afGetTrackBytes
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NAME
afGetFrameCount, afGetTrackBytes, afGetDataOffset - get the total sample
frame count, length of audio track in bytes, offset of the audio track for a
specified audio track in a specified AFfilehandle structure
SYNOPSIS
#include <audiofile.h>
AFframecount afGetFrameCount (AFfilehandle file, int track);
AFfileoffset afGetTrackBytes (AFfilehandle file, int track);
AFfileoffset afGetDataOffset (AFfilehandle file, int track);
PARAMETERS
file is an AFfilehandle that has been created by a previous call to
afOpenFile.
track is an integer which specifies an audio track within file. All
supported file formats contain exactly one audio track per file, so the
constant AF_DEFAULT_TRACK should always be used.
DESCRIPTION
afGetFrameCount returns the total number of sample frames contained
within the specified track of the specified file.
Each sample frame of audio consists of a fixed number of samples (equal to
the number of audio channels in the file, equal to the value returned by
afGetChannels for the particular track and file). For monaural data, a
sample frame consists of one audio sample. For stereophonic data, a sample
frame consists of a stereo pair.
afGetTrackBytes returns the total number of bytes of raw audio data
(i.e., prior to decompression) in track. This is useful for determining
raw file seek points, etc.
afGetDataOffset returns the offset in bytes of the start of the audio
data contained within the specified track of the specified file.
RETURN VALUE
afGetFrameCount returns the total number of sample frames in track.
afGetTrackBytes() returns the total number of bytes of audio data in
track. afGetDataOffset() returns the offset in bytes to the beginning
of the audio data in track.
If an error occurs, -1 is returned by all of these routines.