CDreadda(3dm)							 CDreadda(3dm)

NAME    [Toc]    [Back]

     CDreadda -	read digital audio data	from audio CD in CD-ROM

SYNOPSIS    [Toc]    [Back]

     #include <sys/types.h>
     #include <dmedia/cdaudio.h>

     int CDreadda(CDPLAYER* cd,	CDFRAME* buf, int numframes)

PARAMETERS    [Toc]    [Back]

     cd		 A pointer to the CDPLAYER structure representing the target
		 CD-ROM	drive.

     buf	 A pointer to a	buffer in which	to put the data.

     numframe	 The number of frames of digital audio data to read.

RETURNED VALUE    [Toc]    [Back]

     If	successful, this function returns the number of	frames read (a
     nonnegative integer value). Otherwise -1 is returned and errno is set to
     indicated the error. A return value of 0 indicates	the logical read
     pointer has reached the end of the	audio CD data.

DESCRIPTION    [Toc]    [Back]

     CDreadda(3dm) reads numframes frames [see cdframe (4)] of digital audio
     data from an audio	CD mounted in the CD-ROM drive.	 The digital audio
     data stream contains 75 frames every second.  A file pointer is
     maintained	which points at	the starting location for the read.  CDopen
     initializes the file pointer to 0.	 On successful completion CDreadda
     sets the pointer to the end of the	requested data.	 The pointer may be
     set to any	random location	with CDseek.

     CDopen sets the CD-ROM drive read-ahead buffer parameters to values
     carefully chosen to allow continuous reading of audio data	without
     interruption.  To keep up with this data transfer and maintain an
     uninterrupted audio stream, numframes must	be twelve.

     CDreadda will fail	and no data will be returned if	one of more of the
     following are true:


     [EAGAIN]	    The	CD-ROM status is not STA_GOOD.

     [EBADF]	    The	specified CDPLAYER is not valid.

     [EIO]	    An error occurred during the read operation.

     [ENXIO]	    The	specified CD-ROM drive does not	support	this
		    operation.






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CDreadda(3dm)							 CDreadda(3dm)

SEE ALSO    [Toc]    [Back]

     CDintro(3dm), CDclose(3dm), CDgetstatus(3dm), CDgettrackinfo(3dm),
     CDeject(3dm), CDframetomsf(3dm), CDframetotc(3dm),	CDmsftoframe(3dm),
     CDopen(3dm), CDparseframe(3dm), CDseek(3dm), CDseekblock(3dm),
     CDseektrack(3dm), CDtctoframe(3dm)

AUTHOR    [Toc]    [Back]

     Mark Callow


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