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>
40 #include SDL_INCLUDE_FILE
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 ( aout_instance_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 aout_instance_t *p_aout = (aout_instance_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 ) )
95 /* Win32 SDL implementation doesn't support SDL_INIT_EVENTTHREAD yet */
96 i_flags |= SDL_INIT_EVENTTHREAD;
99 /* In debug mode you may want vlc to dump a core instead of staying
101 i_flags |= SDL_INIT_NOPARACHUTE;
104 /* Initialize library */
105 if( SDL_Init( i_flags ) < 0 )
107 msg_Err( p_aout, "cannot initialize SDL (%s)", SDL_GetError() );
111 if ( var_Type( p_aout, "audio-device" ) != 0 )
113 /* The user has selected an audio device. */
115 var_Get( p_aout, "audio-device", &val );
116 if ( val.i_int == AOUT_VAR_STEREO )
118 p_aout->output.output.i_physical_channels
119 = AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT;
121 else if ( val.i_int == AOUT_VAR_MONO )
123 p_aout->output.output.i_physical_channels = AOUT_CHAN_CENTER;
127 i_nb_channels = aout_FormatNbChannels( &p_aout->output.output );
128 if ( i_nb_channels > 2 )
130 /* SDL doesn't support more than two channels. */
132 p_aout->output.output.i_physical_channels
133 = AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT;
135 desired.freq = p_aout->output.output.i_rate;
136 desired.format = AUDIO_S16SYS;
137 desired.channels = i_nb_channels;
138 desired.callback = SDLCallback;
139 desired.userdata = p_aout;
140 desired.samples = FRAME_SIZE;
142 /* Open the sound device. */
143 if( SDL_OpenAudio( &desired, &obtained ) < 0 )
150 /* Now have a look at what we got. */
151 switch ( obtained.format )
154 p_aout->output.output.i_format = VLC_FOURCC('s','1','6','l'); break;
156 p_aout->output.output.i_format = VLC_FOURCC('s','1','6','b'); break;
158 p_aout->output.output.i_format = VLC_FOURCC('u','1','6','l'); break;
160 p_aout->output.output.i_format = VLC_FOURCC('u','1','6','b'); break;
162 p_aout->output.output.i_format = VLC_FOURCC('s','8',' ',' '); break;
164 p_aout->output.output.i_format = VLC_FOURCC('u','8',' ',' '); break;
166 /* Volume is entirely done in software. */
167 aout_VolumeSoftInit( p_aout );
169 if ( obtained.channels != i_nb_channels )
171 p_aout->output.output.i_physical_channels = (obtained.channels == 2 ?
172 AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT :
175 if ( var_Type( p_aout, "audio-device" ) == 0 )
177 var_Create( p_aout, "audio-device",
178 VLC_VAR_INTEGER | VLC_VAR_HASCHOICE );
179 text.psz_string = _("Audio Device");
180 var_Change( p_aout, "audio-device", VLC_VAR_SETTEXT, &text, NULL );
182 val.i_int = (obtained.channels == 2) ? AOUT_VAR_STEREO :
184 text.psz_string = (obtained.channels == 2) ? _("Stereo") :
186 var_Change( p_aout, "audio-device",
187 VLC_VAR_ADDCHOICE, &val, &text );
188 var_AddCallback( p_aout, "audio-device", aout_ChannelsRestart,
192 else if ( var_Type( p_aout, "audio-device" ) == 0 )
195 var_Create( p_aout, "audio-device",
196 VLC_VAR_INTEGER | VLC_VAR_HASCHOICE );
197 text.psz_string = _("Audio Device");
198 var_Change( p_aout, "audio-device", VLC_VAR_SETTEXT, &text, NULL );
200 val.i_int = AOUT_VAR_STEREO;
201 text.psz_string = _("Stereo");
202 var_Change( p_aout, "audio-device", VLC_VAR_ADDCHOICE, &val, &text );
203 val.i_int = AOUT_VAR_MONO;
204 text.psz_string = _("Mono");
205 var_Change( p_aout, "audio-device", VLC_VAR_ADDCHOICE, &val, &text );
206 if ( i_nb_channels == 2 )
208 val.i_int = AOUT_VAR_STEREO;
212 val.i_int = AOUT_VAR_MONO;
214 var_Change( p_aout, "audio-device", VLC_VAR_SETDEFAULT, &val, NULL );
215 var_AddCallback( p_aout, "audio-device", aout_ChannelsRestart, NULL );
219 var_Set( p_aout, "intf-change", val );
221 p_aout->output.output.i_rate = obtained.freq;
222 p_aout->output.i_nb_samples = obtained.samples;
223 p_aout->output.pf_play = Play;
228 /*****************************************************************************
229 * Play: play a sound samples buffer
230 *****************************************************************************/
231 static void Play( aout_instance_t * p_aout )
236 /*****************************************************************************
237 * Close: close the audio device
238 *****************************************************************************/
239 static void Close ( vlc_object_t *p_this )
244 SDL_QuitSubSystem( SDL_INIT_AUDIO );
247 /*****************************************************************************
248 * SDLCallback: what to do once SDL has played sound samples
249 *****************************************************************************/
250 static void SDLCallback( void * _p_aout, uint8_t * p_stream, int i_len )
252 aout_instance_t * p_aout = (aout_instance_t *)_p_aout;
253 aout_buffer_t * p_buffer;
255 /* SDL is unable to call us at regular times, or tell us its current
256 * hardware latency, or the buffer state. So we just pop data and throw
257 * it at SDL's face. Nah. */
259 vlc_mutex_lock( &p_aout->output_fifo_lock );
260 p_buffer = aout_FifoPop( p_aout, &p_aout->output.fifo );
261 vlc_mutex_unlock( &p_aout->output_fifo_lock );
263 if ( p_buffer != NULL )
265 vlc_memcpy( p_stream, p_buffer->p_buffer, i_len );
266 aout_BufferFree( p_buffer );
270 vlc_memset( p_stream, 0, i_len );