Mercurial > sdl-ios-xcode
view docs/html/sdlcreateyuvoverlay.html @ 2042:3908e1f808e1
Fixed bug #292
I might be on crack here.
It looks like SDL_ConvertMono() in src/audio/SDL_audiocvt.c adds the left and
right channels of a stereo stream together, and clamps the new mono channel if
it would overflow.
Shouldn't it be dividing by 2 to average the two sample points instead of
clamping? Otherwise the mono sample point's volume doubles in the conversion.
This would also make the conversion faster, as it replaces two branches per
sample frame with a bitwise shift.
--ryan.
author | Sam Lantinga <slouken@libsdl.org> |
---|---|
date | Sun, 24 Sep 2006 15:56:36 +0000 |
parents | 355632dca928 |
children |
line wrap: on
line source
<HTML ><HEAD ><TITLE >SDL_CreateYUVOverlay</TITLE ><META NAME="GENERATOR" CONTENT="Modular DocBook HTML Stylesheet Version 1.76b+ "><LINK REL="HOME" TITLE="SDL Library Documentation" HREF="index.html"><LINK REL="UP" TITLE="Video" HREF="video.html"><LINK REL="PREVIOUS" TITLE="SDL_GL_SwapBuffers" HREF="sdlglswapbuffers.html"><LINK REL="NEXT" TITLE="SDL_LockYUVOverlay" HREF="sdllockyuvoverlay.html"></HEAD ><BODY CLASS="REFENTRY" BGCOLOR="#FFF8DC" TEXT="#000000" LINK="#0000ee" VLINK="#551a8b" ALINK="#ff0000" ><DIV CLASS="NAVHEADER" ><TABLE SUMMARY="Header navigation table" WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TH COLSPAN="3" ALIGN="center" >SDL Library Documentation</TH ></TR ><TR ><TD WIDTH="10%" ALIGN="left" VALIGN="bottom" ><A HREF="sdlglswapbuffers.html" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="80%" ALIGN="center" VALIGN="bottom" ></TD ><TD WIDTH="10%" ALIGN="right" VALIGN="bottom" ><A HREF="sdllockyuvoverlay.html" ACCESSKEY="N" >Next</A ></TD ></TR ></TABLE ><HR ALIGN="LEFT" WIDTH="100%"></DIV ><H1 ><A NAME="SDLCREATEYUVOVERLAY" ></A >SDL_CreateYUVOverlay</H1 ><DIV CLASS="REFNAMEDIV" ><A NAME="AEN2808" ></A ><H2 >Name</H2 >SDL_CreateYUVOverlay -- Create a YUV video overlay</DIV ><DIV CLASS="REFSYNOPSISDIV" ><A NAME="AEN2811" ></A ><H2 >Synopsis</H2 ><DIV CLASS="FUNCSYNOPSIS" ><A NAME="AEN2812" ></A ><P ></P ><PRE CLASS="FUNCSYNOPSISINFO" >#include "SDL.h"</PRE ><P ><CODE ><CODE CLASS="FUNCDEF" >SDL_Overlay *<B CLASS="FSFUNC" >SDL_CreateYUVOverlay</B ></CODE >(int width, int height, Uint32 format, SDL_Surface *display);</CODE ></P ><P ></P ></DIV ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN2818" ></A ><H2 >Description</H2 ><P ><TT CLASS="FUNCTION" >SDL_CreateYUVOverlay</TT > creates a YUV overlay of the specified <TT CLASS="PARAMETER" ><I >width</I ></TT >, <TT CLASS="PARAMETER" ><I >height</I ></TT > and <TT CLASS="PARAMETER" ><I >format</I ></TT > (see <A HREF="sdloverlay.html" ><SPAN CLASS="STRUCTNAME" >SDL_Overlay</SPAN ></A > for a list of available formats), for the provided <TT CLASS="PARAMETER" ><I >display</I ></TT >. A <A HREF="sdloverlay.html" ><SPAN CLASS="STRUCTNAME" >SDL_Overlay</SPAN ></A > structure is returned.</P ><P >The term 'overlay' is a misnomer since, unless the overlay is created in hardware, the contents for the display surface underneath the area where the overlay is shown will be overwritten when the overlay is displayed.</P ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN2831" ></A ><H2 >See Also</H2 ><P ><A HREF="sdloverlay.html" ><SPAN CLASS="STRUCTNAME" >SDL_Overlay</SPAN ></A >, <A HREF="sdldisplayyuvoverlay.html" ><TT CLASS="FUNCTION" >SDL_DisplayYUVOverlay</TT ></A >, <A HREF="sdlfreeyuvoverlay.html" ><TT CLASS="FUNCTION" >SDL_FreeYUVOverlay</TT ></A ></P ></DIV ><DIV CLASS="NAVFOOTER" ><HR ALIGN="LEFT" WIDTH="100%"><TABLE SUMMARY="Footer navigation table" WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" ><A HREF="sdlglswapbuffers.html" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="index.html" ACCESSKEY="H" >Home</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" ><A HREF="sdllockyuvoverlay.html" ACCESSKEY="N" >Next</A ></TD ></TR ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" >SDL_GL_SwapBuffers</TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="video.html" ACCESSKEY="U" >Up</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" >SDL_LockYUVOverlay</TD ></TR ></TABLE ></DIV ></BODY ></HTML >