[Ffmpeg-devel] [RFC]: vhook Documentation

[Diego Biurrun]

On Sun, Jan 21, 2007 at 04:38:43PM +0100, V?ctor Paesa wrote:
> > Here's a review of your patch..
> >
> > On Tue, Jan 16, 2007 at 09:45:45PM -0800, C.Ren Boca wrote:
> >>
> >> --- hooks.texi 2007-01-17 00:30:30.000000000 -0500
> >> +++ hooks.texi.new 2007-01-17 00:38:32.000000000 -0500
> >> @@ -39,63 +39,57 @@
> >>
> >> -You may also overlay an image (even semi-transparent) like TV stations
> >> do.
> >> -You may move either the text or the image around your video to create
> >> -scrolling credits, for example.
> >> +Features:
> >> +- True Type, Type1 and others via FreeType2 library
> >
> > TrueType
> >
> >> +- Font kerning (better output)
> >> +- Line Wrap (if the text doesn't fit, the next char goes to the next
> >> line)
> >> +- Background box (currently in development)
> >> +- Outline
> >
> > Trailing whitespace, please remove that from patches.
> >
> > Also, why not make this feature list a proper bulletted list with
> > texinfo markup?
> >
> >>  Text fonts are being looked for in a FONTPATH environment variable.
> >>
> >>  Options:
> >>  @multitable @columnfractions .2 .8
> >> - at item @option{-c <color>}     @tab The color of the text
> >> - at item @option{-F <fontname>}  @tab The font face and size
> >> - at item @option{-t <text>}      @tab The text
> >> - at item @option{-f <filename>}  @tab The filename to read text from
> >> - at item @option{-x <expresion>} @tab X coordinate of text or image
> >> - at item @option{-y <expresion>} @tab Y coordinate of text or image
> >> - at item @option{-i <filename>}  @tab The filename to read a image from
> >> - at end multitable
> >> -
> >> -Expresions are functions of these variables:
> >> - at multitable @columnfractions .2 .8
> >> - at item @var{N} @tab frame number (starting at zero)
> >> - at item @var{H} @tab frame height
> >> - at item @var{W} @tab frame width
> >> - at item @var{h} @tab image height
> >> - at item @var{w} @tab image width
> >> - at item @var{X} @tab previous x coordinate of text or image
> >> - at item @var{Y} @tab previous y coordinate of text or image
> >> + at item @option{-c <color>}          @tab Foreground color of the text
> >> ('internet' way) <#RRGGBB> [default #ffffff]
> >> + at item @option{-C <color>}          @tab Background color of the text
> >> ('internet' way) <#RRGGBB> [default #000000]
> >> + at item @option{-f <font-filename>}  @tab The font file to use
> >> + at item @option{-o }                 @tab Outline glyphs using the
> >> background color
> >> + at item @option{-t <text>}           @tab The text to display
> >> + at item @option{-T <filename>}       @tab The filename to read text from
> >> + at item @option{-x <pos>}            @tab X coordinate of the start of
> >> text
> >> + at item @option{-y <pos>}            @tab Y coordinate of the start of
> >> text
> >>  @end multitable
> >>
> >> -You may also use the constants @var{PI}, @var{E}, and the math
> >> functions available at the
> >> -FFmpeg formula evaluator at (@url{ffmpeg-doc.html#SEC13}), except
> >> @var{bits2qp(bits)}
> >> -and @var{qp2bits(qp)}.
> >> -
> >> -Usage examples:
> >> -
> >> +Usage Example:
> >>  @example
> >>     # Remember to set the path to your fonts
> >> -   FONTPATH="/cygdrive/c/WINDOWS/Fonts/"
> >> -   FONTPATH="$FONTPATH:/usr/share/imlib2/data/fonts/"
> >>     FONTPATH="$FONTPATH:/usr/X11R6/lib/X11/fonts/TTF/"
> >>     export FONTPATH
> >>
> >> -   # Bulb dancing in a Lissajous pattern
> >> -   ffmpeg -i input.avi -vhook \
> >> -     'vhook/imlib2.dll -x W*(0.5+0.25*sin(N/47*PI))-w/2 -y
> >> H*(0.5+0.50*cos(N/97*PI))-h/2 -i /usr/share/imlib2/data/images/bulb.png'
> >> \
> >> -     -acodec copy -sameq output.avi
> >> -
> >> -   # Text scrolling
> >> -   ffmpeg -i input.avi -vhook \
> >> -     'vhook/imlib2.dll -c red -F Vera.ttf/20 -x 150+0.5*N -y 70+0.25*N
> >> -t Hello' \
> >> -     -acodec copy -sameq output.avi
> >> +   # When run from your build location:
> >
> > I would just assume an installed version of ffmpeg.  Don't bother with
> > these details.
> >
> >> +   Will grab video from the first capture card and output it to a MPEG
> >> video,
> >
> > an MPEG
> >
> >> +   And place  "Weekday-dd/mm/yy-hh:mm:ss" at the top left of the frame,
> >> updated every second,
> >> +   using the Vera Bold TrueType Font, which should exist in:
> >> /usr/X11R6/lib/X11/fonts/TTF/
> >
> > Ideally, keep lines below 80 characters.
> >
> >> +   If ffmpeg is installed, it should be in your $PATH, make sure to
> >> specify the full path
> >> +   of the vhook ".so" file that you are using.
> >
> > see above
> >
> >> +   Check the manpage for strftime() for all the various ways you can
> >> format the date and time.
> >
> > man page
> >
> >> +Command Line options:
> >> +-m [0|1]  Mode. Zero is the default Mode, see below.
> >
> > default mode
> >
> >> + If mask color is < 0x80 the abs difference is subtracted from the
> >> frame. If
> >
> > absolute
> >
> >> + This way a mask that is visible both in light pictures and in dark can
> >> be
> >
> > "light pictures and in dark ones" or IMO better "light and dark pictures".
> >
> > You've removed some parts of the documentation, I'll have to trust that
> > it's correct since I haven't played around with vhook at all.
> 
> imlib2 docs appear as removed and then substituted by drawtext's ones.
> 
> I bet that is the result of diff'ing against a hooks.texi
> that already had imlib's docs copied&pasted again.
> 
> P., please use "svn diff" or use diff against the original hooks.texi

What happened to this patch?  I'd like to apply it if the issues from
the review get addressed...

Diego