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Patch from Antonio SJ Musumeci: " This code with SDL-1.2.8 and CVS: #include <stdio.h> #include <stdlib.h> #include <SDL.h> int main(int argc, char** argv) { char alphabet[26] = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"; char buffer_file[27] = {0}; char buffer_mem[27] = {0}; int rv_file; int rv_mem; FILE* file_ptr; SDL_RWops* rwop_file; SDL_RWops* rwop_mem; file_ptr = fopen("./blah", "w"); fwrite(alphabet, 1, sizeof(alphabet), file_ptr); fclose(file_ptr); rwop_mem = SDL_RWFromMem(alphabet, sizeof(alphabet)); rwop_file = SDL_RWFromFile("./blah", "r"); rv_mem = SDL_RWread(rwop_mem , buffer_mem, 5, 6); rv_file = SDL_RWread(rwop_file, buffer_file, 5, 6); printf("From File: %d %s\n" "From Mem: %d %s\n", rv_file, buffer_file, rv_mem, buffer_mem); printf("Seek end of File: %d\n" "Seek end of Mem: %d\n", SDL_RWseek(rwop_file, 0, SEEK_END), SDL_RWseek(rwop_mem , 0, SEEK_END)); SDL_RWclose(rwop_file); SDL_RWclose(rwop_mem); return 0; } Produces this output: From File: 5 ABCDEFGHIJKLMNOPQRSTUVWXYZ From Mem: 5 ABCDEFGHIJKLMNOPQRSTUVWXY Seek end of File: 26 Seek end of Mem: 26 " --ryan.
author Ryan C. Gordon <icculus@icculus.org>
date Fri, 24 Jun 2005 12:48:38 +0000
parents 355632dca928
children
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<HTML
><HEAD
><TITLE
>SDL_MixAudio</TITLE
><META
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"><LINK
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><H1
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>SDL_MixAudio</H1
><DIV
CLASS="REFNAMEDIV"
><A
NAME="AEN7107"
></A
><H2
>Name</H2
>SDL_MixAudio&nbsp;--&nbsp;Mix audio data</DIV
><DIV
CLASS="REFSYNOPSISDIV"
><A
NAME="AEN7110"
></A
><H2
>Synopsis</H2
><DIV
CLASS="FUNCSYNOPSIS"
><A
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></A
><P
></P
><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
></P
><P
></P
></DIV
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN7117"
></A
><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
CLASS="NOTE"
><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
></DIV
></DIV
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><A
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></A
><H2
>See Also</H2
><P
><A
HREF="sdlopenaudio.html"
><TT
CLASS="FUNCTION"
>SDL_OpenAudio</TT
></A
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