[FFmpeg-devel] [PATCH] ffprobe: report audio bit rate in stream description

[Matthieu Bouron]

2012/2/6 Stefano Sabatini <stefasab at gmail.com>:
> On date Monday 2012-02-06 12:13:02 +0100, Matthieu Bouron encoded:
>> 2012/2/6 Stefano Sabatini <stefasab at gmail.com>:
>> > On date Sunday 2012-02-05 22:26:14 +0100, Matthieu Bouron encoded:
>> >> $title
>> >
>> >> From 4bca8fd1dddfcf4851a0ba1cc6bd52d597e9ab8b Mon Sep 17 00:00:00 2001
>> >> From: Matthieu Bouron <matthieu.bouron at gmail.com>
>> >> Date: Sun, 5 Feb 2012 21:59:23 +0100
>> >> Subject: [PATCH] ffprobe: report audio bit rate in stream description
>> >>
>> >> ---
>> >>  doc/ffprobe.xsd |    1 +
>> >>  ffprobe.c       |    8 +++++++-
>> >>  2 files changed, 8 insertions(+), 1 deletions(-)
> [...]
>> Patch updated.
>> >
>> > Some output formats (compact/csv) demand a fixed number of fields, so
>> > in you need to display a field even in the case the information is not
>> > available. In this case this should work:
>> >
>> >              if (bit_rate > 0) print_int    ("bit_rate", bit_rate);
>> >              else              print_str_opt("bit_rate", "N/A");
>> >
>> > Also I'm not sure this is a good idea, since this only shows the
>> > *uncompressed data* bitrate, which is in general different from the
>> > effective bitrate.
>> This code has the same behaviour as ffmpeg (libavcodec/util.c). If
>> bits_per_sample is set, the bit_rate is computed but if not
>> AVCodecContext.bit_rate is used.
>
> Yes, I wonder if it would make sense to export the get_bit_rate()
> function, or even better to set the value right into the codec
> context which should be even more robust.

It seems like all the demuxer/decoder does not set the
AVCodecContext.bit_rate value. For example, gxf does whereas mxfdec
does not. For now, exporting get_bit_rate seems a good idea to me.

>
>> Maybe this entry should be called avg_bit_rate ?
> --
> FFmpeg = Foolish & Forgiving Magic Practical Epic Ghost
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