corrscope/ovgenpy/wave.py

94 wiersze
2.6 KiB
Python

from typing import NamedTuple, TYPE_CHECKING, Optional
import numpy as np
from scipy.io import wavfile
if TYPE_CHECKING:
from ovgenpy.triggers import Trigger
class WaveConfig(NamedTuple):
wave_path: str
# TODO color
# TODO wave-specific trigger options?
FLOAT = np.double
class Wave:
def __init__(self, wcfg: Optional[WaveConfig], wave_path: str):
self.cfg = wcfg
# TODO mmap
self.smp_s, self.data = wavfile.read(wave_path) # type: int, np.ndarray
self.nsamp = len(self.data)
self.trigger: Trigger = None
# Calculate scaling factor.
# TODO extract function, unit tests... switch to pysoundfile and drop logic
dtype = self.data.dtype
max_val = np.iinfo(dtype).max + 1
assert max_val & (max_val - 1) == 0 # power of 2
if np.issubdtype(dtype, np.uint):
self.offset = -max_val // 2
self.max_val = max_val // 2
else:
self.offset = 0
self.max_val = max_val
def __getitem__(self, index: int) -> 'np.ndarray[FLOAT]':
""" Copies self.data[item], converted to a FLOAT within range [-1, 1). """
data = self.data[index].astype(FLOAT)
data += self.offset
data /= self.max_val
return data
def get(self, begin: int, end: int):
""" Copies self.data[begin:end] with zero-padding. """
if 0 <= begin and end <= self.nsamp:
return self[begin:end]
region_len = end - begin
def constrain(idx):
delta = 0
if idx < 0:
delta = 0 - idx # delta > 0
assert idx + delta == 0
if idx > self.nsamp:
delta = self.nsamp - idx # delta < 0
assert idx + delta == self.nsamp
return delta, idx
delta_begin, begin = constrain(begin)
delta_end, end = constrain(end)
out = np.zeros(region_len, dtype=FLOAT)
# out[0 : region_len]. == self[begin: end]
# out[Δbegin : region_len+Δend] == self[begin + Δbegin: end + Δend]
out[delta_begin : region_len+delta_end] = self[begin+delta_begin : end+delta_end]
return out
def get_around(self, sample: int, region_len: int):
"""" Copies self.data[...] """
end = sample + region_len // 2
begin = end - region_len
return self.get(begin, end)
def set_trigger(self, trigger: 'Trigger'):
self.trigger = trigger
def get_s(self) -> float:
"""
:return: time (seconds)
"""
return self.nsamp / self.smp_s