debian man page for sample

SAMPLE(3alleg4) 						  Allegro manual						   SAMPLE(3alleg4)

NAME
       SAMPLE - Stores sound data. Allegro game programming library.

SYNOPSIS
       #include <allegro.h>

       typedef struct SAMPLE

DESCRIPTION
	  int bits;		      - 8 or 16
	  int stereo;		      - sample type flag
	  int freq;		      - sample frequency
	  int priority; 	      - 0-255
	  unsigned long len;	      - length (in samples)
	  unsigned long loop_start;   - loop start position
	  unsigned long loop_end;     - loop finish position
	  void *data;		      - raw sample data

       A  sample  structure, which holds sound data, used by the digital sample routines. You can consider all of these fields as read only except
       priority, loop_start and loop_end, which you can change them for example after loading a sample from disk.

       The priority is a value from 0 to 255 (by default set to 128) and controls how hardware voices on the  sound  card  are	allocated  if  you
       attempt	to play more than the driver can handle. This may be used to ensure that the less important sounds are cut off while the important
       ones are preserved.

       The variables loop_start and loop_end specify the loop position in sample units, and are set by default to the start and end of the sample.

       If you are creating your own samples on the fly, you might also want to modify the raw data of the sample pointed by the  data  field.  The
       sample  data  are  always  in  unsigned format. This means that if you are loading a PCM encoded sound file with signed 16-bit samples, you
       would have to XOR every two bytes (i.e. every sample value) with 0x8000 to change the signedness.

SEE ALSO
       load_sample(3alleg4), exsample(3alleg4)

Allegro 							   version 4.4.2						   SAMPLE(3alleg4)