[FFmpeg-devel] [PATCH 1/2] lavfi/ebur128: add support for smaller video sizes

[Clément Bœsch]

On Sat, Nov 22, 2014 at 03:28:06PM +0100, Marton Balint wrote:
> 
> 
> On Fri, 21 Nov 2014, Clément Bœsch wrote:
> 
> >(sorry for the delay)
> >
> >On Sun, Nov 16, 2014 at 10:53:15PM +0100, Marton Balint wrote:
> >>Signed-off-by: Marton Balint <cus at passwd.hu>
> >>---
> >> doc/filters.texi        |  4 ++--
> >> libavfilter/f_ebur128.c | 11 ++++++++---
> >> 2 files changed, 10 insertions(+), 5 deletions(-)
> >>
> >>diff --git a/doc/filters.texi b/doc/filters.texi
> >>index 53f4cb2..713989c 100644
> >>--- a/doc/filters.texi
> >>+++ b/doc/filters.texi
> >>@@ -10146,8 +10146,8 @@ activated. Default is @code{0}.
> >>
> >> @item size
> >> Set the video size. This option is for video only. For the syntax of this
> >>-option, check the "Video size" section in the ffmpeg-utils manual. Default
> >>-and minimum resolution is @code{640x480}.
> >>+option, check the "Video size" section in the ffmpeg-utils manual. The default
> >>+resolution is @code{640x480}, the minimum is @code{480x102}.
> >>
> >
> >Quoting the EBU 3341:
> > An ‘EBU Mode’ meter shall offer two scales, for when a scale is shown,
> > selectable by the user:
> > 1. range -18.0 LU to +9.0 LU (-41.0 LUFS to -14.0 LUFS), named ‘EBU +9
> > scale’
> > 2. range -36.0 LU to +18.0 LU (-59.0 LUFS to -5.0 LUFS), named ‘EBU +18
> > scale’
> >
> >When you go down to 480x102, the printed range becomes [-16;+8] LU for +9
> >scale and [-32;+16] LU for +18 scale (see meter option). I think these
> >range boundaries should be preserved in the output.
> >
> 
> The proper range is still shown in the graph, only the legend lacks the
> value for the up and the bottom of the graph.
> 
> If you insist on showing the values for the top and the bottom of the graph,
> then in order for the lines to remain simmetrical, you will have to start
> showing rounded or non-whole values. Or if you insist on whole values, you
> may will not be able to show the lines with the same distance from each
> other.
> 
> What would be the approach you prefer in order to be able to show smaller
> graphs?

I think the boundaries are important, so what about printing a warning if
the grain of the legend can't be kept?

(note: sorry about the delay between my replies)

-- 
Clément B.
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