Re: [ANNOUNCE] ly2video 0.3.0

[Adam Spiers]

On Tue, Jan 29, 2013 at 08:22:33PM +0100, David Kastrup wrote:
> Adam Spiers <address@hidden> writes:
> 
> >     + a new default scrolling mode where the notation stay still
> >       and the cursor line scrolls from left to right
> 
> You jump the notation leftwards.  You should rather _pull_ it left.

Yeah, this was my initial intention, since the video which lead to my
searching for something like ly2video and subsequent discovery of it
does already do this:

    http://www.youtube.com/watch?v=YC5mfm2C-ZI

In fact, I even already have a git branch where I started the
implementation.

> Start with a pixel per frame, increase the speed by 1 pixel/frame/frame
> until you are half through, then decrease by 1 pixel/frame/frame.  If
> this is not fast enough to keep the cursor on-screen, start earlier
> and/or faster.  Ok, the metrics are certainly debatable: you probably
> want everything over in 0.5 seconds or less, and want to have this in
> two phases (possibly more): acceleration and deceleration.

Nice.  I hadn't thought of doing it like that - I had only considered
a simple scroll with constant speed.

> But a mere discontinuous jump is confusing since it can happen when
> blinking.

Right, that's the obvious justification for the feature.  I have two
minor concerns: firstly, whether the scrolling can happen smoothly
enough within < 0.5 seconds, especially at lower frame rates, and
secondly, whether there is a significant risk of the scrolling
coinciding with playback of a particularly detailed / interesting bit
of the music where it would be more satisfactory to keep the notation
motionless.

However, since you and I both had pretty much the same idea, I think
that's a good enough sign that it should be implemented; filed as:

    https://github.com/aspiers/ly2video/issues/27

FYI, there's a related issue:

    https://github.com/aspiers/ly2video/issues/22

Thanks!
Adam