audiodata package

Subpackages

• audiodata.aio package
  • Submodules
  • audiodata.aio.aiffio module
  • audiodata.aio.audiofactory module
  • audiodata.aio.sunauio module
  • audiodata.aio.waveio module
  • Module contents

Submodules

audiodata.audio module

filename

sppas.src.audiodata.audio.py

author

Nicolas Chazeau, Brigitte Bigi

contact

develop@sppas.org

summary

Main class to work with a recorded audio file.

Pulse-code modulation (PCM) is a method used to digitally represent sampled analog signals. A PCM signal is a sequence of digital audio samples containing the data providing the necessary information to reconstruct the original analog signal. Each sample represents the amplitude of the signal at a specific point in time, and the samples are uniformly spaced in time. The amplitude is the only information explicitly stored in the sample

A PCM stream has two basic properties that determine the stream’s fidelity to the original analog signal: the sampling rate, which is the number of times per second that samples are taken; and the bit depth, which determines the number of possible digital values that can be used to represent each sample.

For speech analysis, recommended sampling rate are 16000 (for automatic analysis) or 48000 (for manual analysis); and recommended sample depths are 16 per sample.

class audiodata.audio.sppasAudioPCM

Bases: object

An audio manager.

These variables are user gettable through appropriate methods:

• nchannels – the number of audio channels

• framerate – the sampling frequency

• sampwidth – the number of bytes per audio sample (1, 2 or 4)

• nframes – the number of frames

• params – parameters of the wave file

• filename – the name of the wave file

The audiofp member is assigned by the IO classes (WaveIO, AifIO, SunauIO). It is expected that it can access the following methods:

• readframes()

• writeframes()

• getsampwidth()

• getframerate()

• getnframes()

• getnchannels()

• setpos()

• tell()

• rewind()

__init__()

Create a new sppasAudioPCM instance.

append_channel(channel)

Append a channel to the list of uploaded channels.

Parameters

channel – (sppasChannel) the channel to append

Returns

index of the channel

clipping_rate(factor)

Return the clipping rate of the frames.

Parameters

factor – (float) An interval to be more precise on clipping rate.

It will consider that all frames outside the interval are clipped. Factor has to be between 0 and 1. :returns: (float)

close()

Close the audio file.

extract_channel(index=0)

Extract a channel from the Audio File Pointer.

Append the channel into the list of channels.

Frames are stored into a sppasChannel() instance. Index of the channel in the audio file: 0 = 1st channel (left); 1 = 2nd channel (right); 2 = 3rd channel…

Parameters

index – (int) The index of the channel to extract

Returns

the index of the sppasChannel() in the list

extract_channels()

Extract all channels from the Audio File Pointer.

Append the extracted channels to the list of channels.

get_audiofp()

Return the audio file pointer.

Returns

audio file pointer

get_channel(idx)

Get an uploaded channel.

Parameters

idx – (int) the index of the channel to return

Returns

(sppasChannel)

get_channels()

Return the list of uploaded channels.

Returns

(list) channels

get_duration()

Return the duration of the Audio File Pointer.

Returns

(float) duration of the audio file (in seconds)

get_framerate()

Return the frame rate of the Audio File Pointer.

Returns

(int) frame rate of the audio file

get_nchannels()

Return the number of channels of the Audio File Pointer.

Returns

(int) number of channels of the audio file

get_nframes()

Return the number of frames of the Audio File Pointer.

Returns

(int) number of frames of the audio file

get_sampwidth()

Return the sample width of the Audio File Pointer.

Returns

(int) sample width of the audio file

insert_channel(idx, channel)

Insert a channel at the position given in the list of uploaded channels.

Parameters

• idx – (int) the index where the channel has to be inserted

• channel – (sppasChannel) the channel to insert

open(filename)

Open an audio file.

pop_channel(idx)

Pop a channel at the position given from the list of uploaded channels.

Parameters

idx – (int) the index of the channel to remove

read()

Read all frames of the audio file.

Returns

(str) frames

read_frames(nframes)

Read n frames from the audio file.

Parameters

nframes – (int) the number of frames to read

Returns

(str) frames

read_samples(nframes)

Read the samples from the audio file.

Parameters

nframes – (int) the number of frames to read

Returns

(list of list) list of samples of each channel

remove_channel(channel)

Remove a channel from the list of uploaded channels.

Parameters

channel – (sppasChannel) the channel to remove

rewind()

Set reader position at the beginning of the file.

rms()

Return the root mean square of the whole file.

Returns

(int) rms of the audio file

save(filename)

Save an audio file.

save_fragments(filename)

Save a fragment of an audio file.

seek(pos)

Fix the reader pointer position.

Parameters

pos – (int) the position to set.

set(other)

Set a new sppasAudioPCM() instance.

It can be set either with an audio file pointer, or a list of channels or both.

Parameters

other – (sppasAudioPCM) the other sppasAudioPCM to set

tell()

Get the reader pointer position.

Returns

(int) the current position

verify_channels()

Check that the uploaded channels have the same parameters.

Check the frame rate, sample width and number of frames.

Returns

(bool)

audiodata.audioconvert module

filename

sppas.src.audiodata.audioconvert.py

author

Brigitte Bigi

contact

develop@sppas.org

summary

An utility to convert audio data formats

class audiodata.audioconvert.sppasAudioConverter

Bases: object

An utility to convert data formats.

__init__()

Create a sppasAudioConverter instance.

static amp2db(value)

Return the equivalent value in a dB scale, from an amplitude value.

Decibels express a power ratio, not an amount. They tell how many times more (positive dB) or less (negative dB) but not how much in absolute terms. Decibels are logarithmic, not linear. Doubling of the value leads to an increase of 6.02dB.

Parameters

value – (int) the amplitude value to convert

Returns

(float) the value in dB

static hz2mel(value)

Return the equivalent value in a mel scale, from a frequency value.

Mel is a unit of pitch proposed by Stevens, Volkmann and Newmann in 1937. The mel scale is a scale of pitches judged by listeners to be equal in distance one from another. The name mel comes from the word melody to indicate that the scale is based on pitch comparisons.

Parameters

value – (int) the value to convert

Returns

(int) the value in mel

static mel2hz(value)

Return the equivalent value in frequency, from a mel value.

Parameters

value – (int) the value in mel to convert

Returns

(int) the value in dB

static samples2frames(samples, samples_width, nchannels=1)

Turn samples into frames.

Parameters

samples – (int[][]) samples list,

first index is the index of the channel, second is the index of the sample. :param samples_width: (int) sample width of the frames. :param nchannels: (int) number of channels in the samples :returns: frames

static unpack_data(frames, samples_width, nchannels=1)

Turn frames into samples.

Unpack the data frames depending on their sample width.

Parameters

• frames – (str) Audio frames

• samples_width – (int)

• nchannels – (int) number of channels in the frames

audiodata.audiodataexc module

filename

sppas.src.audiodata.audiodataexc.py

author

Brigitte Bigi

contact

develop@sppas.org

summary

Exceptions for the audiodata package.

exception audiodata.audiodataexc.AudioDataError(filename='')

Bases: Exception

:ERROR 2015:.

No data or corrupted data in the audio file {filename}.

__init__(filename='')

exception audiodata.audiodataexc.AudioError

Bases: Exception

:ERROR 2000:.

No audio file is defined.

__init__()

exception audiodata.audiodataexc.AudioIOError(message='', filename='')

Bases: OSError

:ERROR 2010:.

Opening, reading or writing error.

__init__(message='', filename='')

exception audiodata.audiodataexc.AudioTypeError(extension)

Bases: TypeError

:ERROR 2005:.

Audio type error: not supported file format {extension}.

__init__(extension)

exception audiodata.audiodataexc.ChannelError

Bases: Exception

:ERROR 2050:.

No channel defined.

__init__()

exception audiodata.audiodataexc.ChannelIndexError(index)

Bases: ValueError

:ERROR 2020:.

{number} is not a right index of channel.

__init__(index)

exception audiodata.audiodataexc.FrameRateError(value)

Bases: ValueError

ERROR 2080

Invalid framerate {value}.

__init__(value)

exception audiodata.audiodataexc.IntervalError(value1, value2)

Bases: ValueError

:ERROR 2025:.

From {value1} to {value2} is not a proper interval.

__init__(value1, value2)

exception audiodata.audiodataexc.MixChannelError(value=0)

Bases: ValueError

ERROR 2060

ERROR 2061

ERROR 2062

ERROR 2050

.

Channels have not the same sample width. Channels have not the same frame rate. Channels have not the same number of frames.

__init__(value=0)

exception audiodata.audiodataexc.SampleWidthError(value)

Bases: ValueError

:ERROR 2070:.

Invalid sample width {value}.

__init__(value)

audiodata.audioframes module

filename

sppas.src.audiodata.audioframes.py

authors

Nicolas Chazeau, Brigitte Bigi

contact

develop@sppas.org

summary

Manipulate frames of an Audio()

class audiodata.audioframes.sppasAudioFrames(frames=b'', sampwidth=2, nchannels=1)

Bases: object

An utility class for audio frames.

TODO: There’s no unittests of this class.

__init__(frames=b'', sampwidth=2, nchannels=1)

Create an instance.

Parameters

• frames – (str) input frames

• sampwidth – (int) sample width of the frames (1, 2 or 4)

• nchannels – (int) number of channels in the samples

avg()

Return the average of all the frames.

bias(value)

Return frames that is the original fragment with a bias added to each sample.

Samples wrap around in case of overflow.

Parameters

value – (int) the bias which will be applied to each sample.

Returns

(str) converted frames

change_sampwidth(new_sampwidth)

Return frames with the given number of bytes.

Parameters

new_sampwidth – (int) new sample width of the frames. (1 for 8 bits, 2 for 16 bits, 4 for 32 bits)

Returns

(str) converted frames

clipping_rate(factor)

Return the clipping rate of the frames.

Parameters

factor – (float) An interval to be more precise on clipping rate.

It will consider that all frames outside the interval are clipped. Factor has to be between 0 and 1. :returns: (float) the clipping rate

cross()

Return the number of zero crossings in frames.

Returns

number of zero crossing

get_frames()

static get_maxval(size, signed=True)

Return the max value for a given sampwidth.

Parameters

• size – (int) the sampwidth

• signed – (bool) if the values will be signed or not

Returns

(int) the max value

static get_minval(size, signed=True)

Return the min value for a given sampwidth.

Parameters

• size – (int) the sampwidth

• signed – (bool) if the values will be signed or not

Returns

(int) the min value

get_nchannels()

get_sampwidth()

max()

Return the maximum of the values of all frames.

min()

Return the minimum of the values of all frames.

minmax()

Return the (minimum,maximum) of the values of all frames.

Returns

(min,max)

mul(factor)

Return frames for which all samples are multiplied by factor.

Samples are truncated in case of overflow.

Parameters

factor – (int) the factor which will be applied to each sample.

Returns

(str) converted frames

resample(rate, new_rate=16000)

Return re-sampled frames.

Parameters

• rate – (int) current frame rate of the frames

• new_rate – (int) new frame rate of the frames

Returns

(str) converted frames

rms()

Return the root mean square of the frames.

audiodata.audiopitch module

filename

sppas.src.audiodata.audiopitch.py

author

Brigitte Bigi

contact

develop@sppas.org

summary

TO BE IMPLEMENTED.

class audiodata.audiopitch.AudioPitch(delta=0.01)

Bases: object

Estimate pitch values of a speech audio recording.

__init__(delta=0.01)

Create a new AudioPitch instance.

eval_pitch(filename)

WILL evaluate pitch values…

get_pitch(time)

Return the pitch value at a given time.

Parameters

time – a float value representing the time in seconds.

Returns

float

get_pitch_delta()

Return the delta time used to estimate pitch.

get_pitch_list()

Return pitch values.

audiodata.audiovolume module

audiodata.autils module

audiodata.basevolume module

audiodata.channel module

filename

sppas.src.audiodata.channel.py

author

Nicolas Chazeau, Brigitte Bigi

contact

develop@sppas.org

summary

Represent a channel (frames) of an audio file.

class audiodata.channel.sppasChannel(framerate=16000, sampwidth=2, frames=b'')

Bases: object

Manage data and information of a channel.

__init__(framerate=16000, sampwidth=2, frames=b'')

Create a sppasChannel instance.

Parameters

• framerate – (int) The frame rate of this channel, in Hertz.

• sampwidth – (int) 1 for 8 bits, 2 for 16 bits, 4 for 32 bits.

• frames – (str) The frames represented by a string.

clipping_rate(factor)

Return the clipping rate of the frames.

Parameters

factor – (float) An interval to be more precise on clipping rate.

It will consider that all frames outside the interval are clipped. Factor has to be between 0 and 1. :returns: (float) the clipping rate

extract_fragment(begin=None, end=None)

Extract a fragment between the beginning and the end.

Parameters

• begin – (int: number of frames) the beginning of the fragment to extract

• end – (int: number of frames) the end of the fragment to extract

Returns

(sppasChannel) the fragment extracted.

get_cross()

Return the number of zero crossings.

Returns

(int) number of zero crossing

get_duration()

Return the duration of the channel, in seconds.

Returns

(float) the duration of the channel

get_framerate()

Return the frame rate, in Hz.

Returns

(int) the frame rate of the channel

get_frames(chunck_size=None)

Return some frames from the current position.

Parameters

chunck_size – (int) the size of the chunk to return.

None for all frames of the channel. :returns: (str) the frames

get_nframes()

Return the number of frames.

A frame has a length of (sampwidth) bytes.

Returns

(int) the total number of frames

get_sampwidth()

Return the sample width.

Returns

(int) the sample width of the channel

rewind()

Set the position to 0.

rms()

Return the root mean square of the channel.

Returns

(int) the root mean square of the channel

seek(position)

Fix the current position.

Parameters

position – (int)

set_framerate(framerate)

Set a new framerate to the channel.

Parameters

framerate – (int) The frame rate of this channel, in Hertz.

A value between 8000 and 192000

set_frames(frames)

Set new frames to the channel.

It is supposed the sampwidth and framerate are the same as the current ones.

Parameters

frames – (str) the new frames

set_sampwidth(sampwidth)

Set a new samples width to the channel.

Parameters

sampwidth – (int) 1 for 8 bits, 2 for 16 bits, 4 for 32 bits.

tell()

Return the current position.

audiodata.channelformatter module

filename

sppas.src.audiodata.channelformatter.py

author

Nicolas Chazeau, Brigitte Bigi

contact

develop@sppas.org

summary

Tools to apply on frames of a channel.

class audiodata.channelformatter.sppasChannelFormatter(channel)

Bases: object

Utility to format frames of a channel.

__init__(channel)

Create a sppasChannelFormatter instance.

Parameters

channel – (sppasChannel) The channel to work on.

add_frames(frames, position)

Convert the channel by adding frames.

Parameters

• frames – (str)

• position – (int) the position where the frames will be inserted

append_frames(frames)

Convert the channel by appending frames.

Parameters

frames – (str) the frames to append

bias(bias_value)

Convert the channel with a bias added to each frame.

Samples wrap around in case of overflow.

Parameters

bias_value – (int) the value to bias the frames

convert()

Convert the channel.

Convert to the expected (already) given sample width and frame rate.

get_channel()

Return the sppasChannel.

get_framerate()

Return the expected frame rate for the channel.

Notice that while convert is not applied, it can be different of the current one of the channel.

Returns

the frame rate that will be used by the converter

get_sampwidth()

Return the expected sample width for the channel.

Notice that while convert is not applied, it can be different of the current one of the channel.

Returns

the sample width that will be used by the converter

mul(factor)

Convert the channel.

All frames in the original channel are multiplied by the floating- point value factor. Samples are truncated in case of overflow.

Parameters

factor – (float) the factor to multiply the frames

remove_frames(begin, end)

Convert the channel by removing frames.

Parameters

• begin – (int) the position of the beginning of the frames to remove

• end – (int) the position of the end of the frames to remove

remove_offset()

Convert the channel by removing the offset in the channel.

set_framerate(framerate)

Fix the expected frame rate for the channel.

Notice that while convert is not applied, it can be different of the current one of the channel.

Parameters

framerate –

set_sampwidth(sampwidth)

Fix the expected sample width for the channel.

Notice that while convert is not applied, it can be different of the current one of the channel.

Parameters

sampwidth –

sync(channel)

Convert the channel with the parameters from the channel put in input.

Parameters

channel – (sppasChannel) the channel used as a model

audiodata.channelframes module

filename

sppas.src.audiodata.channelframes.py

author

Nicolas Chazeau, Brigitte Bigi

contact

develop@sppas.org

summary

Represent frames of a channel.

class audiodata.channelframes.sppasChannelFrames(frames=b'')

Bases: object

Data structure to deal with the frames of a channel.

__init__(frames=b'')

Create a sppasChannelFrames instance.

Parameters

frames – (str) Frames that must be MONO ONLY.

append_silence(nframes)

Create n frames of silence and append it to the frames.

Parameters

nframes – (int) the number of frames of silence to append

change_sampwidth(sampwidth, newsampwidth)

Change the number of bytes used to encode the frames.

Parameters

sampwidth – (int) current sample width of the frames.

(1 for 8 bits, 2 for 16 bits, 4 for 32 bits) :param newsampwidth: (int) new sample width of the frames. (1 for 8 bits, 2 for 16 bits, 4 for 32 bits)

get_frames()

Return the frames

Returns

(str) the frames

static get_maxval(size, signed=True)

static get_minval(size, signed=True)

prepend_silence(nframes)

Create n frames of silence and prepend it to the frames.

Parameters

nframes – (int) the number of frames of silence to append

resample(sampwidth, rate, newrate)

Resample the frames with a new frame rate.

Parameters

• sampwidth – (int) sample width of the frames.

• rate – (int) current frame rate of the frames

• newrate – (int) new frame rate of the frames

set_frames(frames)

Set the frames.

Parameters

frames – (str) the frames to set

audiodata.channelmfcc module

filename

sppas.src.audiodata.channelmfcc.py

author

Brigitte Bigi

contact

develop@sppas.org

summary

Estimate MFCC. TO BE IMPLEMENTED.

Requires HTK to be installed.

Mel-frequency cepstrum (MFC) is a representation of the short-term power spectrum of a sound, based on a linear cosine transform of a log power spectrum on a nonlinear mel scale of frequency.

MFCCs are commonly derived as follows:

1. Take the Fourier transform of (a windowed excerpt of) a signal.

2. Map the powers of the spectrum obtained above onto the mel scale, using triangular overlapping windows.

3. Take the logs of the powers at each of the mel frequencies.

4. Take the discrete cosine transform of the list of mel log powers, as if it were a signal.

5. The MFCCs are the amplitudes of the resulting spectrum.

class audiodata.channelmfcc.sppasChannelMFCC(channel=None)

Bases: object

A channel MFCC extractor class.

__init__(channel=None)

Create a sppasChannelMFCC instance.

Parameters

channel – (sppasChannel) The channel to work on. Currently not used…!!!

evaluate(features)

Evaluate MFCC of the given channel.

hcopy(wavconfigfile, scpfile)

Create MFCC files from features described in the config file.

Requires HCopy to be installed.

Parameters

• wavconfigfile – (str)

• scpfile – (str)

audiodata.channelsilence module

audiodata.channelsmixer module

filename

sppas.src.audiodata.channelmixer.py

author

Nicolas Chazeau, Brigitte Bigi

contact

develop@sppas.org

summary

A channel utility class to mix several channels in one.

class audiodata.channelsmixer.sppasChannelMixer

Bases: object

A channel utility class to mix several channels in one.

__init__()

Create a ChannelMixer instance.

append_channel(channel, factor=1)

Append a channel and the corresponding factor for a mix.

Parameters

• channel – (Channel object) the channel to append

• factor – (float) the factor associated to the channel

check_channels()

Checking the conformity of the channels.

get_channel(idx)

Return the channel of a given index.

Parameters

idx – (int) the index of the channel to return

Returns

(sppasChannel)

get_minmax()

Return a tuple with the minimum and the maximum samples values.

Returns

the tuple (minvalue, maxvalue)

mix(attenuator=1)

Mix the channels of the list in one.

Parameters

attenuator – (float) the factor to apply to each sample calculated

Returns

the result Channel

norm_length()

Normalize the number of frames of all the channels, by appending silence at the end.

audiodata.channelvolume module

Module contents

filename

sppas.src.audiodata.__init__.py

author

Nicolas Chazeau, Brigitte Bigi

contact

develop@sppas.org

summary

audio file manager.

audiodata: management of digital audio data.

Requires the following other packages:

• config

class audiodata.sppasAudioFrames(frames=b'', sampwidth=2, nchannels=1)

Bases: object

An utility class for audio frames.

TODO: There’s no unittests of this class.

__init__(frames=b'', sampwidth=2, nchannels=1)

Create an instance.

Parameters

• frames – (str) input frames

• sampwidth – (int) sample width of the frames (1, 2 or 4)

• nchannels – (int) number of channels in the samples

avg()

Return the average of all the frames.

bias(value)

Return frames that is the original fragment with a bias added to each sample.

Samples wrap around in case of overflow.

Parameters

value – (int) the bias which will be applied to each sample.

Returns

(str) converted frames

change_sampwidth(new_sampwidth)

Return frames with the given number of bytes.

Parameters

new_sampwidth – (int) new sample width of the frames. (1 for 8 bits, 2 for 16 bits, 4 for 32 bits)

Returns

(str) converted frames

clipping_rate(factor)

Return the clipping rate of the frames.

Parameters

factor – (float) An interval to be more precise on clipping rate.

It will consider that all frames outside the interval are clipped. Factor has to be between 0 and 1. :returns: (float) the clipping rate

cross()

Return the number of zero crossings in frames.

Returns

number of zero crossing

get_frames()

static get_maxval(size, signed=True)

Return the max value for a given sampwidth.

Parameters

• size – (int) the sampwidth

• signed – (bool) if the values will be signed or not

Returns

(int) the max value

static get_minval(size, signed=True)

Return the min value for a given sampwidth.

Parameters

• size – (int) the sampwidth

• signed – (bool) if the values will be signed or not

Returns

(int) the min value

get_nchannels()

get_sampwidth()

max()

Return the maximum of the values of all frames.

min()

Return the minimum of the values of all frames.

minmax()

Return the (minimum,maximum) of the values of all frames.

Returns

(min,max)

mul(factor)

Return frames for which all samples are multiplied by factor.

Samples are truncated in case of overflow.

Parameters

factor – (int) the factor which will be applied to each sample.

Returns

(str) converted frames

resample(rate, new_rate=16000)

Return re-sampled frames.

Parameters

• rate – (int) current frame rate of the frames

• new_rate – (int) new frame rate of the frames

Returns

(str) converted frames

rms()

Return the root mean square of the frames.

class audiodata.sppasAudioPCM

Bases: object

An audio manager.

These variables are user gettable through appropriate methods:

• nchannels – the number of audio channels

• framerate – the sampling frequency

• sampwidth – the number of bytes per audio sample (1, 2 or 4)

• nframes – the number of frames

• params – parameters of the wave file

• filename – the name of the wave file

The audiofp member is assigned by the IO classes (WaveIO, AifIO, SunauIO). It is expected that it can access the following methods:

• readframes()

• writeframes()

• getsampwidth()

• getframerate()

• getnframes()

• getnchannels()

• setpos()

• tell()

• rewind()

__init__()

Create a new sppasAudioPCM instance.

append_channel(channel)

Append a channel to the list of uploaded channels.

Parameters

channel – (sppasChannel) the channel to append

Returns

index of the channel

clipping_rate(factor)

Return the clipping rate of the frames.

Parameters

factor – (float) An interval to be more precise on clipping rate.

It will consider that all frames outside the interval are clipped. Factor has to be between 0 and 1. :returns: (float)

close()

Close the audio file.

extract_channel(index=0)

Extract a channel from the Audio File Pointer.

Append the channel into the list of channels.

Frames are stored into a sppasChannel() instance. Index of the channel in the audio file: 0 = 1st channel (left); 1 = 2nd channel (right); 2 = 3rd channel…

Parameters

index – (int) The index of the channel to extract

Returns

the index of the sppasChannel() in the list

extract_channels()

Extract all channels from the Audio File Pointer.

Append the extracted channels to the list of channels.

get_audiofp()

Return the audio file pointer.

Returns

audio file pointer

get_channel(idx)

Get an uploaded channel.

Parameters

idx – (int) the index of the channel to return

Returns

(sppasChannel)

get_channels()

Return the list of uploaded channels.

Returns

(list) channels

get_duration()

Return the duration of the Audio File Pointer.

Returns

(float) duration of the audio file (in seconds)

get_framerate()

Return the frame rate of the Audio File Pointer.

Returns

(int) frame rate of the audio file

get_nchannels()

Return the number of channels of the Audio File Pointer.

Returns

(int) number of channels of the audio file

get_nframes()

Return the number of frames of the Audio File Pointer.

Returns

(int) number of frames of the audio file

get_sampwidth()

Return the sample width of the Audio File Pointer.

Returns

(int) sample width of the audio file

insert_channel(idx, channel)

Insert a channel at the position given in the list of uploaded channels.

Parameters

• idx – (int) the index where the channel has to be inserted

• channel – (sppasChannel) the channel to insert

open(filename)

Open an audio file.

pop_channel(idx)

Pop a channel at the position given from the list of uploaded channels.

Parameters

idx – (int) the index of the channel to remove

read()

Read all frames of the audio file.

Returns

(str) frames

read_frames(nframes)

Read n frames from the audio file.

Parameters

nframes – (int) the number of frames to read

Returns

(str) frames

read_samples(nframes)

Read the samples from the audio file.

Parameters

nframes – (int) the number of frames to read

Returns

(list of list) list of samples of each channel

remove_channel(channel)

Remove a channel from the list of uploaded channels.

Parameters

channel – (sppasChannel) the channel to remove

rewind()

Set reader position at the beginning of the file.

rms()

Return the root mean square of the whole file.

Returns

(int) rms of the audio file

save(filename)

Save an audio file.

save_fragments(filename)

Save a fragment of an audio file.

seek(pos)

Fix the reader pointer position.

Parameters

pos – (int) the position to set.

set(other)

Set a new sppasAudioPCM() instance.

It can be set either with an audio file pointer, or a list of channels or both.

Parameters

other – (sppasAudioPCM) the other sppasAudioPCM to set

tell()

Get the reader pointer position.

Returns

(int) the current position

verify_channels()

Check that the uploaded channels have the same parameters.

Check the frame rate, sample width and number of frames.

Returns

(bool)

class audiodata.sppasChannel(framerate=16000, sampwidth=2, frames=b'')

Bases: object

Manage data and information of a channel.

__init__(framerate=16000, sampwidth=2, frames=b'')

Create a sppasChannel instance.

Parameters

• framerate – (int) The frame rate of this channel, in Hertz.

• sampwidth – (int) 1 for 8 bits, 2 for 16 bits, 4 for 32 bits.

• frames – (str) The frames represented by a string.

clipping_rate(factor)

Return the clipping rate of the frames.

Parameters

factor – (float) An interval to be more precise on clipping rate.

It will consider that all frames outside the interval are clipped. Factor has to be between 0 and 1. :returns: (float) the clipping rate

extract_fragment(begin=None, end=None)

Extract a fragment between the beginning and the end.

Parameters

• begin – (int: number of frames) the beginning of the fragment to extract

• end – (int: number of frames) the end of the fragment to extract

Returns

(sppasChannel) the fragment extracted.

get_cross()

Return the number of zero crossings.

Returns

(int) number of zero crossing

get_duration()

Return the duration of the channel, in seconds.

Returns

(float) the duration of the channel

get_framerate()

Return the frame rate, in Hz.

Returns

(int) the frame rate of the channel

get_frames(chunck_size=None)

Return some frames from the current position.

Parameters

chunck_size – (int) the size of the chunk to return.

None for all frames of the channel. :returns: (str) the frames

get_nframes()

Return the number of frames.

A frame has a length of (sampwidth) bytes.

Returns

(int) the total number of frames

get_sampwidth()

Return the sample width.

Returns

(int) the sample width of the channel

rewind()

Set the position to 0.

rms()

Return the root mean square of the channel.

Returns

(int) the root mean square of the channel

seek(position)

Fix the current position.

Parameters

position – (int)

set_framerate(framerate)

Set a new framerate to the channel.

Parameters

framerate – (int) The frame rate of this channel, in Hertz.

A value between 8000 and 192000

set_frames(frames)

Set new frames to the channel.

It is supposed the sampwidth and framerate are the same as the current ones.

Parameters

frames – (str) the new frames

set_sampwidth(sampwidth)

Set a new samples width to the channel.

Parameters

sampwidth – (int) 1 for 8 bits, 2 for 16 bits, 4 for 32 bits.

tell()

Return the current position.