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view docs/html/sdlsetvideomode.html @ 773:da0a2ad35bf4
Date: Sun, 4 Jan 2004 23:48:19 +0100
From: Max Horn
Subject: Re: Again Audio CD patch
Am 04.01.2004 um 22:38 schrieb Sam Lantinga:
>
> Okay, I fixed the buffering problems by simply using a 4 second buffer
> instead of a 1 second buffer. However, using your code I can't play an
> entire CD - the playback stops after the first song.
>
Found the problem: FSReadFork returns eofErr when the file is finished.
However, we check its return value for errors, and if anything but
noErr occurs, the reader thread aborts its current iteration. That is
bad, because it aborts before it can ever set the flag which tells that
the file is over (also, any remaining data which FSRead did return is
lost - so you'd not hear about to 4 seconds from the end of the file.
Furthermore, the computed data size was 8 bytes to high (I forgot to
account for the fact that the size of an (A)IFF chunk always contains
the chunk header & size fields, too). This is enough to make it work.
However, the end condition is rather fragile, so I tuned some other
things to be pessimistic (check for <= 0 instead of == 0, when eofErr
is encountered enforce mReadFilePosition == mFileLength). You never
know...
The attached patch fixes the issue for me.
author | Sam Lantinga <slouken@libsdl.org> |
---|---|
date | Mon, 05 Jan 2004 00:57:51 +0000 |
parents | e5bc29de3f0a |
children | 355632dca928 |
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<HTML ><HEAD ><TITLE >SDL_SetVideoMode</TITLE ><META NAME="GENERATOR" CONTENT="Modular DocBook HTML Stylesheet Version 1.64 "><LINK REL="HOME" TITLE="SDL Library Documentation" HREF="index.html"><LINK REL="UP" TITLE="Video" HREF="video.html"><LINK REL="PREVIOUS" TITLE="SDL_VideoModeOK" HREF="sdlvideomodeok.html"><LINK REL="NEXT" TITLE="SDL_UpdateRect" HREF="sdlupdaterect.html"></HEAD ><BODY CLASS="REFENTRY" BGCOLOR="#FFF8DC" TEXT="#000000" LINK="#0000ee" VLINK="#551a8b" ALINK="#ff0000" ><DIV CLASS="NAVHEADER" ><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="sdlvideomodeok.html" >Prev</A ></TD ><TD WIDTH="80%" ALIGN="center" VALIGN="bottom" ></TD ><TD WIDTH="10%" ALIGN="right" VALIGN="bottom" ><A HREF="sdlupdaterect.html" >Next</A ></TD ></TR ></TABLE ><HR ALIGN="LEFT" WIDTH="100%"></DIV ><H1 ><A NAME="SDLSETVIDEOMODE" >SDL_SetVideoMode</A ></H1 ><DIV CLASS="REFNAMEDIV" ><A NAME="AEN856" ></A ><H2 >Name</H2 >SDL_SetVideoMode -- Set up a video mode with the specified width, height and bits-per-pixel.</DIV ><DIV CLASS="REFSYNOPSISDIV" ><A NAME="AEN859" ></A ><H2 >Synopsis</H2 ><DIV CLASS="FUNCSYNOPSIS" ><A NAME="AEN860" ></A ><P ></P ><PRE CLASS="FUNCSYNOPSISINFO" >#include "SDL.h"</PRE ><P ><CODE ><CODE CLASS="FUNCDEF" >SDL_Surface *<B CLASS="FSFUNC" >SDL_SetVideoMode</B ></CODE >(int width, int height, int bpp, Uint32 flags);</CODE ></P ><P ></P ></DIV ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN866" ></A ><H2 >Description</H2 ><P >Set up a video mode with the specified width, height and bits-per-pixel.</P ><P >If <TT CLASS="PARAMETER" ><I >bpp</I ></TT > is 0, it is treated as the current display bits per pixel.</P ><P >The <TT CLASS="PARAMETER" ><I >flags</I ></TT > parameter is the same as the <TT CLASS="STRUCTFIELD" ><I >flags</I ></TT > field of the <A HREF="sdlsurface.html" ><SPAN CLASS="STRUCTNAME" >SDL_Surface</SPAN ></A > structure. OR'd combinations of the following values are valid.</P ><DIV CLASS="INFORMALTABLE" ><A NAME="AEN876" ></A ><P ></P ><TABLE BORDER="1" CLASS="CALSTABLE" ><TBODY ><TR ><TD ALIGN="LEFT" VALIGN="TOP" ><TT CLASS="LITERAL" >SDL_SWSURFACE</TT ></TD ><TD ALIGN="LEFT" VALIGN="TOP" >Create the video surface in system memory</TD ></TR ><TR ><TD ALIGN="LEFT" VALIGN="TOP" ><TT CLASS="LITERAL" >SDL_HWSURFACE</TT ></TD ><TD ALIGN="LEFT" VALIGN="TOP" >Create the video surface in video memory</TD ></TR ><TR ><TD ALIGN="LEFT" VALIGN="TOP" ><TT CLASS="LITERAL" >SDL_ASYNCBLIT</TT ></TD ><TD ALIGN="LEFT" VALIGN="TOP" >Enables the use of asynchronous updates of the display surface. This will usually slow down blitting on single CPU machines, but may provide a speed increase on SMP systems.</TD ></TR ><TR ><TD ALIGN="LEFT" VALIGN="TOP" ><TT CLASS="LITERAL" >SDL_ANYFORMAT</TT ></TD ><TD ALIGN="LEFT" VALIGN="TOP" >Normally, if a video surface of the requested bits-per-pixel (<TT CLASS="PARAMETER" ><I >bpp</I ></TT >) is not available, SDL will emulate one with a shadow surface. Passing <TT CLASS="LITERAL" >SDL_ANYFORMAT</TT > prevents this and causes SDL to use the video surface, regardless of its pixel depth.</TD ></TR ><TR ><TD ALIGN="LEFT" VALIGN="TOP" ><TT CLASS="LITERAL" >SDL_HWPALETTE</TT ></TD ><TD ALIGN="LEFT" VALIGN="TOP" >Give SDL exclusive palette access. Without this flag you may not always get the the colors you request with <A HREF="sdlsetcolors.html" ><TT CLASS="FUNCTION" >SDL_SetColors</TT ></A > or <A HREF="sdlsetpalette.html" ><TT CLASS="FUNCTION" >SDL_SetPalette</TT ></A >.</TD ></TR ><TR ><TD ALIGN="LEFT" VALIGN="TOP" ><TT CLASS="LITERAL" >SDL_DOUBLEBUF</TT ></TD ><TD ALIGN="LEFT" VALIGN="TOP" >Enable hardware double buffering; only valid with SDL_HWSURFACE. Calling <A HREF="sdlflip.html" ><TT CLASS="FUNCTION" >SDL_Flip</TT ></A > will flip the buffers and update the screen. All drawing will take place on the surface that is not displayed at the moment. If double buffering could not be enabled then <TT CLASS="FUNCTION" >SDL_Flip</TT > will just perform a <A HREF="sdlupdaterect.html" ><TT CLASS="FUNCTION" >SDL_UpdateRect</TT ></A > on the entire screen.</TD ></TR ><TR ><TD ALIGN="LEFT" VALIGN="TOP" ><TT CLASS="LITERAL" >SDL_FULLSCREEN</TT ></TD ><TD ALIGN="LEFT" VALIGN="TOP" >SDL will attempt to use a fullscreen mode. If a hardware resolution change is not possible (for whatever reason), the next higher resolution will be used and the display window centered on a black background.</TD ></TR ><TR ><TD ALIGN="LEFT" VALIGN="TOP" ><TT CLASS="LITERAL" >SDL_OPENGL</TT ></TD ><TD ALIGN="LEFT" VALIGN="TOP" >Create an OpenGL rendering context. You should have previously set OpenGL video attributes with <A HREF="sdlglsetattribute.html" ><TT CLASS="FUNCTION" >SDL_GL_SetAttribute</TT ></A >.</TD ></TR ><TR ><TD ALIGN="LEFT" VALIGN="TOP" ><TT CLASS="LITERAL" >SDL_OPENGLBLIT</TT ></TD ><TD ALIGN="LEFT" VALIGN="TOP" >Create an OpenGL rendering context, like above, but allow normal blitting operations. The screen (2D) surface may have an alpha channel, and <A HREF="sdlupdaterects.html" ><TT CLASS="FUNCTION" >SDL_UpdateRects</TT ></A > must be used for updating changes to the screen surface.</TD ></TR ><TR ><TD ALIGN="LEFT" VALIGN="TOP" ><TT CLASS="LITERAL" >SDL_RESIZABLE</TT ></TD ><TD ALIGN="LEFT" VALIGN="TOP" >Create a resizable window. When the window is resized by the user a <A HREF="sdlresizeevent.html" ><TT CLASS="LITERAL" >SDL_VIDEORESIZE</TT ></A > event is generated and <TT CLASS="FUNCTION" >SDL_SetVideoMode</TT > can be called again with the new size.</TD ></TR ><TR ><TD ALIGN="LEFT" VALIGN="TOP" ><TT CLASS="LITERAL" >SDL_NOFRAME</TT ></TD ><TD ALIGN="LEFT" VALIGN="TOP" >If possible, <TT CLASS="LITERAL" >SDL_NOFRAME</TT > causes SDL to create a window with no title bar or frame decoration. Fullscreen modes automatically have this flag set.</TD ></TR ></TBODY ></TABLE ><P ></P ></DIV ><DIV CLASS="NOTE" ><BLOCKQUOTE CLASS="NOTE" ><P ><B >Note: </B >Whatever <TT CLASS="PARAMETER" ><I >flags</I ></TT > <TT CLASS="FUNCTION" >SDL_SetVideoMode</TT > could satisfy are set in the <TT CLASS="STRUCTFIELD" ><I >flags</I ></TT > member of the returned surface.</P ></BLOCKQUOTE ></DIV ><DIV CLASS="NOTE" ><BLOCKQUOTE CLASS="NOTE" ><P ><B >Note: </B >The <TT CLASS="PARAMETER" ><I >bpp</I ></TT > parameter is the number of bits per pixel, so a <TT CLASS="PARAMETER" ><I >bpp</I ></TT > of 24 uses the packed representation of 3 bytes/pixel. For the more common 4 bytes/pixel mode, use a <TT CLASS="PARAMETER" ><I >bpp</I ></TT > of 32. Somewhat oddly, both 15 and 16 will request a 2 bytes/pixel mode, but different pixel formats.</P ></BLOCKQUOTE ></DIV ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN952" ></A ><H2 >Return Value</H2 ><P >The framebuffer surface, or <SPAN CLASS="RETURNVALUE" >NULL</SPAN > if it fails. The surface returned is freed by SDL_Quit() and should nt be freed by the caller.</P ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN956" ></A ><H2 >See Also</H2 ><P ><A HREF="sdllocksurface.html" ><TT CLASS="FUNCTION" >SDL_LockSurface</TT ></A >, <A HREF="sdlsetcolors.html" ><TT CLASS="FUNCTION" >SDL_SetColors</TT ></A >, <A HREF="sdlflip.html" ><TT CLASS="FUNCTION" >SDL_Flip</TT ></A >, <A HREF="sdlsurface.html" ><SPAN CLASS="STRUCTNAME" >SDL_Surface</SPAN ></A ></P ></DIV ><DIV CLASS="NAVFOOTER" ><HR ALIGN="LEFT" WIDTH="100%"><TABLE WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" ><A HREF="sdlvideomodeok.html" >Prev</A ></TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="index.html" >Home</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" ><A HREF="sdlupdaterect.html" >Next</A ></TD ></TR ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" >SDL_VideoModeOK</TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="video.html" >Up</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" >SDL_UpdateRect</TD ></TR ></TABLE ></DIV ></BODY ></HTML >