[Ardour-Dev] waveform display for master track

[Paul Davis]

> I'm thinking of leaving the bus system alone and adding a case where the 
> master bus pipes to a master track which generates the peakfiles but not 
> the waveform?

peakfiles are generated asynchronously by a thread that reads audio data
from disk. ergo, not only would this require somehow associated on-disk
data with an object that by definition (at present) doesn't have any, it
would also require changing or extending the entire method by which
peakfiles are computed. remember that because ardour is non-destructive
when it comes to data on disk, peakfile generation is a "set-and-forget"
operation - we compute the data for a given audiofile and then the task
is done, forever.it is not a task that we ever plan on doing multiple
times for a given piece of data, hence the current design. we also don't
want peakfile i/o to disk (which can be quite substantial) to interfere
at the thread level with the butler thread, which is why we don't
compute it in the disk butler thread. and we certainly can't compute it
*and* write it to disk from the audio thread.

finally, when ardour is fully zoomed in, it creates waveform images from
the *audio* data not the peakfiles. it could get very confusing to zoom
in and see the entire "track" vanish for no apparent reason.