chipaudette
commented
2 years ago Hi,
You have a lot happening in your code, so it's hard to know what is going wrong. Here are some thoughts:
-
You have the line
const int FFT_overlap_factor = 1;. Presumably, you are setting this to 1 because you want no overlap of your FFTs. I have never done this. I have only used 2 or 4. If you switch to 2, does it work? -
In your constuctor, you have the line
AudioMemory_F32(30, audio_settings);. This should not go here. It should be called only once and it should be placed in your program's overall "setup()" function. (Also, given how many operations you are doing in the frequency domain, you might want to increase this value to 60, instead of 30. This is just a guess.) -
I see that you use
complex_2N_buffer[0]andcomplex_2N_buffer[1]. I see where you allocate the memory for these two arrays via thenewcommand, which is great. But, where iscomplex_2N_bufferitself created? Somewhere, you must have a line likefloat* complex_2N_buffer[2];? -
In your
update()method, I see that you receive theleftandrightdata blocks, which is good. But, I also see that you do not release them in thisupdatemethod. This is not good practice. Instead, I see that you try to release these data blocks in yourprocess()method. But, it looks like there are paths through your code that would result in theleftorrightnot being released. Every time you receive but do not release, you lose the memory block forever. If you run out of memory blocks, your audio will stop. Memory leaks of audio blocks is my own most common bug. It is hard to get it right! The way to check to see if you are not releasing all of your memory blocks is to put a print statement in your mainloop()function and to watch your usage going up to the maximum that you have allocated (via your AudioMemory_F32() call). If you have a leak, you will quickly consume all of the blocks that you allocated. In yourloop()function, you can print your audio memory use via:
Serial.print("MEM Cur/Pk: ");
Serial.print(AudioMemoryUsage_F32());
Serial.print("/");
Serial.print(AudioMemoryUsageMax_F32());
Serial.println();- Finally, your approach of using
#ifdef FFT_Noise_Subtractionis a good approach. Unfortunately, when you try this approach and the system fails to play audio, you do not know if it is failing because of a memory leak (see previous bullet) or because the FFT / IFFT are failing, or because the NoiseReduction is failing. I suggest that you continue narrowing down the code using this#ifapproach. For example, if putt a#ifjust around the calls to the NoiseReduction itself, you will see if it is the cause of yor problem. Specifically, I suggest that you put the#ifand the#endifin your code like the example below. If you do it this way, the system will use the FFT and IFFT, but it will not use the NoiseReduction. If the code fails to produce audio, you know that your problem is something other than the noise reduction. However, if the code does produce audio, then you know that your problem is the noise reduction. That would be progress!
//convert to frequency domain
myFFT_Right.execute(in_audio_block_right, complex_2N_buffer[0]);
myFFT_Left.execute(in_audio_block_left, complex_2N_buffer[1]);
AudioStream_F32::release(in_audio_block_right);
AudioStream_F32::release(in_audio_block_left);
//define some variables
#if 0 //ADD THIS LINE
noiseReduction_right.processAudioFD(complex_2N_buffer[0], myFFT_Right.getNFFT()); //in your derived class, overwrite this!!
noiseReduction_left.processAudioFD(complex_2N_buffer[1], myFFT_Left.getNFFT()); //in your derived class, overwrite this!!
#endif //AND ADD THIS LINE
//rebuild the negative frequency space
myFFT_Right.rebuildNegativeFrequencySpace(complex_2N_buffer[0]); //set the negative frequency space based on the positive
myFFT_Left.rebuildNegativeFrequencySpace(complex_2N_buffer[1]); //set the negative frequency space based on the positive
//call the IFFT
audio_block_f32_t *out_audio_block_right = myIFFT_Right.execute(complex_2N_buffer[0]); //out_block is pre-allocated in here.
audio_block_f32_t *out_audio_block_left = myIFFT_Left.execute(complex_2N_buffer[1]); //out_block is pre-allocated in here.Chip
michaelliesenberg
Hi,
i am trying to use the tympan library for my custom board. I use the TLV32ßADC6140 and everything is working fine.
I have a stereo input at 192kHz and i do an average down to 48kHz and after that i am trying to do a noice reduction but the audio output is zero. If i uncomment "#define FFT_Noise_Subtraction", everything is working fine, but using the noise subtraction algorithmus i dont see any audio signal output.
Here is my code:
Any idea?