# FFT Spectrum nullPtr
**URL:** https://qa.fmod.com/t/fft-spectrum-nullptr/12242
**Category:** FMOD Engine
**Created:** [January 13, 2016, 5:32pm UTC](https://qa.fmod.com/t/fft-spectrum-nullptr/12242 "2016-01-13T17:32:50Z")
**Posts on this page:** 8
**Page:** 1
### Author:  [@international01](https://qa.fmod.com/u/international01)
#### Post date: [January 13, 2016, 5:32pm UTC](https://qa.fmod.com/t/fft-spectrum-nullptr/12242/1 "2016-01-13T17:32:50Z")
Hello there,
Can you even look at my code something can not be right since .
I always bekomm the error message FFT what nullptr .
```
#pragma comment(lib,"fmod64_vc.lib")
using namespace std;
FMOD::System* fmodSystem;
FMOD::Sound *music;
FMOD::Channel* musicChannel = 0;
FMOD_RESULT result;
FMOD::DSP *dsp1;
FMOD_DSP_PARAMETER_FFT *fft;
int fmodini()
{
if (FAILED(result = FMOD::System_Create(&fmodSystem))) {
MessageBox(NULL, "Failed", "Failed", MB_OK | MB_ICONEXCLAMATION);
}
if (FAILED(result = fmodSystem->init(32, FMOD_INIT_NORMAL, NULL))) {
MessageBox(NULL, "Failed", "Failed", MB_OK | MB_ICONEXCLAMATION);
}
if (FAILED(result = fmodSystem->createStream("Hawaii5O.mp3", FMOD_DEFAULT, 0, &music))) {
MessageBox(NULL, "Failed", "Failed", MB_OK | MB_ICONEXCLAMATION);
}
if (FAILED(result = fmodSystem->playSound(music, 0, false, &musicChannel))) {
MessageBox(NULL, "Failed", "Failed", MB_OK | MB_ICONEXCLAMATION);
}
fmodSystem->createDSPByType(FMOD_DSP_TYPE::FMOD_DSP_TYPE_FFT, &dsp1);
musicChannel->addDSP(FMOD_DSP_PARAMETER_DATA_TYPE_FFT, dsp1);
dsp1->getParameterData(FMOD_DSP_FFT_SPECTRUMDATA, (void **)fft, 0, 0, 0);
return 0;
}
```
Always in accessing the variable \* fft I get the error message .
---
### Author:  [@nick1](https://qa.fmod.com/u/nick1)
#### Post date: [January 13, 2016, 11:36pm UTC](https://qa.fmod.com/t/fft-spectrum-nullptr/12242/2 "2016-01-13T23:36:58Z")
As a rule you should check the return code of all FMOD functions.
Channel::addDSP will be returning INVALID\_PARAM because the first argument is wrong. It specifies the position in the DSP chain to add, not the DSP type.
Try
```
result = musicChannel->addDSP(FMOD_CHANNELCONTROL_DSP_HEAD, dsp1);
```
Which places the DSP at the head of the channels effect chain.
---
### Author:  [@international01](https://qa.fmod.com/u/international01)
#### Post date: [January 14, 2016, 4:08pm UTC](https://qa.fmod.com/t/fft-spectrum-nullptr/12242/3 "2016-01-14T16:08:42Z")
Thanks for the help.
I have modified the code and have carried out a test
the result.
float test = FFT \> lenght ;
result = FFT \> lenght \< Unable to read memory \>
result = FFT \> numChannels \< Unable to read memory \>
fft was nullptr.
---
### Author:  [@international01](https://qa.fmod.com/u/international01)
#### Post date: [January 14, 2016, 6:27pm UTC](https://qa.fmod.com/t/fft-spectrum-nullptr/12242/4 "2016-01-14T18:27:10Z")
OK thanks for the help.
Have solved the problem .
When you enter this code
result = dsp1- \> getParameterData ( FMOD\_DSP\_FFT\_SPECTRUMDATA , (void \*\* ) & FFT , 0 , 0 , 0 ) ;
Must be a ( & ) character before the pointer ( \* FFT ) are set .
Without it does not go with me .
---
### Author:  [@international01](https://qa.fmod.com/u/international01)
#### Post date: [January 14, 2016, 8:56pm UTC](https://qa.fmod.com/t/fft-spectrum-nullptr/12242/5 "2016-01-14T20:56:22Z")
I need a little help again .
I get all zeros as output .
if (FAILED(result = dsp1-\>getParameterData(FMOD\_DSP\_FFT\_SPECTRUMDATA, (void \*\*)&fft, 0, 0, 0))) {
MessageBox(NULL, “Failed”, “Failed”, MB\_OK | MB\_ICONEXCLAMATION);
}
```
for (int channel = 0; channel < fft->numchannels; channel++) {
for (int lenght = 0; lenght < fft->length; lenght++) {
fmoddata = fft->spectrum[channel][lenght];
}
}
result=fmodSystem->update();
```
---
### Author:  [@international01](https://qa.fmod.com/u/international01)
#### Post date: [January 17, 2016, 9:54pm UTC](https://qa.fmod.com/t/fft-spectrum-nullptr/12242/6 "2016-01-17T21:54:22Z")
> [@](#):
>
> I need a little help again .
>
> I get all zeros as output .
>
> if (FAILED(result = dsp1-\>getParameterData(FMOD\_DSP\_FFT\_SPECTRUMDATA, (void \*\*)&fft, 0, 0, 0))) {
> MessageBox(NULL, “Failed”, “Failed”, MB\_OK | MB\_ICONEXCLAMATION);
> }
>
> ```
> for (int channel = 0; channel < fft->numchannels; channel++) {
> for (int lenght = 0; lenght < fft->length; lenght++) {
> fmoddata = fft->spectrum[channel][lenght];
> }
> }
>
> result=fmodSystem->update();
>
> ```
Thank you have the problem found .
Did reading the data easy in the message loop in mainthread called and so the data is read continuously , and are no longer zero .
---
### Author:  [@nick1](https://qa.fmod.com/u/nick1)
#### Post date: [January 14, 2016, 11:58pm UTC](https://qa.fmod.com/t/fft-spectrum-nullptr/12242/7 "2016-01-14T23:58:44Z")
You need to let the sound play and read the spectrum continuously.
---
### Author:  [@international01](https://qa.fmod.com/u/international01)
#### Post date: [January 15, 2016, 1:03pm UTC](https://qa.fmod.com/t/fft-spectrum-nullptr/12242/8 "2016-01-15T13:03:38Z")
Whit this code,I get all zeros.
dsp1-\>setBypass(false);
dsp1-\>setActive(TRUE);
```
if (FAILED(result = FMOD::System_Create(&fmodSystem))) {
MessageBox(NULL, "Failed", "Failed", MB_OK | MB_ICONEXCLAMATION);
}
if (FAILED(result = fmodSystem->init(32, FMOD_INIT_NORMAL, NULL))) {
MessageBox(NULL, "Failed", "Failed", MB_OK | MB_ICONEXCLAMATION);
}
if (FAILED(result = fmodSystem->createStream("Hawaii5O.mp3", FMOD_DEFAULT, 0, &music))) {
MessageBox(NULL, "Failed", "Failed", MB_OK | MB_ICONEXCLAMATION);
}
if (FAILED(result = fmodSystem->playSound(music, 0,FALSE, &musicChannel))) {
MessageBox(NULL, "Failed", "Failed", MB_OK | MB_ICONEXCLAMATION);
}
if (FAILED(result = fmodSystem->createDSPByType(FMOD_DSP_TYPE::FMOD_DSP_TYPE_FFT, &dsp1))) {
MessageBox(NULL, "Failed", "Failed", MB_OK | MB_ICONEXCLAMATION);
}
if (FAILED(result = musicChannel->addDSP(FMOD_DSP_PARAMETER_DATA_TYPE_FFT, dsp1))) {
MessageBox(NULL, "Failed", "Failed", MB_OK | MB_ICONEXCLAMATION);
}
if (FAILED(result = dsp1->getParameterData(FMOD_DSP_FFT_SPECTRUMDATA, (void **)&fft, 0, 0,0))) {
MessageBox(NULL, "Failed", "Failed", MB_OK | MB_ICONEXCLAMATION);
}
for (int channel = 0; channel < fft->numchannels; channel++) {
for (int lenght = 0; lenght < fft->length; lenght++) {
fmoddata = fft->spectrum[channel][lenght];
}
}
fmodSystem->update();
```
The sound runs.