This has been overkill from the start, and it has been bugging me for a
long time. With this change, we're probably a bit slower on most
platforms but save huge amounts of space with all in-memory sample
datastructures.
The file is now renamed to Queue.h, and the Resampler APIs with
LegacyBuffer are also removed. These changes look large because nobody
actually needs Buffer.h (or Queue.h). It was mostly transitive
dependencies on the massive list of includes in that header, which are
now almost all gone. Instead, we include common things like Sample.h
directly, which should give faster compile times as very few files
actually need Queue.h.
Now that we have y-axis (gain) logarithmic display, we should also have
x-axis (frequency) logarithmic display; that's how our ears work. This
can be turned off with an option, but it generally looks much nicer.
For DSP reasons I can't explain myself (yet, sorry), short-time Fourier
transform (STFT) is much more accurate and aesthetically pleasing when
the windows that select the samples for STFT overlap. This implements
that behavior by storing the previous samples and performing windowed
FFT over both it as well as the current samples. This gives us 50%
overlap between windows, a common standard that is nice to look at.
The input to the FFT was distorted by the usage of fabs on the samples.
It led to a big DC offset and a distorted spectrum. Simply removing fabs
improves the quality of the spectrum a lot.
The FFT input should be windowed to reduce spectral leakage. This also
improves the visual quality of the spectrum.
Also, no need to do a FFT of the whole buffer if we only mean to render
64 bars. A 8192 point FFT may smooth out fast local changes but at 44100
hz samplerate that's 200 ms worth of sound which significantly reduces
FPS.
A better approach for a fluent visualization is to do small FFTs at the
current playing position inside the current buffer.
There may be a better way to get the current playing position, but for
now it's implemented as an estimation depending on how many frames where
already rendered with the current buffer.
Also I picked y-axis log scale as a default because there's usually a
big difference in energy between low and high frequency bands. log scale
looks nicer.
Visualization widgets should only have to tell how many samples they
need per frame and have a render method which receives all data relevant
to draw the next frame.
This is a first pass at refactoring SoundPlayer so that the View widget
is decoupled from the player itself.
In doing so, this fixed a couple of issues, including possibly
inconsistent states (e.g. player could be paused and stopped at the
same time).
With the change, Player actually controls the show, and calls methods
overriden by its subclasses to perform actions, such as update the Seek
bar; the hard work of massaging the raw data is done by the Player
class, so subclasses don't need to reimplement any of these things.
This also removes some copies of playlist management code that happened
to be copied+pasted inside callbacks of buttons -- it now lives inside
a neatly packaged Playlist class, and the Player only asks for the next
song to play.
In addition, the menu bar has been slightly rearranged.
SPDX License Identifiers are a more compact / standardized
way of representing file license information.
See: https://spdx.dev/resources/use/#identifiers
This was done with the `ambr` search and replace tool.
ambr --no-parent-ignore --key-from-file --rep-from-file key.txt rep.txt *
