annotate src/audio/nto/SDL_nto_audio.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 19418e4422cb
rev   line source
0
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
1 /*
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
2 SDL - Simple DirectMedia Layer
769
b8d311d90021 Updated copyright information for 2004 (Happy New Year!)
Sam Lantinga <slouken@libsdl.org>
parents: 718
diff changeset
3 Copyright (C) 1997-2004 Sam Lantinga
0
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
4
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
5 This library is free software; you can redistribute it and/or
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
6 modify it under the terms of the GNU Library General Public
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
7 License as published by the Free Software Foundation; either
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
8 version 2 of the License, or (at your option) any later version.
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
9
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
10 This library is distributed in the hope that it will be useful,
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
13 Library General Public License for more details.
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
14
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
15 You should have received a copy of the GNU Library General Public
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
16 License along with this library; if not, write to the Free
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
17 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
18
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
19 Sam Lantinga
252
e8157fcb3114 Updated the source with the correct e-mail address
Sam Lantinga <slouken@libsdl.org>
parents: 0
diff changeset
20 slouken@libsdl.org
0
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
21 */
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
22
718
cbc0f7fabd1c Date: Sat, 13 Sep 2003 15:50:43 +0300
Sam Lantinga <slouken@libsdl.org>
parents: 297
diff changeset
23 #ifndef __SDL_NTO_AUDIO_H__
cbc0f7fabd1c Date: Sat, 13 Sep 2003 15:50:43 +0300
Sam Lantinga <slouken@libsdl.org>
parents: 297
diff changeset
24 #define __SDL_NTO_AUDIO_H__
0
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
25
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
26 #include "SDL_sysaudio.h"
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
27 #include <sys/asoundlib.h>
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
28
718
cbc0f7fabd1c Date: Sat, 13 Sep 2003 15:50:43 +0300
Sam Lantinga <slouken@libsdl.org>
parents: 297
diff changeset
29 /* Hidden "this" pointer for the audio functions */
0
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
30 #define _THIS SDL_AudioDevice *this
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
31
718
cbc0f7fabd1c Date: Sat, 13 Sep 2003 15:50:43 +0300
Sam Lantinga <slouken@libsdl.org>
parents: 297
diff changeset
32 struct SDL_PrivateAudioData
cbc0f7fabd1c Date: Sat, 13 Sep 2003 15:50:43 +0300
Sam Lantinga <slouken@libsdl.org>
parents: 297
diff changeset
33 {
cbc0f7fabd1c Date: Sat, 13 Sep 2003 15:50:43 +0300
Sam Lantinga <slouken@libsdl.org>
parents: 297
diff changeset
34 /* The audio device handle */
cbc0f7fabd1c Date: Sat, 13 Sep 2003 15:50:43 +0300
Sam Lantinga <slouken@libsdl.org>
parents: 297
diff changeset
35 int cardno;
cbc0f7fabd1c Date: Sat, 13 Sep 2003 15:50:43 +0300
Sam Lantinga <slouken@libsdl.org>
parents: 297
diff changeset
36 int deviceno;
cbc0f7fabd1c Date: Sat, 13 Sep 2003 15:50:43 +0300
Sam Lantinga <slouken@libsdl.org>
parents: 297
diff changeset
37 snd_pcm_t* audio_handle;
0
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
38
718
cbc0f7fabd1c Date: Sat, 13 Sep 2003 15:50:43 +0300
Sam Lantinga <slouken@libsdl.org>
parents: 297
diff changeset
39 /* The audio file descriptor */
cbc0f7fabd1c Date: Sat, 13 Sep 2003 15:50:43 +0300
Sam Lantinga <slouken@libsdl.org>
parents: 297
diff changeset
40 int audio_fd;
0
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
41
718
cbc0f7fabd1c Date: Sat, 13 Sep 2003 15:50:43 +0300
Sam Lantinga <slouken@libsdl.org>
parents: 297
diff changeset
42 /* The parent process id, to detect when application quits */
cbc0f7fabd1c Date: Sat, 13 Sep 2003 15:50:43 +0300
Sam Lantinga <slouken@libsdl.org>
parents: 297
diff changeset
43 pid_t parent;
cbc0f7fabd1c Date: Sat, 13 Sep 2003 15:50:43 +0300
Sam Lantinga <slouken@libsdl.org>
parents: 297
diff changeset
44
cbc0f7fabd1c Date: Sat, 13 Sep 2003 15:50:43 +0300
Sam Lantinga <slouken@libsdl.org>
parents: 297
diff changeset
45 /* Raw mixing buffer */
cbc0f7fabd1c Date: Sat, 13 Sep 2003 15:50:43 +0300
Sam Lantinga <slouken@libsdl.org>
parents: 297
diff changeset
46 Uint8* pcm_buf;
cbc0f7fabd1c Date: Sat, 13 Sep 2003 15:50:43 +0300
Sam Lantinga <slouken@libsdl.org>
parents: 297
diff changeset
47 Uint32 pcm_len;
0
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
48
718
cbc0f7fabd1c Date: Sat, 13 Sep 2003 15:50:43 +0300
Sam Lantinga <slouken@libsdl.org>
parents: 297
diff changeset
49 /* QSA parameters */
cbc0f7fabd1c Date: Sat, 13 Sep 2003 15:50:43 +0300
Sam Lantinga <slouken@libsdl.org>
parents: 297
diff changeset
50 snd_pcm_channel_status_t cstatus;
cbc0f7fabd1c Date: Sat, 13 Sep 2003 15:50:43 +0300
Sam Lantinga <slouken@libsdl.org>
parents: 297
diff changeset
51 snd_pcm_channel_params_t cparams;
cbc0f7fabd1c Date: Sat, 13 Sep 2003 15:50:43 +0300
Sam Lantinga <slouken@libsdl.org>
parents: 297
diff changeset
52 snd_pcm_channel_setup_t csetup;
0
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
53 };
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
54
718
cbc0f7fabd1c Date: Sat, 13 Sep 2003 15:50:43 +0300
Sam Lantinga <slouken@libsdl.org>
parents: 297
diff changeset
55 #define cardno (this->hidden->cardno)
cbc0f7fabd1c Date: Sat, 13 Sep 2003 15:50:43 +0300
Sam Lantinga <slouken@libsdl.org>
parents: 297
diff changeset
56 #define deviceno (this->hidden->deviceno)
cbc0f7fabd1c Date: Sat, 13 Sep 2003 15:50:43 +0300
Sam Lantinga <slouken@libsdl.org>
parents: 297
diff changeset
57 #define audio_handle (this->hidden->audio_handle)
cbc0f7fabd1c Date: Sat, 13 Sep 2003 15:50:43 +0300
Sam Lantinga <slouken@libsdl.org>
parents: 297
diff changeset
58 #define audio_fd (this->hidden->audio_fd)
cbc0f7fabd1c Date: Sat, 13 Sep 2003 15:50:43 +0300
Sam Lantinga <slouken@libsdl.org>
parents: 297
diff changeset
59 #define parent (this->hidden->parent)
cbc0f7fabd1c Date: Sat, 13 Sep 2003 15:50:43 +0300
Sam Lantinga <slouken@libsdl.org>
parents: 297
diff changeset
60 #define pcm_buf (this->hidden->pcm_buf)
cbc0f7fabd1c Date: Sat, 13 Sep 2003 15:50:43 +0300
Sam Lantinga <slouken@libsdl.org>
parents: 297
diff changeset
61 #define pcm_len (this->hidden->pcm_len)
cbc0f7fabd1c Date: Sat, 13 Sep 2003 15:50:43 +0300
Sam Lantinga <slouken@libsdl.org>
parents: 297
diff changeset
62 #define cstatus (this->hidden->cstatus)
cbc0f7fabd1c Date: Sat, 13 Sep 2003 15:50:43 +0300
Sam Lantinga <slouken@libsdl.org>
parents: 297
diff changeset
63 #define cparams (this->hidden->cparams)
cbc0f7fabd1c Date: Sat, 13 Sep 2003 15:50:43 +0300
Sam Lantinga <slouken@libsdl.org>
parents: 297
diff changeset
64 #define csetup (this->hidden->csetup)
0
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
65
718
cbc0f7fabd1c Date: Sat, 13 Sep 2003 15:50:43 +0300
Sam Lantinga <slouken@libsdl.org>
parents: 297
diff changeset
66 #endif /* __SDL_NTO_AUDIO_H__ */