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OpenDAS
Torchaudio
Commits
2f62e573
Unverified
Commit
2f62e573
authored
Jul 25, 2019
by
jamarshon
Committed by
GitHub
Jul 25, 2019
Browse files
A quick update of docstrings of kaldi.py and transforms.py (#163)
parent
51401084
Changes
2
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with
120 additions
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118 deletions
+120
-118
torchaudio/compliance/kaldi.py
torchaudio/compliance/kaldi.py
+115
-112
torchaudio/transforms.py
torchaudio/transforms.py
+5
-6
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torchaudio/compliance/kaldi.py
View file @
2f62e573
...
...
@@ -31,25 +31,25 @@ WINDOWS = [HAMMING, HANNING, POVEY, RECTANGULAR, BLACKMAN]
def
_next_power_of_2
(
x
):
"""
Returns the smallest power of 2 that is greater than x
r
"""Returns the smallest power of 2 that is greater than x
"""
return
1
if
x
==
0
else
2
**
(
x
-
1
).
bit_length
()
def
_get_strided
(
waveform
,
window_size
,
window_shift
,
snip_edges
):
"""
Given a waveform (1D tensor of size num_samples), it returns a 2D tensor (m, window_size)
r
"""Given a waveform (1D tensor of size
`
num_samples
`
), it returns a 2D tensor (m,
`
window_size
`
)
representing how the window is shifted along the waveform. Each row is a frame.
Input
s:
sig (
Tensor): Tensor of size num_samples
Arg
s:
waveform (torch.
Tensor): Tensor of size
`
num_samples
`
window_size (int): Frame length
window_shift (int): Frame shift
snip_edges (bool): If True, end effects will be handled by outputting only frames that completely fit
in the file, and the number of frames depends on the frame_length. If False, the number of frames
depends only on the frame_shift, and we reflect the data at the ends.
Output
:
Tensor: 2D tensor of size (m, window_size) where each row is a frame
Returns
:
torch.
Tensor: 2D tensor of size (m,
`
window_size
`
) where each row is a frame
"""
assert
waveform
.
dim
()
==
1
num_samples
=
waveform
.
size
(
0
)
...
...
@@ -79,7 +79,7 @@ def _get_strided(waveform, window_size, window_shift, snip_edges):
def
_feature_window_function
(
window_type
,
window_size
,
blackman_coeff
):
"""
Returns a window function with the given type and size
r
"""Returns a window function with the given type and size
"""
if
window_type
==
HANNING
:
return
torch
.
hann_window
(
window_size
,
periodic
=
False
)
...
...
@@ -101,7 +101,7 @@ def _feature_window_function(window_type, window_size, blackman_coeff):
def
_get_log_energy
(
strided_input
,
epsilon
,
energy_floor
):
"""
Returns the log energy of size (m) for a strided_input (m,*)
r
"""Returns the log energy of size (m) for a strided_input (m,*)
"""
log_energy
=
torch
.
max
(
strided_input
.
pow
(
2
).
sum
(
1
),
epsilon
).
log
()
# size (m)
if
energy_floor
==
0.0
:
...
...
@@ -111,11 +111,11 @@ def _get_log_energy(strided_input, epsilon, energy_floor):
torch
.
tensor
(
math
.
log
(
energy_floor
),
dtype
=
torch
.
get_default_dtype
()))
def
_get_waveform_and_window_properties
(
sig
,
channel
,
sample_frequency
,
frame_shift
,
def
_get_waveform_and_window_properties
(
waveform
,
channel
,
sample_frequency
,
frame_shift
,
frame_length
,
round_to_power_of_two
,
preemphasis_coefficient
):
"""Gets the waveform and window properties
r
"""Gets the waveform and window properties
"""
waveform
=
sig
[
max
(
channel
,
0
),
:]
# size (n)
waveform
=
waveform
[
max
(
channel
,
0
),
:]
# size (n)
window_shift
=
int
(
sample_frequency
*
frame_shift
*
MILLISECONDS_TO_SECONDS
)
window_size
=
int
(
sample_frequency
*
frame_length
*
MILLISECONDS_TO_SECONDS
)
padded_window_size
=
_next_power_of_2
(
window_size
)
if
round_to_power_of_two
else
window_size
...
...
@@ -131,10 +131,11 @@ def _get_waveform_and_window_properties(sig, channel, sample_frequency, frame_sh
def
_get_window
(
waveform
,
padded_window_size
,
window_size
,
window_shift
,
window_type
,
blackman_coeff
,
snip_edges
,
raw_energy
,
energy_floor
,
dither
,
remove_dc_offset
,
preemphasis_coefficient
):
"""Gets a window and its log energy
Outputs:
strided_input (Tensor): size (m, padded_window_size)
signal_log_energy (Tensor): size (m)
r
"""Gets a window and its log energy
Returns:
strided_input (torch.Tensor): size (m, `padded_window_size`)
signal_log_energy (torch.Tensor): size (m)
"""
# size (m, window_size)
strided_input
=
_get_strided
(
waveform
,
window_size
,
window_shift
,
snip_edges
)
...
...
@@ -180,7 +181,7 @@ def _get_window(waveform, padded_window_size, window_size, window_shift, window_
def
spectrogram
(
sig
,
blackman_coeff
=
0.42
,
channel
=-
1
,
dither
=
1.0
,
energy_floor
=
0.0
,
waveform
,
blackman_coeff
=
0.42
,
channel
=-
1
,
dither
=
1.0
,
energy_floor
=
0.0
,
frame_length
=
25.0
,
frame_shift
=
10.0
,
min_duration
=
0.0
,
preemphasis_coefficient
=
0.97
,
raw_energy
=
True
,
remove_dc_offset
=
True
,
round_to_power_of_two
=
True
,
sample_frequency
=
16000.0
,
snip_edges
=
True
,
...
...
@@ -189,37 +190,37 @@ def spectrogram(
compute-spectrogram-feats.
Args:
sig (
Tensor): Tensor of audio of size (c, n) where c is in the range [0,2)
blackman_coeff (float): Constant coefficient for generalized Blackman window. (
d
efault
=
0.42)
channel (int): Channel to extract (-1 -> expect mono, 0 -> left, 1 -> right) (
d
efault
=
-1)
waveform (torch.
Tensor): Tensor of audio of size (c, n) where c is in the range [0,2)
blackman_coeff (float): Constant coefficient for generalized Blackman window. (
D
efault
:
0.42)
channel (int): Channel to extract (-1 -> expect mono, 0 -> left, 1 -> right) (
D
efault
:
-1)
dither (float): Dithering constant (0.0 means no dither). If you turn this off, you should set
the energy_floor option, e.g. to 1.0 or 0.1 (
d
efault
=
1.0)
the energy_floor option, e.g. to 1.0 or 0.1 (
D
efault
:
1.0)
energy_floor (float): Floor on energy (absolute, not relative) in Spectrogram computation. Caution:
this floor is applied to the zeroth component, representing the total signal energy. The floor on the
individual spectrogram elements is fixed at std::numeric_limits<float>::epsilon(). (
d
efault
=
0.0)
frame_length (float): Frame length in milliseconds (
d
efault
=
25.0)
frame_shift (float): Frame shift in milliseconds (
d
efault
=
10.0)
min_duration (float): Minimum duration of segments to process (in seconds). (
d
efault
=
0.0)
preemphasis_coefficient (float): Coefficient for use in signal preemphasis (
d
efault
=
0.97)
raw_energy (bool): If True, compute energy before preemphasis and windowing (
d
efault
=
True)
remove_dc_offset: Subtract mean from waveform on each frame (
d
efault
=
True)
individual spectrogram elements is fixed at std::numeric_limits<float>::epsilon(). (
D
efault
:
0.0)
frame_length (float): Frame length in milliseconds (
D
efault
:
25.0)
frame_shift (float): Frame shift in milliseconds (
D
efault
:
10.0)
min_duration (float): Minimum duration of segments to process (in seconds). (
D
efault
:
0.0)
preemphasis_coefficient (float): Coefficient for use in signal preemphasis (
D
efault
:
0.97)
raw_energy (bool): If True, compute energy before preemphasis and windowing (
D
efault
:
True)
remove_dc_offset: Subtract mean from waveform on each frame (
D
efault
:
True)
round_to_power_of_two (bool): If True, round window size to power of two by zero-padding input
to FFT. (
d
efault
=
True)
to FFT. (
D
efault
:
True)
sample_frequency (float): Waveform data sample frequency (must match the waveform file, if
specified there) (
d
efault
=
16000.0)
specified there) (
D
efault
:
16000.0)
snip_edges (bool): If True, end effects will be handled by outputting only frames that completely fit
in the file, and the number of frames depends on the frame_length. If False, the number of frames
depends only on the frame_shift, and we reflect the data at the ends. (
d
efault
=
True)
depends only on the frame_shift, and we reflect the data at the ends. (
D
efault
:
True)
subtract_mean (bool): Subtract mean of each feature file [CMS]; not recommended to do
it this way. (
d
efault
=
False)
window_type (str): Type of window ('hamming'|'hanning'|'povey'|'rectangular'|'blackman') (
d
efault
=
'povey')
it this way. (
D
efault
:
False)
window_type (str): Type of window ('hamming'|'hanning'|'povey'|'rectangular'|'blackman') (
D
efault
:
'povey')
Returns:
Tensor:
a
spectrogram identical to what Kaldi would output. The shape is
torch.
Tensor:
A
spectrogram identical to what Kaldi would output. The shape is
(m, `padded_window_size` // 2 + 1) where m is calculated in _get_strided
"""
waveform
,
window_shift
,
window_size
,
padded_window_size
=
_get_waveform_and_window_properties
(
sig
,
channel
,
sample_frequency
,
frame_shift
,
frame_length
,
round_to_power_of_two
,
preemphasis_coefficient
)
waveform
,
channel
,
sample_frequency
,
frame_shift
,
frame_length
,
round_to_power_of_two
,
preemphasis_coefficient
)
if
len
(
waveform
)
<
min_duration
*
sample_frequency
:
# signal is too short
...
...
@@ -263,8 +264,7 @@ def mel_scale(freq):
def
vtln_warp_freq
(
vtln_low_cutoff
,
vtln_high_cutoff
,
low_freq
,
high_freq
,
vtln_warp_factor
,
freq
):
"""
This computes a VTLN warping function that is not the same as HTK's one,
r
"""This computes a VTLN warping function that is not the same as HTK's one,
but has similar inputs (this function has the advantage of never producing
empty bins).
...
...
@@ -289,15 +289,16 @@ def vtln_warp_freq(vtln_low_cutoff, vtln_high_cutoff, low_freq, high_freq,
frequency) is at l, then min(l, F(l)) == vtln_low_cutoff
This implies that l = vtln_low_cutoff / min(1, 1/vtln_warp_factor)
= vtln_low_cutoff * max(1, vtln_warp_factor)
Input
s:
vtln_low_cutoff (float):
l
ower frequency cutoffs for VTLN
vtln_high_cutoff (float):
u
pper frequency cutoffs for VTLN
low_freq (float):
l
ower frequency cutoffs in mel computation
high_freq (float):
u
pper frequency cutoffs in mel computation
Arg
s:
vtln_low_cutoff (float):
L
ower frequency cutoffs for VTLN
vtln_high_cutoff (float):
U
pper frequency cutoffs for VTLN
low_freq (float):
L
ower frequency cutoffs in mel computation
high_freq (float):
U
pper frequency cutoffs in mel computation
vtln_warp_factor (float): Vtln warp factor
freq (Tensor): given frequency in Hz
Outputs:
Tensor: freq after vtln warp
freq (torch.Tensor): given frequency in Hz
Returns:
torch.Tensor: Freq after vtln warp
"""
assert
vtln_low_cutoff
>
low_freq
,
'be sure to set the vtln_low option higher than low_freq'
assert
vtln_high_cutoff
<
high_freq
,
'be sure to set the vtln_high option lower than high_freq [or negative]'
...
...
@@ -332,16 +333,17 @@ def vtln_warp_freq(vtln_low_cutoff, vtln_high_cutoff, low_freq, high_freq,
def
vtln_warp_mel_freq
(
vtln_low_cutoff
,
vtln_high_cutoff
,
low_freq
,
high_freq
,
vtln_warp_factor
,
mel_freq
):
"""
Input
s:
vtln_low_cutoff (float):
l
ower frequency cutoffs for VTLN
vtln_high_cutoff (float):
u
pper frequency cutoffs for VTLN
low_freq (float):
l
ower frequency cutoffs in mel computation
high_freq (float):
u
pper frequency cutoffs in mel computation
r
"""
Arg
s:
vtln_low_cutoff (float):
L
ower frequency cutoffs for VTLN
vtln_high_cutoff (float):
U
pper frequency cutoffs for VTLN
low_freq (float):
L
ower frequency cutoffs in mel computation
high_freq (float):
U
pper frequency cutoffs in mel computation
vtln_warp_factor (float): Vtln warp factor
mel_freq (Tensor): given frequency in Mel
Outputs:
Tensor: mel_freq after vtln warp
mel_freq (torch.Tensor): Given frequency in Mel
Returns:
torch.Tensor: `mel_freq` after vtln warp
"""
return
mel_scale
(
vtln_warp_freq
(
vtln_low_cutoff
,
vtln_high_cutoff
,
low_freq
,
high_freq
,
vtln_warp_factor
,
inverse_mel_scale
(
mel_freq
)))
...
...
@@ -351,9 +353,10 @@ def get_mel_banks(num_bins, window_length_padded, sample_freq,
low_freq
,
high_freq
,
vtln_low
,
vtln_high
,
vtln_warp_factor
):
# type: (int, int, float, float, float, float, float)
"""
Outputs:
bins (Tensor): melbank of size (num_bins, num_fft_bins)
center_freqs (Tensor): center frequencies of bins of size (num_bins)
Returns:
Tuple[torch.Tensor, torch.Tensor]: The tuple consists of `bins` (which is
Melbank of size (`num_bins`, `num_fft_bins`)) and `center_freqs` (which is
Center frequencies of bins of size (`num_bins`)).
"""
assert
num_bins
>
3
,
'Must have at least 3 mel bins'
assert
window_length_padded
%
2
==
0
...
...
@@ -416,59 +419,59 @@ def get_mel_banks(num_bins, window_length_padded, sample_freq,
def
fbank
(
sig
,
blackman_coeff
=
0.42
,
channel
=-
1
,
dither
=
1.0
,
energy_floor
=
0.0
,
waveform
,
blackman_coeff
=
0.42
,
channel
=-
1
,
dither
=
1.0
,
energy_floor
=
0.0
,
frame_length
=
25.0
,
frame_shift
=
10.0
,
high_freq
=
0.0
,
htk_compat
=
False
,
low_freq
=
20.0
,
min_duration
=
0.0
,
num_mel_bins
=
23
,
preemphasis_coefficient
=
0.97
,
raw_energy
=
True
,
remove_dc_offset
=
True
,
round_to_power_of_two
=
True
,
sample_frequency
=
16000.0
,
snip_edges
=
True
,
subtract_mean
=
False
,
use_energy
=
False
,
use_log_fbank
=
True
,
use_power
=
True
,
vtln_high
=-
500.0
,
vtln_low
=
100.0
,
vtln_warp
=
1.0
,
window_type
=
'povey'
):
vtln_high
=-
500.0
,
vtln_low
=
100.0
,
vtln_warp
=
1.0
,
window_type
=
POVEY
):
r
"""Create a fbank from a raw audio signal. This matches the input/output of Kaldi's
compute-fbank-feats.
Args:
sig (
Tensor): Tensor of audio of size (c, n) where c is in the range [0,2)
blackman_coeff (float): Constant coefficient for generalized Blackman window. (
d
efault
=
0.42)
channel (int): Channel to extract (-1 -> expect mono, 0 -> left, 1 -> right) (
d
efault
=
-1)
waveform (torch.
Tensor): Tensor of audio of size (c, n) where c is in the range [0,2)
blackman_coeff (float): Constant coefficient for generalized Blackman window. (
D
efault
:
0.42)
channel (int): Channel to extract (-1 -> expect mono, 0 -> left, 1 -> right) (
D
efault
:
-1)
dither (float): Dithering constant (0.0 means no dither). If you turn this off, you should set
the energy_floor option, e.g. to 1.0 or 0.1 (
d
efault
=
1.0)
the energy_floor option, e.g. to 1.0 or 0.1 (
D
efault
:
1.0)
energy_floor (float): Floor on energy (absolute, not relative) in Spectrogram computation. Caution:
this floor is applied to the zeroth component, representing the total signal energy. The floor on the
individual spectrogram elements is fixed at std::numeric_limits<float>::epsilon(). (
d
efault
=
0.0)
frame_length (float): Frame length in milliseconds (
d
efault
=
25.0)
frame_shift (float): Frame shift in milliseconds (
d
efault
=
10.0)
high_freq (float): High cutoff frequency for mel bins (if <= 0, offset from Nyquist) (
d
efault
=
0.0)
individual spectrogram elements is fixed at std::numeric_limits<float>::epsilon(). (
D
efault
:
0.0)
frame_length (float): Frame length in milliseconds (
D
efault
:
25.0)
frame_shift (float): Frame shift in milliseconds (
D
efault
:
10.0)
high_freq (float): High cutoff frequency for mel bins (if <= 0, offset from Nyquist) (
D
efault
:
0.0)
htk_compat (bool): If true, put energy last. Warning: not sufficient to get HTK compatible features (need
to change other parameters). (
d
efault
=
False)
low_freq (float): Low cutoff frequency for mel bins (
d
efault
=
20.0)
min_duration (float): Minimum duration of segments to process (in seconds). (
d
efault
=
0.0)
num_mel_bins (int): Number of triangular mel-frequency bins (
d
efault
=
23)
preemphasis_coefficient (float): Coefficient for use in signal preemphasis (
d
efault
=
0.97)
raw_energy (bool): If True, compute energy before preemphasis and windowing (
d
efault
=
True)
remove_dc_offset: Subtract mean from waveform on each frame (
d
efault
=
True)
to change other parameters). (
D
efault
:
False)
low_freq (float): Low cutoff frequency for mel bins (
D
efault
:
20.0)
min_duration (float): Minimum duration of segments to process (in seconds). (
D
efault
:
0.0)
num_mel_bins (int): Number of triangular mel-frequency bins (
D
efault
:
23)
preemphasis_coefficient (float): Coefficient for use in signal preemphasis (
D
efault
:
0.97)
raw_energy (bool): If True, compute energy before preemphasis and windowing (
D
efault
:
True)
remove_dc_offset: Subtract mean from waveform on each frame (
D
efault
:
True)
round_to_power_of_two (bool): If True, round window size to power of two by zero-padding input
to FFT. (
d
efault
=
True)
to FFT. (
D
efault
:
True)
sample_frequency (float): Waveform data sample frequency (must match the waveform file, if
specified there) (
d
efault
=
16000.0)
specified there) (
D
efault
:
16000.0)
snip_edges (bool): If True, end effects will be handled by outputting only frames that completely fit
in the file, and the number of frames depends on the frame_length. If False, the number of frames
depends only on the frame_shift, and we reflect the data at the ends. (
d
efault
=
True)
depends only on the frame_shift, and we reflect the data at the ends. (
D
efault
:
True)
subtract_mean (bool): Subtract mean of each feature file [CMS]; not recommended to do
it this way. (
d
efault
=
False)
use_energy (bool): Add an extra dimension with energy to the FBANK output. (
d
efault
=
False)
use_log_fbank (bool):If true, produce log-filterbank, else produce linear. (
d
efault
=
True)
use_power (bool): If true, use power, else use magnitude. (
d
efault
=
True)
it this way. (
D
efault
:
False)
use_energy (bool): Add an extra dimension with energy to the FBANK output. (
D
efault
:
False)
use_log_fbank (bool):If true, produce log-filterbank, else produce linear. (
D
efault
:
True)
use_power (bool): If true, use power, else use magnitude. (
D
efault
:
True)
vtln_high (float): High inflection point in piecewise linear VTLN warping function (if
negative, offset from high-mel-freq (
d
efault
=
-500.0)
vtln_low (float): Low inflection point in piecewise linear VTLN warping function (
float, d
efault
=
100.0)
vtln_warp (float): Vtln warp factor (only applicable if vtln_map not specified) (
float, d
efault
=
1.0)
window_type (str): Type of window ('hamming'|'hanning'|'povey'|'rectangular'|'blackman') (
d
efault
=
'povey')
negative, offset from high-mel-freq (
D
efault
:
-500.0)
vtln_low (float): Low inflection point in piecewise linear VTLN warping function (
D
efault
:
100.0)
vtln_warp (float): Vtln warp factor (only applicable if vtln_map not specified) (
D
efault
:
1.0)
window_type (str): Type of window ('hamming'|'hanning'|'povey'|'rectangular'|'blackman') (
D
efault
:
'povey')
Returns:
Tensor:
a
fbank identical to what Kaldi would output. The shape is (m, `num_mel_bins` + `use_energy`)
torch.
Tensor:
A
fbank identical to what Kaldi would output. The shape is (m, `num_mel_bins` + `use_energy`)
where m is calculated in _get_strided
"""
waveform
,
window_shift
,
window_size
,
padded_window_size
=
_get_waveform_and_window_properties
(
sig
,
channel
,
sample_frequency
,
frame_shift
,
frame_length
,
round_to_power_of_two
,
preemphasis_coefficient
)
waveform
,
channel
,
sample_frequency
,
frame_shift
,
frame_length
,
round_to_power_of_two
,
preemphasis_coefficient
)
if
len
(
waveform
)
<
min_duration
*
sample_frequency
:
# signal is too short
...
...
@@ -517,7 +520,7 @@ def fbank(
def
_get_LR_indices_and_weights
(
orig_freq
,
new_freq
,
output_samples_in_unit
,
window_width
,
lowpass_cutoff
,
lowpass_filter_width
):
"""Based on LinearResample::SetIndexesAndWeights where it retrieves the weights for
r
"""Based on LinearResample::SetIndexesAndWeights where it retrieves the weights for
resampling as well as the indices in which they are valid. LinearResample (LR) means
that the output signal is at linearly spaced intervals (i.e the output signal has a
frequency of `new_freq`). It uses sinc/bandlimited interpolation to upsample/downsample
...
...
@@ -548,20 +551,20 @@ def _get_LR_indices_and_weights(orig_freq, new_freq, output_samples_in_unit, win
[1] Chapter 16: Windowed-Sinc Filters, https://www.dspguide.com/ch16/1.htm
Args:
orig_freq (float):
t
he original frequency of the signal
new_freq (float):
t
he desired frequency
output_samples_in_unit (int):
t
he number of output samples in the smallest repeating unit:
orig_freq (float):
T
he original frequency of the signal
new_freq (float):
T
he desired frequency
output_samples_in_unit (int):
T
he number of output samples in the smallest repeating unit:
num_samp_out = new_freq / Gcd(orig_freq, new_freq)
window_width (float):
t
he width of the window which is nonzero
lowpass_cutoff (float):
t
he filter cutoff in Hz. The filter cutoff needs to be less
window_width (float):
T
he width of the window which is nonzero
lowpass_cutoff (float):
T
he filter cutoff in Hz. The filter cutoff needs to be less
than samp_rate_in_hz/2 and less than samp_rate_out_hz/2.
lowpass_filter_width (int):
c
ontrols the sharpness of the filter, more == sharper but less
lowpass_filter_width (int):
C
ontrols the sharpness of the filter, more == sharper but less
efficient. We suggest around 4 to 10 for normal use
Returns:
min_input_index (
Tensor
)
:
the minimum indices where
the
w
in
dow is valid. size (output_samples_in_unit)
w
eights (Tensor): the
weights
which
correspond with min_input_index. size (
output_samples_in_unit, max_weight_width
)
Tuple[torch.Tensor, torch.
Tensor
]
:
A tuple of `min_input_index` (which is
the
m
in
imum indices
w
here the window is valid, size (`output_samples_in_unit`)) and `
weights
` (
which
is the weights
which correspond with min_input_index, size (`
output_samples_in_unit
`
,
`
max_weight_width
`)).
"""
assert
lowpass_cutoff
<
min
(
orig_freq
,
new_freq
)
/
2
output_t
=
torch
.
arange
(
0
,
output_samples_in_unit
,
dtype
=
torch
.
get_default_dtype
())
/
new_freq
...
...
@@ -601,18 +604,18 @@ def _lcm(a, b):
def
_get_num_LR_output_samples
(
input_num_samp
,
samp_rate_in
,
samp_rate_out
):
"""
Based on LinearResample::GetNumOutputSamples. LinearResample (LR) means that
r
"""Based on LinearResample::GetNumOutputSamples. LinearResample (LR) means that
the output signal is at linearly spaced intervals (i.e the output signal has a
frequency of `new_freq`). It uses sinc/bandlimited interpolation to upsample/downsample
the signal.
Args:
input_num_samp (int):
t
he number of samples in the input
samp_rate_in (float):
t
he original frequency of the signal
samp_rate_out (float):
t
he desired frequency
input_num_samp (int):
T
he number of samples in the input
samp_rate_in (float):
T
he original frequency of the signal
samp_rate_out (float):
T
he desired frequency
Returns:
int:
t
he number of output samples
int:
T
he number of output samples
"""
# For exact computation, we measure time in "ticks" of 1.0 / tick_freq,
# where tick_freq is the least common multiple of samp_rate_in and
...
...
@@ -644,8 +647,8 @@ def _get_num_LR_output_samples(input_num_samp, samp_rate_in, samp_rate_out):
return
num_output_samp
def
resample_waveform
(
wave
,
orig_freq
,
new_freq
,
lowpass_filter_width
=
6
):
r
"""Resamples the wave at the new frequency. This matches Kaldi's OfflineFeatureTpl ResampleWaveform
def
resample_waveform
(
wave
form
,
orig_freq
,
new_freq
,
lowpass_filter_width
=
6
):
r
"""Resamples the wave
form
at the new frequency. This matches Kaldi's OfflineFeatureTpl ResampleWaveform
which uses a LinearResample (resample a signal at linearly spaced intervals to upsample/downsample
a signal). LinearResample (LR) means that the output signal is at linearly spaced intervals (i.e
the output signal has a frequency of `new_freq`). It uses sinc/bandlimited interpolation to
...
...
@@ -655,16 +658,16 @@ def resample_waveform(wave, orig_freq, new_freq, lowpass_filter_width=6):
https://github.com/kaldi-asr/kaldi/blob/master/src/feat/resample.h#L56
Args:
wave
(
Tensor):
t
he input signal of size (c, n)
orig_freq (float):
t
he original frequency of the signal
new_freq (float):
t
he desired frequency
lowpass_filter_width (int):
c
ontrols the sharpness of the filter, more == sharper
but less efficient. We suggest around 4 to 10 for normal use
wave
form (torch.
Tensor):
T
he input signal of size (c, n)
orig_freq (float):
T
he original frequency of the signal
new_freq (float):
T
he desired frequency
lowpass_filter_width (int):
C
ontrols the sharpness of the filter, more == sharper
but less efficient. We suggest around 4 to 10 for normal use
. (Default: 6)
Returns:
Tensor:
t
he signal at the new frequency
torch.
Tensor:
T
he signal at the new frequency
"""
assert
wave
.
dim
()
==
2
assert
wave
form
.
dim
()
==
2
assert
orig_freq
>
0.0
and
new_freq
>
0.0
min_freq
=
min
(
orig_freq
,
new_freq
)
...
...
@@ -687,13 +690,13 @@ def resample_waveform(wave, orig_freq, new_freq, lowpass_filter_width=6):
# doing a conv1d for that specific weight.
conv_stride
=
input_samples_in_unit
conv_transpose_stride
=
output_samples_in_unit
num_channels
,
wave_len
=
wave
.
size
()
num_channels
,
wave_len
=
wave
form
.
size
()
window_size
=
weights
.
size
(
1
)
tot_output_samp
=
_get_num_LR_output_samples
(
wave_len
,
orig_freq
,
new_freq
)
output
=
torch
.
zeros
((
num_channels
,
tot_output_samp
))
eye
=
torch
.
eye
(
num_channels
).
unsqueeze
(
2
)
# size (num_channels, num_channels, 1)
for
i
in
range
(
first_indices
.
size
(
0
)):
wave_to_conv
=
wave
wave_to_conv
=
wave
form
first_index
=
int
(
first_indices
[
i
].
item
())
if
first_index
>=
0
:
# trim the signal as the filter will not be applied before the first_index
...
...
torchaudio/transforms.py
View file @
2f62e573
...
...
@@ -275,7 +275,7 @@ class MuLawEncoding(torch.jit.ScriptModule):
returns a signal encoded with values from 0 to quantization_channels - 1
Args:
quantization_channels (int): Number of channels
. d
efault: 256
quantization_channels (int): Number of channels
(D
efault: 256
)
"""
__constants__
=
[
'quantization_channels'
]
...
...
@@ -303,7 +303,7 @@ class MuLawDecoding(torch.jit.ScriptModule):
and returns a signal scaled between -1 and 1.
Args:
quantization_channels (int): Number of channels
. d
efault: 256
quantization_channels (int): Number of channels
(D
efault: 256
)
"""
__constants__
=
[
'quantization_channels'
]
...
...
@@ -328,10 +328,9 @@ class Resample(torch.nn.Module):
be given.
Args:
orig_freq (float): the original frequency of the signal
new_freq (float): the desired frequency
resampling_method (str): the resampling method (Default: 'kaldi' which uses
sinc interpolation)
orig_freq (float): The original frequency of the signal
new_freq (float): The desired frequency
resampling_method (str): The resampling method (Default: 'sinc_interpolation')
"""
def
__init__
(
self
,
orig_freq
,
new_freq
,
resampling_method
=
'sinc_interpolation'
):
super
(
Resample
,
self
).
__init__
()
...
...
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