[MPlayer-dev-eng] [DOCS] [3rd try] missing option descriptions

[D Richard Felker III]

On Sat, Aug 30, 2003 at 11:32:09AM +0200, Diego Biurrun wrote:
> D Richard Felker III writes:
>  > On Mon, Aug 25, 2003 at 02:00:37AM +0200, Arpi wrote:
>  > > > - (no)autoexpand
>  > > > 
>  > > >   Rich made some mysterious rumbling about this being a very obscure
>  > > >   option that was added for some encoding work he needed to do and he
>  > > >   was unsure whether such a hack should be documented at all..  I'd
>  > > >   say document or remove, so I guess we should go for the former.
>  > > 
>  > > ok this is not easy.
>  > > as you probably know, OSD rendering in g1 is handled by vo drivers.
>  > > (it has historical reasons, osd existed before filter layer).
>  > > but mencoder doesnt use libvo, but users still want osd rendering with it,
>  > > to render subtitles into the encoded avi (which is silly anyway).
>  > > to workaround this, mencoder by default inserts the 'expand' video filter,
>  > > which can do the osd rendering. but since we support slices, and DR and some
>  > > other tricks has been done in vf_expand, sometimes it's broken/buggy/slow,
>  > > so it's better not inserting it at all. so, to avoid auto-inserting expand
>  > > filter in mencoder, you can use -noautoexpand
>  > 
>  > Yes, Arpi is mostly right about this, but it has another use. IMO,
>  > subtitles look MUCH better when rendered at high resolution then
>  > scaled by swscaler, as opposed to rendered at low res. So when I was
>  > making small encodes with hardcoded subs for hopeless WMP users who
>  > can't figure out how to install the .srt filter or whatever :))))) I
>  > wanted to render subs at the beginning of the filter chain rather than
>  > the end. However, mencoder's auto-inserted vf_expand always renders
>  > subs, so it was double-rendering them, and doing it in a bogus manner
>  > since the OSD code does not support multiple instances (image/font
>  > size are initialized only once)... The only clean way I found around
>  > this problem was to allow the user to disable the auto-inserted expand
>  > filter.
> 
> Hmm, this is tricky indeed.  What about:
> 
>   Do not automatically insert the expand filter into the MEncoder filter chain.
>   Useful to control at which point of the filter chain subtitles are rendered
>   when hardcoding subtitles onto a movie.

Perfect. :)

Rich