[FFmpeg-devel] [PATCH 2/2] ffprobe: show seekability details in format section

[softworkz .]

> -----Original Message-----
> From: ffmpeg-devel <ffmpeg-devel-bounces at ffmpeg.org> On Behalf Of Gyan
> Doshi
> Sent: Sonntag, 13. April 2025 13:16
> To: ffmpeg-devel at ffmpeg.org
> Subject: [FFmpeg-devel] [PATCH 2/2] ffprobe: show seekability details in
> format section
> 
> ---
>  fftools/ffprobe.c                    | 49 +++++++++++++++++++++++++++-
>  tests/ref/fate/cavs-demux            |  2 +-
>  tests/ref/fate/ffprobe_compact       |  2 +-
>  tests/ref/fate/ffprobe_csv           |  2 +-
>  tests/ref/fate/ffprobe_default       |  1 +
>  tests/ref/fate/ffprobe_flat          |  1 +
>  tests/ref/fate/ffprobe_ini           |  1 +
>  tests/ref/fate/ffprobe_json          |  1 +
>  tests/ref/fate/ffprobe_xml           |  2 +-
>  tests/ref/fate/ffprobe_xsd           |  2 +-
>  tests/ref/fate/flv-demux             |  2 +-
>  tests/ref/fate/gapless-mp3-side-data |  2 +-
>  tests/ref/fate/oggopus-demux         |  2 +-
>  tests/ref/fate/ts-demux              |  2 +-
>  tests/ref/fate/ts-opus-demux         |  2 +-
>  tests/ref/fate/ts-small-demux        |  2 +-
>  tests/ref/fate/ts-timed-id3-demux    |  2 +-
>  17 files changed, 64 insertions(+), 13 deletions(-)
> 
> diff --git a/fftools/ffprobe.c b/fftools/ffprobe.c
> index e0a7322523..8b09afb8c1 100644
> --- a/fftools/ffprobe.c
> +++ b/fftools/ffprobe.c
> @@ -2260,7 +2260,7 @@ static int show_format(AVTextFormatContext *tfc,
> InputFile *ifile)
>  {
>      AVFormatContext *fmt_ctx = ifile->fmt_ctx;
>      int64_t size = fmt_ctx->pb ? avio_size(fmt_ctx->pb) : -1;
> -    int ret = 0;
> +    int seekable, ret = 0;
> 
>      avtext_print_section_header(tfc, NULL, SECTION_ID_FORMAT);
>      print_str_validate("filename", fmt_ctx->url);
> @@ -2279,6 +2279,53 @@ static int show_format(AVTextFormatContext *tfc,
> InputFile *ifile)
>      if (fmt_ctx->bit_rate > 0) print_val    ("bit_rate", fmt_ctx-
> >bit_rate, unit_bit_per_second_str);
>      else                       print_str_opt("bit_rate", "N/A");
>      print_int("probe_score", fmt_ctx->probe_score);
> +
> +    seekable = avformat_query_seekable(fmt_ctx);
> +    if (seekable > 0) {
> +        int gen = 1, ante = 0;
> +        AVBPrint seek_str;
> +        av_bprint_init(&seek_str, 0, AV_BPRINT_SIZE_AUTOMATIC);
> +
> +        av_bprintf(&seek_str, "yes, by");
> +        if (seekable & AVSEEKABLE_TIME) {
> +            av_bprintf(&seek_str, " time");
> +            if (seekable & AVSEEKABLE_PTS)
> +                av_bprintf(&seek_str, "(pts)");
> +            else
> +                av_bprintf(&seek_str, "(dts)");
> +            ante = 1;
> +        }
> +        if (seekable & AVSEEKABLE_BYTE) {
> +            av_bprintf(&seek_str, "%cbyte-offset", ante ? ',':' ');
> +            ante = 1;
> +        }
> +        if (seekable & AVSEEKABLE_FRAME) {
> +            av_bprintf(&seek_str, "%cframe-index", ante ? ',':' ');
> +        }
> +
> +        ante = 0;
> +        av_bprintf(&seek_str, " via");
> +        if (seekable & AVSEEKABLE_DEMUXER) {
> +            av_bprintf(&seek_str, " demuxer");
> +            gen = 0;
> +            ante = 1;
> +        }
> +        if (seekable & AVSEEKABLE_PKTSCAN) {
> +            av_bprintf(&seek_str, "%cpacket-scan", ante ? ',':' ');
> +            gen = 0;
> +            ante = 0;
> +        }
> +        if (gen)
> +            av_bprintf(&seek_str, " generic seek");
> +
> +        if (seekable & AVSEEKABLE_FWDONLY)
> +            av_bprintf(&seek_str, " (forward only)");
> +
> +        print_str("seekable",      seek_str.str);
> +    }
> +    else
> +        print_str("seekable",      "no");
> +
>      if (do_show_format_tags)
>          ret = show_tags(tfc, fmt_ctx->metadata,
> SECTION_ID_FORMAT_TAGS);


Hi Gyan,

the problem that I see here is that it's not machine-readable and would require non-trivial parsing to translate back to the actual information behind it.
I think that either a separate sub-section or at least three separate values would be better.

Another note: When you skim through the ffprobe code, you can see that ffprobe rarely does its own "numbers-to-string" translations (only for cases of absence, like 'none', 'unknown', etc.). Normally, those translations are included in the libs where they are defined.

Oh, and I believe you also need to add new output fields to the xml schema file (ffprobe.xsd).

Still like it! 😊

Thanks,
sw