[MPlayer-dev-eng] [PATCH] af_pan: hard clipping, and more than 100% of source channels

[The Wanderer]

Since comment was re-requested, addressing the one thing I can really be
sure about:

Corey Hickey wrote:

>      * remove_logo filter
>      * lavcresample now used by default (-af-adv force=0 gives old behavior)
>      * vf_expand and vf_dsize now support aspect and round parameters
> +    * af_pan can mix channels in portions greater than 100%

I'm not entirely sure this is quite right... it's not inaccurate, it
just seems like a strange choice of words. The only thing I can think of
off the top of my head is that maybe you mean "proportions" instead, and
I'm not completely sure that that means the same thing.

>  .IPs <lij>
> -How much of input channel j is mixed into output channel i (0\-1).
> +The percentage (as a decimal, 0.5=50%, 2=200%, etc.) that input channel
> +j is to be mixed into output channel i (0\-512). That is 0% \- 51200%.

I'm not sure it's helpful to talk about this as a percentage; in
addition to making the phrasing more difficult to handle without
mangling the language, it also doesn't seem particularly clear, since
the arguments to the option are not given as percentages. I might say
something like "The multiple of input channel j which is to be mixed
into output channel i"; that's not necessarily entirely clear, but it
does avoid the additional level of obfuscation. (It took me a few
seconds to figure out exactly what was being described here, with the
current phrasing, and that's coming right after having read the much
better description of the concept of mixing in the advanced audio
features guide.)

Making the suggested change would arguably eliminate the need for the
final above sentence entirely, but if you decide to keep it, it needs
rejiggering. It refers back by pronoun ("that") to something inside
parentheses in the previous sentence, the available range; the only way
I can think of to use the current phrasing and be grammatically correct
would be to say "(0-512, that is, 0% - 51200%).", which is inconsistent
with the fact that the parenthetical bit is supposed to be simply a
notation of the valid arguments for the function. I don't really have a
good alternate suggestion; I haven't had enough sleep right now, but I'm
up and reading E-mail because I couldn't get back to sleep for some
reason.

> +Be careful when using values higher than 1; higher values can be quite
> +loud and may exceed the sample range of your sound card. If you hear any
> +painful pops or clicks, either decrease the values or follow pan with
> +",volume" so the volume filter will clip out-of-range values. Clipping
> +damages sound quality so use it sparingly.

I thought I noticed several minor grammatical issues here, but looking
at it now I only see one: you need a comma after "sound quality".

-- 
       The Wanderer

Warning: Simply because I argue an issue does not mean I agree with any
side of it.

A government exists to serve its citizens, not to control them.