Greetings:
I'm a programmer new to working with DSP related algorithms and have run
into an issue with my current project. I need to ask the experts to get
some better understanding of this.
My question is can a wave file segment be pitch ****fted multiple octaves
up or down?
I have a wave file segment with these (Java audio format) characteristics:
PCM_SIGNED 25000.0 Hz, 16 bit, mono, 2 bytes/frame, little-endian
The unaltered sound/pitch of this segment occurs on key/note 55 where
middle C is note 60.
I need to use the samples from the wave segment to scale down to key/note
0 and up to note 67. I have a second wave segment that needs to go from
key/not 67 - 96.
With the authors permission, I am using the FFT routine found here
http://www.adetorres.com/keychanger/KeyChangerReadme.html
to ****ft the
segment up 1 octave (12 half steps) or down 1 octave (12 half steps).
This works fine for 1 octave in each direction and I am able to hear the
sound of the notes go lower 12 half steps and up 12 half steps. This
takes
me down to note 43 and up to 67. After the octave has passed, the lower
and upper half steps become in audible. I don't know how to ****ft the
wave
segment, an octave lower so that I can use the FFT routine keep ****fing it
downward. Is this possible?
I do not know if there is no more sound is because I have reached some
physical ceiling on the wave file properties or If I need to use some
other
technique to change the wave segment down multiple octaves.
Is there someone in this DSP community who can comment on this issue or
suggest a way that I might be able to achieve the lower picth ****ft with
the original segment?
Thanks.
Bill.
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