lasp/lasp/lasp_measurement.py

565 lines
19 KiB
Python

#!/usr/bin/env python3
# -*- coding: utf-8 -*-
"""!
Author: J.A. de Jong - ASCEE
Description: Measurement class
The ASCEE hdf5 measurement file format contains the following fields:
- Attributes:
'version': If not given, version 1 is assumed. For version 1, measurement data
is assumed to be acoustic data.
'samplerate': The audio data sample rate in Hz.
'nchannels': The number of audio channels in the file
'sensitivity': (Optionally) the stored sensitivity of the record channels.
This can be a single value, or a list of sensitivities for
each channel. Both representations are allowed.
- Datasets:
'audio': 3-dimensional array of blocks of audio data. The first axis is the
block index, the second axis the sample number and the third axis is the channel
number. The data type is either int16, int32 or float64 / float32. In case the
data is stored as integers. The raw data should be scaled with the maximum value
that can be stored for the integer bit depth to get a number between -1.0 and
1.0.
'video': 4-dimensional array of video frames. The first index is the frame
number, the second the x-value of the pixel and the third is the
y-value of the pixel. Then, the last axis is the color. This axis has
length 3 and the colors are stored as (r,g,b). Where typically a
color depth of 256 is used (np.uint8 data format)
The video dataset can possibly be not present in the data.
"""
__all__ = ['Measurement', 'scaleBlockSens']
from contextlib import contextmanager
import h5py as h5
import numpy as np
from .lasp_config import LASP_NUMPY_FLOAT_TYPE
from scipy.io import wavfile
import os
import time
import wave
class BlockIter:
"""Iterate over the blocks in the audio data of a h5 file."""
def __init__(self, f):
"""Initialize a BlockIter object.
Args:
faudio: Audio dataset in the h5 file, accessed as f['audio']
"""
self.i = 0
self.nblocks = f['audio'].shape[0]
self.fa = f['audio']
def __iter__(self):
return self
def __next__(self):
"""Return the next block."""
if self.i == self.nblocks:
raise StopIteration
self.i += 1
return self.fa[self.i - 1][:, :]
def getSampWidth(dtype):
"""Returns the width of a single sample in bytes.
Args:
dtype: numpy dtype
Returns:
Size of a sample in bytes (int)
"""
if dtype in (np.int32, np.float32):
return 4
elif dtype == np.int16:
return 2
elif dtype == np.float64:
return 8
else:
raise ValueError('Invalid data type: %s' % dtype)
def scaleBlockSens(block, sens):
"""Scale a block of raw data to return raw acoustic pressure data.
Args:
block: block of raw data with integer data type
sensitivity: array of sensitivity coeficients for
each channel
"""
assert sens.ndim == 1
assert sens.size == block.shape[1]
if np.issubdtype(block.dtype.type, np.integer):
sw = getSampWidth(block.dtype)
fac = 2**(8 * sw - 1) - 1
else:
fac = 1.
return block.astype(LASP_NUMPY_FLOAT_TYPE) / fac / sens[np.newaxis, :]
def exportAsWave(fn, fs, data, force=False):
if '.wav' not in fn[-4:]:
fn += '.wav'
nchannels = data.shape[1]
sampwidth = getSampWidth(data.dtype)
if os.path.exists(fn) and not force:
raise RuntimeError('File already exists: %s', fn)
with wave.open(fn, 'w') as wf:
wf.setparams((nchannels, sampwidth, fs, 0, 'NONE', 'NONE'))
wf.writeframes(np.asfortranarray(data).tobytes())
class Measurement:
"""Provides access to measurement data stored in the h5 measurement file
format."""
def __init__(self, fn):
"""Initialize a Measurement object based on the filename."""
if '.h5' not in fn:
fn += '.h5'
# Full filepath
self.fn = fn
# Base filename
self.fn_base = os.path.split(fn)[1]
# Open the h5 file in read-plus mode, to allow for changing the
# measurement comment.
with h5.File(fn, 'r+') as f:
# Check for video data
try:
f['video']
self.has_video = True
except KeyError:
self.has_video = False
self.nblocks, self.blocksize, self.nchannels = f['audio'].shape
dtype = f['audio'].dtype
self.sampwidth = getSampWidth(dtype)
self.samplerate = f.attrs['samplerate']
self.N = (self.nblocks * self.blocksize)
self.T = self.N / self.samplerate
try:
self._channel_names = f.attrs['channel_names']
except KeyError:
# No channel names found in measurement file
self._channel_names = [f'Unnamed {i}' for i in range(self.nchannels)]
# comment = read-write thing
try:
self._comment = f.attrs['comment']
except KeyError:
f.attrs['comment'] = ''
self._comment = ''
# Sensitivity
try:
sens = f.attrs['sensitivity']
self._sens = sens * \
np.ones(self.nchannels) if isinstance(
sens, float) else sens
except KeyError:
self._sens = np.ones(self.nchannels)
self._time = f.attrs['time']
@property
def name(self):
"""Returns filename base without extension."""
return os.path.splitext(self.fn_base)[0]
@property
def channelNames(self):
return self._channel_names
@contextmanager
def file(self, mode='r'):
"""Contextmanager which opens the storage file and yields the file.
Args:
mode: Opening mode for the file. Should either be 'r', or 'r+'
"""
if mode not in ('r', 'r+'):
raise ValueError('Invalid file opening mode.')
with h5.File(self.fn, mode) as f:
yield f
@property
def comment(self):
"""Return the measurement comment.
Returns:
The measurement comment (text string)
"""
return self._comment
@comment.setter
def comment(self, cmt):
"""Set the measurement comment.
Args:
cmt: Comment text string to set
"""
with self.file('r+') as f:
# Update comment attribute in the file
f.attrs['comment'] = cmt
self._comment = cmt
@property
def recTime(self):
"""Returns the total recording time of the measurement, in float
seconds."""
return self.blocksize * self.nblocks / self.samplerate
@property
def time(self):
"""Returns the measurement time in seconds since the epoch."""
return self._time
def scaleBlock(self, block):
"""When the data is stored as integers, we assume dB full-scale
scaling. Hence, when we convert the data to floats, we divide by the
maximum possible value.
Returns:
Block of measurement data, scaled using sensitivity values and
retured as floating point values
"""
return scaleBlockSens(block, self.sensitivity)
@property
def prms(self):
"""Returns the root mean square of the uncalibrated rms sound pressure
level (equivalend SPL).
Returns:
1D array with rms values for each channel
"""
#
try:
return self._prms
except AttributeError:
pass
pms = 0.
with self.file() as f:
for block in self.iterBlocks(f):
block = self.scaleBlock(block)
pms += np.sum(block**2, axis=0) / self.N
self._prms = np.sqrt(pms)
return self._prms
def praw(self, block=None):
"""Returns the uncalibrated acoustic pressure signal, converted to
floating point acoustic pressure values [Pa]."""
if block is not None:
with self.file() as f:
blocks = f['audio'][block]
else:
blocks = []
with self.file() as f:
for block in self.iterBlocks(f):
blocks.append(block)
blocks = np.asarray(blocks)
blocks = blocks.reshape(self.nblocks * self.blocksize,
self.nchannels)
# Apply scaling (sensitivity, integer -> float)
blocks = self.scaleBlock(blocks)
return blocks
def iterBlocks(self, opened_file):
"""Iterate over all the audio blocks in the opened file.
Args:
opened_file: The h5File with the data
"""
return BlockIter(opened_file)
@property
def sensitivity(self):
"""Sensitivity of the data in Pa^-1, from floating point data scaled
between -1.0 and 1.0 to Pascal.
If the sensitivity is not stored in the measurement file, this
function returns 1.0
"""
return self._sens
def checkOverflow(self):
"""Coarse check for overflow in measurement.
Return:
True if overflow is possible, else False
"""
with self.file() as f:
for block in self.iterBlocks(f):
dtype = block.dtype
if dtype.kind == 'i':
# minvalue = np.iinfo(dtype).min
maxvalue = np.iinfo(dtype).max
if np.max(np.abs(block)) >= 0.9*maxvalue:
return True
else:
# Cannot check for floating point values.
return False
return False
@sensitivity.setter
def sensitivity(self, sens):
"""Set the sensitivity of the measurement in the file.
Args:
sens: sensitivity data, should be a float, or an array of floats
equal to the number of channels.
"""
if isinstance(sens, float):
# Put all sensitivities equal
sens = sens * np.ones(self.nchannels)
valid = sens.ndim == 1
valid &= sens.shape[0] == self.nchannels
valid &= sens.dtype == float
if not valid:
raise ValueError('Invalid sensitivity value(s) given')
with self.file('r+') as f:
f.attrs['sensitivity'] = sens
self._sens = sens
def exportAsWave(self, fn=None, force=False, newsampwidth=2, normalize=True):
"""Export measurement file as wave. In case the measurement data is
stored as floats, the values are scaled between 0 and 1.
Args:
fn: If given, this will be the filename to write to. If the
filename does not end with '.wav', this extension is added.
force: If True, overwrites any existing files with the given name
, otherwise a RuntimeError is raised.
newsampwidth: sample width in bytes with which to export the data.
This should only be given in case the measurement data is stored as
floating point values, otherwise an error is thrown
normalize: If set: normalize the level to something sensible.
"""
if fn is None:
fn = self.fn
fn = os.path.splitext(fn)[0]
if '.wav' not in fn[-4:]:
fn += '.wav'
if os.path.exists(fn) and not force:
raise RuntimeError(f'File already exists: {fn}')
with self.file() as f:
audio = f['audio']
oldsampwidth = getSampWidth(audio.dtype)
max_ = 1.
if normalize:
# Find maximum value
for block in self.iterBlocks(f):
blockmax = np.max(np.abs(block))
max_ = blockmax if blockmax > max_ else max_
# Scale with maximum value only if we have a nonzero maximum value.
if max_ == 0.:
max_ = 1.
if newsampwidth == 2:
newtype = np.int16
elif newsampwidth == 4:
newtype = np.int32
else:
raise ValueError('Invalid sample width, should be 2 or 4')
scalefac = 2**(8*(newsampwidth-oldsampwidth))
if normalize or isinstance(audio.dtype, float):
scalefac *= .01*max
with wave.open(fn, 'w') as wf:
wf.setparams((self.nchannels, self.sampwidth,
self.samplerate, 0, 'NONE', 'NONE'))
for block in self.iterBlocks(f):
# Convert block to integral data type
block = (block*scalefac).astype(newtype)
wf.writeframes(np.asfortranarray(block).tobytes())
@staticmethod
def fromtxt(fn,
skiprows,
samplerate,
sensitivity,
mfn=None,
timestamp=None,
delimiter='\t',
firstcoltime=True):
"""Converts a txt file to a LASP Measurement file, opens the associated
Measurement object and returns it. The measurement file will have the
same file name as the txt file, except with h5 extension.
Args:
fn: Filename of text file
skiprows: Number of header rows in text file to skip
samplerate: Sampling frequency in [Hz]
sensitivity: 1D array of channel sensitivities
mfn: Filepath where measurement file is stored. If not given,
a h5 file will be created along fn, which shares its basename
timestamp: If given, a custom timestamp for the measurement
(integer containing seconds since epoch). If not given, the
timestamp is obtained from the last modification time.
delimiter: Column delimiter
firstcoltime: If true, the first column is the treated as the
sample time.
"""
if not os.path.exists(fn):
raise ValueError(f'File {fn} does not exist.')
if timestamp is None:
timestamp = os.path.getmtime(fn)
if mfn is None:
mfn = os.path.splitext(fn)[0] + '.h5'
else:
mfn = os.path.splitext(mfn)[0] + '.h5'
dat = np.loadtxt(fn, skiprows=skiprows, delimiter=delimiter)
if firstcoltime:
time = dat[:, 0]
if not np.isclose(time[1] - time[0], 1 / samplerate):
raise ValueError('Samplerate given does not agree with '
'samplerate in file')
# Chop off first column
dat = dat[:, 1:]
nchannels = dat.shape[1]
if nchannels != sensitivity.shape[0]:
raise ValueError(
f'Invalid sensitivity length given. Should be: {nchannels}')
with h5.File(mfn, 'w') as hf:
hf.attrs['samplerate'] = samplerate
hf.attrs['sensitivity'] = sensitivity
hf.attrs['time'] = timestamp
hf.attrs['blocksize'] = 1
hf.attrs['nchannels'] = nchannels
ad = hf.create_dataset('audio', (1, dat.shape[0], dat.shape[1]),
dtype=dat.dtype,
maxshape=(1, dat.shape[0], dat.shape[1]),
compression='gzip')
ad[0] = dat
return Measurement(mfn)
@staticmethod
def fromnpy(data,
samplerate,
sensitivity,
mfn,
timestamp=None):
"""Converts a numpy array to a LASP Measurement file, opens the
associated Measurement object and returns it. The measurement file will
have the same file name as the txt file, except with h5 extension.
Args:
data: Numpy array, first column is sample, second is channel. Can
also be specified with a single column for single-channel data
samplerate: Sampling frequency in [Hz]
sensitivity: 1D array of channel sensitivities [Pa^-1]
mfn: Filepath where measurement file is stored.
timestamp: If given, a custom timestamp for the measurement
(integer containing seconds since epoch). If not given, the
timestamp is obtained from the last modification time.
delimiter: Column delimiter
firstcoltime: If true, the first column is the treated as the
sample time.
"""
if os.path.splitext(mfn)[1] != '.h5':
mfn += '.h5'
if os.path.exists(mfn):
raise ValueError(f'File {mfn} already exist.')
if timestamp is None:
timestamp = int(time.time())
if data.ndim != 2:
data = data[:, np.newaxis]
try:
len(sensitivity)
except:
raise ValueError('Sensitivity should be given as array-like data type')
sensitivity = np.asarray(sensitivity)
nchannels = data.shape[1]
if nchannels != sensitivity.shape[0]:
raise ValueError(
f'Invalid sensitivity length given. Should be: {nchannels}')
with h5.File(mfn, 'w') as hf:
hf.attrs['samplerate'] = samplerate
hf.attrs['sensitivity'] = sensitivity
hf.attrs['time'] = timestamp
hf.attrs['blocksize'] = 1
hf.attrs['nchannels'] = nchannels
ad = hf.create_dataset('audio', (1, data.shape[0], data.shape[1]),
dtype=data.dtype,
maxshape=(1, data.shape[0], data.shape[1]),
compression='gzip')
ad[0] = data
return Measurement(mfn)
@staticmethod
def fromWaveFile(fn, newfn=None, force=False, timestamp=None):
"""Convert a measurement file to a wave file, and return the
measurement handle."""
if timestamp is None:
timestamp = int(time.time())
base_fn = os.path.splitext(fn)[0]
if newfn is None:
newfn = base_fn + '.h5'
if os.path.exists(newfn) and not force:
raise RuntimeError(f'Measurement file name {newfn} already exists in path, set "force" to true to overwrite')
samplerate, data = wavfile.read(fn)
if data.ndim == 2:
nframes, nchannels = data.shape
else:
nchannels = 1
nframes = len(data)
data = data[:, np.newaxis]
sensitivity = np.ones(nchannels)
with h5.File(newfn, 'w') as hf:
hf.attrs['samplerate'] = samplerate
hf.attrs['nchannels'] = nchannels
hf.attrs['time'] = timestamp
hf.attrs['blocksize'] = 1
hf.attrs['sensitivity'] = sensitivity
ad = hf.create_dataset('audio', (1, nframes, nchannels),
dtype=data.dtype,
maxshape=(1, nframes, nchannels),
compression='gzip')
ad[0] = data
return Measurement(newfn)