shithub: aubio

Info  •  Files  •  Log  •  Branches

python/demos/demo_mfcc.py: add options to plot first and second derivatives, and set samplerate/win_s/hop_s, thanks to @jhoelzl (closes #68)

--- a/python/demos/demo_mfcc.py

+++ b/python/demos/demo_mfcc.py

@@ -2,20 +2,27 @@

 import sys

 from aubio import source, pvoc, mfcc

-from numpy import vstack, zeros

+from numpy import vstack, zeros, diff

-win_s = 512                 # fft size

-hop_s = win_s // 4          # hop size

 n_filters = 40              # must be 40 for mfcc

 n_coeffs = 13

-samplerate = 44100

 if len(sys.argv) < 2:

-    print("Usage: %s <source_filename>" % sys.argv[0])

+    print("Usage: %s <source_filename> [samplerate] [win_s] [hop_s] [mode]" % sys.argv[0])

+    print("  where [mode] can be 'delta' or 'ddelta' for first and second derivatives")

     sys.exit(1)

 source_filename = sys.argv[1]

+if len(sys.argv) > 2: samplerate = int(sys.argv[2])

+else: samplerate = 0

+if len(sys.argv) > 3: win_s = int(sys.argv[3])

+else: win_s = 512

+if len(sys.argv) > 4: hop_s = int(sys.argv[4])

+else: hop_s = win_s // 4

+if len(sys.argv) > 5: mode = sys.argv[5]

+else: mode = "default"

+

 samplerate = 0

 if len( sys.argv ) > 2: samplerate = int(sys.argv[2])

@@ -48,18 +55,28 @@

 wave.xaxis.set_visible(False)

 wave.yaxis.set_visible(False)

+# compute first and second derivatives

+if mode in ["delta", "ddelta"]:

+    mfccs = diff(mfccs, axis = 0)

+if mode == "ddelta":

+    mfccs = diff(mfccs, axis = 0)

+

 all_times = arange(mfccs.shape[0]) * hop_s

 n_coeffs = mfccs.shape[1]

 for i in range(n_coeffs):

     ax = plt.axes ( [0.1, 0.75 - ((i+1) * 0.65 / n_coeffs),  0.8, 0.65 / n_coeffs], sharex = wave )

     ax.xaxis.set_visible(False)

-    ax.yaxis.set_visible(False)

+    ax.set_yticks([])

+    ax.set_ylabel('%d' % i)

     ax.plot(all_times, mfccs.T[i])

 # add time to the last axis

-set_xlabels_sample2time( ax, frames_read, samplerate) 

+set_xlabels_sample2time( ax, frames_read, samplerate)

 #plt.ylabel('spectral descriptor value')

 ax.xaxis.set_visible(True)

-wave.set_title('MFCC for %s' % source_filename)

+title = 'MFCC for %s' % source_filename

+if mode == "delta": title = mode + " " + title

+elif mode == "ddelta": title = "double-delta" + " " + title

+wave.set_title(title)

 plt.show()