NAME¶
afGetFrameCount, afGetTrackBytes, afGetDataOffset - get the total sample frame
count, length of audio track in bytes, offset of the audio track for a track
in an audio file
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 audio file handle created by a previous call to
afOpenFile(3).
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 track. 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 or conversion) in the track.
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.
Each of these routines returns -1 in case of error.
AUTHOR¶
Michael Pruett <michael@68k.org>