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Date: 10 Jun 2003 15:30:59 -0400 From: Mike Shal Subject: [SDL] Bug in SDL_wave.c? Hey everyone, I'm not sure if this is a bug in SDL, or if I just have incorrect WAV files. The problem I'm having is loading multiple concatenated WAVs from SDL_LoadWAV_RW. Some WAV files put comments at the end of the file (which may be bad form), and SDL doesn't skip past them when reading from the RWops. So the next WAV I try to load will start at the comment section of the previous WAV, which obviously doesn't work. If anyone else is having this problem, one quick fix you can do is run sox on the bad WAVs, which strips out all of the comment sections. Eg: $ sox sound.wav tmp.wav $ mv -f tmp.wav sound.wav The other fix is to patch SDL_wave.c, which is included with this email. (Assuming I made the patch correctly :). All it does is calculate how much remaining space there is in the WAV file after the data chunk, and does SDL_RWseek to skip it. I don't think it should interfere with anything else, but if someone could check it that would be nice :). If the bug is really with SDL and not with my WAVs, can someone work this into the next version of SDL? Thanks, -Mike Shal
author Sam Lantinga <slouken@libsdl.org>
date Tue, 24 Jan 2006 07:20:18 +0000
parents 355632dca928
children
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<HTML
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><TITLE
>SDL_SetColorKey</TITLE
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><H1
><A
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>SDL_SetColorKey</H1
><DIV
CLASS="REFNAMEDIV"
><A
NAME="AEN2045"
></A
><H2
>Name</H2
>SDL_SetColorKey&nbsp;--&nbsp;Sets the color key (transparent pixel) in a blittable surface and
RLE acceleration.</DIV
><DIV
CLASS="REFSYNOPSISDIV"
><A
NAME="AEN2048"
></A
><H2
>Synopsis</H2
><DIV
CLASS="FUNCSYNOPSIS"
><A
NAME="AEN2049"
></A
><P
></P
><PRE
CLASS="FUNCSYNOPSISINFO"
>#include "SDL.h"</PRE
><P
><CODE
><CODE
CLASS="FUNCDEF"
>int <B
CLASS="FSFUNC"
>SDL_SetColorKey</B
></CODE
>(SDL_Surface *surface, Uint32 flag, Uint32 key);</CODE
></P
><P
></P
></DIV
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN2055"
></A
><H2
>Description</H2
><P
> Sets the color key (transparent pixel) in a blittable surface and enables or
 disables RLE blit acceleration.</P
><P
>RLE acceleration can substantially speed up blitting of images with large
horizontal runs of transparent pixels (i.e., pixels that match the
<TT
CLASS="PARAMETER"
><I
>key</I
></TT
> value). The <TT
CLASS="PARAMETER"
><I
>key</I
></TT
> must be of the same pixel format as the <TT
CLASS="PARAMETER"
><I
>surface</I
></TT
>, <A
HREF="sdlmaprgb.html"
><TT
CLASS="FUNCTION"
>SDL_MapRGB</TT
></A
> is often useful for obtaining an acceptable value.</P
><P
>If <TT
CLASS="PARAMETER"
><I
>flag</I
></TT
> is <TT
CLASS="LITERAL"
>SDL_SRCCOLORKEY</TT
> then
<TT
CLASS="PARAMETER"
><I
>key</I
></TT
> is the transparent pixel value in the source image of a
blit.</P
><P
>If <TT
CLASS="PARAMETER"
><I
>flag</I
></TT
> is OR'd with
<TT
CLASS="LITERAL"
>SDL_RLEACCEL</TT
> then the surface will be draw using RLE
acceleration when drawn with
<A
HREF="sdlblitsurface.html"
>SDL_BlitSurface</A
>.  The surface will
actually be encoded for RLE acceleration the first time
<A
HREF="sdlblitsurface.html"
>SDL_BlitSurface</A
> or
<A
HREF="sdldisplayformat.html"
>SDL_DisplayFormat</A
> is called on the
surface.</P
><P
>If <TT
CLASS="PARAMETER"
><I
>flag</I
></TT
> is 0, this function clears
any current color key.</P
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN2076"
></A
><H2
>Return Value</H2
><P
>This function returns <SPAN
CLASS="RETURNVALUE"
>0</SPAN
>, or
<SPAN
CLASS="RETURNVALUE"
>-1</SPAN
> if there was an error.</P
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN2081"
></A
><H2
>See Also</H2
><P
><A
HREF="sdlblitsurface.html"
><TT
CLASS="FUNCTION"
>SDL_BlitSurface</TT
></A
>,
<A
HREF="sdldisplayformat.html"
><TT
CLASS="FUNCTION"
>SDL_DisplayFormat</TT
></A
>,
<A
HREF="sdlmaprgb.html"
><TT
CLASS="FUNCTION"
>SDL_MapRGB</TT
></A
>,
<A
HREF="sdlsetalpha.html"
><TT
CLASS="FUNCTION"
>SDL_SetAlpha</TT
></A
></P
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