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Date: Tue, 4 Mar 2003 15:05:31 -0800 From: "Jim" Subject: [SDL] Frame Buffer patches... Okay I'm new at patch generation - so please tell me if there's a better way I could have done this. Attached are two patch files generated with 'cvs diff -u' SDL-fb-open-lock.patch applies to SDL_fbvideo.c Modifies the open loop to check /dev/fb/0 found on devfs... Modifies the lock code to return failure if the current virtual terminal is not the one opened for frame buffer writing... Lock would hang forever if switched away (ctrl-alt-F1) ... SDL-fb-mousedrv-screensave.patch applies to SDL_fbevents.c Switches default mouse mode based on SDL_MOUSEDRV - currently only accepts PS2 - otherwise default is MS Mouse. When the screen is switched - exisiting code (wrapped in ifdef SAVE_SCREEN_COTENTS) would save the wrong bit of the screen.... ( I run frame buffer 1600x1200, the size I requested was 800x600 - the save would save the top 800 lines (non biased) and restore them... Adding screen->offset fixed that ) However, if that option is not set, then a call to SDL_UpdateRect (full screen) is made. (which may have had it's contents changed since the screen is not entirely locked because of lock-failure patch) Jim [patches slightly tweaked for SDL 1.2.10]
author Sam Lantinga <slouken@libsdl.org>
date Wed, 22 Mar 2006 07:48:22 +0000
parents 355632dca928
children
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<HTML
><HEAD
><TITLE
>Audio</TITLE
><META
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CONTENT="Modular DocBook HTML Stylesheet Version 1.76b+
"><LINK
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><DIV
CLASS="CHAPTER"
><H1
><A
NAME="AUDIO"
></A
>Chapter 10. Audio</H1
><DIV
CLASS="TOC"
><DL
><DT
><B
>Table of Contents</B
></DT
><DT
><A
HREF="sdlaudiospec.html"
>SDL_AudioSpec</A
>&nbsp;--&nbsp;Audio Specification Structure</DT
><DT
><A
HREF="sdlopenaudio.html"
>SDL_OpenAudio</A
>&nbsp;--&nbsp;Opens the audio device with the desired parameters.</DT
><DT
><A
HREF="sdlpauseaudio.html"
>SDL_PauseAudio</A
>&nbsp;--&nbsp;Pauses and unpauses the audio callback processing</DT
><DT
><A
HREF="sdlgetaudiostatus.html"
>SDL_GetAudioStatus</A
>&nbsp;--&nbsp;Get the current audio state</DT
><DT
><A
HREF="sdlloadwav.html"
>SDL_LoadWAV</A
>&nbsp;--&nbsp;Load a WAVE file</DT
><DT
><A
HREF="sdlfreewav.html"
>SDL_FreeWAV</A
>&nbsp;--&nbsp;Frees previously opened WAV data</DT
><DT
><A
HREF="sdlaudiocvt.html"
>SDL_AudioCVT</A
>&nbsp;--&nbsp;Audio Conversion Structure</DT
><DT
><A
HREF="sdlbuildaudiocvt.html"
>SDL_BuildAudioCVT</A
>&nbsp;--&nbsp;Initializes a SDL_AudioCVT structure for conversion</DT
><DT
><A
HREF="sdlconvertaudio.html"
>SDL_ConvertAudio</A
>&nbsp;--&nbsp;Convert audio data to a desired audio format.</DT
><DT
><A
HREF="sdlmixaudio.html"
>SDL_MixAudio</A
>&nbsp;--&nbsp;Mix audio data</DT
><DT
><A
HREF="sdllockaudio.html"
>SDL_LockAudio</A
>&nbsp;--&nbsp;Lock out the callback function</DT
><DT
><A
HREF="sdlunlockaudio.html"
>SDL_UnlockAudio</A
>&nbsp;--&nbsp;Unlock the callback function</DT
><DT
><A
HREF="sdlcloseaudio.html"
>SDL_CloseAudio</A
>&nbsp;--&nbsp;Shuts down audio processing and closes the audio device.</DT
></DL
></DIV
><P
>Sound on the computer is translated from waves that you hear into a series of 
values, or samples, each representing the amplitude of the wave.  When these
samples are sent in a stream to a sound card, an approximation of the original
wave can be recreated.  The more bits used to represent the amplitude, and the
greater frequency these samples are gathered, the closer the approximated
sound is to the original, and the better the quality of sound.</P
><P
>This library supports both 8 and 16 bit signed and unsigned sound samples,
at frequencies ranging from 11025 Hz to 44100 Hz, depending on the 
underlying hardware.  If the hardware doesn't support the desired audio
format or frequency, it can be emulated if desired (See 
<A
HREF="sdlopenaudio.html"
><TT
CLASS="FUNCTION"
>SDL_OpenAudio()</TT
></A
>)</P
><P
>A commonly supported audio format is 16 bits per sample at 22050 Hz.</P
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