1 /*****************************************************************************
2 * sdl.c : SDL audio output plugin for vlc
3 *****************************************************************************
4 * Copyright (C) 2000-2002 the VideoLAN team
7 * Authors: Michel Kaempf <maxx@via.ecp.fr>
8 * Sam Hocevar <sam@zoy.org>
9 * Pierre Baillet <oct@zoy.org>
10 * Christophe Massiot <massiot@via.ecp.fr>
12 * This program is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU General Public License as published by
14 * the Free Software Foundation; either version 2 of the License, or
15 * (at your option) any later version.
17 * This program is distributed in the hope that it will be useful,
18 * but WITHOUT ANY WARRANTY; without even the implied warranty of
19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20 * GNU General Public License for more details.
22 * You should have received a copy of the GNU General Public License
23 * along with this program; if not, write to the Free Software
24 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
25 *****************************************************************************/
27 /*****************************************************************************
29 *****************************************************************************/
30 #include <unistd.h> /* write(), close() */
36 #include <vlc_common.h>
37 #include <vlc_plugin.h>
42 #define FRAME_SIZE 2048
44 /*****************************************************************************
45 * aout_sys_t: SDL audio output method descriptor
46 *****************************************************************************
47 * This structure is part of the audio output thread descriptor.
48 * It describes the specific properties of an audio device.
49 *****************************************************************************/
56 /*****************************************************************************
58 *****************************************************************************/
59 static int Open ( vlc_object_t * );
60 static void Close ( vlc_object_t * );
61 static void Play ( audio_output_t *, block_t * );
62 static void SDLCallback ( void *, uint8_t *, int );
64 /*****************************************************************************
66 *****************************************************************************/
68 set_shortname( "SDL" )
69 set_description( N_("Simple DirectMedia Layer audio output") )
70 set_capability( "audio output", 40 )
71 set_category( CAT_AUDIO )
72 set_subcategory( SUBCAT_AUDIO_AOUT )
74 set_callbacks( Open, Close )
77 /*****************************************************************************
78 * Open: open the audio device
79 *****************************************************************************/
80 static int Open ( vlc_object_t *p_this )
82 audio_output_t *p_aout = (audio_output_t *)p_this;
83 SDL_AudioSpec desired, obtained;
85 vlc_value_t val, text;
87 /* Check that no one uses the DSP. */
88 uint32_t i_flags = SDL_INIT_AUDIO;
89 if( SDL_WasInit( i_flags ) )
94 i_flags |= SDL_INIT_EVENTTHREAD;
96 /* In debug mode you may want vlc to dump a core instead of staying
98 i_flags |= SDL_INIT_NOPARACHUTE;
101 /* Initialize library */
102 if( SDL_Init( i_flags ) < 0 )
104 msg_Err( p_aout, "cannot initialize SDL (%s)", SDL_GetError() );
108 if( var_Get( p_aout, "audio-device", &val ) != VLC_ENOVAR )
110 /* The user has selected an audio device. */
111 if ( val.i_int == AOUT_VAR_STEREO )
113 p_aout->format.i_physical_channels
114 = AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT;
116 else if ( val.i_int == AOUT_VAR_MONO )
118 p_aout->format.i_physical_channels = AOUT_CHAN_CENTER;
122 i_nb_channels = aout_FormatNbChannels( &p_aout->format );
123 if ( i_nb_channels > 2 )
125 /* SDL doesn't support more than two channels. */
127 p_aout->format.i_physical_channels
128 = AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT;
130 desired.freq = p_aout->format.i_rate;
131 desired.format = AUDIO_S16SYS;
132 desired.channels = i_nb_channels;
133 desired.callback = SDLCallback;
134 desired.userdata = p_aout;
135 desired.samples = FRAME_SIZE;
137 /* Open the sound device. */
138 if( SDL_OpenAudio( &desired, &obtained ) < 0 )
145 /* Now have a look at what we got. */
146 switch ( obtained.format )
149 p_aout->format.i_format = VLC_CODEC_S16L; break;
151 p_aout->format.i_format = VLC_CODEC_S16B; break;
153 p_aout->format.i_format = VLC_CODEC_U16L; break;
155 p_aout->format.i_format = VLC_CODEC_U16B; break;
157 p_aout->format.i_format = VLC_CODEC_S8; break;
159 p_aout->format.i_format = VLC_CODEC_U8; break;
161 /* Volume is entirely done in software. */
162 aout_VolumeSoftInit( p_aout );
164 if ( obtained.channels != i_nb_channels )
166 p_aout->format.i_physical_channels = (obtained.channels == 2 ?
167 AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT :
170 if ( var_Type( p_aout, "audio-device" ) == 0 )
172 var_Create( p_aout, "audio-device",
173 VLC_VAR_INTEGER | VLC_VAR_HASCHOICE );
174 text.psz_string = _("Audio Device");
175 var_Change( p_aout, "audio-device", VLC_VAR_SETTEXT, &text, NULL );
177 val.i_int = (obtained.channels == 2) ? AOUT_VAR_STEREO :
179 text.psz_string = (obtained.channels == 2) ? _("Stereo") :
181 var_Change( p_aout, "audio-device",
182 VLC_VAR_ADDCHOICE, &val, &text );
183 var_AddCallback( p_aout, "audio-device", aout_ChannelsRestart,
187 else if ( var_Type( p_aout, "audio-device" ) == 0 )
190 var_Create( p_aout, "audio-device",
191 VLC_VAR_INTEGER | VLC_VAR_HASCHOICE );
192 text.psz_string = _("Audio Device");
193 var_Change( p_aout, "audio-device", VLC_VAR_SETTEXT, &text, NULL );
195 val.i_int = AOUT_VAR_STEREO;
196 text.psz_string = _("Stereo");
197 var_Change( p_aout, "audio-device", VLC_VAR_ADDCHOICE, &val, &text );
198 val.i_int = AOUT_VAR_MONO;
199 text.psz_string = _("Mono");
200 var_Change( p_aout, "audio-device", VLC_VAR_ADDCHOICE, &val, &text );
201 if ( i_nb_channels == 2 )
203 val.i_int = AOUT_VAR_STEREO;
207 val.i_int = AOUT_VAR_MONO;
209 var_Change( p_aout, "audio-device", VLC_VAR_SETDEFAULT, &val, NULL );
210 var_AddCallback( p_aout, "audio-device", aout_ChannelsRestart, NULL );
213 var_TriggerCallback( p_aout, "intf-change" );
215 p_aout->format.i_rate = obtained.freq;
216 p_aout->i_nb_samples = obtained.samples;
217 p_aout->pf_play = Play;
218 p_aout->pf_pause = NULL;
219 p_aout->pf_flush = NULL;
224 /*****************************************************************************
225 * Play: play a sound samples buffer
226 *****************************************************************************/
227 static void Play( audio_output_t * p_aout, block_t *block )
229 aout_FifoPush( &p_aout->fifo, block );
232 /*****************************************************************************
233 * Close: close the audio device
234 *****************************************************************************/
235 static void Close ( vlc_object_t *p_this )
240 SDL_QuitSubSystem( SDL_INIT_AUDIO );
243 /*****************************************************************************
244 * SDLCallback: what to do once SDL has played sound samples
245 *****************************************************************************/
246 static void SDLCallback( void * _p_aout, uint8_t * p_stream, int i_len )
248 audio_output_t * p_aout = (audio_output_t *)_p_aout;
249 aout_buffer_t * p_buffer;
251 /* SDL is unable to call us at regular times, or tell us its current
252 * hardware latency, or the buffer state. So we just pop data and throw
253 * it at SDL's face. Nah. */
255 vlc_mutex_lock( &p_aout->lock );
256 p_buffer = aout_FifoPop( &p_aout->fifo );
257 vlc_mutex_unlock( &p_aout->lock );
259 if ( p_buffer != NULL )
261 vlc_memcpy( p_stream, p_buffer->p_buffer, i_len );
262 aout_BufferFree( p_buffer );
266 vlc_memset( p_stream, 0, i_len );