1 /*****************************************************************************
2 * oss.c : OSS /dev/dsp module for vlc
3 *****************************************************************************
4 * Copyright (C) 2000-2002 VideoLAN
5 * $Id: oss.c,v 1.58 2003/05/04 22:42:15 gbazin 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 /* Patches for ignorant OSS versions */
58 # define AFMT_AC3 0x00000400 /* Dolby Digital AC3 */
62 # ifdef WORDS_BIGENDIAN
63 # define AFMT_S16_NE AFMT_S16_BE
65 # define AFMT_S16_NE AFMT_S16_LE
69 /*****************************************************************************
70 * aout_sys_t: OSS audio output method descriptor
71 *****************************************************************************
72 * This structure is part of the audio output thread descriptor.
73 * It describes the dsp specific properties of an audio device.
74 *****************************************************************************/
78 int b_workaround_buggy_driver;
80 mtime_t max_buffer_duration;
83 /* This must be a power of 2. */
84 #define FRAME_SIZE 1024
87 /*****************************************************************************
89 *****************************************************************************/
90 static int Open ( vlc_object_t * );
91 static void Close ( vlc_object_t * );
93 static void Play ( aout_instance_t * );
94 static int OSSThread ( aout_instance_t * );
96 static mtime_t BufferDuration( aout_instance_t * p_aout );
98 /*****************************************************************************
100 *****************************************************************************/
101 #define BUGGY_TEXT N_("try to work around buggy OSS drivers")
102 #define BUGGY_LONGTEXT N_( \
103 "Some buggy OSS drivers just don't like when their internal buffers " \
104 "are completely filled (the sound gets heavily hashed). If you have one " \
105 "of these drivers, then you need to enable this option." )
108 add_category_hint( N_("OSS"), NULL, VLC_FALSE );
109 add_file( "dspdev", "/dev/dsp", aout_FindAndRestart,
110 N_("OSS dsp device"), NULL, VLC_FALSE );
111 add_bool( "oss-buggy", 0, NULL, BUGGY_TEXT, BUGGY_LONGTEXT, VLC_TRUE );
112 set_description( _("Linux OSS audio output") );
113 set_capability( "audio output", 100 );
115 add_shortcut( "oss" );
116 set_callbacks( Open, Close );
119 /*****************************************************************************
120 * Probe: probe the audio device for available formats and channels
121 *****************************************************************************/
122 static void Probe( aout_instance_t * p_aout )
124 struct aout_sys_t * p_sys = p_aout->output.p_sys;
125 vlc_value_t val, text;
126 int i_format, i_nb_channels;
128 var_Create( p_aout, "audio-device", VLC_VAR_INTEGER | VLC_VAR_HASCHOICE );
129 text.psz_string = _("Audio device");
130 var_Change( p_aout, "audio-device", VLC_VAR_SETTEXT, &text, NULL );
132 /* Test for multi-channel. */
133 #ifdef SNDCTL_DSP_GETCHANNELMASK
134 if ( aout_FormatNbChannels( &p_aout->output.output ) > 2 )
136 /* Check that the device supports this. */
141 i_format = AFMT_S16_NE;
142 if( ioctl( p_sys->i_fd, SNDCTL_DSP_RESET, NULL ) < 0 ||
143 ioctl( p_sys->i_fd, SNDCTL_DSP_SETFMT, &i_format ) < 0 )
145 msg_Err( p_aout, "cannot reset OSS audio device" );
146 var_Destroy( p_aout, "audio-device" );
150 if ( ioctl( p_sys->i_fd, SNDCTL_DSP_GETCHANNELMASK,
153 if ( !(i_chanmask & DSP_BIND_FRONT) )
155 msg_Err( p_aout, "No front channels ! (%x)",
160 if ( (i_chanmask & (DSP_BIND_SURR | DSP_BIND_CENTER_LFE))
161 && (p_aout->output.output.i_physical_channels ==
162 (AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_CENTER
163 | AOUT_CHAN_REARLEFT | AOUT_CHAN_REARRIGHT
166 val.i_int = AOUT_VAR_5_1;
167 text.psz_string = N_("5.1");
168 var_Change( p_aout, "audio-device",
169 VLC_VAR_ADDCHOICE, &val, &text );
172 if ( (i_chanmask & DSP_BIND_SURR)
173 && (p_aout->output.output.i_physical_channels &
174 (AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT
175 | AOUT_CHAN_REARLEFT | AOUT_CHAN_REARRIGHT)) )
177 val.i_int = AOUT_VAR_2F2R;
178 text.psz_string = N_("2 Front 2 Rear");
179 var_Change( p_aout, "audio-device",
180 VLC_VAR_ADDCHOICE, &val, &text );
187 i_format = AFMT_S16_NE;
188 if( ioctl( p_sys->i_fd, SNDCTL_DSP_RESET, NULL ) < 0 ||
189 ioctl( p_sys->i_fd, SNDCTL_DSP_SETFMT, &i_format ) < 0 )
191 msg_Err( p_aout, "cannot reset OSS audio device" );
192 var_Destroy( p_aout, "audio-device" );
196 /* Test for stereo. */
198 if( ioctl( p_sys->i_fd, SNDCTL_DSP_CHANNELS, &i_nb_channels ) >= 0
199 && i_nb_channels == 2 )
201 val.i_int = AOUT_VAR_STEREO;
202 text.psz_string = N_("Stereo");
203 var_Change( p_aout, "audio-device", VLC_VAR_ADDCHOICE, &val, &text );
207 i_format = AFMT_S16_NE;
208 if( ioctl( p_sys->i_fd, SNDCTL_DSP_RESET, NULL ) < 0 ||
209 ioctl( p_sys->i_fd, SNDCTL_DSP_SETFMT, &i_format ) < 0 )
211 msg_Err( p_aout, "cannot reset OSS audio device" );
212 var_Destroy( p_aout, "audio-device" );
218 if( ioctl( p_sys->i_fd, SNDCTL_DSP_CHANNELS, &i_nb_channels ) >= 0
219 && i_nb_channels == 1 )
221 val.i_int = AOUT_VAR_MONO;
222 text.psz_string = N_("Mono");
223 var_Change( p_aout, "audio-device", VLC_VAR_ADDCHOICE, &val, &text );
224 if ( p_aout->output.output.i_physical_channels == AOUT_CHAN_CENTER )
226 var_Set( p_aout, "audio-device", val );
230 if( ioctl( p_sys->i_fd, SNDCTL_DSP_RESET, NULL ) < 0 )
232 msg_Err( p_aout, "cannot reset OSS audio device" );
233 var_Destroy( p_aout, "audio-device" );
237 /* Test for spdif. */
238 if ( AOUT_FMT_NON_LINEAR( &p_aout->output.output ) )
242 if( ioctl( p_sys->i_fd, SNDCTL_DSP_SETFMT, &i_format ) >= 0
243 && i_format == AFMT_AC3 )
245 val.i_int = AOUT_VAR_SPDIF;
246 text.psz_string = N_("A/52 over S/PDIF");
247 var_Change( p_aout, "audio-device",
248 VLC_VAR_ADDCHOICE, &val, &text );
249 if( config_GetInt( p_aout, "spdif" ) )
250 var_Set( p_aout, "audio-device", val );
254 var_AddCallback( p_aout, "audio-device", aout_ChannelsRestart,
258 /*****************************************************************************
259 * Open: open the audio device (the digital sound processor)
260 *****************************************************************************
261 * This function opens the dsp as a usual non-blocking write-only file, and
262 * modifies the p_aout->p_sys->i_fd with the file's descriptor.
263 *****************************************************************************/
264 static int Open( vlc_object_t *p_this )
266 aout_instance_t * p_aout = (aout_instance_t *)p_this;
267 struct aout_sys_t * p_sys;
271 /* Allocate structure */
272 p_aout->output.p_sys = p_sys = malloc( sizeof( aout_sys_t ) );
275 msg_Err( p_aout, "out of memory" );
279 /* Get device name */
280 if( (psz_device = config_GetPsz( p_aout, "dspdev" )) == NULL )
282 msg_Err( p_aout, "no audio device given (maybe /dev/dsp ?)" );
287 /* Open the sound device in non-blocking mode, because ALSA's OSS
288 * emulation and some broken OSS drivers would make a blocking call
289 * wait forever until the device is available. Since this breaks the
290 * OSS spec, we immediately put it back to blocking mode if the
291 * operation was successful. */
292 p_sys->i_fd = open( psz_device, O_WRONLY | O_NDELAY );
293 if( p_sys->i_fd < 0 )
295 msg_Err( p_aout, "cannot open audio device (%s)", psz_device );
300 /* if the opening was ok, put the device back in blocking mode */
301 fcntl( p_sys->i_fd, F_SETFL,
302 fcntl( p_sys->i_fd, F_GETFL ) &~ FNDELAY );
306 p_aout->output.pf_play = Play;
308 if ( var_Type( p_aout, "audio-device" ) == 0 )
313 if ( var_Get( p_aout, "audio-device", &val ) < 0 )
315 /* Probe() has failed. */
320 if ( val.i_int == AOUT_VAR_SPDIF )
322 p_aout->output.output.i_format = VLC_FOURCC('s','p','d','i');
324 else if ( val.i_int == AOUT_VAR_5_1 )
326 p_aout->output.output.i_format = AOUT_FMT_S16_NE;
327 p_aout->output.output.i_physical_channels
328 = AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_CENTER
329 | AOUT_CHAN_REARLEFT | AOUT_CHAN_REARRIGHT
332 else if ( val.i_int == AOUT_VAR_2F2R )
334 p_aout->output.output.i_format = AOUT_FMT_S16_NE;
335 p_aout->output.output.i_physical_channels
336 = AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT
337 | AOUT_CHAN_REARLEFT | AOUT_CHAN_REARRIGHT;
339 else if ( val.i_int == AOUT_VAR_STEREO )
341 p_aout->output.output.i_format = AOUT_FMT_S16_NE;
342 p_aout->output.output.i_physical_channels
343 = AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT;
345 else if ( val.i_int == AOUT_VAR_MONO )
347 p_aout->output.output.i_format = AOUT_FMT_S16_NE;
348 p_aout->output.output.i_physical_channels = AOUT_CHAN_CENTER;
352 /* This should not happen ! */
353 msg_Err( p_aout, "internal: can't find audio-device (%i)", val.i_int );
358 val.b_bool = VLC_TRUE;
359 var_Set( p_aout, "intf-change", val );
361 /* Reset the DSP device */
362 if( ioctl( p_sys->i_fd, SNDCTL_DSP_RESET, NULL ) < 0 )
364 msg_Err( p_aout, "cannot reset OSS audio device" );
365 close( p_sys->i_fd );
370 /* Set the output format */
371 if ( AOUT_FMT_NON_LINEAR( &p_aout->output.output ) )
373 int i_format = AFMT_AC3;
375 if( ioctl( p_sys->i_fd, SNDCTL_DSP_SETFMT, &i_format ) < 0
376 || i_format != AFMT_AC3 )
378 msg_Err( p_aout, "cannot reset OSS audio device" );
379 close( p_sys->i_fd );
384 p_aout->output.output.i_format = VLC_FOURCC('s','p','d','i');
385 p_aout->output.i_nb_samples = A52_FRAME_NB;
386 p_aout->output.output.i_bytes_per_frame = AOUT_SPDIF_SIZE;
387 p_aout->output.output.i_frame_length = A52_FRAME_NB;
389 aout_VolumeNoneInit( p_aout );
392 if ( !AOUT_FMT_NON_LINEAR( &p_aout->output.output ) )
394 unsigned int i_format = AFMT_S16_NE;
395 unsigned int i_frame_size, i_fragments;
397 unsigned int i_nb_channels;
398 audio_buf_info audio_buf;
400 if( ioctl( p_sys->i_fd, SNDCTL_DSP_SETFMT, &i_format ) < 0 )
402 msg_Err( p_aout, "cannot set audio output format" );
403 close( p_sys->i_fd );
411 p_aout->output.output.i_format = VLC_FOURCC('u','8',' ',' ');
414 p_aout->output.output.i_format = VLC_FOURCC('s','8',' ',' ');
417 p_aout->output.output.i_format = VLC_FOURCC('u','1','6','l');
420 p_aout->output.output.i_format = VLC_FOURCC('s','1','6','l');
423 p_aout->output.output.i_format = VLC_FOURCC('u','1','6','b');
426 p_aout->output.output.i_format = VLC_FOURCC('s','1','6','b');
429 msg_Err( p_aout, "OSS fell back to an unknown format (%d)",
431 close( p_sys->i_fd );
436 i_nb_channels = aout_FormatNbChannels( &p_aout->output.output );
438 /* Set the number of channels */
439 if( ioctl( p_sys->i_fd, SNDCTL_DSP_CHANNELS, &i_nb_channels ) < 0 ||
440 i_nb_channels != aout_FormatNbChannels( &p_aout->output.output ) )
442 msg_Err( p_aout, "cannot set number of audio channels (%s)",
443 aout_FormatPrintChannels( &p_aout->output.output) );
444 close( p_sys->i_fd );
449 /* Set the output rate */
450 i_rate = p_aout->output.output.i_rate;
451 if( ioctl( p_sys->i_fd, SNDCTL_DSP_SPEED, &i_rate ) < 0 )
453 msg_Err( p_aout, "cannot set audio output rate (%i)",
454 p_aout->output.output.i_rate );
455 close( p_sys->i_fd );
460 if( i_rate != p_aout->output.output.i_rate )
462 p_aout->output.output.i_rate = i_rate;
465 /* Set the fragment size */
466 aout_FormatPrepare( &p_aout->output.output );
468 /* i_fragment = xxxxyyyy where: xxxx is fragtotal
469 * 1 << yyyy is fragsize */
471 i_frame_size = FRAME_SIZE * p_aout->output.output.i_bytes_per_frame;
472 while( i_frame_size >>= 1 )
476 i_fragments |= FRAME_COUNT << 16;
477 if( ioctl( p_sys->i_fd, SNDCTL_DSP_SETFRAGMENT, &i_fragments ) < 0 )
479 msg_Warn( p_aout, "cannot set fragment size (%.8x)", i_fragments );
482 if( ioctl( p_sys->i_fd, SNDCTL_DSP_GETOSPACE, &audio_buf ) < 0 )
484 msg_Err( p_aout, "cannot get fragment size" );
485 close( p_sys->i_fd );
491 /* Number of fragments actually allocated */
492 p_aout->output.p_sys->i_fragstotal = audio_buf.fragstotal;
494 /* Maximum duration the soundcard's buffer can hold */
495 p_aout->output.p_sys->max_buffer_duration =
496 (mtime_t)audio_buf.fragstotal * audio_buf.fragsize * 1000000
497 / p_aout->output.output.i_bytes_per_frame
498 / p_aout->output.output.i_rate
499 * p_aout->output.output.i_frame_length;
501 p_aout->output.i_nb_samples = audio_buf.fragsize /
502 p_aout->output.output.i_bytes_per_frame;
505 aout_VolumeSoftInit( p_aout );
508 p_aout->output.p_sys->b_workaround_buggy_driver =
509 config_GetInt( p_aout, "oss-buggy" );
511 /* Create OSS thread and wait for its readiness. */
512 if( vlc_thread_create( p_aout, "aout", OSSThread,
513 VLC_THREAD_PRIORITY_OUTPUT, VLC_FALSE ) )
515 msg_Err( p_aout, "cannot create OSS thread (%s)", strerror(errno) );
516 close( p_sys->i_fd );
524 /*****************************************************************************
525 * Play: nothing to do
526 *****************************************************************************/
527 static void Play( aout_instance_t *p_aout )
531 /*****************************************************************************
532 * Close: close the dsp audio device
533 *****************************************************************************/
534 static void Close( vlc_object_t * p_this )
536 aout_instance_t *p_aout = (aout_instance_t *)p_this;
537 struct aout_sys_t * p_sys = p_aout->output.p_sys;
539 p_aout->b_die = VLC_TRUE;
540 vlc_thread_join( p_aout );
541 p_aout->b_die = VLC_FALSE;
543 ioctl( p_sys->i_fd, SNDCTL_DSP_RESET, NULL );
544 close( p_sys->i_fd );
549 /*****************************************************************************
550 * BufferDuration: buffer status query
551 *****************************************************************************
552 * This function returns the duration in microseconds of the current buffer.
553 *****************************************************************************/
554 static mtime_t BufferDuration( aout_instance_t * p_aout )
556 struct aout_sys_t * p_sys = p_aout->output.p_sys;
557 audio_buf_info audio_buf;
560 /* Fill the audio_buf_info structure:
561 * - fragstotal: total number of fragments allocated
562 * - fragsize: size of a fragment in bytes
563 * - bytes: available space in bytes (includes partially used fragments)
564 * Note! 'bytes' could be more than fragments*fragsize */
565 ioctl( p_sys->i_fd, SNDCTL_DSP_GETOSPACE, &audio_buf );
567 /* calculate number of available fragments (not partially used ones) */
568 i_bytes = (audio_buf.fragstotal * audio_buf.fragsize) - audio_buf.bytes;
570 /* Return the fragment duration */
571 return (mtime_t)i_bytes * 1000000
572 / p_aout->output.output.i_bytes_per_frame
573 / p_aout->output.output.i_rate
574 * p_aout->output.output.i_frame_length;
577 /*****************************************************************************
578 * OSSThread: asynchronous thread used to DMA the data to the device
579 *****************************************************************************/
580 static int OSSThread( aout_instance_t * p_aout )
582 struct aout_sys_t * p_sys = p_aout->output.p_sys;
583 mtime_t next_date = 0;
585 while ( !p_aout->b_die )
587 aout_buffer_t * p_buffer = NULL;
591 if ( p_aout->output.output.i_format != VLC_FOURCC('s','p','d','i') )
593 mtime_t buffered = BufferDuration( p_aout );
595 if( p_aout->output.p_sys->b_workaround_buggy_driver )
597 #define i_fragstotal p_aout->output.p_sys->i_fragstotal
598 /* Wait a bit - we don't want our buffer to be full */
599 if( buffered > (p_aout->output.p_sys->max_buffer_duration
600 / i_fragstotal * (i_fragstotal - 1)) )
602 msleep((p_aout->output.p_sys->max_buffer_duration
604 buffered = BufferDuration( p_aout );
609 /* Next buffer will be played at mdate() + buffered */
610 p_buffer = aout_OutputNextBuffer( p_aout, mdate() + buffered,
613 if( p_buffer == NULL &&
614 buffered > ( p_aout->output.p_sys->max_buffer_duration
615 / p_aout->output.p_sys->i_fragstotal ) )
617 /* If we have at least a fragment full, then we can wait a
618 * little and retry to get a new audio buffer instead of
619 * playing a blank sample */
620 msleep( ( p_aout->output.p_sys->max_buffer_duration
621 / p_aout->output.p_sys->i_fragstotal / 2 ) );
627 /* emu10k1 driver does not report Buffer Duration correctly in
628 * passthrough mode so we have to cheat */
635 mtime_t delay = next_date - mdate();
636 if( delay > AOUT_PTS_TOLERANCE )
642 while( !p_aout->b_die && ! ( p_buffer =
643 aout_OutputNextBuffer( p_aout, next_date, VLC_TRUE ) ) )
650 if ( p_buffer != NULL )
652 p_bytes = p_buffer->p_buffer;
653 i_size = p_buffer->i_nb_bytes;
654 /* This is theoretical ... we'll see next iteration whether
656 next_date += p_buffer->end_date - p_buffer->start_date;
660 i_size = FRAME_SIZE / p_aout->output.output.i_frame_length
661 * p_aout->output.output.i_bytes_per_frame;
662 p_bytes = malloc( i_size );
663 memset( p_bytes, 0, i_size );
667 i_tmp = write( p_sys->i_fd, p_bytes, i_size );
671 msg_Err( p_aout, "write failed (%s)", strerror(errno) );
674 if ( p_buffer != NULL )
676 aout_BufferFree( p_buffer );