sdl-ios-xcode: src/audio/alsa/SDL_alsa

annotate src/audio/alsa/SDL_alsa_audio.c @ 765:4c2ba6161939

Editors Note: The original patch was modified to use SDL_Delay() instead of nanosleep because nanosleep may not be portable to all systems using SDL with the ALSA backend. This may be a moot point with the switch to blocking writes anyway... Date: Sat, 27 Dec 2003 21:47:36 +0100 From: Michel Daenzer To: Debian Bug Tracking System Subject: [SDL] Bug#225252: [PATCH] ALSA fixes Package: libsdl1.2debian-all Version: 1.2.6-2 Severity: normal Tags: patch For SDL 1.2.6, the ALSA backend was changed to call snd_pcm_open() with SND_PCM_NONBLOCK. That's a good idea per se, however, it causes high CPU usage, interrupted sound and stuttering in some games here. Taking a nanosleep whenever snd_pcm_writei() returns -EAGAIN fixes this, but I think it's more efficient to use blocking mode for the actual sound playback. Feedback from the SDL and ALSA lists appreciated. The patch also fixes the default ALSA device to be used.

author	Sam Lantinga <slouken@libsdl.org>
date	Sun, 04 Jan 2004 15:40:50 +0000
parents	5d07f9a47f17
children	b8d311d90021

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
297 f6ffac90895c Updated copyright information for 2002 Sam Lantinga <slouken@libsdl.org> parents: 252 diff changeset	3 Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002 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
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	23
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	24
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	25 /* Allow access to a raw mixing buffer */
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	26
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	27 #include <stdlib.h>
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	28 #include <stdio.h>
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	29 #include <string.h>
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	30 #include <errno.h>
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	31 #include <unistd.h>
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	32 #include <fcntl.h>
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	33 #include <signal.h>
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	34 #include <sys/types.h>
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	35 #include <sys/time.h>
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	36
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	37 #include "SDL_audio.h"
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	38 #include "SDL_error.h"
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	39 #include "SDL_audiomem.h"
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	40 #include "SDL_audio_c.h"
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	41 #include "SDL_timer.h"
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	42 #include "SDL_alsa_audio.h"
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	43
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	44 /* The tag name used by ALSA audio */
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	45 #define DRIVER_NAME "alsa"
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	46
354 30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	47 /* The default ALSA audio driver */
765 4c2ba6161939 Editors Note: The original patch was modified to use SDL_Delay() instead of Sam Lantinga <slouken@libsdl.org> parents: 547 diff changeset	48 #define DEFAULT_DEVICE "default"
0 74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	49
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	50 /* Audio driver functions */
354 30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	51 static int ALSA_OpenAudio(_THIS, SDL_AudioSpec *spec);
30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	52 static void ALSA_WaitAudio(_THIS);
30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	53 static void ALSA_PlayAudio(_THIS);
30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	54 static Uint8 *ALSA_GetAudioBuf(_THIS);
30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	55 static void ALSA_CloseAudio(_THIS);
0 74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	56
354 30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	57 static const char *get_audio_device()
30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	58 {
30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	59 const char *device;
30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	60
30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	61 device = getenv("AUDIODEV"); /* Is there a standard variable name? */
30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	62 if ( device == NULL ) {
30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	63 device = DEFAULT_DEVICE;
30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	64 }
30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	65 return device;
0 74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	66 }
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	67
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	68 /* Audio driver bootstrap functions */
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	69
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	70 static int Audio_Available(void)
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	71 {
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	72 int available;
354 30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	73 int status;
0 74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	74 snd_pcm_t *handle;
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	75
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	76 available = 0;
547 5d07f9a47f17 Open the ALSA devices in non-blocking mode (thanks Aleksey!) Sam Lantinga <slouken@libsdl.org> parents: 357 diff changeset	77 status = snd_pcm_open(&handle, get_audio_device(), SND_PCM_STREAM_PLAYBACK, SND_PCM_NONBLOCK);
354 30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	78 if ( status >= 0 ) {
30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	79 available = 1;
30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	80 snd_pcm_close(handle);
0 74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	81 }
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	82 return(available);
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	83 }
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	84
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	85 static void Audio_DeleteDevice(SDL_AudioDevice *device)
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	86 {
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	87 free(device->hidden);
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	88 free(device);
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	89 }
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	90
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	91 static SDL_AudioDevice *Audio_CreateDevice(int devindex)
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	92 {
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	93 SDL_AudioDevice *this;
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	94
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	95 /* Initialize all variables that we clean on shutdown */
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	96 this = (SDL_AudioDevice *)malloc(sizeof(SDL_AudioDevice));
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	97 if ( this ) {
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	98 memset(this, 0, (sizeof *this));
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	99 this->hidden = (struct SDL_PrivateAudioData *)
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	100 malloc((sizeof *this->hidden));
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	101 }
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	102 if ( (this == NULL) \|\| (this->hidden == NULL) ) {
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	103 SDL_OutOfMemory();
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	104 if ( this ) {
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	105 free(this);
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	106 }
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	107 return(0);
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	108 }
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	109 memset(this->hidden, 0, (sizeof *this->hidden));
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	110
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	111 /* Set the function pointers */
354 30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	112 this->OpenAudio = ALSA_OpenAudio;
30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	113 this->WaitAudio = ALSA_WaitAudio;
30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	114 this->PlayAudio = ALSA_PlayAudio;
30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	115 this->GetAudioBuf = ALSA_GetAudioBuf;
30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	116 this->CloseAudio = ALSA_CloseAudio;
0 74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	117
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	118 this->free = Audio_DeleteDevice;
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	119
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	120 return this;
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	121 }
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	122
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	123 AudioBootStrap ALSA_bootstrap = {
354 30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	124 DRIVER_NAME, "ALSA 0.9 PCM audio",
0 74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	125 Audio_Available, Audio_CreateDevice
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	126 };
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	127
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	128 /* This function waits until it is possible to write a full sound buffer */
354 30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	129 static void ALSA_WaitAudio(_THIS)
0 74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	130 {
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	131 /* Check to see if the thread-parent process is still alive */
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	132 { static int cnt = 0;
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	133 /* Note that this only works with thread implementations
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	134 that use a different process id for each thread.
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	135 */
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	136 if (parent && (((++cnt)%10) == 0)) { /* Check every 10 loops */
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	137 if ( kill(parent, 0) < 0 ) {
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	138 this->enabled = 0;
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	139 }
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	140 }
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	141 }
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	142 }
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	143
354 30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	144 static void ALSA_PlayAudio(_THIS)
0 74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	145 {
354 30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	146 int status;
30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	147 int sample_len;
30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	148 signed short *sample_buf;
765 4c2ba6161939 Editors Note: The original patch was modified to use SDL_Delay() instead of Sam Lantinga <slouken@libsdl.org> parents: 547 diff changeset	149
354 30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	150 sample_len = this->spec.samples;
30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	151 sample_buf = (signed short *)mixbuf;
30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	152 while ( sample_len > 0 ) {
30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	153 status = snd_pcm_writei(pcm_handle, sample_buf, sample_len);
30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	154 if ( status < 0 ) {
30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	155 if ( status == -EAGAIN ) {
765 4c2ba6161939 Editors Note: The original patch was modified to use SDL_Delay() instead of Sam Lantinga <slouken@libsdl.org> parents: 547 diff changeset	156 SDL_Delay(1);
354 30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	157 continue;
30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	158 }
30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	159 if ( status == -ESTRPIPE ) {
30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	160 do {
765 4c2ba6161939 Editors Note: The original patch was modified to use SDL_Delay() instead of Sam Lantinga <slouken@libsdl.org> parents: 547 diff changeset	161 SDL_Delay(1);
354 30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	162 status = snd_pcm_resume(pcm_handle);
30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	163 } while ( status == -EAGAIN );
30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	164 }
30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	165 if ( status < 0 ) {
30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	166 status = snd_pcm_prepare(pcm_handle);
30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	167 }
30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	168 if ( status < 0 ) {
30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	169 /* Hmm, not much we can do - abort */
30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	170 this->enabled = 0;
30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	171 return;
0 74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	172 }
356 a1e54d1ba16f * empty log message * Sam Lantinga <slouken@libsdl.org> parents: 354 diff changeset	173 continue;
0 74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	174 }
354 30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	175 sample_buf += status * this->spec.channels;
30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	176 sample_len -= status;
0 74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	177 }
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	178 }
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	179
354 30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	180 static Uint8 *ALSA_GetAudioBuf(_THIS)
0 74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	181 {
354 30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	182 return(mixbuf);
0 74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	183 }
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	184
354 30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	185 static void ALSA_CloseAudio(_THIS)
0 74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	186 {
354 30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	187 if ( mixbuf != NULL ) {
30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	188 SDL_FreeAudioMem(mixbuf);
30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	189 mixbuf = NULL;
0 74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	190 }
354 30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	191 if ( pcm_handle ) {
357 5868b0f832f2 * empty log message * Sam Lantinga <slouken@libsdl.org> parents: 356 diff changeset	192 snd_pcm_drain(pcm_handle);
354 30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	193 snd_pcm_close(pcm_handle);
30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	194 pcm_handle = NULL;
0 74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	195 }
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	196 }
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	197
354 30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	198 static int ALSA_OpenAudio(_THIS, SDL_AudioSpec *spec)
0 74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	199 {
354 30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	200 int status;
30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	201 snd_pcm_hw_params_t *params;
30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	202 snd_pcm_format_t format;
30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	203 snd_pcm_uframes_t frames;
30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	204 Uint16 test_format;
0 74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	205
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	206 /* Open the audio device */
547 5d07f9a47f17 Open the ALSA devices in non-blocking mode (thanks Aleksey!) Sam Lantinga <slouken@libsdl.org> parents: 357 diff changeset	207 status = snd_pcm_open(&pcm_handle, get_audio_device(), SND_PCM_STREAM_PLAYBACK, SND_PCM_NONBLOCK);
354 30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	208 if ( status < 0 ) {
30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	209 SDL_SetError("Couldn't open audio device: %s", snd_strerror(status));
30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	210 return(-1);
30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	211 }
30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	212
30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	213 /* Figure out what the hardware is capable of */
30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	214 snd_pcm_hw_params_alloca(&params);
30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	215 status = snd_pcm_hw_params_any(pcm_handle, params);
30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	216 if ( status < 0 ) {
30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	217 SDL_SetError("Couldn't get hardware config: %s", snd_strerror(status));
30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	218 ALSA_CloseAudio(this);
30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	219 return(-1);
30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	220 }
30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	221
30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	222 /* SDL only uses interleaved sample output */
30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	223 status = snd_pcm_hw_params_set_access(pcm_handle, params, SND_PCM_ACCESS_RW_INTERLEAVED);
30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	224 if ( status < 0 ) {
30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	225 SDL_SetError("Couldn't set interleaved access: %s", snd_strerror(status));
30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	226 ALSA_CloseAudio(this);
0 74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	227 return(-1);
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	228 }
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	229
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	230 /* Try for a closest match on audio format */
354 30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	231 status = -1;
0 74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	232 for ( test_format = SDL_FirstAudioFormat(spec->format);
354 30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	233 test_format && (status < 0); ) {
30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	234 switch ( test_format ) {
0 74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	235 case AUDIO_U8:
354 30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	236 format = SND_PCM_FORMAT_U8;
0 74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	237 break;
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	238 case AUDIO_S8:
354 30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	239 format = SND_PCM_FORMAT_S8;
0 74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	240 break;
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	241 case AUDIO_S16LSB:
354 30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	242 format = SND_PCM_FORMAT_S16_LE;
0 74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	243 break;
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	244 case AUDIO_S16MSB:
354 30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	245 format = SND_PCM_FORMAT_S16_BE;
0 74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	246 break;
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	247 case AUDIO_U16LSB:
354 30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	248 format = SND_PCM_FORMAT_U16_LE;
0 74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	249 break;
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	250 case AUDIO_U16MSB:
354 30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	251 format = SND_PCM_FORMAT_U16_BE;
0 74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	252 break;
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	253 default:
354 30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	254 format = 0;
0 74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	255 break;
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	256 }
354 30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	257 if ( format != 0 ) {
30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	258 status = snd_pcm_hw_params_set_format(pcm_handle, params, format);
30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	259 }
30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	260 if ( status < 0 ) {
0 74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	261 test_format = SDL_NextAudioFormat();
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	262 }
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	263 }
354 30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	264 if ( status < 0 ) {
0 74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	265 SDL_SetError("Couldn't find any hardware audio formats");
354 30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	266 ALSA_CloseAudio(this);
0 74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	267 return(-1);
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	268 }
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	269 spec->format = test_format;
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	270
354 30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	271 /* Set the number of channels */
30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	272 status = snd_pcm_hw_params_set_channels(pcm_handle, params, spec->channels);
30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	273 if ( status < 0 ) {
30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	274 status = snd_pcm_hw_params_get_channels(params);
30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	275 if ( (status <= 0) \|\| (status > 2) ) {
30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	276 SDL_SetError("Couldn't set audio channels");
30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	277 ALSA_CloseAudio(this);
30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	278 return(-1);
30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	279 }
30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	280 spec->channels = status;
30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	281 }
0 74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	282
354 30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	283 /* Set the audio rate */
30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	284 status = snd_pcm_hw_params_set_rate_near(pcm_handle, params, spec->freq, NULL);
30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	285 if ( status < 0 ) {
30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	286 SDL_SetError("Couldn't set audio frequency: %s", snd_strerror(status));
30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	287 ALSA_CloseAudio(this);
30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	288 return(-1);
30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	289 }
30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	290 spec->freq = status;
0 74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	291
354 30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	292 /* Set the buffer size, in samples */
30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	293 frames = spec->samples;
30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	294 frames = snd_pcm_hw_params_set_period_size_near(pcm_handle, params, frames, NULL);
30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	295 spec->samples = frames;
30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	296 snd_pcm_hw_params_set_periods_near(pcm_handle, params, 2, NULL);
30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	297
30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	298 /* "set" the hardware with the desired parameters */
30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	299 status = snd_pcm_hw_params(pcm_handle, params);
30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	300 if ( status < 0 ) {
30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	301 SDL_SetError("Couldn't set audio parameters: %s", snd_strerror(status));
30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	302 ALSA_CloseAudio(this);
0 74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	303 return(-1);
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	304 }
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	305
354 30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	306 /* Calculate the final parameters for this audio specification */
30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	307 SDL_CalculateAudioSpec(spec);
0 74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	308
354 30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	309 /* Allocate mixing buffer */
30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	310 mixlen = spec->size;
30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	311 mixbuf = (Uint8 *)SDL_AllocAudioMem(mixlen);
30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	312 if ( mixbuf == NULL ) {
30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	313 ALSA_CloseAudio(this);
30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	314 return(-1);
0 74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	315 }
354 30935e76acb5 Updated ALSA audio support for ALSA 0.9 Sam Lantinga <slouken@libsdl.org> parents: 297 diff changeset	316 memset(mixbuf, spec->silence, spec->size);
0 74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	317
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	318 /* Get the parent process id (we're the parent of the audio thread) */
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	319 parent = getpid();
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	320
765 4c2ba6161939 Editors Note: The original patch was modified to use SDL_Delay() instead of Sam Lantinga <slouken@libsdl.org> parents: 547 diff changeset	321 /* Switch to blocking mode for playback */
4c2ba6161939 Editors Note: The original patch was modified to use SDL_Delay() instead of Sam Lantinga <slouken@libsdl.org> parents: 547 diff changeset	322 snd_pcm_nonblock(pcm_handle, 0);
4c2ba6161939 Editors Note: The original patch was modified to use SDL_Delay() instead of Sam Lantinga <slouken@libsdl.org> parents: 547 diff changeset	323
0 74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	324 /* We're ready to rock and roll. :-) */
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	325 return(0);
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	326 }

Mercurial > sdl-ios-xcode

annotate src/audio/alsa/SDL_alsa_audio.c @ 765:4c2ba6161939