bitlair/bitvis
8
0
Fork 0
Code Activity Actions

fixed: use a ringbuffer to avoid calling memmove on every sample

Browse source
This commit is contained in:
Bob 2012-11-08 21:42:55 +01:00
parent c7e683ac29
commit d872a79a27
2 changed files with 15 additions and 4 deletions
Download patch file Download diff file Expand all files Collapse all files

18
src/fft.cpp
View file

@ -27,6 +27,7 @@
Cfft::Cfft() Cfft::Cfft()
{ {
m_inbuf = NULL; m_inbuf = NULL;
m_inbufpos = 0;
m_fftin = NULL; m_fftin = NULL;
m_outbuf = NULL; m_outbuf = NULL;
m_window = NULL; m_window = NULL;
@ -69,6 +70,7 @@ void Cfft::Free()
fftw_free(m_outbuf); fftw_free(m_outbuf);
delete[] m_window; delete[] m_window;
m_inbuf = NULL; m_inbuf = NULL;
m_inbufpos = 0;
m_fftin = NULL; m_fftin = NULL;
m_outbuf = NULL; m_outbuf = NULL;
m_window = NULL; m_window = NULL;
@ -83,10 +85,16 @@ void Cfft::Free()
void Cfft::ApplyWindow() void Cfft::ApplyWindow()
{ {
float* in = m_inbuf; float* in = m_inbuf + m_inbufpos;
float* inend = m_inbuf + m_bufsize; float* inend = m_inbuf + m_bufsize;
float* window = m_window;
float* out = m_fftin; float* out = m_fftin;
float* window = m_window;
while (in != inend)
*(out++) = *(in++) * *(window++);
in = m_inbuf;
inend = m_inbuf + m_inbufpos;
while (in != inend) while (in != inend)
*(out++) = *(in++) * *(window++); *(out++) = *(in++) * *(window++);
@ -94,7 +102,9 @@ void Cfft::ApplyWindow()
void Cfft::AddSample(float sample) void Cfft::AddSample(float sample)
{ {
memmove(m_inbuf, m_inbuf + 1, (m_bufsize - 1) * sizeof(float)); m_inbuf[m_inbufpos] = sample;
m_inbuf[m_bufsize - 1] = sample; m_inbufpos++;
if (m_inbufpos == m_bufsize)
m_inbufpos = 0;
} }

1
src/fft.h
View file

@ -34,6 +34,7 @@ class Cfft
void AddSample(float sample); void AddSample(float sample);
float* m_inbuf; float* m_inbuf;
unsigned int m_inbufpos;
float* m_fftin; float* m_fftin;
float* m_window; float* m_window;
fftwf_complex* m_outbuf; fftwf_complex* m_outbuf;