view docs/html/sdlmixaudio.html @ 720:f90d80d68071

N Sep 17 8791 Sam Lantinga Re: tks source released Date: Sun, 07 Sep 2003 02:51:58 +0200 From: Stephane Marchesin Subject: [SDL] Two little patches Compiling SDL with a recent gcc (gcc 3.3.1, 3.3 doesn't have this behaviour) gives some nasty warnings : SDL_blit_A.c: In function `BlitRGBtoRGBSurfaceAlpha128MMX': SDL_blit_A.c:223: warning: integer constant is too large for "long" type SDL_blit_A.c:225: warning: integer constant is too large for "long" type SDL_blit_A.c:227: warning: integer constant is too large for "long" type [...] The first attached patch (longlongfix.patch) tells gcc to really treat those constants as unsigned long long and not long. The second patch (nasinclude.patch) fixes an include problem I had while compiling nas audio : when the <audio/audiolib.h> file lies in /usr/X11R6/include, a -I/usr/X11R6/include option is needed or the file isn't found.
author Sam Lantinga <slouken@libsdl.org>
date Sun, 21 Sep 2003 18:32:04 +0000
parents e5bc29de3f0a
children 355632dca928
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>SDL_MixAudio</A
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><A
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><H2
>Name</H2
>SDL_MixAudio&nbsp;--&nbsp;Mix audio data</DIV
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>Synopsis</H2
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><PRE
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>#include "SDL.h"</PRE
><P
><CODE
><CODE
CLASS="FUNCDEF"
>void <B
CLASS="FSFUNC"
>SDL_MixAudio</B
></CODE
>(Uint8 *dst, Uint8 *src, Uint32 len, int volume);</CODE
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><H2
>Description</H2
><P
>This function takes two audio buffers of <TT
CLASS="PARAMETER"
><I
>len</I
></TT
> bytes each
of the playing audio format and mixes them, performing addition, volume
adjustment, and overflow clipping. The <TT
CLASS="PARAMETER"
><I
>volume</I
></TT
> ranges
from 0 to <TT
CLASS="LITERAL"
>SDL_MIX_MAXVOLUME</TT
> and should be set to the maximum
value for full audio volume. Note this does not change hardware volume. This is
provided for convenience -- you can mix your own audio data.</P
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><B
>Note: </B
>Do not use this function for mixing together more than two streams of sample
data. The output from repeated application of this function may be distorted
by clipping, because there is no accumulator with greater range than the
input (not to mention this being an inefficient way of doing it).
Use mixing functions from SDL_mixer, OpenAL, or write your own mixer instead.</P
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>See Also</H2
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><TT
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>SDL_OpenAudio</TT
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