qoa
QOA is fast. It decodes audio 3x faster than Ogg-Vorbis, while offering better quality and compression (278 kbits/s for 44khz stereo) than ADPCM.
This R-package is a wrapper to handle QOA files with R. The
package is completely written in base R with no dependencies and pure
C-code. To handle the raw audio data the R-package tuneRis highly
recommended.
See this blogpost for an introduction https://phoboslab.org/log/2023/02/qoa-time-domain-audio-compression
Installation
You can install the development version from GitHub with the following command:
if (!require("devtools")) install.packages("devtools")
devtools::install_github("JohannesFriedrich/qoa4R")Usage
There are just two main functions: readQOA() and writeQOA().
readQOA(): Takes an qoa-format audio file and decodes it into it´s raw audio data. Return value is a list with decoded values represented as matrix, used channels, sample rate and samples.writeQOA(): Takes an matrix with every channel in new column and the sample rate as input and and encodes it into an qoa audio file.
readQOA()
Let´s read in an QOA-file delivered with this package:
library(qoa)
qoa_file <- system.file("extdata", "58_guitar_sarasate_stereo.qoa", package = "qoa")
qoa_data <- readQOA(qoa_file)qoa_data is a list with the following elements: * data: a matrix
with all the samples. The dimension of the matrix is samples x channels
* channels: Number of channels * samples: Number of samples per
channel * samplerate: Sample rate of the file
It is possible to write these samples and information with the tuneR
package back to an wave file:
tuneR::writeWave(
WaveMC(
data = qoa_data$data,
samp.rate = qoa_data$samplerate,
bit = 16),
"wave_from_qoa.wav",
extensible = FALSE)writeQOA()
With this function it is possible to write an qoa-file. The input arguments are:
- samples: a matrix with dimensions samples x channels
- samplerate: samplerate of the audio file
- target: Either name of the file to write, a binary connection or a raw vector indicating that the output should be a raw vector (the hex-interpretation of the qoa-file).
If no second argument is given, the returned value is the hex-interpretation of the image in the QOI-file format.
wav_original <- tuneR::readWave("wave_from_qoa.wav", toWaveMC = TRUE)
writeQOA(samples = wav_original@.Data,
samplerate = wav_original@samp.rate)If an second argument is given as character the image is saved to this name:
writeQOA(samples = wav_original@.Data,
samplerate = wav_original@samp.rate,
target = "test.qoa")If the second argument is of type connection the hex interpretation of
the audio file will be send to this connection, e.g. via sockets or FTP.
file <- file("file.qoa", "wb")
writeQOA(samples = wav_original@.Data,
samplerate = wav_original@samp.rate,
target = "test.qoa")
close(file)Acknowlegment
This package would not exist without the following persons/homepages/tutorial/…: