Mercurial > sdl-ios-xcode
view src/audio/SDL_wave.h @ 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 | b8d311d90021 |
| children | c9b51268668f |
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/* SDL - Simple DirectMedia Layer Copyright (C) 1997-2004 Sam Lantinga This library is free software; you can redistribute it and/or modify it under the terms of the GNU Library General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Library General Public License for more details. You should have received a copy of the GNU Library General Public License along with this library; if not, write to the Free Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA Sam Lantinga slouken@libsdl.org */ #ifdef SAVE_RCSID static char rcsid = "@(#) $Id$"; #endif /* WAVE files are little-endian */ /*******************************************/ /* Define values for Microsoft WAVE format */ /*******************************************/ #define RIFF 0x46464952 /* "RIFF" */ #define WAVE 0x45564157 /* "WAVE" */ #define FACT 0x74636166 /* "fact" */ #define LIST 0x5453494c /* "LIST" */ #define FMT 0x20746D66 /* "fmt " */ #define DATA 0x61746164 /* "data" */ #define PCM_CODE 0x0001 #define MS_ADPCM_CODE 0x0002 #define IMA_ADPCM_CODE 0x0011 #define WAVE_MONO 1 #define WAVE_STEREO 2 /* Normally, these three chunks come consecutively in a WAVE file */ typedef struct WaveFMT { /* Not saved in the chunk we read: Uint32 FMTchunk; Uint32 fmtlen; */ Uint16 encoding; Uint16 channels; /* 1 = mono, 2 = stereo */ Uint32 frequency; /* One of 11025, 22050, or 44100 Hz */ Uint32 byterate; /* Average bytes per second */ Uint16 blockalign; /* Bytes per sample block */ Uint16 bitspersample; /* One of 8, 12, 16, or 4 for ADPCM */ } WaveFMT; /* The general chunk found in the WAVE file */ typedef struct Chunk { Uint32 magic; Uint32 length; Uint8 *data; } Chunk;