57 lines
1.7 KiB
Plaintext
57 lines
1.7 KiB
Plaintext
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afSeekFrame(3)
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==============
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NAME
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----
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afSeekFrame, afTellFrame - update or access the current sample frame
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position for a 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 afSeekFrame(AFfilehandle file, int track,
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AFframecount frameOffset);
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AFframecount afTellFrame(AFfilehandle file, int track);
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PARAMETERS
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----------
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'file' is a valid audio file handle created by linkaf:afOpenFile[3].
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'track' identifies an audio track within the file. `track` is always
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`AF_DEFAULT_TRACK` for all currently supported audio file formats.
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'frameOffset' is a sample frame offset. Valid sample frame offsets must
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be greater than or equal to zero and strictly less than the number of
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sample frames contained within the specified audio track. The special
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value `-1` is also allowed.
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DESCRIPTION
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-----------
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`afSeekFrame` moves the logical file position for a specified audio
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track to a desired sample frame location. If `frameOffset` is `-1`,
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`afSeekFrame` will not modify the current file offset and will instead
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return the current file position.
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`afTellFrame` returns current file position in sample frames.
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RETURN VALUE
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------------
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On success, `afSeekFrame` and `afTellFrame` will return the current file
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position as measured in sample frames from the start of the audio
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track. On failure, `afSeekFrame` and `afTellFrame` will return the value
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`-1`.
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ERRORS
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------
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The following errors can be generated by `afSeekFrame` or `afTellFrame`:
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`AF_BAD_FILEHANDLE`:: `file` does not represent a valid file handle.
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`AF_BAD_TRACK`:: `track` does not identify a valid track.
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`AF_BAD_LSEEK`:: A call to `lseek` failed.
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AUTHOR
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------
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Michael Pruett <michael@68k.org>
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