1 /*****************************************************************************
2 * aout_sdl.c : audio sdl functions library
3 *****************************************************************************
4 * Copyright (C) 1999, 2000 VideoLAN
5 * $Id: aout_sdl.c,v 1.17 2001/07/27 16:40:20 massiot Exp $
7 * Authors: Michel Kaempf <maxx@via.ecp.fr>
8 * Samuel Hocevar <sam@zoy.org>
9 * Pierre Baillet <oct@zoy.org>
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License as published by
13 * the Free Software Foundation; either version 2 of the License, or
14 * (at your option) any later version.
16 * This program is distributed in the hope that it will be useful,
17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19 * GNU General Public License for more details.
21 * You should have received a copy of the GNU General Public License
22 * along with this program; if not, write to the Free Software
23 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111, USA.
24 *****************************************************************************/
26 #define MODULE_NAME sdl
27 #include "modules_inner.h"
29 /*****************************************************************************
31 *****************************************************************************/
34 #include <errno.h> /* ENOMEM */
35 #include <fcntl.h> /* open(), O_WRONLY */
36 #include <string.h> /* strerror() */
37 #include <unistd.h> /* write(), close() */
38 #include <stdio.h> /* "intf_msg.h" */
39 #include <stdlib.h> /* calloc(), malloc(), free() */
43 #elif HAVE_SDL11_SDL_H
44 # include <SDL11/SDL.h>
45 #elif HAVE_SDL12_SDL_H
46 # include <SDL12/SDL.h>
52 #include "common.h" /* boolean_t, byte_t */
57 #include "audio_output.h" /* aout_thread_t */
59 #include "intf_msg.h" /* intf_DbgMsg(), intf_ErrMsg() */
63 #include "modules_export.h"
65 /*****************************************************************************
66 * aout_sys_t: dsp audio output method descriptor
67 *****************************************************************************
68 * This structure is part of the audio output thread descriptor.
69 * It describes the dsp specific properties of an audio device.
70 *****************************************************************************/
72 /* the overflow limit is used to prevent the fifo from growing too big */
73 #define OVERFLOWLIMIT 100000
75 typedef struct aout_sys_s
84 /*****************************************************************************
86 *****************************************************************************/
87 static int aout_Probe ( probedata_t *p_data );
88 static int aout_Open ( aout_thread_t *p_aout );
89 static int aout_SetFormat ( aout_thread_t *p_aout );
90 static long aout_GetBufInfo ( aout_thread_t *p_aout, long l_buffer_info );
91 static void aout_Play ( aout_thread_t *p_aout,
92 byte_t *buffer, int i_size );
93 static void aout_Close ( aout_thread_t *p_aout );
95 static void aout_SDLCallback ( void *userdata, Uint8 *stream, int len );
97 /*****************************************************************************
98 * Functions exported as capabilities. They are declared as static so that
99 * we don't pollute the namespace too much.
100 *****************************************************************************/
101 void _M( aout_getfunctions )( function_list_t * p_function_list )
103 p_function_list->pf_probe = aout_Probe;
104 p_function_list->functions.aout.pf_open = aout_Open;
105 p_function_list->functions.aout.pf_setformat = aout_SetFormat;
106 p_function_list->functions.aout.pf_getbufinfo = aout_GetBufInfo;
107 p_function_list->functions.aout.pf_play = aout_Play;
108 p_function_list->functions.aout.pf_close = aout_Close;
111 /*****************************************************************************
112 * aout_Probe: probe the audio device and return a score
113 *****************************************************************************
114 * This function tries to initialize SDL audio and returns a score to the
115 * plugin manager so that it can select the best plugin.
116 *****************************************************************************/
117 static int aout_Probe( probedata_t *p_data )
120 SDL_AudioSpec desired, obtained;
123 if( SDL_Init(SDL_INIT_AUDIO | SDL_INIT_NOPARACHUTE) != 0 )
125 intf_DbgMsg( "aout: SDL_Init failed (%s)", SDL_GetError() );
129 desired.freq = 11025; /* frequency */
130 desired.format = AUDIO_U8; /* unsigned 8 bits */
131 desired.channels = 2; /* mono */
132 desired.callback = aout_SDLCallback; /* callback function mandatory */
133 desired.userdata = NULL; /* null parm for callback */
134 desired.samples = 4096;
136 /* If we were unable to open the device, there is no way we can use
137 * the plugin. Return a score of 0. */
138 if( SDL_OpenAudio( &desired, &obtained ) < 0 )
140 intf_DbgMsg( "aout: SDL_OpenAudio failed (%s)", SDL_GetError() );
144 /* Otherwise, there are good chances we can use this plugin, return 100. */
145 intf_DbgMsg( "aout: SDL_OpenAudio successfully run" );
149 if( TestMethod( AOUT_METHOD_VAR, "sdl" ) )
157 /*****************************************************************************
158 * aout_Open: open the audio device
159 *****************************************************************************
160 * This function opens the dsp as a usual non-blocking write-only file, and
161 * modifies the p_aout->i_fd with the file's descriptor.
162 *****************************************************************************/
163 static int aout_Open( aout_thread_t *p_aout )
165 SDL_AudioSpec desired;
166 int i_channels = p_aout->b_stereo ? 2 : 1;
168 /* Allocate structure */
169 p_aout->p_sys = malloc( sizeof( aout_sys_t ) );
171 if( p_aout->p_sys == NULL )
173 intf_ErrMsg( "aout error: %s", strerror(ENOMEM) );
177 p_aout->p_sys->i_audio_end = 0;
178 p_aout->p_sys->audio_buf = malloc( OVERFLOWLIMIT );
180 /* Initialize some variables */
181 p_aout->psz_device = 0;
182 p_aout->i_format = AOUT_FORMAT_DEFAULT;
183 p_aout->i_channels = 1 + main_GetIntVariable( AOUT_STEREO_VAR,
184 AOUT_STEREO_DEFAULT );
185 p_aout->l_rate = main_GetIntVariable( AOUT_RATE_VAR,
188 desired.freq = p_aout->l_rate;
190 /* TODO: write conversion beetween AOUT_FORMAT_DEFAULT
191 * AND AUDIO* from SDL. */
192 desired.format = AUDIO_S16LSB; /* stereo 16 bits */
193 desired.channels = i_channels;
194 desired.callback = aout_SDLCallback;
195 desired.userdata = p_aout->p_sys;
196 desired.samples = 1024;
198 /* Open the sound device
199 * we just ask the SDL to wrap at the good frequency if the one we
200 * ask for is unavailable. This is done by setting the second parar
203 if( SDL_OpenAudio( &desired, NULL ) < 0 )
205 intf_ErrMsg( "aout error: SDL_OpenAudio failed (%s)", SDL_GetError() );
209 p_aout->p_sys->b_active = 1;
215 /*****************************************************************************
216 * aout_SetFormat: reset the audio device and sets its format
217 *****************************************************************************
218 * This functions resets the audio device, tries to initialize the output
219 * format with the value contained in the dsp structure, and if this value
220 * could not be set, the default value returned by ioctl is set. It then
221 * does the same for the stereo mode, and for the output rate.
222 *****************************************************************************/
223 static int aout_SetFormat( aout_thread_t *p_aout )
225 /* TODO: finish and clean this */
226 SDL_AudioSpec desired;
227 int i_stereo = p_aout->b_stereo ? 2 : 1;
229 /*i_format = p_aout->i_format;*/
230 desired.freq = p_aout->l_rate; /* Set the output rate */
231 desired.format = AUDIO_S16LSB; /* stereo 16 bits */
232 desired.channels = i_stereo;
233 desired.callback = aout_SDLCallback;
234 desired.userdata = p_aout->p_sys;
235 desired.samples = 2048;
237 /* Open the sound device */
241 if( SDL_OpenAudio( &desired, NULL ) < 0 )
243 p_aout->p_sys->b_active = 0;
247 p_aout->p_sys->b_active = 1;
250 p_aout->i_latency = 0;
255 /*****************************************************************************
256 * aout_GetBufInfo: buffer status query
257 *****************************************************************************
258 * returns the number of bytes in the audio buffer compared to the size of
260 *****************************************************************************/
261 static long aout_GetBufInfo( aout_thread_t *p_aout, long l_buffer_limit )
263 if(l_buffer_limit > p_aout->p_sys->i_audio_end)
265 /* returning 0 here juste gives awful sound in the speakers :/ */
266 return( l_buffer_limit );
268 return( p_aout->p_sys->i_audio_end - l_buffer_limit);
271 /*****************************************************************************
272 * aout_Play: play a sound samples buffer
273 *****************************************************************************
274 * This function writes a buffer of i_length bytes in the dsp
275 *****************************************************************************/
276 static void aout_Play( aout_thread_t *p_aout, byte_t *buffer, int i_size )
278 byte_t * audio_buf = p_aout->p_sys->audio_buf;
280 SDL_LockAudio(); /* Stop callbacking */
282 p_aout->p_sys->audio_buf = realloc( audio_buf,
283 p_aout->p_sys->i_audio_end + i_size);
284 memcpy( p_aout->p_sys->audio_buf + p_aout->p_sys->i_audio_end,
287 p_aout->p_sys->i_audio_end += i_size;
289 SDL_UnlockAudio(); /* go on callbacking */
292 /*****************************************************************************
293 * aout_Close: close the audio device
294 *****************************************************************************/
295 static void aout_Close( aout_thread_t *p_aout )
297 if( p_aout->p_sys->b_active )
299 SDL_PauseAudio( 1 ); /* pause audio */
301 if( p_aout->p_sys->audio_buf != NULL ) /* do we have a buffer now ? */
303 free( p_aout->p_sys->audio_buf );
309 free( p_aout->p_sys ); /* Close the Output. */
312 /*****************************************************************************
313 * aout_SDLCallback: what to do once SDL has played sound samples
314 *****************************************************************************/
315 static void aout_SDLCallback( void *userdata, byte_t *stream, int len )
317 struct aout_sys_s * p_sys = userdata;
319 if( p_sys->i_audio_end > OVERFLOWLIMIT )
321 intf_ErrMsg( "aout error: aout_SDLCallback overflowed" );
323 free( p_sys->audio_buf );
324 p_sys->audio_buf = NULL;
326 p_sys->i_audio_end = 0;
327 /* we've gone to slow, increase output freq */
330 /* if we are not in underrun */
331 if( p_sys->i_audio_end > len )
333 p_sys->i_audio_end -= len;
334 memcpy( stream, p_sys->audio_buf, len );
335 memmove( p_sys->audio_buf, p_sys->audio_buf + len, p_sys->i_audio_end );