[FFmpeg-devel] [PATCH] avfilter: add stereo tools filter

[Lou Logan]

Just some annoying simple stuff.

On Tue, 15 Sep 2015 17:26:00 +0000, Paul B Mahol wrote:

> Signed-off-by: Paul B Mahol <onemda at gmail.com>
> ---
>  doc/filters.texi             |  84 +++++++++++++
>  libavfilter/Makefile         |   1 +
>  libavfilter/af_stereotools.c | 290 +++++++++++++++++++++++++++++++++++++++++++
>  libavfilter/allfilters.c     |   1 +
>  4 files changed, 376 insertions(+)
>  create mode 100644 libavfilter/af_stereotools.c
> 
> diff --git a/doc/filters.texi b/doc/filters.texi
> index c4360fa..9f17cfd 100644
> --- a/doc/filters.texi
> +++ b/doc/filters.texi
> @@ -2394,6 +2394,90 @@ silenceremove=1:5:0.02
>  @end example
>  @end itemize
>  
> + at section stereotools
> +
> +This filter have some handy utilities to manage stereo signals, for converting
> +M/S stereo recordings to L/R signal while having control over the parameters
> +or spreading the stereo image of master track.

s/This filter have/This filter has/

Breaking up this long sentence will make it easier to follow.

> +The filter accepts the following options:
> +
> + at table @option
> + at item ibalance
> +Set input balance between both channels. Default is 0.
> +Allowed range is from -1 to 1.
> +
> + at item obalance
> +Set output balance between both channels. Default is 0.
> +Allowed range is from -1 to 1.
> +
> + at item softclip
> +Enable softclipping. This is analog distortion instead of harsh digital 0dB
> +clipping. By default is disabled.

Some minor rewording:

Enable softclipping. Results in analog distortion instead of harsh
digital 0dB clipping. Disabled by default.

> + at item mutel
> +Mute the left channel.
> +
> + at item muter
> +Mute the right channel.
> +
> + at item phasel
> +Change the phase of the  left channel.

Extra space between "the" and "left".

> +
> + at item phaser
> +Change the phase of the right channel.
> +
> + at item mode
> +Set stereo mode. Available values are:
> +
> + at table @samp
> + at item lr>lr
> +Left/Right to Left/Right.
> +
> + at item lr>ms
> +Left/Right to Mid/Side.
> +
> + at item ms>lr
> +Mid/Side to Left/Right.
> +
> + at item lr>ll
> +Left/Right to Left/Left.
> +
> + at item lr>rr
> +Left/Right to Right/Right.
> +
> + at item lr>l+r
> +Left/Right to Left + Right
> +
> + at item lr>rl
> +Left/Right to Right/Left
> + at end table
> +
> + at item slev
> +Set level of side signal. Default is 1.
> +
> + at item sbal
> +Set balance of side signal. Default is 0.
> +
> + at item mlev
> +Set level of the middle signal. Default is 1.
> +
> + at item mpan
> +Set middle signal pan. Default is 0.
> +
> + at item base
> +Set stereo base. Default is 0.

Would be nice to see some allowed ranges in some of the above ranges,
but don't consider it blocking.