CMSIS-DSP: MFCC F32
MFCC F32 implementation
MFCC F32 tests
MFCC F32 in Python wrapper
Python wrapper structure updated to support submodule like
cmsisdsp.mfcc and cmsisdsp.fixedpoint
PythonWrapper tests updated to use the new fixedpoint
cmsisdsp.mfcc is used to generate the mel filter, dct and window coefficients.
diff --git a/CMSIS/DSP/Scripts/mfccdata.py b/CMSIS/DSP/Scripts/mfccdata.py
new file mode 100755
index 0000000..80546d5
--- /dev/null
+++ b/CMSIS/DSP/Scripts/mfccdata.py
@@ -0,0 +1,231 @@
+###########################################
+# Project: CMSIS DSP Library
+# Title: mfccdata.py
+# Description: Generation of MFCC arays for the MFCC C init function
+#
+# $Date: 07 September 2021
+# $Revision: V1.10.0
+#
+# Target Processor: Cortex-M and Cortex-A cores
+# -------------------------------------------------------------------- */
+#
+# Copyright (C) 2010-2021 ARM Limited or its affiliates. All rights reserved.
+#
+# SPDX-License-Identifier: Apache-2.0
+#
+# Licensed under the Apache License, Version 2.0 (the License); you may
+# not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an AS IS BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+############################################
+import numpy as np
+from jinja2 import Environment, PackageLoader, select_autoescape,FileSystemLoader
+import os.path
+import struct
+import scipy.signal as sig
+
+def to_q31(v):
+ r = int(round(v * 2**31))
+ if (r > 0x07FFFFFFF):
+ r = 0x07FFFFFFF
+ if (r < -0x080000000):
+ r = -0x080000000
+ return ("0x%s" % format(struct.unpack('<I', struct.pack('<i', r))[0],'08X'))
+
+def to_q15(v):
+ r = int(round(v * 2**15))
+ if (r > 0x07FFF):
+ r = 0x07FFF
+ if (r < -0x08000):
+ r = -0x08000
+ return ("0x%s" % format(struct.unpack('<H', struct.pack('<h', r))[0],'04X'))
+
+def to_f16(v):
+ return("(float16_t)%f" % struct.unpack('<e',struct.pack('<e',v)))
+
+def to_f32(v):
+ return("%ff" % struct.unpack('<f',struct.pack('<f',v)))
+
+class ConvertArray:
+ def __init__(self,theType):
+ self._cvt = lambda x : x
+ if theType=="f32":
+ self._cvt = to_f32
+ if theType=="f16":
+ self._cvt = to_f16
+ if theType=="q31":
+ self._cvt = to_q31
+ if theType=="q15":
+ self._cvt = to_q15
+
+ def getArrayContent(self,samples):
+ nb = 0
+ res=""
+ res += "{\n"
+ for sample in samples:
+ res += str(self._cvt(sample))
+ res += ","
+ nb = nb + 1
+ if nb == 10:
+ res += "\n"
+ nb = 0
+ res += "}"
+ return(res)
+
+
+
+def frequencyToMelSpace(freq):
+ return 1127.0 * np.log(1.0 + freq / 700.0)
+
+def melSpaceToFrequency(mels):
+ return 700.0 * (np.exp(mels / 1127.0) - 1.0)
+
+def melFilterMatrix(fmin, fmax, numOfMelFilters,fs,FFTSize):
+
+ filters = np.zeros((numOfMelFilters,int(FFTSize/2+1)))
+ zeros = np.zeros(int(FFTSize // 2 ))
+
+
+ fmin_mel = frequencyToMelSpace(fmin)
+ fmax_mel = frequencyToMelSpace(fmax)
+ mels = np.linspace(fmin_mel, fmax_mel, num=numOfMelFilters+2)
+
+
+ linearfreqs = np.linspace( 0, fs/2.0, int(FFTSize // 2 + 1) )
+ spectrogrammels = frequencyToMelSpace(linearfreqs)[1:]
+
+
+ filtPos=[]
+ filtLen=[]
+ totalLen = 0
+ packedFilters = []
+ for n in range(numOfMelFilters):
+
+
+ upper = (spectrogrammels - mels[n])/(mels[n+1]-mels[n])
+ lower = (mels[n+2] - spectrogrammels)/(mels[n+2]-mels[n+1])
+
+
+ filters[n, :] = np.hstack([0,np.maximum(zeros,np.minimum(upper,lower))])
+ nb = 0
+ startFound = False
+ for sample in filters[n, :]:
+ if not startFound and sample != 0.0:
+ startFound = True
+ startPos = nb
+
+ if startFound and sample == 0.0:
+ endPos = nb - 1
+ break
+ nb = nb + 1
+ filtLen.append(endPos - startPos+1)
+ totalLen += endPos - startPos + 1
+ filtPos.append(startPos)
+ packedFilters += list(filters[n, startPos:endPos+1])
+
+ return filtLen,filtPos,totalLen,packedFilters,filters
+
+
+def dctMatrix(numOfDctOutputs, numOfMelFilters):
+
+ result = np.zeros((numOfDctOutputs,numOfMelFilters))
+ s=(np.linspace(1,numOfMelFilters,numOfMelFilters) - 0.5)/numOfMelFilters
+
+ for i in range(0, numOfDctOutputs):
+ result[i,:]=np.cos(i * np.pi*s) * np.sqrt(2.0/numOfMelFilters)
+
+ return result
+
+
+def ctype(s):
+ if s == "f64":
+ return("float64_t")
+ if s == "f32":
+ return("float32_t")
+ if s == "f16":
+ return("float16_t")
+ if s == "q31":
+ return("q31_t")
+ if s == "q15":
+ return("q15_t")
+
+def typeext(s):
+ if s == "f64":
+ return("_f64")
+ if s == "f32":
+ return("_f32")
+ if s == "f16":
+ return("_f16")
+ if s == "q31":
+ return("_q31")
+ if s == "q15":
+ return("_q15")
+
+def prepareWindowConfig(configs):
+ # sig.hamming(FFTSize, sym=False)
+ for config in configs:
+ c=configs[config]
+ if c["win"] == "hamming":
+ win = sig.hamming(c["fftlength"], sym=False)
+ if c["win"] == "hanning":
+ win = sig.hann(c["fftlength"], sym=False)
+
+ cvt=ConvertArray(c["type"])
+ c["ctype"]=ctype(c["type"])
+ c["ext"]=typeext(c["type"])
+
+ c["winSamples"] = cvt.getArrayContent(win)
+
+def prepareMelconfig(configs):
+ for config in configs:
+ c=configs[config]
+
+ cvt=ConvertArray(c["type"])
+ cvtInt=ConvertArray(None)
+ c["ctype"]=ctype(c["type"])
+ c["ext"]=typeext(c["type"])
+
+ filtLen,filtPos,totalLen,packedFilters,filters = melFilterMatrix(c["fmin"], c["fmax"], c["melFilters"],c["samplingRate"],c["fftlength"])
+
+ c["filtLenArray"]=cvtInt.getArrayContent(filtLen)
+ c["filtPosArray"]=cvtInt.getArrayContent(filtPos)
+ c["totalLen"]=totalLen
+ c["filters"]=cvt.getArrayContent(packedFilters)
+
+def prepareDctconfig(configs):
+ for config in configs:
+ c=configs[config]
+
+ cvt=ConvertArray(c["type"])
+ c["ctype"]=ctype(c["type"])
+ c["ext"]=typeext(c["type"])
+ c["dctMatrixLength"]=c["dctOutputs"] * c["melFilters"]
+
+ dctMat = dctMatrix(c["dctOutputs"],c["melFilters"])
+ dctMat=dctMat.reshape(c["dctMatrixLength"])
+ c["dctMatrix"]=cvt.getArrayContent(dctMat)
+
+ #print(configs)
+
+env = Environment(
+ loader=PackageLoader("mfccdata","mfcctemplates"),
+ autoescape=select_autoescape(),
+ trim_blocks=True
+ )
+
+ctemplate = env.get_template("mfccdata.c")
+htemplate = env.get_template("mfccdata.h")
+
+
+def genMfccHeader(f,configs,filename):
+ print(htemplate.render(configs=configs,filename=filename),file=f)
+
+def genMfccInit(f,configs,filename):
+ print(ctemplate.render(configs=configs,filename=filename),file=f)
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