Re: [Rosegarden-devel] rethinking audio

[Chris C. <ca...@al...>]

On Saturday 14 May 2005 22:23, Silvan wrote:
> So let's start the discussion from that question.  Why should audio
> be different?  What is wrong with the following scenarios?  What am I
> not thinking of?

Well, my gut feeling is that it's not a good idea to disregard the fact 
that audio really _is_ different, because it involves separate and 
potentially very large files on disc.  Also, they're more often (than 
MIDI segments) the results of a specific take made in real-time that 
might not be so easily repeatable.  This means, for example, that we 
don't want to risk doing anything that will simply remove a file if 
there's the slightest chance we may be mistaken.  Similarly, we want 
the user to have enough personal control to feel like they can make 
decisions about which files to keep and which to remove, from the 
perspective of e.g. avoiding running out of disc space.

I would feel more comfortable about having the sequencer manage audio 
files silently in this way if there was a stronger connection between 
the audio files and the composition file -- for example, if the 
composition was a tar file containing all its audio files (as a 
Rosegarden project file is -- but I think this is not the most 
practical thing for general load/save use) or if the user was expected 
not to mess around with audio files themselves, instead leaving them at 
Rosegarden's whim, in a project directory that Rosegarden created and 
named (as is the case for e.g. Ardour -- almost certainly a better 
scheme for audio projects, but it would be a right pain for plain MIDI 
and notation compositions).

> a) I record an audio segment.  A file X gets created on disk.  I
> don't like the recording.  I hit undo.  The file gets flagged for
> deletion.  I hit redo, the segment comes back, and the file is no
> longer flagged for deletion.

OK, problem 1: you can't keep deleting and re-recording takes because 
you'll run out of disc space because the files aren't actually being 
deleted.  You need the manual control to be able to say you definitely 
want to get rid of something.

You can say "well, when you record something new it can safely reuse 
file X because you've undone the original recording and when you do 
something new you lose the capability of invoking a redo".  But that's 
relying on a particular usage of yours -- i.e. you evidently seem 
inclined to hit Undo to discard a new recording, whereas someone else 
(e.g. me) would naturally select it and hit Delete.  Thus, Rosegarden 
would not be able to reuse the deleted segment in case the delete was 
later undone.

> [The project packager] does need testing though, and it is a very
> useful thing.  I intend to have a good play with it, and send you that
> small test project I promised umpty weeks ago.

You'll notice it's now integrated into the Rosegarden tree (File -> 
Export -> Export Rosegarden Project file...).

The main bug at the moment that I'm aware of is that it screws up when 
you ask it to unpack to a .rg file with a different basename from that 
of the .rgp file.  Not overwhelmingly hard to fix, just needs a few 
spare minutes here and there...


Chris