view src/audio/SDL_sysaudio.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 f8d5ddc7aef1
line wrap: on
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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

#ifndef _SDL_sysaudio_h
#define _SDL_sysaudio_h

#include "SDL_mutex.h"
#include "SDL_thread.h"

/* The SDL audio driver */
typedef struct SDL_AudioDevice SDL_AudioDevice;

/* Define the SDL audio driver structure */
#define _THIS	SDL_AudioDevice *_this
#ifndef _STATUS
#define _STATUS	SDL_status *status
#endif
struct SDL_AudioDevice {
	/* * * */
	/* The name of this audio driver */
	const char *name;

	/* * * */
	/* The description of this audio driver */
	const char *desc;

	/* * * */
	/* Public driver functions */
	int  (*OpenAudio)(_THIS, SDL_AudioSpec *spec);
	void (*ThreadInit)(_THIS);	/* Called by audio thread at start */
	void (*WaitAudio)(_THIS);
	void (*PlayAudio)(_THIS);
	Uint8 *(*GetAudioBuf)(_THIS);
	void (*WaitDone)(_THIS);
	void (*CloseAudio)(_THIS);

	/* * * */
	/* Lock / Unlock functions added for the Mac port */
	void (*LockAudio)(_THIS);
	void (*UnlockAudio)(_THIS);

	/* * * */
	/* Data common to all devices */

	/* The current audio specification (shared with audio thread) */
	SDL_AudioSpec spec;

	/* An audio conversion block for audio format emulation */
	SDL_AudioCVT convert;

	/* Current state flags */
	int enabled;
	int paused;
	int opened;

	/* Fake audio buffer for when the audio hardware is busy */
	Uint8 *fake_stream;

	/* A semaphore for locking the mixing buffers */
	SDL_mutex *mixer_lock;

	/* A thread to feed the audio device */
	SDL_Thread *thread;
	Uint32 threadid;

	/* * * */
	/* Data private to this driver */
	struct SDL_PrivateAudioData *hidden;

	/* * * */
	/* The function used to dispose of this structure */
	void (*free)(_THIS);
};
#undef _THIS

typedef struct AudioBootStrap {
	const char *name;
	const char *desc;
	int (*available)(void);
	SDL_AudioDevice *(*create)(int devindex);
} AudioBootStrap;

#ifdef OPENBSD_AUDIO_SUPPORT
extern AudioBootStrap OPENBSD_AUDIO_bootstrap;
#endif
#ifdef OSS_SUPPORT
extern AudioBootStrap DSP_bootstrap;
extern AudioBootStrap DMA_bootstrap;
#endif
#ifdef ALSA_SUPPORT
extern AudioBootStrap ALSA_bootstrap;
#endif
#ifdef QNXNTOAUDIO_SUPPORT
extern AudioBootStrap QNXNTOAUDIO_bootstrap;
#endif
#ifdef SUNAUDIO_SUPPORT
extern AudioBootStrap SUNAUDIO_bootstrap;
#endif
#ifdef DMEDIA_SUPPORT
extern AudioBootStrap DMEDIA_bootstrap;
#endif
#ifdef ARTSC_SUPPORT
extern AudioBootStrap ARTSC_bootstrap;
#endif
#ifdef ESD_SUPPORT
extern AudioBootStrap ESD_bootstrap;
#endif
#ifdef NAS_SUPPORT
extern AudioBootStrap NAS_bootstrap;
#endif
#ifdef ENABLE_DIRECTX
extern AudioBootStrap DSOUND_bootstrap;
#endif
#ifdef ENABLE_WINDIB
extern AudioBootStrap WAVEOUT_bootstrap;
#endif
#ifdef _AIX
extern AudioBootStrap Paud_bootstrap;
#endif
#ifdef __BEOS__
extern AudioBootStrap BAUDIO_bootstrap;
#endif
#if defined(macintosh) || TARGET_API_MAC_CARBON
extern AudioBootStrap SNDMGR_bootstrap;
#endif
#ifdef ENABLE_AHI
extern AudioBootStrap AHI_bootstrap;
#endif
#ifdef MINTAUDIO_SUPPORT
extern AudioBootStrap MINTAUDIO_GSXB_bootstrap;
extern AudioBootStrap MINTAUDIO_MCSN_bootstrap;
extern AudioBootStrap MINTAUDIO_STFA_bootstrap;
extern AudioBootStrap MINTAUDIO_XBIOS_bootstrap;
extern AudioBootStrap MINTAUDIO_DMA8_bootstrap;
#endif
#ifdef DISKAUD_SUPPORT
extern AudioBootStrap DISKAUD_bootstrap;
#endif
#ifdef ENABLE_DC
extern AudioBootStrap DCAUD_bootstrap;
#endif
#ifdef DRENDERER_SUPPORT
extern AudioBootStrap DRENDERER_bootstrap;
#endif
#ifdef MMEAUDIO_SUPPORT
extern AudioBootStrap MMEAUDIO_bootstrap;
#endif

/* This is the current audio device */
extern SDL_AudioDevice *current_audio;

#endif /* _SDL_sysaudio_h */