[FFmpeg-devel] [RFC 0/1] avfilter/f_sendcmd: add format expressions

[Ignacy Gawędzki]

Hi,

I'd like to submit the following patch adding a feature that I was
missing and decided to try to implement myself.

The problem I had was that although the parameters of the lutyuv
filter are all commands, there was no way to use sendcmd to generate
the expressions for the parameters using time-dependent [expr] flag.

So I added a [format] flag that indicates ARG is to be interpreted as
a format string (printf-style) followed by arguments separated by
commas (that require proper escaping for it to work), and used to
generate the string that is eventually sent to the filter.

This is currently limited to %f with optional width and precision.

Tested to work with ARG as "gammaval(%.2f), 1-TI*.3", to make a gamma
ramp over an interval of time.

What do you think about it?

Cheers,

Ignacy


Ignacy Gawędzki (1):
  avfilter/f_sendcmd: add format expressions

 libavfilter/f_sendcmd.c | 161 +++++++++++++++++++++++++++++++++++-----
 1 file changed, 143 insertions(+), 18 deletions(-)

-- 
2.48.1