1 /*****************************************************************************
2 * oss.c : OSS /dev/dsp module 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 * 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., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
24 *****************************************************************************/
26 /*****************************************************************************
28 *****************************************************************************/
34 #include <errno.h> /* ENOMEM */
35 #include <fcntl.h> /* open(), O_WRONLY */
36 #include <sys/ioctl.h> /* ioctl() */
37 #include <unistd.h> /* write(), close() */
39 #include <vlc_common.h>
40 #include <vlc_plugin.h>
48 /* SNDCTL_DSP_RESET, SNDCTL_DSP_SETFMT, SNDCTL_DSP_STEREO, SNDCTL_DSP_SPEED,
49 * SNDCTL_DSP_GETOSPACE */
50 #ifdef HAVE_SOUNDCARD_H
51 # include <soundcard.h>
52 #elif defined( HAVE_SYS_SOUNDCARD_H )
53 # include <sys/soundcard.h>
54 #elif defined( HAVE_MACHINE_SOUNDCARD_H )
55 # include <machine/soundcard.h>
58 /* Patches for ignorant OSS versions */
60 # define AFMT_AC3 0x00000400 /* Dolby Digital AC3 */
64 # ifdef WORDS_BIGENDIAN
65 # define AFMT_S16_NE AFMT_S16_BE
67 # define AFMT_S16_NE AFMT_S16_LE
71 /*****************************************************************************
72 * aout_sys_t: OSS audio output method descriptor
73 *****************************************************************************
74 * This structure is part of the audio output thread descriptor.
75 * It describes the DSP specific properties of an audio device.
76 *****************************************************************************/
80 int b_workaround_buggy_driver;
82 mtime_t max_buffer_duration;
85 /* This must be a power of 2. */
86 #define FRAME_SIZE 1024
87 #define FRAME_COUNT 32
89 /*****************************************************************************
91 *****************************************************************************/
92 static int Open ( vlc_object_t * );
93 static void Close ( vlc_object_t * );
95 static void Play ( aout_instance_t * );
96 static int OSSThread ( aout_instance_t * );
98 static mtime_t BufferDuration( aout_instance_t * p_aout );
100 /*****************************************************************************
102 *****************************************************************************/
103 #define BUGGY_TEXT N_("Try to work around buggy OSS drivers")
104 #define BUGGY_LONGTEXT N_( \
105 "Some buggy OSS drivers just don't like when their internal buffers " \
106 "are completely filled (the sound gets heavily hashed). If you have one " \
107 "of these drivers, then you need to enable this option." )
110 set_shortname( "OSS" );
111 set_description( N_("UNIX OSS audio output") );
113 set_category( CAT_AUDIO );
114 set_subcategory( SUBCAT_AUDIO_AOUT );
115 add_file( "dspdev", "/dev/dsp", aout_FindAndRestart,
116 N_("OSS DSP device"), NULL, false );
117 add_bool( "oss-buggy", 0, NULL, BUGGY_TEXT, BUGGY_LONGTEXT, true );
119 set_capability( "audio output", 100 );
120 add_shortcut( "oss" );
121 set_callbacks( Open, Close );
124 /*****************************************************************************
125 * Probe: probe the audio device for available formats and channels
126 *****************************************************************************/
127 static void Probe( aout_instance_t * p_aout )
129 struct aout_sys_t * p_sys = p_aout->output.p_sys;
130 vlc_value_t val, text;
131 int i_format, i_nb_channels;
133 var_Create( p_aout, "audio-device", VLC_VAR_INTEGER | VLC_VAR_HASCHOICE );
134 text.psz_string = _("Audio Device");
135 var_Change( p_aout, "audio-device", VLC_VAR_SETTEXT, &text, NULL );
137 /* Test for multi-channel. */
138 #ifdef SNDCTL_DSP_GETCHANNELMASK
139 if ( aout_FormatNbChannels( &p_aout->output.output ) > 2 )
141 /* Check that the device supports this. */
146 i_format = AFMT_S16_NE;
147 if( ioctl( p_sys->i_fd, SNDCTL_DSP_RESET, NULL ) < 0 ||
148 ioctl( p_sys->i_fd, SNDCTL_DSP_SETFMT, &i_format ) < 0 )
150 msg_Err( p_aout, "cannot reset OSS audio device" );
151 var_Destroy( p_aout, "audio-device" );
155 if ( ioctl( p_sys->i_fd, SNDCTL_DSP_GETCHANNELMASK,
158 if ( !(i_chanmask & DSP_BIND_FRONT) )
160 msg_Err( p_aout, "no front channels! (%x)",
165 if ( (i_chanmask & (DSP_BIND_SURR | DSP_BIND_CENTER_LFE))
166 && (p_aout->output.output.i_physical_channels ==
167 (AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_CENTER
168 | AOUT_CHAN_REARLEFT | AOUT_CHAN_REARRIGHT
171 val.i_int = AOUT_VAR_5_1;
172 text.psz_string = "5.1";
173 var_Change( p_aout, "audio-device",
174 VLC_VAR_ADDCHOICE, &val, &text );
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.i_int = AOUT_VAR_2F2R;
183 text.psz_string = N_("2 Front 2 Rear");
184 var_Change( p_aout, "audio-device",
185 VLC_VAR_ADDCHOICE, &val, &text );
192 i_format = AFMT_S16_NE;
193 if( ioctl( p_sys->i_fd, SNDCTL_DSP_RESET, NULL ) < 0 ||
194 ioctl( p_sys->i_fd, SNDCTL_DSP_SETFMT, &i_format ) < 0 )
196 msg_Err( p_aout, "cannot reset OSS audio device" );
197 var_Destroy( p_aout, "audio-device" );
201 /* Test for stereo. */
203 if( ioctl( p_sys->i_fd, SNDCTL_DSP_CHANNELS, &i_nb_channels ) >= 0
204 && i_nb_channels == 2 )
206 val.i_int = AOUT_VAR_STEREO;
207 text.psz_string = N_("Stereo");
208 var_Change( p_aout, "audio-device", VLC_VAR_ADDCHOICE, &val, &text );
212 i_format = AFMT_S16_NE;
213 if( ioctl( p_sys->i_fd, SNDCTL_DSP_RESET, NULL ) < 0 ||
214 ioctl( p_sys->i_fd, SNDCTL_DSP_SETFMT, &i_format ) < 0 )
216 msg_Err( p_aout, "cannot reset OSS audio device" );
217 var_Destroy( p_aout, "audio-device" );
223 if( ioctl( p_sys->i_fd, SNDCTL_DSP_CHANNELS, &i_nb_channels ) >= 0
224 && i_nb_channels == 1 )
226 val.i_int = AOUT_VAR_MONO;
227 text.psz_string = N_("Mono");
228 var_Change( p_aout, "audio-device", VLC_VAR_ADDCHOICE, &val, &text );
229 if ( p_aout->output.output.i_physical_channels == AOUT_CHAN_CENTER )
231 var_Set( p_aout, "audio-device", val );
235 if( ioctl( p_sys->i_fd, SNDCTL_DSP_RESET, NULL ) < 0 )
237 msg_Err( p_aout, "cannot reset OSS audio device" );
238 var_Destroy( p_aout, "audio-device" );
242 /* Test for spdif. */
243 if ( AOUT_FMT_NON_LINEAR( &p_aout->output.output ) )
247 if( ioctl( p_sys->i_fd, SNDCTL_DSP_SETFMT, &i_format ) >= 0
248 && i_format == AFMT_AC3 )
250 val.i_int = AOUT_VAR_SPDIF;
251 text.psz_string = N_("A/52 over S/PDIF");
252 var_Change( p_aout, "audio-device",
253 VLC_VAR_ADDCHOICE, &val, &text );
254 if( config_GetInt( p_aout, "spdif" ) )
255 var_Set( p_aout, "audio-device", val );
257 else if( config_GetInt( p_aout, "spdif" ) )
259 msg_Warn( p_aout, "S/PDIF not supported by card" );
263 var_AddCallback( p_aout, "audio-device", aout_ChannelsRestart,
267 /*****************************************************************************
268 * Open: open the audio device (the digital sound processor)
269 *****************************************************************************
270 * This function opens the DSP as a usual non-blocking write-only file, and
271 * modifies the p_aout->p_sys->i_fd with the file's descriptor.
272 *****************************************************************************/
273 static int Open( vlc_object_t *p_this )
275 aout_instance_t * p_aout = (aout_instance_t *)p_this;
276 struct aout_sys_t * p_sys;
280 /* Allocate structure */
281 p_aout->output.p_sys = p_sys = malloc( sizeof( aout_sys_t ) );
285 /* Get device name */
286 if( (psz_device = config_GetPsz( p_aout, "dspdev" )) == NULL )
288 msg_Err( p_aout, "no audio device specified (maybe /dev/dsp?)" );
293 /* Open the sound device in non-blocking mode, because ALSA's OSS
294 * emulation and some broken OSS drivers would make a blocking call
295 * wait forever until the device is available. Since this breaks the
296 * OSS spec, we immediately put it back to blocking mode if the
297 * operation was successful. */
298 p_sys->i_fd = open( psz_device, O_WRONLY | O_NDELAY );
299 if( p_sys->i_fd < 0 )
301 msg_Err( p_aout, "cannot open audio device (%s)", psz_device );
306 /* if the opening was ok, put the device back in blocking mode */
307 fcntl( p_sys->i_fd, F_SETFL,
308 fcntl( p_sys->i_fd, F_GETFL ) &~ FNDELAY );
312 p_aout->output.pf_play = Play;
314 if ( var_Type( p_aout, "audio-device" ) == 0 )
319 if ( var_Get( p_aout, "audio-device", &val ) < 0 )
321 /* Probe() has failed. */
326 if ( val.i_int == AOUT_VAR_SPDIF )
328 p_aout->output.output.i_format = VLC_FOURCC('s','p','d','i');
330 else if ( val.i_int == AOUT_VAR_5_1 )
332 p_aout->output.output.i_format = AOUT_FMT_S16_NE;
333 p_aout->output.output.i_physical_channels
334 = AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_CENTER
335 | AOUT_CHAN_REARLEFT | AOUT_CHAN_REARRIGHT
338 else if ( val.i_int == AOUT_VAR_2F2R )
340 p_aout->output.output.i_format = AOUT_FMT_S16_NE;
341 p_aout->output.output.i_physical_channels
342 = AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT
343 | AOUT_CHAN_REARLEFT | AOUT_CHAN_REARRIGHT;
345 else if ( val.i_int == AOUT_VAR_STEREO )
347 p_aout->output.output.i_format = AOUT_FMT_S16_NE;
348 p_aout->output.output.i_physical_channels
349 = AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT;
351 else if ( val.i_int == AOUT_VAR_MONO )
353 p_aout->output.output.i_format = AOUT_FMT_S16_NE;
354 p_aout->output.output.i_physical_channels = AOUT_CHAN_CENTER;
358 /* This should not happen ! */
359 msg_Err( p_aout, "internal: can't find audio-device (%i)", val.i_int );
365 var_Set( p_aout, "intf-change", val );
367 /* Reset the DSP device */
368 if( ioctl( p_sys->i_fd, SNDCTL_DSP_RESET, NULL ) < 0 )
370 msg_Err( p_aout, "cannot reset OSS audio device" );
371 close( p_sys->i_fd );
376 /* Set the output format */
377 if ( AOUT_FMT_NON_LINEAR( &p_aout->output.output ) )
379 int i_format = AFMT_AC3;
381 if( ioctl( p_sys->i_fd, SNDCTL_DSP_SETFMT, &i_format ) < 0
382 || i_format != AFMT_AC3 )
384 msg_Err( p_aout, "cannot reset OSS audio device" );
385 close( p_sys->i_fd );
390 p_aout->output.output.i_format = VLC_FOURCC('s','p','d','i');
391 p_aout->output.i_nb_samples = A52_FRAME_NB;
392 p_aout->output.output.i_bytes_per_frame = AOUT_SPDIF_SIZE;
393 p_aout->output.output.i_frame_length = A52_FRAME_NB;
395 aout_VolumeNoneInit( p_aout );
398 if ( !AOUT_FMT_NON_LINEAR( &p_aout->output.output ) )
400 unsigned int i_format = AFMT_S16_NE;
401 unsigned int i_frame_size, i_fragments;
403 unsigned int i_nb_channels;
404 audio_buf_info audio_buf;
406 if( ioctl( p_sys->i_fd, SNDCTL_DSP_SETFMT, &i_format ) < 0 )
408 msg_Err( p_aout, "cannot set audio output format" );
409 close( p_sys->i_fd );
417 p_aout->output.output.i_format = VLC_FOURCC('u','8',' ',' ');
420 p_aout->output.output.i_format = VLC_FOURCC('s','8',' ',' ');
423 p_aout->output.output.i_format = VLC_FOURCC('u','1','6','l');
426 p_aout->output.output.i_format = VLC_FOURCC('s','1','6','l');
429 p_aout->output.output.i_format = VLC_FOURCC('u','1','6','b');
432 p_aout->output.output.i_format = VLC_FOURCC('s','1','6','b');
435 msg_Err( p_aout, "OSS fell back to an unknown format (%d)",
437 close( p_sys->i_fd );
442 i_nb_channels = aout_FormatNbChannels( &p_aout->output.output );
444 /* Set the number of channels */
445 if( ioctl( p_sys->i_fd, SNDCTL_DSP_CHANNELS, &i_nb_channels ) < 0 ||
446 i_nb_channels != aout_FormatNbChannels( &p_aout->output.output ) )
448 msg_Err( p_aout, "cannot set number of audio channels (%s)",
449 aout_FormatPrintChannels( &p_aout->output.output) );
450 close( p_sys->i_fd );
455 /* Set the output rate */
456 i_rate = p_aout->output.output.i_rate;
457 if( ioctl( p_sys->i_fd, SNDCTL_DSP_SPEED, &i_rate ) < 0 )
459 msg_Err( p_aout, "cannot set audio output rate (%i)",
460 p_aout->output.output.i_rate );
461 close( p_sys->i_fd );
466 if( i_rate != p_aout->output.output.i_rate )
468 p_aout->output.output.i_rate = i_rate;
471 /* Set the fragment size */
472 aout_FormatPrepare( &p_aout->output.output );
474 /* i_fragment = xxxxyyyy where: xxxx is fragtotal
475 * 1 << yyyy is fragsize */
476 i_frame_size = ((uint64_t)p_aout->output.output.i_bytes_per_frame * p_aout->output.output.i_rate * 65536) / (48000 * 2 * 2) / FRAME_COUNT;
478 while( i_fragments < 12 && (1U << i_fragments) < i_frame_size )
482 i_fragments |= FRAME_COUNT << 16;
483 if( ioctl( p_sys->i_fd, SNDCTL_DSP_SETFRAGMENT, &i_fragments ) < 0 )
485 msg_Warn( p_aout, "cannot set fragment size (%.8x)", i_fragments );
488 if( ioctl( p_sys->i_fd, SNDCTL_DSP_GETOSPACE, &audio_buf ) < 0 )
490 msg_Err( p_aout, "cannot get fragment size" );
491 close( p_sys->i_fd );
497 /* Number of fragments actually allocated */
498 p_aout->output.p_sys->i_fragstotal = audio_buf.fragstotal;
500 /* Maximum duration the soundcard's buffer can hold */
501 p_aout->output.p_sys->max_buffer_duration =
502 (mtime_t)audio_buf.fragstotal * audio_buf.fragsize * 1000000
503 / p_aout->output.output.i_bytes_per_frame
504 / p_aout->output.output.i_rate
505 * p_aout->output.output.i_frame_length;
507 p_aout->output.i_nb_samples = audio_buf.fragsize /
508 p_aout->output.output.i_bytes_per_frame;
511 aout_VolumeSoftInit( p_aout );
514 p_aout->output.p_sys->b_workaround_buggy_driver =
515 config_GetInt( p_aout, "oss-buggy" );
517 /* Create OSS thread and wait for its readiness. */
518 if( vlc_thread_create( p_aout, "aout", OSSThread,
519 VLC_THREAD_PRIORITY_OUTPUT, false ) )
521 msg_Err( p_aout, "cannot create OSS thread (%m)" );
522 close( p_sys->i_fd );
530 /*****************************************************************************
531 * Play: nothing to do
532 *****************************************************************************/
533 static void Play( aout_instance_t *p_aout )
538 /*****************************************************************************
539 * Close: close the DSP audio device
540 *****************************************************************************/
541 static void Close( vlc_object_t * p_this )
543 aout_instance_t *p_aout = (aout_instance_t *)p_this;
544 struct aout_sys_t * p_sys = p_aout->output.p_sys;
546 vlc_object_kill( p_aout );
547 vlc_thread_join( p_aout );
548 p_aout->b_die = false;
550 ioctl( p_sys->i_fd, SNDCTL_DSP_RESET, NULL );
551 close( p_sys->i_fd );
556 /*****************************************************************************
557 * BufferDuration: buffer status query
558 *****************************************************************************
559 * This function returns the duration in microseconds of the current buffer.
560 *****************************************************************************/
561 static mtime_t BufferDuration( aout_instance_t * p_aout )
563 struct aout_sys_t * p_sys = p_aout->output.p_sys;
564 audio_buf_info audio_buf;
567 /* Fill the audio_buf_info structure:
568 * - fragstotal: total number of fragments allocated
569 * - fragsize: size of a fragment in bytes
570 * - bytes: available space in bytes (includes partially used fragments)
571 * Note! 'bytes' could be more than fragments*fragsize */
572 ioctl( p_sys->i_fd, SNDCTL_DSP_GETOSPACE, &audio_buf );
574 /* calculate number of available fragments (not partially used ones) */
575 i_bytes = (audio_buf.fragstotal * audio_buf.fragsize) - audio_buf.bytes;
577 /* Return the fragment duration */
578 return (mtime_t)i_bytes * 1000000
579 / p_aout->output.output.i_bytes_per_frame
580 / p_aout->output.output.i_rate
581 * p_aout->output.output.i_frame_length;
584 /*****************************************************************************
585 * OSSThread: asynchronous thread used to DMA the data to the device
586 *****************************************************************************/
587 static int OSSThread( aout_instance_t * p_aout )
589 struct aout_sys_t * p_sys = p_aout->output.p_sys;
590 mtime_t next_date = 0;
592 while ( vlc_object_alive (p_aout) )
594 aout_buffer_t * p_buffer = NULL;
598 if ( p_aout->output.output.i_format != VLC_FOURCC('s','p','d','i') )
600 mtime_t buffered = BufferDuration( p_aout );
602 if( p_aout->output.p_sys->b_workaround_buggy_driver )
604 #define i_fragstotal p_aout->output.p_sys->i_fragstotal
605 /* Wait a bit - we don't want our buffer to be full */
606 if( buffered > (p_aout->output.p_sys->max_buffer_duration
607 / i_fragstotal * (i_fragstotal - 1)) )
609 msleep((p_aout->output.p_sys->max_buffer_duration
611 buffered = BufferDuration( p_aout );
616 /* Next buffer will be played at mdate() + buffered */
617 p_buffer = aout_OutputNextBuffer( p_aout, mdate() + buffered,
620 if( p_buffer == NULL &&
621 buffered > ( p_aout->output.p_sys->max_buffer_duration
622 / p_aout->output.p_sys->i_fragstotal ) )
624 /* If we have at least a fragment full, then we can wait a
625 * little and retry to get a new audio buffer instead of
626 * playing a blank sample */
627 msleep( ( p_aout->output.p_sys->max_buffer_duration
628 / p_aout->output.p_sys->i_fragstotal / 2 ) );
634 /* emu10k1 driver does not report Buffer Duration correctly in
635 * passthrough mode so we have to cheat */
642 mtime_t delay = next_date - mdate();
643 if( delay > AOUT_PTS_TOLERANCE )
649 while( vlc_object_alive (p_aout) && ! ( p_buffer =
650 aout_OutputNextBuffer( p_aout, next_date, true ) ) )
657 if ( p_buffer != NULL )
659 p_bytes = p_buffer->p_buffer;
660 i_size = p_buffer->i_nb_bytes;
661 /* This is theoretical ... we'll see next iteration whether
663 next_date += p_buffer->end_date - p_buffer->start_date;
667 i_size = FRAME_SIZE / p_aout->output.output.i_frame_length
668 * p_aout->output.output.i_bytes_per_frame;
669 p_bytes = malloc( i_size );
670 memset( p_bytes, 0, i_size );
674 i_tmp = write( p_sys->i_fd, p_bytes, i_size );
678 msg_Err( p_aout, "write failed (%m)" );
681 if ( p_buffer != NULL )
683 aout_BufferFree( p_buffer );