SNDWaveData

Definition

#include <nitro/snd.h>
typedef struct SNDWaveParam
{
u8  format;
u8  loopflag;
u16 rate;
u16 timer;
u16 loopstart;
u32 looplen;
} SNDWaveParam;

typedef struct SNDWaveData
{
struct SNDWaveParam param;
u8 samples[0];
} SNDWaveData;







Elements

      
      







format
Sample format.




loopflag
Loop flag. If zero, there is no loop. If non-zero, a loop exists.




rate
Sampling rate. It is expressed in MHz.




timer
Description. It corresponds to SND_TIMER_CLOCK / rate.




loopstart
Starting point of the loop. It is expressed in words (32-bit).




looplen
Length of the loop. If there is no loop, this corresponds to the length of the waveform. It is expressed in words (32-bit).




samples
Array of the sample data. The size of the array, in words, is loopstart + looplen.
          







    




Description

      

Waveform data structure. It holds the header information and the sample data for the waveform data.


      

The sample format format takes one of the following values.



Table. SNDWaveFormat







Label
Description






SND_WAVE_FORMAT_PCM8
8-bit PCM




SND_WAVE_FORMAT_PCM16
16-bit PCM




SND_WAVE_FORMAT_ADPCM
IMA-ADPCM







      

If the sample format is SND_WAVE_FORMAT_ADPCM, ADPCM header information similar to the following is stored in the first word of the sample data samples.


      
struct {
s16 prevsample; // Previous sample value
u8  previndex;  // Previous index value
u8  padding;    // Padding (always 0)
};


      
    


See Also


None.


Revision History


2005/01/19 Initial version.




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