code: def testZerodbPow(self):
      # zero input should return dct(lin2db(0)). Try with different sizes
      size = 1025
      val = pow2db(0)
      expected = DCT(inputSize=40, outputSize=13)(
          [val for x in range(40)]
      )
      while size > 256:
          bands, gfcc = GFCC(inputSize=size, logType="dbpow")(
              zeros(size)
          )
          self.assertEqualVector(gfcc, expected)
  
          # also assess that the thresholding is working
          self.assertTrue(
              not np.isnan(gfcc).any() and not np.isinf(gfcc).any()
          )
          size = int(size / 2)
  
file_path: essentia/test/src/unittests/spectral/test_gfcc.py
imports: from essentia_test import *
  from math import *
  import numpy
label_desc: Use image node_id 4 for calling the TestGFCC obj's underlying member method code with example usage: obj.testZerodbPow() without return types