zresample(1)

NAME
zresample - resample and change sample format of audio files

SYNOPSIS
zresample [options] input-file output-file

DESCRIPTION
zresample copies an audio file, changing the sample rate and/or the sample format. For 16-bit output it can also dither the audio signal. Input can be any audio file readable by the libsndfile library. The output file type is either WAV, WAVEX, CAF, AIFF or FLAC.

OPTIONS

--help
    Display a short help text.

--rate sample-rate
    Set the output sample rate. Zresample uses the zita-resampler library which means that not all combinations of input/output sample rate will be accepted. The resample ratio must be a reducable to a fraction a/b with both a and b less than or equal to 1000.

--gain gain
    Gain in dB, default zero.

  Output file type

--wav
    Produce a WAV file, or for more than 2 channels, a WAVEX file. This is the default.

--amb
    Produce a WAVEX file with the Ambisonic GUID. Such files should have the .amb filename extension.

--caf
    Produce a Core Audio file.

--aiff
    Produce an AIFF file.

--flac
    Produce a FLAC file.

  Output sample format

--16bit
    Output sample format is signed 16-bit. This option also enables the use of dithering, described below.

--24bit
    Output sample format is 24-bit. This is the default.

--float
    Output sample format is 32-bit floating point.

  Dithering

--rec
    Add white dithering noise with a rectangular distribution. This is the best option if the output data is going to processed again, but in that case it would be advisable to use 24-bit or float.

--tri
    Add filtered noise with a triangular distribution. Compared to the rectangular dither this reduces the noise density in the lower frequency range.

--lips
    This uses the optimal error feedback filter described by Stanley Lipschitz. This is recommended is the output is the final distribution format, e.g. for a CD.

  Timing

--pad
    Insert zero valued input samples at the start and end so that the output includes the full symmetric filter response even for the first and last samples.

EXIT STATUS
Zero in case there are no errors, non-zero otherwise.

AUTHOR
Fons Adriaensen (fons (at) linuxaudio.org)