Write audio file
audiowrite( writes
a matrix of audio data, filename,y,Fs)y, with sample rate Fs to
a file called filename. The filename input
also specifies the output file format. The output data type depends on the output
file format and the data type of the audio data, y.
audiowrite( uses
additional options specified by one or more filename,y,Fs,Name,Value)Name,Value pair
arguments.
Create a WAVE file from the example file handel.mat, and read the file back into MATLAB®.
Write a WAVE (.wav) file in the current folder.
load handel.mat filename = 'handel.wav'; audiowrite(filename,y,Fs); clear y Fs
Read the data back into MATLAB using audioread.
[y,Fs] = audioread(filename);
Listen to the audio.
sound(y,Fs);
Create a FLAC file from the example file handel.mat and specify the number of output bits per sample and a comment.
load handel.mat filename = 'handel.flac'; audiowrite(filename,y,Fs,'BitsPerSample',24,... 'Comment','This is my new audio file.'); clear y Fs
View information about the new FLAC file by using the audioinfo function
info = audioinfo(filename) ;
The info structure contains the following information fields: Filename, CompressionMethod, NumChannels, SampleRate, TotalSamples, Duration, Title, Comment, Artist, and BitsPerSample.
filename — Name of file to writeName of file to write, or the full path to the file, specified as a character vector that includes the file extension. If a path is specified, it can be absolute or relative. If you do not specify the path, then the destination directory is the current working directory.
audiowrite supports the following file formats.
| Platform Support | File Format |
|---|---|
| All platforms | WAVE (.wav) |
OGG (.ogg) | |
FLAC (.flac) | |
| Windows® and Mac | MPEG-4 AAC (.m4a, .mp4) |
Example: 'myFile.m4a'
Example: '../myFile.m4a'
Example: 'C:\temp\myFile.m4a'
When writing AAC files on Windows, audiowrite pads
the front and back of the output signal with extra samples of silence.
The Windows AAC encoder also places a very sharp fade-in and
fade-out on the audio. This results in audio with an increased number
of samples after being written to disk.
y — Audio data to writeAudio data to write, specified as an m-by-n matrix,
where m is the number of audio samples to write
and n is the number of audio channels to write.
If either m or n is 1,
then audiowrite assumes that this dimension specifies
the number of audio channels, and the other dimension specifies the
number of audio samples.
The maximum number of channels depends on the file format.
| File Format | Maximum Number of Channels |
|---|---|
WAVE (.wav) | 256 |
OGG (.ogg) | 255 |
FLAC (.flac) | 8 |
MPEG-4 AAC (.m4a, .mp4) | 2 |
The valid range for the data in y depends
on the data type of y.
| Data Type of y | Valid Range for y |
|---|---|
uint8 | 0 ≤ y ≤ 255 |
int16 | -32768 ≤ y ≤ +32767 |
int32 | -2^32 ≤ y ≤ 2^32–1 |
single | -1.0 ≤ y ≤ +1.0 |
double | -1.0 ≤ y ≤ +1.0 |
Data beyond the valid range is clipped.
If y is single or double,
then audio data in y should be normalized to values
in the range −1.0 and 1.0, inclusive.
Data Types: single | double | int16 | int32 | uint8
Fs — Sample rateSample rate, in hertz, of audio data y, specified
as a positive scalar greater than 0. Values of Fs are
truncated to integer boundaries. When writing to .m4a or .mp4 files
on Windows platforms, audiowrite supports
only samples rates of 44100 and 48000.
Example: 44100
Data Types: double
Specify optional comma-separated pairs of Name,Value arguments.
Name is the argument
name and Value is the corresponding
value. Name must appear
inside single quotes (' ').
You can specify several name and value pair
arguments in any order as Name1,Value1,...,NameN,ValueN.
'Title','Symphony No. 9','Artist','My Orchestra' instructs audiowrite to
write an audio file with the title "Symphony No. 9"
and the artist information "My Orchestra."'BitsPerSample' — Number of output bits per sampleNumber of output bits per sample, specified as the comma-separated
pair consisting of 'BitsPerSample' and a number.
Only available for WAVE (.wav) and FLAC (.flac)
files. For FLAC files, only 8, 16, or 24 bits per sample are supported.
Example: 'BitsPerSample',32
'BitRate' — Kilobits per second (kbit/s)Number of kilobits per second (kbit/s) used for compressed audio
files, specified as the comma-separated pair consisting of 'BitRate' and
an integer. Noninteger values are truncated. On Windows 7 or later,
the only valid values are 96, 128, 160, and 192.
In general, a larger BitRate value results
in higher compression quality.
Only available for MPEG-4 (.m4a, .mp4)
files.
Example: 'BitRate',96
'Quality' — Quality setting for the Ogg Vorbis CompressorQuality setting for the Ogg Vorbis Compressor, specified as
the comma-separated pair consisting of 'Quality' and
a number in the range [0 100], where 0 is lower quality and higher
compression, and 100 is higher quality and lower compression.
Only available for OGG (.ogg) files.
Example: 'Quality',25
'Title' — Title information[] (default) | character vectorTitle information, specified as the comma-separated pair consisting
of 'Title' and a character vector.
'Artist' — Artist information[] (default) | character vectorArtist information, specified as the comma-separated pair consisting
of 'Artist' and a character vector.
'Comment' — Additional information[] (default) | character vectorAdditional information, specified as the comma-separated pair
consisting of 'Comment' and a character vector.
Note:
On Mac platforms, |
The output data type is determined by the file
format, the data type of y, and the specified output BitsPerSample.
| File Formats | Data Type of y | Output BitsPerSample | Output Data Type |
|---|---|---|---|
WAVE (.wav), | uint8, int16, int32, single, double | 8 | uint8 |
| 16 | int16 | ||
| 24 | int32 | ||
uint8, int16, int32 | 32 | int32 | |
single, double | 32 | single | |
single, double | 64 | double | |
FLAC (.flac) | uint8, int16, int32, single, double | 8 | int8 |
| 16 | int16 | ||
| 24 | int32 | ||
MPEG-4 (.m4a, .mp4),OGG ( .ogg) | uint8, int16, int32, single, double | N/A | single |