CDreadda(3dm)

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

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

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

PARAMETERS
     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
     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
     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.
SEE ALSO
     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
     Mark Callow