view docs/html/sdlmixaudio.html @ 1018:012af0b7e8e6

Date: Fri, 24 Dec 2004 23:32:06 -0500 From: Mike Frysinger Subject: [SDL] minor fix for gcc-2.x building in src/video/directfb/SDL_DirectFB_video.c, some variables are not declared at the beginning of scope ... newer gcc's will accept this, but gcc-2.x does not find attached a simple patch by Matt Taylor to resolve this http://bugs.gentoo.org/show_bug.cgi?id=75392
author Sam Lantinga <slouken@libsdl.org>
date Mon, 27 Dec 2004 20:03:53 +0000
parents 355632dca928
children
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>SDL_MixAudio</H1
><DIV
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><A
NAME="AEN7107"
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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
CLASS="FUNCSYNOPSISINFO"
>#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
><DIV
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><BLOCKQUOTE
CLASS="NOTE"
><P
><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
></BLOCKQUOTE
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>See Also</H2
><P
><A
HREF="sdlopenaudio.html"
><TT
CLASS="FUNCTION"
>SDL_OpenAudio</TT
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