64 lines
1.8 KiB
Plaintext
64 lines
1.8 KiB
Plaintext
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afGetFrameCount(3)
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==================
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NAME
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----
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afGetFrameCount, afGetTrackBytes, afGetDataOffset - get the total sample
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frame count, length of audio track in bytes, offset of the audio track for a
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track in an audio file
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SYNOPSIS
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--------
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#include <audiofile.h>
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AFframecount afGetFrameCount (AFfilehandle file, int track);
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AFfileoffset afGetTrackBytes (AFfilehandle file, int track);
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AFfileoffset afGetDataOffset (AFfilehandle file, int track);
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PARAMETERS
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----------
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'file' is an audio file handle created by a previous call to
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linkaf:afOpenFile[3].
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'track' is an integer which specifies an audio track within 'file'.
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All supported file formats contain exactly one audio track per file,
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so the constant `AF_DEFAULT_TRACK` should always be used.
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DESCRIPTION
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-----------
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`afGetFrameCount` returns the total number of sample frames contained
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within the specified track of the specified file.
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Each sample frame of audio consists of a fixed number of samples
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(equal to the number of audio channels in the track. For monaural data,
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a sample frame consists of one audio sample. For stereophonic data,
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a sample frame consists of a stereo pair.
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`afGetTrackBytes` returns the total number of bytes of raw audio data
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(i.e., prior to decompression or conversion) in the track.
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`afGetDataOffset` returns the offset in bytes of the start of the audio
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data contained within the specified track of the specified file.
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RETURN VALUE
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------------
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`afGetFrameCount` returns the total number of sample frames in 'track'.
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`afGetTrackBytes` returns the total number of bytes of audio data
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in 'track'.
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`afGetDataOffset` returns the offset in bytes to the beginning of the
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audio data in 'track'.
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Each of these routines returns -1 in case of error.
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AUTHOR
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------
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Michael Pruett <michael@68k.org>
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