annotate src/audio/mme/SDL_mmeaudio.h @ 968:4675910b0b7b

Date: Mon, 11 Oct 2004 15:17:27 +0300 (EEST) From: Hannu Savolainen Subject: Re: SDL uses obsolete OSS features I did some work on getting OSS to work better with SDL. There have been some problems with select which should be fixed now. I'm having some problems in understanding what is the purpose of the DSP_WaitAudio() routine. I added a return to the very beginning of this routine and commendted out the define for USE_BLOCKING_WRITES. At least lbreakout2 seems to work as well as earlier. The latencies are the same. An ordinary blocking write does exactly the same thing than DSP_WaitAudio does. So I would recommend using the USE_BLOCKING_WRITES approach and removing everything from the DSP_WaitAudio routine. Also enabling USE_BLOCKING_WRITES makes it possible to simplify DSP_PlayAudio() because you don't need to handle the partial writes (the do-while loop). Attached is a patch against SDL-1.2.7. After these changes SDL will use OSS as it's designed to be used (make it as simple as possible). This code should work with all OSS implementations because it uses only the very fundamental features that have been there since the jurassic times.
author Sam Lantinga <slouken@libsdl.org>
date Fri, 12 Nov 2004 21:39:04 +0000
parents b8d311d90021
children 604d73db6802
rev   line source
654
e92bcf2573cb Added audio and CD-ROM support for OSF/Tru64 (thanks Hayashi!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
1 /*
e92bcf2573cb Added audio and CD-ROM support for OSF/Tru64 (thanks Hayashi!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
2 SDL - Simple DirectMedia Layer
769
b8d311d90021 Updated copyright information for 2004 (Happy New Year!)
Sam Lantinga <slouken@libsdl.org>
parents: 654
diff changeset
3 Copyright (C) 1997-2004 Sam Lantinga
654
e92bcf2573cb Added audio and CD-ROM support for OSF/Tru64 (thanks Hayashi!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
4
e92bcf2573cb Added audio and CD-ROM support for OSF/Tru64 (thanks Hayashi!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
5 This library is free software; you can redistribute it and/or
e92bcf2573cb Added audio and CD-ROM support for OSF/Tru64 (thanks Hayashi!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
6 modify it under the terms of the GNU Library General Public
e92bcf2573cb Added audio and CD-ROM support for OSF/Tru64 (thanks Hayashi!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
7 License as published by the Free Software Foundation; either
e92bcf2573cb Added audio and CD-ROM support for OSF/Tru64 (thanks Hayashi!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
8 version 2 of the License, or (at your option) any later version.
e92bcf2573cb Added audio and CD-ROM support for OSF/Tru64 (thanks Hayashi!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
9
e92bcf2573cb Added audio and CD-ROM support for OSF/Tru64 (thanks Hayashi!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
10 This library is distributed in the hope that it will be useful,
e92bcf2573cb Added audio and CD-ROM support for OSF/Tru64 (thanks Hayashi!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
e92bcf2573cb Added audio and CD-ROM support for OSF/Tru64 (thanks Hayashi!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
e92bcf2573cb Added audio and CD-ROM support for OSF/Tru64 (thanks Hayashi!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
13 Library General Public License for more details.
e92bcf2573cb Added audio and CD-ROM support for OSF/Tru64 (thanks Hayashi!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
14
e92bcf2573cb Added audio and CD-ROM support for OSF/Tru64 (thanks Hayashi!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
15 You should have received a copy of the GNU Library General Public
e92bcf2573cb Added audio and CD-ROM support for OSF/Tru64 (thanks Hayashi!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
16 License along with this library; if not, write to the Free
e92bcf2573cb Added audio and CD-ROM support for OSF/Tru64 (thanks Hayashi!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
17 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
e92bcf2573cb Added audio and CD-ROM support for OSF/Tru64 (thanks Hayashi!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
18
e92bcf2573cb Added audio and CD-ROM support for OSF/Tru64 (thanks Hayashi!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
19 Sam Lantinga
e92bcf2573cb Added audio and CD-ROM support for OSF/Tru64 (thanks Hayashi!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
20 slouken@libsdl.org
e92bcf2573cb Added audio and CD-ROM support for OSF/Tru64 (thanks Hayashi!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
21 */
e92bcf2573cb Added audio and CD-ROM support for OSF/Tru64 (thanks Hayashi!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
22
e92bcf2573cb Added audio and CD-ROM support for OSF/Tru64 (thanks Hayashi!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
23 /* Allow access to a raw mixing buffer */
e92bcf2573cb Added audio and CD-ROM support for OSF/Tru64 (thanks Hayashi!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
24
e92bcf2573cb Added audio and CD-ROM support for OSF/Tru64 (thanks Hayashi!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
25 #include <stdio.h>
e92bcf2573cb Added audio and CD-ROM support for OSF/Tru64 (thanks Hayashi!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
26 #include <stdlib.h>
e92bcf2573cb Added audio and CD-ROM support for OSF/Tru64 (thanks Hayashi!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
27 #include <string.h>
e92bcf2573cb Added audio and CD-ROM support for OSF/Tru64 (thanks Hayashi!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
28 #include <mme_api.h>
e92bcf2573cb Added audio and CD-ROM support for OSF/Tru64 (thanks Hayashi!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
29
e92bcf2573cb Added audio and CD-ROM support for OSF/Tru64 (thanks Hayashi!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
30 #include "SDL_audio.h"
e92bcf2573cb Added audio and CD-ROM support for OSF/Tru64 (thanks Hayashi!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
31 #include "SDL_mutex.h"
e92bcf2573cb Added audio and CD-ROM support for OSF/Tru64 (thanks Hayashi!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
32 #include "SDL_timer.h"
e92bcf2573cb Added audio and CD-ROM support for OSF/Tru64 (thanks Hayashi!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
33 #include "SDL_audio_c.h"
e92bcf2573cb Added audio and CD-ROM support for OSF/Tru64 (thanks Hayashi!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
34
e92bcf2573cb Added audio and CD-ROM support for OSF/Tru64 (thanks Hayashi!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
35 #ifndef _SDL_lowaudio_h
e92bcf2573cb Added audio and CD-ROM support for OSF/Tru64 (thanks Hayashi!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
36 #define _SDL_lowaudio_h
e92bcf2573cb Added audio and CD-ROM support for OSF/Tru64 (thanks Hayashi!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
37 #include "SDL_sysaudio.h"
e92bcf2573cb Added audio and CD-ROM support for OSF/Tru64 (thanks Hayashi!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
38
e92bcf2573cb Added audio and CD-ROM support for OSF/Tru64 (thanks Hayashi!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
39 /* Hidden "this" pointer for the video functions */
e92bcf2573cb Added audio and CD-ROM support for OSF/Tru64 (thanks Hayashi!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
40 #define _THIS SDL_AudioDevice *this
e92bcf2573cb Added audio and CD-ROM support for OSF/Tru64 (thanks Hayashi!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
41 #define NUM_BUFFERS 2
e92bcf2573cb Added audio and CD-ROM support for OSF/Tru64 (thanks Hayashi!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
42
e92bcf2573cb Added audio and CD-ROM support for OSF/Tru64 (thanks Hayashi!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
43 struct SharedMem {
e92bcf2573cb Added audio and CD-ROM support for OSF/Tru64 (thanks Hayashi!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
44 HWAVEOUT sound;
e92bcf2573cb Added audio and CD-ROM support for OSF/Tru64 (thanks Hayashi!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
45 WAVEHDR wHdr[NUM_BUFFERS];
e92bcf2573cb Added audio and CD-ROM support for OSF/Tru64 (thanks Hayashi!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
46 PCMWAVEFORMAT wFmt;
e92bcf2573cb Added audio and CD-ROM support for OSF/Tru64 (thanks Hayashi!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
47 };
e92bcf2573cb Added audio and CD-ROM support for OSF/Tru64 (thanks Hayashi!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
48
e92bcf2573cb Added audio and CD-ROM support for OSF/Tru64 (thanks Hayashi!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
49 struct SDL_PrivateAudioData {
e92bcf2573cb Added audio and CD-ROM support for OSF/Tru64 (thanks Hayashi!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
50 Uint8 *mixbuf; /* The raw allocated mixing buffer */
e92bcf2573cb Added audio and CD-ROM support for OSF/Tru64 (thanks Hayashi!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
51 struct SharedMem *shm;
e92bcf2573cb Added audio and CD-ROM support for OSF/Tru64 (thanks Hayashi!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
52 int next_buffer;
e92bcf2573cb Added audio and CD-ROM support for OSF/Tru64 (thanks Hayashi!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
53 };
e92bcf2573cb Added audio and CD-ROM support for OSF/Tru64 (thanks Hayashi!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
54
e92bcf2573cb Added audio and CD-ROM support for OSF/Tru64 (thanks Hayashi!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
55 #define shm (this->hidden->shm)
e92bcf2573cb Added audio and CD-ROM support for OSF/Tru64 (thanks Hayashi!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
56 #define mixbuf (this->hidden->mixbuf)
e92bcf2573cb Added audio and CD-ROM support for OSF/Tru64 (thanks Hayashi!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
57 #define next_buffer (this->hidden->next_buffer)
e92bcf2573cb Added audio and CD-ROM support for OSF/Tru64 (thanks Hayashi!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
58 /* Old variable names */
e92bcf2573cb Added audio and CD-ROM support for OSF/Tru64 (thanks Hayashi!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
59 #endif /* _SDL_lowaudio_h */