {
> -                char dst_filter_ctx_label[128];
> -                const AVFilterContext *dst_filter_ctx = link->dst;
> -
> -                snprintf(dst_filter_ctx_label, sizeof(dst_filter_ctx_label),
> -                         "%s\\n(%s)",
> -                         dst_filter_ctx->name,
> -                         dst_filter_ctx->filter->name);
> -
> -                fprintf(outfile, "\"%s\" -> \"%s\" [ label= \"inpad:%s -> outpad:%s\\n",
> -                        filter_ctx_label, dst_filter_ctx_label,
> -                        avfilter_pad_get_name(link->srcpad, 0),
> -                        avfilter_pad_get_name(link->dstpad, 0));
> -
> -                if (link->type == AVMEDIA_TYPE_VIDEO) {
> -                    const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(link->format);
> -                    fprintf(outfile,
> -                            "fmt:%s w:%d h:%d tb:%d/%d",
> -                            desc->name,
> -                            link->w, link->h,
> -                            link->time_base.num, link->time_base.den);
> -                } else if (link->type == AVMEDIA_TYPE_AUDIO) {
> -                    char buf[255];
> -                    av_get_channel_layout_string(buf, sizeof(buf), -1,
> -                                                 link->channel_layout);
> -                    fprintf(outfile,
> -                            "fmt:%s sr:%d cl:%s tb:%d/%d",
> -                            av_get_sample_fmt_name(link->format),
> -                            link->sample_rate, buf,
> -                            link->time_base.num, link->time_base.den);
> -                }
> -                fprintf(outfile, "\" ];\n");
> -            }
> -        }
> -    }
> -    fprintf(outfile, "}\n");
> -}
> -
> -int main(int argc, char **argv)
> -{
> -    const char *outfilename = NULL;
> -    const char *infilename  = NULL;
> -    FILE *outfile           = NULL;
> -    FILE *infile            = NULL;
> -    char *graph_string      = NULL;
> -    AVFilterGraph *graph = av_mallocz(sizeof(AVFilterGraph));
> -    char c;
> -
> -    av_log_set_level(AV_LOG_DEBUG);
> -
> -    while ((c = getopt(argc, argv, "hi:o:")) != -1) {
> -        switch (c) {
> -        case 'h':
> -            usage();
> -            return 0;
> -        case 'i':
> -            infilename = optarg;
> -            break;
> -        case 'o':
> -            outfilename = optarg;
> -            break;
> -        case '?':
> -            return 1;
> -        }
> -    }
> -
> -    if (!infilename || !strcmp(infilename, "-"))
> -        infilename = "/dev/stdin";
> -    infile = fopen(infilename, "r");
> -    if (!infile) {
> -        fprintf(stderr, "Failed to open input file '%s': %s\n",
> -                infilename, strerror(errno));
> -        return 1;
> -    }
> -
> -    if (!outfilename || !strcmp(outfilename, "-"))
> -        outfilename = "/dev/stdout";
> -    outfile = fopen(outfilename, "w");
> -    if (!outfile) {
> -        fprintf(stderr, "Failed to open output file '%s': %s\n",
> -                outfilename, strerror(errno));
> -        return 1;
> -    }
> -
> -    /* read from infile and put it in a buffer */
> -    {
> -        int64_t count = 0;
> -        struct line *line, *last_line, *first_line;
> -        char *p;
> -        last_line = first_line = av_malloc(sizeof(struct line));
> -        if (!last_line) {
> -            fprintf(stderr, "Memory allocation failure\n");
> -            return 1;
> -        }
> -
> -        while (fgets(last_line->data, sizeof(last_line->data), infile)) {
> -            struct line *new_line = av_malloc(sizeof(struct line));
> -            if (!new_line) {
> -                fprintf(stderr, "Memory allocation failure\n");
> -                return 1;
> -            }
> -            count += strlen(last_line->data);
> -            last_line->next = new_line;
> -            last_line       = new_line;
> -        }
> -        last_line->next = NULL;
> -
> -        graph_string = av_malloc(count + 1);
> -        if (!graph_string) {
> -            fprintf(stderr, "Memory allocation failure\n");
> -            return 1;
> -        }
> -        p = graph_string;
> -        for (line = first_line; line->next; line = line->next) {
> -            size_t l = strlen(line->data);
> -            memcpy(p, line->data, l);
> -            p += l;
> -        }
> -        *p = '\0';
> -    }
> -
> -    if (avfilter_graph_parse(graph, graph_string, NULL, NULL, NULL) < 0) {
> -        fprintf(stderr, "Failed to parse the graph description\n");
> -        return 1;
> -    }
> -
> -    if (avfilter_graph_config(graph, NULL) < 0)
> -        return 1;
> -
> -    print_digraph(outfile, graph);
> -    fflush(outfile);
> -
> -    return 0;
> -}

Regards,

-- 
  Nicolas George
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