Manual Pages for UNIX Operating System command usage for man audio_engine_chinfo

Driver Entry Points                       audio_engine_chinfo(9E)



NAME
     audio_engine_chinfo - return channel layout information  for
     an audio engine

SYNOPSIS
     #include 

     void prefix_chinfo(void *state, int chan, unsigned *offsetp,
          unsigned *incrementp);


PARAMETERS
     state         pointer to driver supplied soft state


     chan          a channel number


     offsetp       pointer  to  an  unsigned  integer  where  the
                   driver stores the offset of the channel within
                   the first sample


     incrementp    pointer  to  an  unsigned  integer  where  the
                   driver  stores  the  increment for the channel
                   between samples


INTERFACE LEVEL
     Solaris DDI specific (Solaris DDI)

DESCRIPTION
     The audio_engine_chinfo() function is used by the  framework
     to  determine  the  layout  of channel data within the audio
     stream.


     The offset indicates the index to the channel's sample  data
     within an audio frame.


     The increment is the number of samples separating the  chan-
     nel between adjacent frames.


     Both offset and increment are in  units  of  the  individual
     sample  size. For example, for signed 16-bit linear PCM, the
     units are given as  int16_t.  This  is  true  regardless  of
     whether  the  engine is monophonic, stereophonic, or in some
     other configuration.





SunOS 5.11          Last change: 16 Apr 2010                    1






Driver Entry Points                       audio_engine_chinfo(9E)



     For engines with typical  interleaved  samples,  the  offset
     value  is  the same as the channel number, and the increment
     value is the number of channels for which the engine is con-
     figured. If NULL is provided for this entry point, then this
     simple interleaved layout is assumed.


     Other layouts can be used to reorder the channels (by chang-
     ing  the  offset  value)  or  interleave  data from separate
     buffers together (by changing the increment value.) This can
     be  used  to  achieve a functionality similar to the "remux"
     feature of other audio systems.


     This entry point is only supported for playback.


     An audio engine may not change the  layout  of  its  buffers
     while it is open

CONTEXT
     This function may be called from user or kernel context.

ATTRIBUTES
     See attributes(5) for descriptions of the  following  attri-
     butes:



     ____________________________________________________________
    |       ATTRIBUTE TYPE        |       ATTRIBUTE VALUE       |
    |_____________________________|_____________________________|
    | Interface Stability         | Committed                   |
    |_____________________________|_____________________________|


SEE ALSO
     attributes(5), audio(7D), audio_engine_ops(9S)

















SunOS 5.11          Last change: 16 Apr 2010                    2