afgetframesize(3) [centos man page]

AFGETFRAMESIZE(3)														 AFGETFRAMESIZE(3)

NAME

       afGetFrameSize - calculate the frame size in bytes for an audio track

SYNOPSIS

       #include <audiofile.h>

       float afGetFrameSize (AFfilehandle file, int track, int expand3to4);

PARAMETERS

       file is a valid AFfilehandle.

       track is an integer which refers to a specific audio track in the file. At present no supported audio file format allows for more than one
       audio track within a file, so track should always be AF_DEFAULT_TRACK.

       expand3to4 is a boolean-valued integer indicating whether frame size calculation will treat 24-bit data as having a size of 3 bytes or 4
       bytes.

DESCRIPTION

       afGetFrameSize returns the number of bytes in a frame in a given audio track.

       A sample frame consists of one or more samples. For a monaural track, a sample frame will always contain one sample. For a stereophonic
       track, a sample frame will always contain two samples, one for the left channel and one for the right channel.

       A non-zero value of expand3to4 should be used when calculating the frame size for storage in memory (since 24-bit audio data is presented
       in memory as a 4-byte sign-extended integer), while a value of zero should be used for calculating storage on disk where no padding is
       added. The parameter expand3to4 is ignored unless the specified audio track contains 24-bit audio data.

AUTHOR

       Michael Pruett <michael@68k.org>

Audio File Library 0.3.6					    03/06/2013							 AFGETFRAMESIZE(3)

AFSEEKFRAME(3)															    AFSEEKFRAME(3)

NAME

       afSeekFrame, afTellFrame - update or access the current sample frame position for a track in an audio file

SYNOPSIS

       #include <audiofile.h>

       AFframecount afSeekFrame(AFfilehandle file, int track,
	   AFframecount frameOffset);

       AFframecount afTellFrame(AFfilehandle file, int track);

PARAMETERS

       file is a valid audio file handle created by afOpenFile(3).

       track identifies an audio track within the file. track is always AF_DEFAULT_TRACK for all currently supported audio file formats.

       frameOffset is a sample frame offset. Valid sample frame offsets must be greater than or equal to zero and strictly less than the number of
       sample frames contained within the specified audio track. The special value -1 is also allowed.

DESCRIPTION

       afSeekFrame moves the logical file position for a specified audio track to a desired sample frame location. If frameOffset is -1,
       afSeekFrame will not modify the current file offset and will instead return the current file position.

       afTellFrame returns current file position in sample frames.

RETURN VALUE

       On success, afSeekFrame and afTellFrame will return the current file position as measured in sample frames from the start of the audio
       track. On failure, afSeekFrame and afTellFrame will return the value -1.

ERRORS

       The following errors can be generated by afSeekFrame or afTellFrame:

       AF_BAD_FILEHANDLE

	   file does not represent a valid file handle.

       AF_BAD_TRACK

	   track does not identify a valid track.

       AF_BAD_LSEEK
	   A call to lseek failed.

AUTHOR

       Michael Pruett <michael@68k.org>

Audio File Library 0.3.6					    03/06/2013							    AFSEEKFRAME(3)