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Dark Killer
Joined: 25 Jan 2005
Posts: 32
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 Posted: Sun Aug 21, 2005 9:53 am Post subject: PSPTune 0.1 |
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PSPTune is a simple guitar tuner coded in LUA:
http://rapidshare.de/files/4196896/PSPTune_0.1-DK.rar.html
anyone have any idea why the wav files are playing back in poor quality? would it be better if I converted them to XM modules? |
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emumaniac
Joined: 08 May 2005
Posts: 79
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Shine
Joined: 03 Dec 2004
Posts: 728
Location: Germany
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| Posted: Mon Aug 22, 2005 12:54 am Post subject: Re: PSPTune 0.1 |
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| Dark Killer wrote: |
anyone have any idea why the wav files are playing back in poor quality? would it be better if I converted them to XM modules? |
You are playing multiple sounds at once, because everytime your controls function is called, another play command is started, until the button is released. There are 4 sound channels (I think), so you hear an overlay of 4 times your sound, started with some pause between. You should start a new sound only when the button state changes. Then it is possible to play chords as well with your program. Try this code:
| Code: |
oldPad = Controls.read()
function controls()
pad = Controls.read()
if pad ~= oldPad then
oldPad = pad
if pad:cross() then
lowe:play()
end
if pad:circle() then
astring:play()
end
if pad:triangle() then
dstring:play()
end
if pad:square() then
gstring:play()
end
if pad:l() then
bstring:play()
end
if pad:r() then
highe:play()
end
if pad:select() then
tabview()
end
end
end
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Some more improvements: the native sampling rate of the PSP is 22050 Hz, so it doesn't make sense to save it in higher sample rates, because it will be scaled down with quality loss on the PSP. And you should set your recordings to maximum gain, the peak level of your wav files are below -10 dB (with 0 dB = maximum digital amplitude). |
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Shine
Joined: 03 Dec 2004
Posts: 728
Location: Germany
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| Posted: Mon Aug 22, 2005 4:33 am Post subject: |
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I don't know anything about guitar tuning, but what about a clear sine, like from a tuning fork? The code below creates the notes for a guitar (change the baseFrequency, if necessary) and caches it as wave files on memory stick (this takes some 2 minutes on PSP for the first start, on the PC emulator on my PC 2 seconds, for every next start it reads it from memory stick).
Looks like Lua is a bit slow for synthesizing sounds, any ideas for a nice Lua interface or some good C library to include for a software synthesizer?
| Code: |
-- write a number as a 32 bit integer to a file
function write32(file, value)
value = math.floor(value)
file:write(string.char(math.mod(value, 256), math.mod(value / 256, 256), math.mod(value / 256 / 256, 256), math.mod(value / 256 / 256 / 256, 256)))
end
-- write a number as a 16 bit integer to a file
function write16(file, value)
value = math.floor(value)
if value < 0 then value = 65536 + value end
file:write(string.char(math.mod(value, 256), math.mod(value / 256, 256)))
end
-- write a samples array to as a wave file
function writeWave(filename, sampleRate, samples)
file = io.open(filename, "w")
file:write("RIFF") -- chunk id
len = table.getn(samples)
write32(file, 2 * len + 36) -- file size
file:write("WAVE") -- riff type
file:write("fmt ") -- format chunk id
write32(file, 16) -- chunk size
write16(file, 1) -- PCM/umcompressed
write16(file, 1) -- number of channels
write32(file, sampleRate) -- sample rate
write32(file, 2 * sampleRate) -- bytes per second
write16(file, 2) -- number of bytes per sample for all channels
write16(file, 16) -- number of bits per sample for one channel
file:write("data")
write32(file, 2 * len)
for i=1,len do write16(file, samples[i] * 32767) end
file:close()
end
-- create note table with frequency entry
function createNotes(octaveCount, base)
factor = math.pow(2, 1/12)
notes = {}
noteNames = { "c", "cs", "d", "ds", "e", "f", "fs", "g", "gs", "a", "as", "b" }
for octave = 1, octaveCount do
i = 0
for _, noteName in noteNames do
fullNoteName = noteName .. octave
notes[fullNoteName] = {}
notes[fullNoteName].freq = base * math.pow(factor, i)
i = i + 1
end
base = base * 2
end
return notes
end
baseFrequency = 440
notes = createNotes(3, baseFrequency)
-- create all guitar notes and cache on memory stick
sampleRate = 22050
pi = math.atan(1) * 4
guitarNotes = { "e1", "a1", "d2", "g2", "b2", "e3" }
for _, guitarNote in guitarNotes do
waveFilename = guitarNote .. ".wav"
file = io.open(waveFilename)
if file then
file:close()
else
samples = {}
step = 2 * pi * notes[guitarNote].freq / sampleRate
seconds = 3
for i = 0, sampleRate * seconds - 1 do
samples[i+1] = math.sin(step * i)
end
writeWave(waveFilename, sampleRate, samples)
end
notes[guitarNote].sound = Sound.load(waveFilename)
end
-- load guitar notes
lowe = notes.e1.sound
astring = notes.a1.sound
dstring = notes.d2.sound
gstring = notes.g2.sound
bstring = notes.b2.sound
highe = notes.e3.sound
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