view docs/man3/SDL_LoadWAV.3 @ 1542:a8bf1aa21020

Fixed bug #15 SDL_blit_A.mmx-speed.patch.txt -- Speed improvements and a bugfix for the current GCC inline mmx asm code: - Changed some ops and removed some resulting useless ones. - Added some instruction parallelism (some gain) The resulting speed on my Xeon improved upto 35% depending on the function (measured in fps). - Fixed a bug where BlitRGBtoRGBSurfaceAlphaMMX() was setting the alpha component on the destination surfaces (to opaque-alpha) even when the surface had none. SDL_blit_A.mmx-msvc.patch.txt -- MSVC mmx intrinsics version of the same GCC asm code. MSVC compiler tries to parallelize the code and to avoid register stalls, but does not always do a very good job. Per-surface blending MSVC functions run quite a bit faster than their pure-asm counterparts (upto 55% faster for 16bit ones), but the per-pixel blending runs somewhat slower than asm. - BlitRGBtoRGBSurfaceAlphaMMX and BlitRGBtoRGBPixelAlphaMMX (and all variants) can now also handle formats other than (A)RGB8888. Formats like RGBA8888 and some quite exotic ones are allowed -- like RAGB8888, or actually anything having channels aligned on 8bit boundary and full 8bit alpha (for per-pixel alpha blending). The performance cost of this change is virtually 0 for per-surface alpha blending (no extra ops inside the loop) and a single non-MMX op inside the loop for per-pixel blending. In testing, the per-pixel alpha blending takes a ~2% performance hit, but it still runs much faster than the current code in CVS. If necessary, a separate function with this functionality can be made. This code requires Processor Pack for VC6.
author Sam Lantinga <slouken@libsdl.org>
date Wed, 15 Mar 2006 15:39:29 +0000
parents e5bc29de3f0a
children 546f7c1eb755
line wrap: on
line source

.TH "SDL_LoadWAV" "3" "Tue 11 Sep 2001, 22:58" "SDL" "SDL API Reference" 
.SH "NAME"
SDL_LoadWAV\- Load a WAVE file
.SH "SYNOPSIS"
.PP
\fB#include "SDL\&.h"
.sp
\fBSDL_AudioSpec *\fBSDL_LoadWAV\fP\fR(\fBconst char *file, SDL_AudioSpec *spec, Uint8 **audio_buf, Uint32 *audio_len\fR);
.SH "DESCRIPTION"
.PP
\fBSDL_LoadWAV\fP This function loads a WAVE \fBfile\fR into memory\&.
.PP
If this function succeeds, it returns the given \fI\fBSDL_AudioSpec\fP\fR, filled with the audio data format of the wave data, and sets \fBaudio_buf\fR to a \fBmalloc\fP\&'d buffer containing the audio data, and sets \fBaudio_len\fR to the length of that audio buffer, in bytes\&. You need to free the audio buffer with \fI\fBSDL_FreeWAV\fP\fR when you are done with it\&.
.PP
This function returns \fBNULL\fP and sets the SDL error message if the wave file cannot be opened, uses an unknown data format, or is corrupt\&. Currently raw, MS-ADPCM and IMA-ADPCM WAVE files are supported\&.
.SH "EXAMPLE"
.PP
.nf
\f(CWSDL_AudioSpec wav_spec;
Uint32 wav_length;
Uint8 *wav_buffer;

/* Load the WAV */
if( SDL_LoadWAV("test\&.wav", &wav_spec, &wav_buffer, &wav_length) == NULL ){
  fprintf(stderr, "Could not open test\&.wav: %s
", SDL_GetError());
  exit(-1);
}
\&.
\&.
\&.
/* Do stuff with the WAV */
\&.
\&.
/* Free It */
SDL_FreeWAV(wav_buffer);\fR
.fi
.PP
.SH "SEE ALSO"
.PP
\fI\fBSDL_AudioSpec\fR\fR, \fI\fBSDL_OpenAudio\fP\fR, \fI\fBSDL_FreeWAV\fP\fR
...\" created by instant / docbook-to-man, Tue 11 Sep 2001, 22:58