source: python/aubiocut @ 7445aea

#!/usr/bin/python

""" this file was written by Paul Brossier 
  it is released under the GNU/GPL license.
"""

from aubio.aubioclass import *
import sys

bufsize   = 1024
hopsize   = bufsize/2

def getonsets(filein,threshold):
        frameread = 0
        filei     = sndfile(filein)
        srate     = filei.samplerate()
        channels  = filei.channels()
        myvec     = fvec(hopsize,channels)
        readsize  = filei.read(hopsize,myvec)
        opick     = onsetpick(bufsize,hopsize,channels,myvec,threshold)
        #newname   = "%s%.8f%s" % ("/tmp/",0.0000000,filein[-4:])
        #fileo     = sndfile(newname,model=filei)
        mylist    = list()
        ovalist   = [0., 0., 0., 0., 0., 0.]
        while(readsize==hopsize):
                readsize = filei.read(hopsize,myvec)
                isonset,val = opick.do(myvec)
                ovalist.append(val)
                ovalist.pop(0)
                if (isonset == 1):
                        i=len(ovalist)-1
                        # find local minima 
                        while ovalist[i-1] < ovalist[i] and i > 0:
                                i -= 1
                        now = (frameread+1-i)*hopsize/(srate+0.)
                        mylist.append(now)
                frameread += 1
        return mylist

def cutfile(filein,onsets):
        frameread = 0
        readsize  = hopsize 
        filei     = sndfile(filein)
        srate     = filei.samplerate()
        channels  = filei.channels()
        newname   = "%s%f%s" % ("/tmp/",0.0000000,filein[-4:])
        fileo     = sndfile(newname,model=filei)
        myvec     = fvec(hopsize,channels)
        mycopy    = fvec(hopsize,channels)
        while(readsize==hopsize):
                readsize = filei.read(hopsize,myvec)
                now = (frameread)*hopsize/(srate+0.)
                # write to current file
                if len(onsets) and now >= onsets[0]:
                    onsets.pop(0)
                    # write up to 1st zero crossing
                    zerocross = 0
                    while ( abs( myvec.get(zerocross,0) ) > 0.002 ):
                        zerocross += 1
                    writesize = fileo.write(zerocross,myvec)
                    fromcross = 0
                    while (zerocross < readsize):
                        for i in range(channels):
                                mycopy.set(myvec.get(zerocross,i),fromcross,i)
                        fromcross += 1
                        zerocross += 1
                    del fileo
                    fileo = sndfile("%s%s%f%s%s" % 
                        (filein.split(".")[0].split("/")[-1],".",now,".",filein.split(".")[-1]),model=filei)
                    # write after 1st zero crossing to new file
                    writesize = fileo.write(fromcross,mycopy)
                else:
                    writesize = fileo.write(readsize,myvec)
                frameread += 1
        del fileo

filename  = sys.argv[1]
threshold = sys.argv[2]
onsets    = getonsets(filename,threshold)
cutfile(filename,onsets)