1 /*****************************************************************************
2 * oss.c : OSS /dev/dsp module for vlc
3 *****************************************************************************
4 * Copyright (C) 2000-2002 VideoLAN
5 * $Id: oss.c,v 1.44 2003/01/13 14:51:25 massiot Exp $
7 * Authors: Michel Kaempf <maxx@via.ecp.fr>
8 * Samuel Hocevar <sam@zoy.org>
9 * Christophe Massiot <massiot@via.ecp.fr>
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 /*****************************************************************************
28 *****************************************************************************/
29 #include <errno.h> /* ENOMEM */
30 #include <fcntl.h> /* open(), O_WRONLY */
31 #include <sys/ioctl.h> /* ioctl() */
32 #include <string.h> /* strerror() */
33 #include <unistd.h> /* write(), close() */
34 #include <stdlib.h> /* calloc(), malloc(), free() */
44 #include "aout_internal.h"
46 /* SNDCTL_DSP_RESET, SNDCTL_DSP_SETFMT, SNDCTL_DSP_STEREO, SNDCTL_DSP_SPEED,
47 * SNDCTL_DSP_GETOSPACE */
48 #ifdef HAVE_SOUNDCARD_H
49 # include <soundcard.h>
50 #elif defined( HAVE_SYS_SOUNDCARD_H )
51 # include <sys/soundcard.h>
52 #elif defined( HAVE_MACHINE_SOUNDCARD_H )
53 # include <machine/soundcard.h>
56 /*****************************************************************************
57 * aout_sys_t: OSS audio output method descriptor
58 *****************************************************************************
59 * This structure is part of the audio output thread descriptor.
60 * It describes the dsp specific properties of an audio device.
61 *****************************************************************************/
65 int b_workaround_buggy_driver;
67 mtime_t max_buffer_duration;
70 /* This must be a power of 2. */
71 #define FRAME_SIZE 1024
74 /*****************************************************************************
76 *****************************************************************************/
77 static int Open ( vlc_object_t * );
78 static void Close ( vlc_object_t * );
80 static void Play ( aout_instance_t * );
81 static int OSSThread ( aout_instance_t * );
83 static mtime_t BufferDuration( aout_instance_t * p_aout );
85 /*****************************************************************************
87 *****************************************************************************/
88 #define BUGGY_TEXT N_("Try to work around buggy OSS drivers")
89 #define BUGGY_LONGTEXT N_( \
90 "Some buggy OSS drivers just don't like when their internal buffers " \
91 "are completely filled (the sound gets heavily hashed). If you have one " \
92 "of these drivers, then you need to enable this option." )
94 #define SPDIF_TEXT N_("Try to use S/PDIF output")
95 #define SPDIF_LONGTEXT N_( \
96 "Sometimes we attempt to use the S/PDIF output, even if nothing is " \
97 "connected to it. Un-checking this option disables this behaviour, " \
98 "and permanently selects analog PCM output." )
101 add_category_hint( N_("OSS"), NULL );
102 add_file( "dspdev", "/dev/dsp", aout_FindAndRestart,
103 N_("OSS dsp device"), NULL );
104 add_bool( "oss-buggy", 0, NULL, BUGGY_TEXT, BUGGY_LONGTEXT );
105 add_bool( "spdif", 1, NULL, SPDIF_TEXT, SPDIF_LONGTEXT );
106 set_description( _("Linux OSS /dev/dsp module") );
107 set_capability( "audio output", 100 );
108 add_shortcut( "oss" );
109 set_callbacks( Open, Close );
112 /*****************************************************************************
113 * Probe: probe the audio device for available formats and channels
114 *****************************************************************************/
115 static void Probe( aout_instance_t * p_aout )
117 struct aout_sys_t * p_sys = p_aout->output.p_sys;
119 int i_format, i_nb_channels;
121 var_Create( p_aout, "audio-device", VLC_VAR_STRING | VLC_VAR_HASCHOICE );
123 if( ioctl( p_sys->i_fd, SNDCTL_DSP_RESET, NULL ) < 0 )
125 msg_Err( p_aout, "cannot reset OSS audio device" );
126 var_Destroy( p_aout, "audio-device" );
130 if ( config_GetInt( p_aout, "spdif" )
131 && AOUT_FMT_NON_LINEAR( &p_aout->output.output ) )
135 if( ioctl( p_sys->i_fd, SNDCTL_DSP_SETFMT, &i_format ) >= 0
136 && i_format == AFMT_AC3 )
138 val.psz_string = N_("A/52 over S/PDIF");
139 var_Change( p_aout, "audio-device", VLC_VAR_ADDCHOICE, &val );
143 /* Go to PCM mode. */
144 i_format = AFMT_S16_NE;
145 if( ioctl( p_sys->i_fd, SNDCTL_DSP_RESET, NULL ) < 0 ||
146 ioctl( p_sys->i_fd, SNDCTL_DSP_SETFMT, &i_format ) < 0 )
151 #ifdef SNDCTL_DSP_GETCHANNELMASK
152 if ( aout_FormatNbChannels( &p_aout->output.output ) > 2 )
154 /* Check that the device supports this. */
157 if ( ioctl( p_sys->i_fd, SNDCTL_DSP_GETCHANNELMASK,
160 if ( !(i_chanmask & DSP_BIND_FRONT) )
162 msg_Err( p_aout, "No front channels ! (%x)",
167 if ( (i_chanmask & (DSP_BIND_SURR | DSP_BIND_CENTER_LFE))
168 && (p_aout->output.output.i_physical_channels ==
169 (AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_CENTER
170 | AOUT_CHAN_REARLEFT | AOUT_CHAN_REARRIGHT
173 val.psz_string = N_("5.1");
174 var_Change( p_aout, "audio-device", VLC_VAR_ADDCHOICE, &val );
177 if ( (i_chanmask & DSP_BIND_SURR)
178 && (p_aout->output.output.i_physical_channels &
179 (AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT
180 | AOUT_CHAN_REARLEFT | AOUT_CHAN_REARRIGHT)) )
182 val.psz_string = N_("2 Front 2 Rear");
183 var_Change( p_aout, "audio-device", VLC_VAR_ADDCHOICE, &val );
189 /* Test for stereo. */
191 if( ioctl( p_sys->i_fd, SNDCTL_DSP_CHANNELS, &i_nb_channels ) >= 0
192 && i_nb_channels == 2 )
194 val.psz_string = N_("Stereo");
195 var_Change( p_aout, "audio-device", VLC_VAR_ADDCHOICE, &val );
199 i_format = AFMT_S16_NE;
200 if( ioctl( p_sys->i_fd, SNDCTL_DSP_RESET, NULL ) < 0 ||
201 ioctl( p_sys->i_fd, SNDCTL_DSP_SETFMT, &i_format ) < 0 )
203 msg_Err( p_aout, "cannot reset OSS audio device" );
204 var_Destroy( p_aout, "audio-device" );
210 if( ioctl( p_sys->i_fd, SNDCTL_DSP_CHANNELS, &i_nb_channels ) >= 0
211 && i_nb_channels == 1 )
213 val.psz_string = N_("Mono");
214 var_Change( p_aout, "audio-device", VLC_VAR_ADDCHOICE, &val );
218 var_AddCallback( p_aout, "audio-device", aout_ChannelsRestart,
222 /*****************************************************************************
223 * Open: open the audio device (the digital sound processor)
224 *****************************************************************************
225 * This function opens the dsp as a usual non-blocking write-only file, and
226 * modifies the p_aout->p_sys->i_fd with the file's descriptor.
227 *****************************************************************************/
228 static int Open( vlc_object_t *p_this )
230 aout_instance_t * p_aout = (aout_instance_t *)p_this;
231 struct aout_sys_t * p_sys;
235 /* Allocate structure */
236 p_aout->output.p_sys = p_sys = malloc( sizeof( aout_sys_t ) );
239 msg_Err( p_aout, "out of memory" );
243 /* Get device name */
244 if( (psz_device = config_GetPsz( p_aout, "dspdev" )) == NULL )
246 msg_Err( p_aout, "no audio device given (maybe /dev/dsp ?)" );
251 /* Open the sound device */
252 p_sys->i_fd = open( psz_device, O_WRONLY );
253 if( p_sys->i_fd < 0 )
255 msg_Err( p_aout, "cannot open audio device (%s)", psz_device );
261 p_aout->output.pf_play = Play;
263 if ( var_Type( p_aout, "audio-device" ) == 0 )
268 if ( var_Get( p_aout, "audio-device", &val ) < 0 )
270 /* Probe() has failed. */
275 if ( !strcmp( val.psz_string, N_("A/52 over S/PDIF") ) )
277 p_aout->output.output.i_format = VLC_FOURCC('s','p','d','i');
279 else if ( !strcmp( val.psz_string, N_("5.1") ) )
281 p_aout->output.output.i_format = AOUT_FMT_S16_NE;
282 p_aout->output.output.i_physical_channels
283 = AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_CENTER
284 | AOUT_CHAN_REARLEFT | AOUT_CHAN_REARLEFT
287 else if ( !strcmp( val.psz_string, N_("2 Front 2 Rear") ) )
289 p_aout->output.output.i_format = AOUT_FMT_S16_NE;
290 p_aout->output.output.i_physical_channels
291 = AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT
292 | AOUT_CHAN_REARLEFT | AOUT_CHAN_REARLEFT;
294 else if ( !strcmp( val.psz_string, N_("Stereo") ) )
296 p_aout->output.output.i_format = AOUT_FMT_S16_NE;
297 p_aout->output.output.i_physical_channels
298 = AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT;
300 else if ( !strcmp( val.psz_string, N_("Mono") ) )
302 p_aout->output.output.i_format = AOUT_FMT_S16_NE;
303 p_aout->output.output.i_physical_channels = AOUT_CHAN_CENTER;
307 /* This should not happen ! */
308 msg_Err( p_aout, "internal: can't find audio-device (%s)",
313 free( val.psz_string );
315 val.b_bool = VLC_TRUE;
316 var_Set( p_aout, "intf-change", val );
318 /* Reset the DSP device */
319 if( ioctl( p_sys->i_fd, SNDCTL_DSP_RESET, NULL ) < 0 )
321 msg_Err( p_aout, "cannot reset OSS audio device" );
322 close( p_sys->i_fd );
327 /* Set the output format */
328 if ( AOUT_FMT_NON_LINEAR( &p_aout->output.output ) )
330 int i_format = AFMT_AC3;
332 if( ioctl( p_sys->i_fd, SNDCTL_DSP_SETFMT, &i_format ) < 0
333 || i_format != AFMT_AC3 )
335 msg_Err( p_aout, "cannot reset OSS audio device" );
336 close( p_sys->i_fd );
341 p_aout->output.output.i_format = VLC_FOURCC('s','p','d','i');
342 p_aout->output.i_nb_samples = A52_FRAME_NB;
343 p_aout->output.output.i_bytes_per_frame = AOUT_SPDIF_SIZE;
344 p_aout->output.output.i_frame_length = A52_FRAME_NB;
346 aout_VolumeNoneInit( p_aout );
349 if ( !AOUT_FMT_NON_LINEAR( &p_aout->output.output ) )
351 unsigned int i_format = AFMT_S16_NE;
352 unsigned int i_frame_size, i_fragments;
354 unsigned int i_nb_channels;
355 audio_buf_info audio_buf;
357 if( ioctl( p_sys->i_fd, SNDCTL_DSP_SETFMT, &i_format ) < 0 )
359 msg_Err( p_aout, "cannot set audio output format" );
360 close( p_sys->i_fd );
368 p_aout->output.output.i_format = VLC_FOURCC('u','8',' ',' ');
371 p_aout->output.output.i_format = VLC_FOURCC('s','8',' ',' ');
374 p_aout->output.output.i_format = VLC_FOURCC('u','1','6','l');
377 p_aout->output.output.i_format = VLC_FOURCC('s','1','6','l');
380 p_aout->output.output.i_format = VLC_FOURCC('u','1','6','b');
383 p_aout->output.output.i_format = VLC_FOURCC('s','1','6','b');
386 msg_Err( p_aout, "OSS fell back to an unknown format (%d)",
388 close( p_sys->i_fd );
393 i_nb_channels = aout_FormatNbChannels( &p_aout->output.output );
395 /* Set the number of channels */
396 if( ioctl( p_sys->i_fd, SNDCTL_DSP_CHANNELS, &i_nb_channels ) < 0 ||
397 i_nb_channels != aout_FormatNbChannels( &p_aout->output.output ) )
399 msg_Err( p_aout, "cannot set number of audio channels (%s)",
400 aout_FormatPrintChannels( &p_aout->output.output) );
401 close( p_sys->i_fd );
406 /* Set the output rate */
407 i_rate = p_aout->output.output.i_rate;
408 if( ioctl( p_sys->i_fd, SNDCTL_DSP_SPEED, &i_rate ) < 0 )
410 msg_Err( p_aout, "cannot set audio output rate (%i)",
411 p_aout->output.output.i_rate );
412 close( p_sys->i_fd );
417 if( i_rate != p_aout->output.output.i_rate )
419 p_aout->output.output.i_rate = i_rate;
422 /* Set the fragment size */
423 aout_FormatPrepare( &p_aout->output.output );
425 /* i_fragment = xxxxyyyy where: xxxx is fragtotal
426 * 1 << yyyy is fragsize */
428 i_frame_size = FRAME_SIZE * p_aout->output.output.i_bytes_per_frame;
429 while( i_frame_size >>= 1 )
433 i_fragments |= FRAME_COUNT << 16;
434 if( ioctl( p_sys->i_fd, SNDCTL_DSP_SETFRAGMENT, &i_fragments ) < 0 )
436 msg_Warn( p_aout, "cannot set fragment size (%.8x)", i_fragments );
439 if( ioctl( p_sys->i_fd, SNDCTL_DSP_GETOSPACE, &audio_buf ) < 0 )
441 msg_Err( p_aout, "cannot get fragment size" );
442 close( p_sys->i_fd );
448 /* Number of fragments actually allocated */
449 p_aout->output.p_sys->i_fragstotal = audio_buf.fragstotal;
451 /* Maximum duration the soundcard's buffer can hold */
452 p_aout->output.p_sys->max_buffer_duration =
453 (mtime_t)audio_buf.fragstotal * audio_buf.fragsize * 1000000
454 / p_aout->output.output.i_bytes_per_frame
455 / p_aout->output.output.i_rate
456 * p_aout->output.output.i_frame_length;
458 p_aout->output.i_nb_samples = audio_buf.fragsize /
459 p_aout->output.output.i_bytes_per_frame;
462 aout_VolumeSoftInit( p_aout );
465 p_aout->output.p_sys->b_workaround_buggy_driver =
466 config_GetInt( p_aout, "oss-buggy" );
468 /* Create OSS thread and wait for its readiness. */
469 if( vlc_thread_create( p_aout, "aout", OSSThread,
470 VLC_THREAD_PRIORITY_OUTPUT, VLC_FALSE ) )
472 msg_Err( p_aout, "cannot create OSS thread (%s)", strerror(errno) );
473 close( p_sys->i_fd );
481 /*****************************************************************************
482 * Play: nothing to do
483 *****************************************************************************/
484 static void Play( aout_instance_t *p_aout )
488 /*****************************************************************************
489 * Close: close the dsp audio device
490 *****************************************************************************/
491 static void Close( vlc_object_t * p_this )
493 aout_instance_t *p_aout = (aout_instance_t *)p_this;
494 struct aout_sys_t * p_sys = p_aout->output.p_sys;
496 p_aout->b_die = VLC_TRUE;
497 vlc_thread_join( p_aout );
498 p_aout->b_die = VLC_FALSE;
500 ioctl( p_sys->i_fd, SNDCTL_DSP_RESET, NULL );
501 close( p_sys->i_fd );
506 /*****************************************************************************
507 * BufferDuration: buffer status query
508 *****************************************************************************
509 * This function returns the duration in microseconds of the current buffer.
510 *****************************************************************************/
511 static mtime_t BufferDuration( aout_instance_t * p_aout )
513 struct aout_sys_t * p_sys = p_aout->output.p_sys;
514 audio_buf_info audio_buf;
517 /* Fill the audio_buf_info structure:
518 * - fragstotal: total number of fragments allocated
519 * - fragsize: size of a fragment in bytes
520 * - bytes: available space in bytes (includes partially used fragments)
521 * Note! 'bytes' could be more than fragments*fragsize */
522 ioctl( p_sys->i_fd, SNDCTL_DSP_GETOSPACE, &audio_buf );
524 /* calculate number of available fragments (not partially used ones) */
525 i_bytes = (audio_buf.fragstotal * audio_buf.fragsize) - audio_buf.bytes;
527 /* Return the fragment duration */
528 return (mtime_t)i_bytes * 1000000
529 / p_aout->output.output.i_bytes_per_frame
530 / p_aout->output.output.i_rate
531 * p_aout->output.output.i_frame_length;
534 /*****************************************************************************
535 * OSSThread: asynchronous thread used to DMA the data to the device
536 *****************************************************************************/
537 static int OSSThread( aout_instance_t * p_aout )
539 struct aout_sys_t * p_sys = p_aout->output.p_sys;
540 mtime_t next_date = 0;
542 while ( !p_aout->b_die )
544 aout_buffer_t * p_buffer = NULL;
548 if ( p_aout->output.output.i_format != VLC_FOURCC('s','p','d','i') )
550 mtime_t buffered = BufferDuration( p_aout );
552 if( p_aout->output.p_sys->b_workaround_buggy_driver )
554 #define i_fragstotal p_aout->output.p_sys->i_fragstotal
555 /* Wait a bit - we don't want our buffer to be full */
556 if( buffered > (p_aout->output.p_sys->max_buffer_duration
557 / i_fragstotal * (i_fragstotal - 1)) )
559 msleep((p_aout->output.p_sys->max_buffer_duration
561 buffered = BufferDuration( p_aout );
566 /* Next buffer will be played at mdate() + buffered */
567 p_buffer = aout_OutputNextBuffer( p_aout, mdate() + buffered,
570 if( p_buffer == NULL &&
571 buffered > ( p_aout->output.p_sys->max_buffer_duration
572 / p_aout->output.p_sys->i_fragstotal ) )
574 /* If we have at least a fragment full, then we can wait a
575 * little and retry to get a new audio buffer instead of
576 * playing a blank sample */
577 msleep( ( p_aout->output.p_sys->max_buffer_duration
578 / p_aout->output.p_sys->i_fragstotal / 2 ) );
584 /* emu10k1 driver does not report Buffer Duration correctly in
585 * passthrough mode so we have to cheat */
592 mtime_t delay = next_date - mdate();
593 if( delay > AOUT_PTS_TOLERANCE )
599 while( !p_aout->b_die && ! ( p_buffer =
600 aout_OutputNextBuffer( p_aout, next_date, VLC_TRUE ) ) )
607 if ( p_buffer != NULL )
609 p_bytes = p_buffer->p_buffer;
610 i_size = p_buffer->i_nb_bytes;
611 /* This is theoretical ... we'll see next iteration whether
613 next_date += p_buffer->end_date - p_buffer->start_date;
617 i_size = FRAME_SIZE / p_aout->output.output.i_frame_length
618 * p_aout->output.output.i_bytes_per_frame;
619 p_bytes = malloc( i_size );
620 memset( p_bytes, 0, i_size );
624 i_tmp = write( p_sys->i_fd, p_bytes, i_size );
628 msg_Err( p_aout, "write failed (%s)", strerror(errno) );
631 if ( p_buffer != NULL )
633 aout_BufferFree( p_buffer );