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 <string.h> /* strerror() */
31 #include <unistd.h> /* write(), close() */
32 #include <stdlib.h> /* calloc(), malloc(), free() */
36 #include "aout_internal.h"
38 #include SDL_INCLUDE_FILE
40 #define FRAME_SIZE 2048
42 /*****************************************************************************
43 * aout_sys_t: SDL audio output method descriptor
44 *****************************************************************************
45 * This structure is part of the audio output thread descriptor.
46 * It describes the specific properties of an audio device.
47 *****************************************************************************/
54 /*****************************************************************************
56 *****************************************************************************/
57 static int Open ( vlc_object_t * );
58 static void Close ( vlc_object_t * );
59 static void Play ( aout_instance_t * );
60 static void SDLCallback ( void *, byte_t *, int );
62 /*****************************************************************************
64 *****************************************************************************/
66 set_shortname( "SDL" );
67 set_description( _("Simple DirectMedia Layer audio output") );
68 set_capability( "audio output", 40 );
69 set_category( CAT_AUDIO );
70 set_subcategory( SUBCAT_AUDIO_AOUT );
71 add_shortcut( "sdl" );
72 set_callbacks( Open, Close );
75 /*****************************************************************************
76 * Open: open the audio device
77 *****************************************************************************/
78 static int Open ( vlc_object_t *p_this )
80 aout_instance_t *p_aout = (aout_instance_t *)p_this;
81 SDL_AudioSpec desired, obtained;
83 vlc_value_t val, text;
85 /* Check that no one uses the DSP. */
86 uint32_t i_flags = SDL_INIT_AUDIO;
87 if( SDL_WasInit( i_flags ) )
93 /* Win32 SDL implementation doesn't support SDL_INIT_EVENTTHREAD yet */
94 i_flags |= SDL_INIT_EVENTTHREAD;
97 /* In debug mode you may want vlc to dump a core instead of staying
99 i_flags |= SDL_INIT_NOPARACHUTE;
102 /* Initialize library */
103 if( SDL_Init( i_flags ) < 0 )
105 msg_Err( p_aout, "cannot initialize SDL (%s)", SDL_GetError() );
109 if ( var_Type( p_aout, "audio-device" ) != 0 )
111 /* The user has selected an audio device. */
113 var_Get( p_aout, "audio-device", &val );
114 if ( val.i_int == AOUT_VAR_STEREO )
116 p_aout->output.output.i_physical_channels
117 = AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT;
119 else if ( val.i_int == AOUT_VAR_MONO )
121 p_aout->output.output.i_physical_channels = AOUT_CHAN_CENTER;
125 i_nb_channels = aout_FormatNbChannels( &p_aout->output.output );
126 if ( i_nb_channels > 2 )
128 /* SDL doesn't support more than two channels. */
130 p_aout->output.output.i_physical_channels
131 = AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT;
133 desired.freq = p_aout->output.output.i_rate;
134 desired.format = AUDIO_S16SYS;
135 desired.channels = i_nb_channels;
136 desired.callback = SDLCallback;
137 desired.userdata = p_aout;
138 desired.samples = FRAME_SIZE;
140 /* Open the sound device. */
141 if( SDL_OpenAudio( &desired, &obtained ) < 0 )
148 /* Now have a look at what we got. */
149 switch ( obtained.format )
152 p_aout->output.output.i_format = VLC_FOURCC('s','1','6','l'); break;
154 p_aout->output.output.i_format = VLC_FOURCC('s','1','6','b'); break;
156 p_aout->output.output.i_format = VLC_FOURCC('u','1','6','l'); break;
158 p_aout->output.output.i_format = VLC_FOURCC('u','1','6','b'); break;
160 p_aout->output.output.i_format = VLC_FOURCC('s','8',' ',' '); break;
162 p_aout->output.output.i_format = VLC_FOURCC('u','8',' ',' '); break;
164 /* Volume is entirely done in software. */
165 aout_VolumeSoftInit( p_aout );
167 if ( obtained.channels != i_nb_channels )
169 p_aout->output.output.i_physical_channels = (obtained.channels == 2 ?
170 AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT :
173 if ( var_Type( p_aout, "audio-device" ) == 0 )
175 var_Create( p_aout, "audio-device",
176 VLC_VAR_INTEGER | VLC_VAR_HASCHOICE );
177 text.psz_string = _("Audio Device");
178 var_Change( p_aout, "audio-device", VLC_VAR_SETTEXT, &text, NULL );
180 val.i_int = (obtained.channels == 2) ? AOUT_VAR_STEREO :
182 text.psz_string = (obtained.channels == 2) ? N_("Stereo") :
184 var_Change( p_aout, "audio-device",
185 VLC_VAR_ADDCHOICE, &val, &text );
186 var_AddCallback( p_aout, "audio-device", aout_ChannelsRestart,
190 else if ( var_Type( p_aout, "audio-device" ) == 0 )
193 var_Create( p_aout, "audio-device",
194 VLC_VAR_INTEGER | VLC_VAR_HASCHOICE );
195 text.psz_string = _("Audio Device");
196 var_Change( p_aout, "audio-device", VLC_VAR_SETTEXT, &text, NULL );
198 val.i_int = AOUT_VAR_STEREO;
199 text.psz_string = N_("Stereo");
200 var_Change( p_aout, "audio-device", VLC_VAR_ADDCHOICE, &val, &text );
201 val.i_int = AOUT_VAR_MONO;
202 text.psz_string = N_("Mono");
203 var_Change( p_aout, "audio-device", VLC_VAR_ADDCHOICE, &val, &text );
204 if ( i_nb_channels == 2 )
206 val.i_int = AOUT_VAR_STEREO;
210 val.i_int = AOUT_VAR_MONO;
212 var_Change( p_aout, "audio-device", VLC_VAR_SETDEFAULT, &val, NULL );
213 var_AddCallback( p_aout, "audio-device", aout_ChannelsRestart, NULL );
216 val.b_bool = VLC_TRUE;
217 var_Set( p_aout, "intf-change", val );
219 p_aout->output.output.i_rate = obtained.freq;
220 p_aout->output.i_nb_samples = obtained.samples;
221 p_aout->output.pf_play = Play;
226 /*****************************************************************************
227 * Play: play a sound samples buffer
228 *****************************************************************************/
229 static void Play( aout_instance_t * p_aout )
233 /*****************************************************************************
234 * Close: close the audio device
235 *****************************************************************************/
236 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, byte_t * p_stream, int i_len )
248 aout_instance_t * p_aout = (aout_instance_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->output_fifo_lock );
256 p_buffer = aout_FifoPop( p_aout, &p_aout->output.fifo );
257 vlc_mutex_unlock( &p_aout->output_fifo_lock );
259 if ( p_buffer != NULL )
261 p_aout->p_libvlc->pf_memcpy( p_stream, p_buffer->p_buffer, i_len );
262 aout_BufferFree( p_buffer );
266 p_aout->p_libvlc->pf_memset( p_stream, 0, i_len );