sdl_buildaudiocvt(3) [redhat man page]

SDL_BuildAudioCVT(3)						 SDL API Reference					      SDL_BuildAudioCVT(3)

NAME

       SDL_BuildAudioCVT- Initializes a SDL_AudioCVT structure for conversion

SYNOPSIS

       #include "SDL.h"

       int  SDL_BuildAudioCVT(SDL_AudioCVT  *cvt,  Uint16 src_format, Uint8 src_channels, int src_rate, Uint16 dst_format, Uint8 dst_channels, int
       dst_rate);

DESCRIPTION

       Before an SDL_AudioCVT structure can be used to convert audio data it must be initialized with source and destination information.

       src_format and dst_format are the source and destination format of the conversion. (For information on audio formats  see   SDL_AudioSpec).
       src_channels and dst_channels are the number of channels in the source and destination formats. Finally, src_rate and dst_rate are the fre-
       quency or samples-per-second of the source and destination formats. Once again, see SDL_AudioSpec.

RETURN VALUES

       Returns -1 if the filter could not be built or 1 if it could.

EXAMPLES

       See SDL_ConvertAudio.

SEE ALSO

       SDL_ConvertAudio, SDL_AudioCVT

SDL
							      Tue 11 Sep 2001, 22:58					      SDL_BuildAudioCVT(3)

SDL_AudioCVT(3) 						 SDL API Reference						   SDL_AudioCVT(3)

NAME

       SDL_AudioCVT - Audio Conversion Structure

STRUCTURE DEFINITION

       typedef struct{
	 int needed;
	 Uint16 src_format;
	 Uint16 dest_format;
	 double rate_incr;
	 Uint8 *buf;
	 int len;
	 int len_cvt;
	 int len_mult;
	 double len_ratio;
	 void (*filters[10])(struct SDL_AudioCVT *cvt, Uint16 format);
	 int filter_index;
       } SDL_AudioCVT;

STRUCTURE DATA

       needed		   Set to one if the conversion is possible

       src_format	   Audio format of the source

       dest_format	   Audio format of the destination

       rate_incr	   Rate conversion increment

       buf		   Audio buffer

       len		   Length of the original audio buffer in bytes

       len_cvt		   Length of converted audio buffer in bytes (calculated)

       len_mult 	   buf must be len*len_mult bytes in size(calculated)

       len_ratio	   Final audio size is len*len_ratio

       filters[10](..)	   Pointers to functions needed for this conversion

       filter_index	   Current conversion function

DESCRIPTION

       The  SDL_AudioCVT  is  used to convert audio data between different formats. A SDL_AudioCVT structure is created with the SDL_BuildAudioCVT
       function, while the actual conversion is done by the SDL_ConvertAudio function.

       Many of the fields in the SDL_AudioCVT structure should be considered private and their function will not be discussed here.

       Uint8 *buf

       int len

       int len_mult

       double len_ratio

SEE ALSO

       SDL_BuildAudioCVT, SDL_ConvertAudio, SDL_AudioSpec

SDL
							      Tue 11 Sep 2001, 22:58						   SDL_AudioCVT(3)