afSetVirtualChannels(3) set the virtual data format for a track in an audio file

Other Alias

afSetVirtualByteOrder, afSetVirtualPCMMapping, afSetVirtualSampleFormat

SYNOPSIS


#include <audiofile.h>

int afSetVirtualByteOrder (AFfilehandle file, int track, int byteOrder);

int afSetVirtualChannels (AFfilehandle file, int track, int channels);

int afSetVirtualSampleFormat (AFfilehandle file, int track,
    int sampleFormat, int sampleWidth);

int afSetVirtualPCMMapping (AFfilehandle file, int track,
    double slope, double intercept, double minclip, double maxclip);

PARAMETERS

file is an AFfilehandle which refers to an open audio file and is usually created by afOpenFile.

track is an integer which identifies a particular track in an open audio file. The only valid track is AF_DEFAULT_TRACK for all currently supported file formats.

sampleFormat is an integer which denotes a virtual sample format. Valid values are AF_SAMPFMT_TWOSCOMP, AF_SAMPFMT_UNSIGNED, AF_SAMPFMT_FLOAT, and AF_SAMPFMT_DOUBLE.

sampleWidth is a positive integer which specifies the number of bits in a sample.

channels is a positive integer which specifies the number of interleaved audio channels in the given audio track.

byteOrder is an integer which specifies the virtual byte order of samples in the given audio track. byteOrder can be either AF_BYTEORDER_BIGENDIAN or AF_BYTEORDER_LITTLEENDIAN.

slope and intercept are double-precision floating point values which indicate the audio data sample slope and zero-crossing value, respectively, for the given sample format.

minclip and maxclip are double-precision floating point values which indicates the minimum or maximum sample values to be returned. Any values less than minclip will be set to minclip, and any values greater than maxclip will be set to maxclip.

RETURN VALUE

These functions return 0 for success and -1 for failure.

AUTHOR

Michael Pruett <[email protected]>