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wavfile.py (enhanced)
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| # wavfile.py (Enhanced) | |
| # Date: 20190213_2328 Joseph Ernest | |
| # | |
| # URL: https://gist.github.com/josephernest/3f22c5ed5dabf1815f16efa8fa53d476 | |
| # Source: scipy/io/wavfile.py | |
| # | |
| # Added: | |
| # * read: also returns bitrate, cue markers + cue marker labels (sorted), loops, pitch | |
| # See https://web.archive.org/web/20141226210234/http://www.sonicspot.com/guide/wavefiles.html#labl | |
| # * read: 24 bit & 32 bit IEEE files support (inspired from wavio_weckesser.py from Warren Weckesser) | |
| # * read: added normalized (default False) that returns everything as float in [-1, 1] | |
| # * read: added forcestereo that returns a 2-dimensional array even if input is mono | |
| # | |
| # * write: can write cue markers, cue marker labels, loops, pitch | |
| # * write: 24 bit support | |
| # * write: can write from a float normalized in [-1, 1] | |
| # * write: 20180430_2335: bug fixed when size of data chunk is odd (previously, metadata could become unreadable because of this) | |
| # | |
| # * removed RIFX support (big-endian) (never seen one in 10+ years of audio production/audio programming), only RIFF (little-endian) are supported | |
| # * removed read(..., mmap) | |
| # | |
| # | |
| # Test: | |
| # ..\wav\____wavfile_demo.py | |
| """ | |
| Module to read / write wav files using numpy arrays | |
| Functions | |
| --------- | |
| `read`: Return the sample rate (in samples/sec) and data from a WAV file. | |
| `write`: Write a numpy array as a WAV file. | |
| """ | |
| from __future__ import division, print_function, absolute_import | |
| import numpy | |
| import struct | |
| import warnings | |
| import collections | |
| from operator import itemgetter | |
| class WavFileWarning(UserWarning): | |
| pass | |
| _ieee = False | |
| # assumes file pointer is immediately | |
| # after the 'fmt ' id | |
| def _read_fmt_chunk(fid): | |
| res = struct.unpack('<ihHIIHH',fid.read(20)) | |
| size, comp, noc, rate, sbytes, ba, bits = res | |
| if (comp != 1 or size > 16): | |
| if (comp == 3): | |
| global _ieee | |
| _ieee = True | |
| #warnings.warn("IEEE format not supported", WavFileWarning) | |
| else: | |
| warnings.warn("Unfamiliar format bytes", WavFileWarning) | |
| if (size>16): | |
| fid.read(size-16) | |
| return size, comp, noc, rate, sbytes, ba, bits | |
| # assumes file pointer is immediately | |
| # after the 'data' id | |
| def _read_data_chunk(fid, noc, bits, normalized=False): | |
| size = struct.unpack('<i',fid.read(4))[0] | |
| if bits == 8 or bits == 24: | |
| dtype = 'u1' | |
| bytes = 1 | |
| else: | |
| bytes = bits//8 | |
| dtype = '<i%d' % bytes | |
| if bits == 32 and _ieee: | |
| dtype = 'float32' | |
| data = numpy.fromfile(fid, dtype=dtype, count=size//bytes) | |
| if bits == 24: | |
| a = numpy.empty((len(data) // 3, 4), dtype='u1') | |
| a[:, :3] = data.reshape((-1, 3)) | |
| a[:, 3:] = (a[:, 3 - 1:3] >> 7) * 255 | |
| data = a.view('<i4').reshape(a.shape[:-1]) | |
| if noc > 1: | |
| data = data.reshape(-1,noc) | |
| if bool(size & 1): # if odd number of bytes, move 1 byte further (data chunk is word-aligned) | |
| fid.seek(1,1) | |
| if normalized: | |
| if bits == 8 or bits == 16 or bits == 24: | |
| normfactor = 2 ** (bits-1) | |
| data = numpy.float32(data) * 1.0 / normfactor | |
| return data | |
| def _skip_unknown_chunk(fid): | |
| data = fid.read(4) | |
| size = struct.unpack('<i', data)[0] | |
| if bool(size & 1): # if odd number of bytes, move 1 byte further (data chunk is word-aligned) | |
| size += 1 | |
| fid.seek(size, 1) | |
| def _read_riff_chunk(fid): | |
| str1 = fid.read(4) | |
| if str1 != b'RIFF': | |
| raise ValueError("Not a WAV file.") | |
| fsize = struct.unpack('<I', fid.read(4))[0] + 8 | |
| str2 = fid.read(4) | |
| if (str2 != b'WAVE'): | |
| raise ValueError("Not a WAV file.") | |
| return fsize | |
| def read(file, readmarkers=False, readmarkerlabels=False, readmarkerslist=False, readloops=False, readpitch=False, normalized=False, forcestereo=False): | |
| """ | |
| Return the sample rate (in samples/sec) and data from a WAV file | |
| Parameters | |
| ---------- | |
| file : file | |
| Input wav file. | |
| Returns | |
| ------- | |
| rate : int | |
| Sample rate of wav file | |
| data : numpy array | |
| Data read from wav file | |
| Notes | |
| ----- | |
| * The file can be an open file or a filename. | |
| * The returned sample rate is a Python integer | |
| * The data is returned as a numpy array with a | |
| data-type determined from the file. | |
| """ | |
| if hasattr(file,'read'): | |
| fid = file | |
| else: | |
| fid = open(file, 'rb') | |
| fsize = _read_riff_chunk(fid) | |
| noc = 1 | |
| bits = 8 | |
| #_cue = [] | |
| #_cuelabels = [] | |
| _markersdict = collections.defaultdict(lambda: {'position': -1, 'label': ''}) | |
| loops = [] | |
| pitch = 0.0 | |
| while (fid.tell() < fsize): | |
| # read the next chunk | |
| chunk_id = fid.read(4) | |
| if chunk_id == b'fmt ': | |
| size, comp, noc, rate, sbytes, ba, bits = _read_fmt_chunk(fid) | |
| elif chunk_id == b'data': | |
| data = _read_data_chunk(fid, noc, bits, normalized) | |
| elif chunk_id == b'cue ': | |
| str1 = fid.read(8) | |
| size, numcue = struct.unpack('<ii',str1) | |
| for c in range(numcue): | |
| str1 = fid.read(24) | |
| id, position, datachunkid, chunkstart, blockstart, sampleoffset = struct.unpack('<iiiiii', str1) | |
| #_cue.append(position) | |
| _markersdict[id]['position'] = position # needed to match labels and markers | |
| elif chunk_id == b'LIST': | |
| str1 = fid.read(8) | |
| size, type = struct.unpack('<ii', str1) | |
| elif chunk_id in [b'ICRD', b'IENG', b'ISFT', b'ISTJ']: # see http://www.pjb.com.au/midi/sfspec21.html#i5 | |
| _skip_unknown_chunk(fid) | |
| elif chunk_id == b'labl': | |
| str1 = fid.read(8) | |
| size, id = struct.unpack('<ii',str1) | |
| size = size + (size % 2) # the size should be even, see WAV specfication, e.g. 16=>16, 23=>24 | |
| label = fid.read(size-4).rstrip('\x00') # remove the trailing null characters | |
| #_cuelabels.append(label) | |
| _markersdict[id]['label'] = label # needed to match labels and markers | |
| elif chunk_id == b'smpl': | |
| str1 = fid.read(40) | |
| size, manuf, prod, sampleperiod, midiunitynote, midipitchfraction, smptefmt, smpteoffs, numsampleloops, samplerdata = struct.unpack('<iiiiiIiiii', str1) | |
| cents = midipitchfraction * 1./(2**32-1) | |
| pitch = 440. * 2 ** ((midiunitynote + cents - 69.)/12) | |
| for i in range(numsampleloops): | |
| str1 = fid.read(24) | |
| cuepointid, type, start, end, fraction, playcount = struct.unpack('<iiiiii', str1) | |
| loops.append([start, end]) | |
| else: | |
| warnings.warn("Chunk " + chunk_id + " skipped", WavFileWarning) | |
| _skip_unknown_chunk(fid) | |
| fid.close() | |
| if data.ndim == 1 and forcestereo: | |
| data = numpy.column_stack((data, data)) | |
| _markerslist = sorted([_markersdict[l] for l in _markersdict], key=lambda k: k['position']) # sort by position | |
| _cue = [m['position'] for m in _markerslist] | |
| _cuelabels = [m['label'] for m in _markerslist] | |
| return (rate, data, bits, ) \ | |
| + ((_cue,) if readmarkers else ()) \ | |
| + ((_cuelabels,) if readmarkerlabels else ()) \ | |
| + ((_markerslist,) if readmarkerslist else ()) \ | |
| + ((loops,) if readloops else ()) \ | |
| + ((pitch,) if readpitch else ()) | |
| def write(filename, rate, data, bitrate=None, markers=None, loops=None, pitch=None, normalized=False): | |
| """ | |
| Write a numpy array as a WAV file | |
| Parameters | |
| ---------- | |
| filename : file | |
| The name of the file to write (will be over-written). | |
| rate : int | |
| The sample rate (in samples/sec). | |
| data : ndarray | |
| A 1-D or 2-D numpy array of integer data-type. | |
| Notes | |
| ----- | |
| * Writes a simple uncompressed WAV file. | |
| * The bits-per-sample will be determined by the data-type. | |
| * To write multiple-channels, use a 2-D array of shape | |
| (Nsamples, Nchannels). | |
| """ | |
| # normalization and 24-bit handling | |
| if bitrate == 24: # special handling of 24 bit wav, because there is no numpy.int24... | |
| if normalized: | |
| data[data > 1.0] = 1.0 | |
| data[data < -1.0] = -1.0 | |
| a32 = numpy.asarray(data * (2 ** 23 - 1), dtype=numpy.int32) | |
| else: | |
| a32 = numpy.asarray(data, dtype=numpy.int32) | |
| if a32.ndim == 1: | |
| a32.shape = a32.shape + (1,) # Convert to a 2D array with a single column. | |
| a8 = (a32.reshape(a32.shape + (1,)) >> numpy.array([0, 8, 16])) & 255 # By shifting first 0 bits, then 8, then 16, the resulting output is 24 bit little-endian. | |
| data = a8.astype(numpy.uint8) | |
| else: | |
| if normalized: # default to 32 bit int | |
| data[data > 1.0] = 1.0 | |
| data[data < -1.0] = -1.0 | |
| data = numpy.asarray(data * (2 ** 31 - 1), dtype=numpy.int32) | |
| fid = open(filename, 'wb') | |
| fid.write(b'RIFF') | |
| fid.write(b'\x00\x00\x00\x00') | |
| fid.write(b'WAVE') | |
| # fmt chunk | |
| fid.write(b'fmt ') | |
| if data.ndim == 1: | |
| noc = 1 | |
| else: | |
| noc = data.shape[1] | |
| bits = data.dtype.itemsize * 8 if bitrate != 24 else 24 | |
| sbytes = rate * (bits // 8) * noc | |
| ba = noc * (bits // 8) | |
| fid.write(struct.pack('<ihHIIHH', 16, 1, noc, rate, sbytes, ba, bits)) | |
| # cue chunk | |
| if markers: # != None and != [] | |
| if isinstance(markers[0], dict): # then we have [{'position': 100, 'label': 'marker1'}, ...] | |
| labels = [m['label'] for m in markers] | |
| markers = [m['position'] for m in markers] | |
| else: | |
| labels = ['' for m in markers] | |
| fid.write(b'cue ') | |
| size = 4 + len(markers) * 24 | |
| fid.write(struct.pack('<ii', size, len(markers))) | |
| for i, c in enumerate(markers): | |
| s = struct.pack('<iiiiii', i + 1, c, 1635017060, 0, 0, c) # 1635017060 is struct.unpack('<i',b'data') | |
| fid.write(s) | |
| lbls = '' | |
| for i, lbl in enumerate(labels): | |
| lbls += b'labl' | |
| label = lbl + ('\x00' if len(lbl) % 2 == 1 else '\x00\x00') | |
| size = len(lbl) + 1 + 4 # because \x00 | |
| lbls += struct.pack('<ii', size, i + 1) | |
| lbls += label | |
| fid.write(b'LIST') | |
| size = len(lbls) + 4 | |
| fid.write(struct.pack('<i', size)) | |
| fid.write(b'adtl') # https://web.archive.org/web/20141226210234/http://www.sonicspot.com/guide/wavefiles.html#list | |
| fid.write(lbls) | |
| # smpl chunk | |
| if loops or pitch: | |
| if not loops: | |
| loops = [] | |
| if pitch: | |
| midiunitynote = 12 * numpy.log2(pitch * 1.0 / 440.0) + 69 | |
| midipitchfraction = int((midiunitynote - int(midiunitynote)) * (2**32-1)) | |
| midiunitynote = int(midiunitynote) | |
| #print(midipitchfraction, midiunitynote) | |
| else: | |
| midiunitynote = 0 | |
| midipitchfraction = 0 | |
| fid.write(b'smpl') | |
| size = 36 + len(loops) * 24 | |
| sampleperiod = int(1000000000.0 / rate) | |
| fid.write(struct.pack('<iiiiiIiiii', size, 0, 0, sampleperiod, midiunitynote, midipitchfraction, 0, 0, len(loops), 0)) | |
| for i, loop in enumerate(loops): | |
| fid.write(struct.pack('<iiiiii', 0, 0, loop[0], loop[1], 0, 0)) | |
| # data chunks | |
| fid.write(b'data') | |
| fid.write(struct.pack('<i', data.nbytes)) | |
| import sys | |
| if data.dtype.byteorder == '>' or (data.dtype.byteorder == '=' and sys.byteorder == 'big'): | |
| data = data.byteswap() | |
| data.tofile(fid) | |
| if data.nbytes % 2 == 1: # add an extra padding byte if data.nbytes is odd: https://web.archive.org/web/20141226210234/http://www.sonicspot.com/guide/wavefiles.html#data | |
| fid.write('\x00') | |
| # Determine file size and place it in correct | |
| # position at start of the file. | |
| size = fid.tell() | |
| fid.seek(4) | |
| fid.write(struct.pack('<i', size-8)) | |
| fid.close() |
Thanks for the code. Got an error with some .wav files though and I think I found the problem:
local variable normfactor referenced before assignment
-> see lines 97 and 98
I added the following line before (new line 96)
normfactor = 1.0
So if the program does not run through the if statement in line 95 the variable normfactor will be assigned and no error occurs.
hi
to be able to read some wave files, had to add this:
line 178: to read more wave files, added INAM, ltxt, and \x00 tags...
elif chunk_id in [b'ICRD', b'IENG', b'ISFT', b'ISTJ', b'INAM', b'ltxt', b'\x00\x00\x00\x00']: _skip_unknown_chunk(fid)
line 198: to avoid TypeError('can only concatenate str (not "bytes") to str')
warnings.warn("Chunk " + str(chunk_id) + " skipped", WavFileWarning)
Thanks!
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I had problems with large wav files until I changed to
<Imight be worth looking over if there are any other places where unsigned values are being read as signed