[FFmpeg-devel] [PATCH] avfilter: Handle =help to show Filter options documentation

[Paul B Mahol]

On 4/2/13, Michael Niedermayer <michaelni at gmx.at> wrote:
> On Sat, Mar 30, 2013 at 02:27:16PM +0000, Paul B Mahol wrote:
>> On 3/30/13, Michael Niedermayer <michaelni at gmx.at> wrote:
>> > On Sat, Mar 30, 2013 at 03:00:45PM +0100, Clement Boesch wrote:
>> >> On Sat, Mar 30, 2013 at 02:47:48AM +0100, Michael Niedermayer wrote:
>> >> [...]
>> >> > > But why the user should know that -vf filter=help will show help,
>> >> > > instead of setting the arguments for the filter as it could be
>> >> > > reasonably expected?
>> >> >
>> >> > its what the user actually tried who asked for it IIRC, its what i
>> >> > would try probably
>> >> > its what some other applications support
>> >> > try qemu for a list of cpus its
>> >> > -cpu '?'
>> >> > or
>> >> > mplayer -vo help
>> >> >
>> >>
>> >> OTOH the first users reflex with an unknown app is to run ./app -h or
>> >> ./app --help.
>> >
>> > which outputs several screenfulls of stuff, not containing a match
>> > for lets say "curves"
>> >
>> > If all help isnt displayed by default then what is shown by default
>> > should explain how to find ANY help and describe it in very few
>> > lines
>> >
>> > The goal is to minimize the amount of reading & time the user needs
>> > to find what he needs.
>> > If the default help scrolls off the screen but contains the most
>> > important at the top that scrolled off then you already fail there
>> > because at least half the users wont look at whats scrolled off and
>> > probably less than 5% would read several screenfulls just to find out
>> > what to type in to get the full help or a specific subset they need.
>>
>> I have not that strong opinion on -vf filter=help like i have strong
>> opinion on hack how it is implemented.
>
> do you see a cleaner way by which this could be implemented?

I did not looked at all that problem. But adding another member to
filter context is so
ugly in my eyes.

I like Clement proposition. Wasn't there already patch posted that
does it? (or I was dreaming).

>
> [...]
>
> --
> Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB
>
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> notwithstanding go out to meet it. -- Thucydides
>