Filter
Top Products
510 Voice API for Windows Operating Systems Library Reference — November 2003
DX_IOTT — input/output transfer table
• IO_UIO – nonstandard storage media data using the dx_setuio( ) function; must be ORed
with IO_DEV
Specify the structure linkage as follows:
• IO_CONT – the next DX_IOTT structure is contiguous (default)
• IO_LINK – the next DX_IOTT structure is part of a linked list
• IO_EOT – this is the last DX_IOTT structure in the chain
If no value is specified, IO_CONT is assumed.
Other Types:
• IO_USEOFFSET – enables use of the io_offset and io_length fields for WAVE data
To enable offset I/O for WAVE data, set the DX_IOTT io_type field to IO_USEOFFSET ORed
with the IO_DEV define (to indicate file data rather than memory buffer).
Wave files cannot be recorded to memory buffers or played from memory buffers.
io_fhandle
Specifies a unique file descriptor provided by the dx_fileopen( ) function if IO_DEV is set in
io_type. If IO_DEV is not set in io_type, io_fhandle should be set to 0.
io_bufp
Specifies a base memory address if IO_MEM is set in io_type.
io_offset
Specifies one of the following:
• if IO_DEV is specified in io_type, an offset from the beginning of a file
• for WAVE file offset I/O (IO_DEV is ORed with IO_USEOFFSET in io_type), a file
offset value that is calculated from the beginning of the WAVE audio data rather than the
beginning of the file (that is, the first 80 bytes that make up the file header are not
counted).
• if IO_MEM is specified in io_type, an offset from the base buffer address specified in
io_bufp
io_length
Specifies the number of bytes allocated for recording or the byte length of the playback file.
Specify -1 to play until end of data. During dx_play( ), a value of -1 causes playback to
continue until an EOF is received or one of the terminating conditions is satisfied. During
dx_rec( ), a value of -1 in io_length causes recording to continue until one of the terminating
conditions is satisfied.
Note: When playing a GSM WAVE file and using an offset, you must set the io_length field
to the actual length of the file. Setting this field to -1 is not supported.
io_nextp
Points to the next DX_IOTT structure in the linked list if IO_LINK is set in io_type.
io_prevp
Points to the previous DX_IOTT structure. This field is automatically filled in when dx_rec( )
or dx_play( ) is called. The io_prevp field of the first DX_IOTT structure is set to NULL.
!
!!
! Example
The following example uses different sources for playback, an array or linked list of DX_IOTT
structures.