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>
41 #include <vlc_charset.h>
45 /* SNDCTL_DSP_RESET, SNDCTL_DSP_SETFMT, SNDCTL_DSP_STEREO, SNDCTL_DSP_SPEED,
46 * SNDCTL_DSP_GETOSPACE */
47 #ifdef HAVE_SOUNDCARD_H
48 # include <soundcard.h>
49 #elif defined( HAVE_SYS_SOUNDCARD_H )
50 # include <sys/soundcard.h>
53 /* Patches for ignorant OSS versions */
55 # define AFMT_AC3 0x00000400 /* Dolby Digital AC3 */
59 # ifdef WORDS_BIGENDIAN
60 # define AFMT_S16_NE AFMT_S16_BE
62 # define AFMT_S16_NE AFMT_S16_LE
66 /*****************************************************************************
67 * aout_sys_t: OSS audio output method descriptor
68 *****************************************************************************
69 * This structure is part of the audio output thread descriptor.
70 * It describes the DSP specific properties of an audio device.
71 *****************************************************************************/
75 int b_workaround_buggy_driver;
77 mtime_t max_buffer_duration;
80 /* This must be a power of 2. */
81 #define FRAME_SIZE 1024
82 #define FRAME_COUNT 32
84 /*****************************************************************************
86 *****************************************************************************/
87 static int Open ( vlc_object_t * );
88 static void Close ( vlc_object_t * );
90 static void Play ( aout_instance_t * );
91 static void* OSSThread ( vlc_object_t * );
93 static mtime_t BufferDuration( aout_instance_t * p_aout );
95 /*****************************************************************************
97 *****************************************************************************/
98 #define BUGGY_TEXT N_("Try to work around buggy OSS drivers")
99 #define BUGGY_LONGTEXT N_( \
100 "Some buggy OSS drivers just don't like when their internal buffers " \
101 "are completely filled (the sound gets heavily hashed). If you have one " \
102 "of these drivers, then you need to enable this option." )
105 set_shortname( "OSS" )
106 set_description( N_("UNIX OSS audio output") )
108 set_category( CAT_AUDIO )
109 set_subcategory( SUBCAT_AUDIO_AOUT )
110 add_file( "oss-audio-device", "/dev/dsp", aout_FindAndRestart,
111 N_("OSS DSP device"), NULL, false )
112 add_deprecated_alias( "dspdev" ) /* deprecated since 0.9.3 */
113 add_bool( "oss-buggy", false, NULL, BUGGY_TEXT, BUGGY_LONGTEXT, true )
115 set_capability( "audio output", 100 )
116 add_shortcut( "oss" )
117 set_callbacks( Open, Close )
120 /*****************************************************************************
121 * Probe: probe the audio device for available formats and channels
122 *****************************************************************************/
123 static void Probe( aout_instance_t * p_aout )
125 struct aout_sys_t * p_sys = p_aout->output.p_sys;
126 vlc_value_t val, text;
127 int i_format, i_nb_channels;
129 var_Create( p_aout, "audio-device", VLC_VAR_INTEGER | VLC_VAR_HASCHOICE );
130 text.psz_string = _("Audio Device");
131 var_Change( p_aout, "audio-device", VLC_VAR_SETTEXT, &text, NULL );
133 /* Test for multi-channel. */
134 #ifdef SNDCTL_DSP_GETCHANNELMASK
135 if ( aout_FormatNbChannels( &p_aout->output.output ) > 2 )
137 /* Check that the device supports this. */
142 i_format = AFMT_S16_NE;
143 if( ioctl( p_sys->i_fd, SNDCTL_DSP_RESET, NULL ) < 0 ||
144 ioctl( p_sys->i_fd, SNDCTL_DSP_SETFMT, &i_format ) < 0 )
146 msg_Err( p_aout, "cannot reset OSS audio device" );
147 var_Destroy( p_aout, "audio-device" );
151 if ( ioctl( p_sys->i_fd, SNDCTL_DSP_GETCHANNELMASK,
154 if ( !(i_chanmask & DSP_BIND_FRONT) )
156 msg_Err( p_aout, "no front channels! (%x)",
161 if ( (i_chanmask & (DSP_BIND_SURR | DSP_BIND_CENTER_LFE))
162 && (p_aout->output.output.i_physical_channels ==
163 (AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_CENTER
164 | AOUT_CHAN_REARLEFT | AOUT_CHAN_REARRIGHT
167 val.i_int = AOUT_VAR_5_1;
168 text.psz_string = (char*) "5.1";
169 var_Change( p_aout, "audio-device",
170 VLC_VAR_ADDCHOICE, &val, &text );
173 if ( (i_chanmask & DSP_BIND_SURR)
174 && (p_aout->output.output.i_physical_channels &
175 (AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT
176 | AOUT_CHAN_REARLEFT | AOUT_CHAN_REARRIGHT)) )
178 val.i_int = AOUT_VAR_2F2R;
179 text.psz_string = _("2 Front 2 Rear");
180 var_Change( p_aout, "audio-device",
181 VLC_VAR_ADDCHOICE, &val, &text );
188 i_format = AFMT_S16_NE;
189 if( ioctl( p_sys->i_fd, SNDCTL_DSP_RESET, NULL ) < 0 ||
190 ioctl( p_sys->i_fd, SNDCTL_DSP_SETFMT, &i_format ) < 0 )
192 msg_Err( p_aout, "cannot reset OSS audio device" );
193 var_Destroy( p_aout, "audio-device" );
197 /* Test for stereo. */
199 if( ioctl( p_sys->i_fd, SNDCTL_DSP_CHANNELS, &i_nb_channels ) >= 0
200 && i_nb_channels == 2 )
202 val.i_int = AOUT_VAR_STEREO;
203 text.psz_string = _("Stereo");
204 var_Change( p_aout, "audio-device", VLC_VAR_ADDCHOICE, &val, &text );
208 i_format = AFMT_S16_NE;
209 if( ioctl( p_sys->i_fd, SNDCTL_DSP_RESET, NULL ) < 0 ||
210 ioctl( p_sys->i_fd, SNDCTL_DSP_SETFMT, &i_format ) < 0 )
212 msg_Err( p_aout, "cannot reset OSS audio device" );
213 var_Destroy( p_aout, "audio-device" );
219 if( ioctl( p_sys->i_fd, SNDCTL_DSP_CHANNELS, &i_nb_channels ) >= 0
220 && i_nb_channels == 1 )
222 val.i_int = AOUT_VAR_MONO;
223 text.psz_string = _("Mono");
224 var_Change( p_aout, "audio-device", VLC_VAR_ADDCHOICE, &val, &text );
225 if ( p_aout->output.output.i_physical_channels == AOUT_CHAN_CENTER )
227 var_Set( p_aout, "audio-device", val );
231 if( ioctl( p_sys->i_fd, SNDCTL_DSP_RESET, NULL ) < 0 )
233 msg_Err( p_aout, "cannot reset OSS audio device" );
234 var_Destroy( p_aout, "audio-device" );
238 /* Test for spdif. */
239 if ( AOUT_FMT_NON_LINEAR( &p_aout->output.output ) )
243 if( ioctl( p_sys->i_fd, SNDCTL_DSP_SETFMT, &i_format ) >= 0
244 && i_format == AFMT_AC3 )
246 val.i_int = AOUT_VAR_SPDIF;
247 text.psz_string = _("A/52 over S/PDIF");
248 var_Change( p_aout, "audio-device",
249 VLC_VAR_ADDCHOICE, &val, &text );
250 if( config_GetInt( p_aout, "spdif" ) )
251 var_Set( p_aout, "audio-device", val );
253 else if( config_GetInt( p_aout, "spdif" ) )
255 msg_Warn( p_aout, "S/PDIF not supported by card" );
259 var_AddCallback( p_aout, "audio-device", aout_ChannelsRestart,
263 /*****************************************************************************
264 * Open: open the audio device (the digital sound processor)
265 *****************************************************************************
266 * This function opens the DSP as a usual non-blocking write-only file, and
267 * modifies the p_aout->p_sys->i_fd with the file's descriptor.
268 *****************************************************************************/
269 static int Open( vlc_object_t *p_this )
271 aout_instance_t * p_aout = (aout_instance_t *)p_this;
272 struct aout_sys_t * p_sys;
276 /* Allocate structure */
277 p_aout->output.p_sys = p_sys = malloc( sizeof( aout_sys_t ) );
281 /* Get device name */
282 if( (psz_device = config_GetPsz( p_aout, "oss-audio-device" )) == NULL )
284 msg_Err( p_aout, "no audio device specified (maybe /dev/dsp?)" );
289 /* Open the sound device in non-blocking mode, because ALSA's OSS
290 * emulation and some broken OSS drivers would make a blocking call
291 * wait forever until the device is available. Since this breaks the
292 * OSS spec, we immediately put it back to blocking mode if the
293 * operation was successful. */
294 p_sys->i_fd = utf8_open( psz_device, O_WRONLY | O_NDELAY );
295 if( p_sys->i_fd < 0 )
297 msg_Err( p_aout, "cannot open audio device (%s)", psz_device );
303 /* if the opening was ok, put the device back in blocking mode */
304 fcntl( p_sys->i_fd, F_SETFL,
305 fcntl( p_sys->i_fd, F_GETFL ) &~ FNDELAY );
309 p_aout->output.pf_play = Play;
311 if ( var_Type( p_aout, "audio-device" ) == 0 )
316 if ( var_Get( p_aout, "audio-device", &val ) < 0 )
318 /* Probe() has failed. */
319 close( p_sys->i_fd );
324 if ( val.i_int == AOUT_VAR_SPDIF )
326 p_aout->output.output.i_format = VLC_CODEC_SPDIFL;
328 else if ( val.i_int == AOUT_VAR_5_1 )
330 p_aout->output.output.i_format = VLC_CODEC_S16N;
331 p_aout->output.output.i_physical_channels
332 = AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_CENTER
333 | AOUT_CHAN_REARLEFT | AOUT_CHAN_REARRIGHT
336 else if ( val.i_int == AOUT_VAR_2F2R )
338 p_aout->output.output.i_format = VLC_CODEC_S16N;
339 p_aout->output.output.i_physical_channels
340 = AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT
341 | AOUT_CHAN_REARLEFT | AOUT_CHAN_REARRIGHT;
343 else if ( val.i_int == AOUT_VAR_STEREO )
345 p_aout->output.output.i_format = VLC_CODEC_S16N;
346 p_aout->output.output.i_physical_channels
347 = AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT;
349 else if ( val.i_int == AOUT_VAR_MONO )
351 p_aout->output.output.i_format = VLC_CODEC_S16N;
352 p_aout->output.output.i_physical_channels = AOUT_CHAN_CENTER;
356 /* This should not happen ! */
357 msg_Err( p_aout, "internal: can't find audio-device (%i)", val.i_int );
358 close( p_sys->i_fd );
363 var_SetBool( p_aout, "intf-change", true );
365 /* Reset the DSP device */
366 if( ioctl( p_sys->i_fd, SNDCTL_DSP_RESET, NULL ) < 0 )
368 msg_Err( p_aout, "cannot reset OSS audio device" );
369 close( p_sys->i_fd );
374 /* Set the output format */
375 if ( AOUT_FMT_NON_LINEAR( &p_aout->output.output ) )
377 int i_format = AFMT_AC3;
379 if( ioctl( p_sys->i_fd, SNDCTL_DSP_SETFMT, &i_format ) < 0
380 || i_format != AFMT_AC3 )
382 msg_Err( p_aout, "cannot reset OSS audio device" );
383 close( p_sys->i_fd );
388 p_aout->output.output.i_format = VLC_CODEC_SPDIFL;
389 p_aout->output.i_nb_samples = A52_FRAME_NB;
390 p_aout->output.output.i_bytes_per_frame = AOUT_SPDIF_SIZE;
391 p_aout->output.output.i_frame_length = A52_FRAME_NB;
393 aout_VolumeNoneInit( p_aout );
396 if ( !AOUT_FMT_NON_LINEAR( &p_aout->output.output ) )
398 unsigned int i_format = AFMT_S16_NE;
399 unsigned int i_frame_size, i_fragments;
401 unsigned int i_nb_channels;
402 audio_buf_info audio_buf;
404 if( ioctl( p_sys->i_fd, SNDCTL_DSP_SETFMT, &i_format ) < 0 )
406 msg_Err( p_aout, "cannot set audio output format" );
407 close( p_sys->i_fd );
415 p_aout->output.output.i_format = VLC_CODEC_U8;
418 p_aout->output.output.i_format = VLC_CODEC_S8;
421 p_aout->output.output.i_format = VLC_CODEC_U16L;
424 p_aout->output.output.i_format = VLC_CODEC_S16L;
427 p_aout->output.output.i_format = VLC_CODEC_U16B;
430 p_aout->output.output.i_format = VLC_CODEC_S16B;
433 msg_Err( p_aout, "OSS fell back to an unknown format (%d)",
435 close( p_sys->i_fd );
440 i_nb_channels = aout_FormatNbChannels( &p_aout->output.output );
442 /* Set the number of channels */
443 if( ioctl( p_sys->i_fd, SNDCTL_DSP_CHANNELS, &i_nb_channels ) < 0 ||
444 i_nb_channels != aout_FormatNbChannels( &p_aout->output.output ) )
446 msg_Err( p_aout, "cannot set number of audio channels (%s)",
447 aout_FormatPrintChannels( &p_aout->output.output) );
448 close( p_sys->i_fd );
453 /* Set the output rate */
454 i_rate = p_aout->output.output.i_rate;
455 if( ioctl( p_sys->i_fd, SNDCTL_DSP_SPEED, &i_rate ) < 0 )
457 msg_Err( p_aout, "cannot set audio output rate (%i)",
458 p_aout->output.output.i_rate );
459 close( p_sys->i_fd );
464 if( i_rate != p_aout->output.output.i_rate )
466 p_aout->output.output.i_rate = i_rate;
469 /* Set the fragment size */
470 aout_FormatPrepare( &p_aout->output.output );
472 /* i_fragment = xxxxyyyy where: xxxx is fragtotal
473 * 1 << yyyy is fragsize */
474 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;
476 while( i_fragments < 12 && (1U << i_fragments) < i_frame_size )
480 i_fragments |= FRAME_COUNT << 16;
481 if( ioctl( p_sys->i_fd, SNDCTL_DSP_SETFRAGMENT, &i_fragments ) < 0 )
483 msg_Warn( p_aout, "cannot set fragment size (%.8x)", i_fragments );
486 if( ioctl( p_sys->i_fd, SNDCTL_DSP_GETOSPACE, &audio_buf ) < 0 )
488 msg_Err( p_aout, "cannot get fragment size" );
489 close( p_sys->i_fd );
495 /* Number of fragments actually allocated */
496 p_aout->output.p_sys->i_fragstotal = audio_buf.fragstotal;
498 /* Maximum duration the soundcard's buffer can hold */
499 p_aout->output.p_sys->max_buffer_duration =
500 (mtime_t)audio_buf.fragstotal * audio_buf.fragsize * 1000000
501 / p_aout->output.output.i_bytes_per_frame
502 / p_aout->output.output.i_rate
503 * p_aout->output.output.i_frame_length;
505 p_aout->output.i_nb_samples = audio_buf.fragsize /
506 p_aout->output.output.i_bytes_per_frame;
509 aout_VolumeSoftInit( p_aout );
512 p_aout->output.p_sys->b_workaround_buggy_driver =
513 config_GetInt( p_aout, "oss-buggy" );
515 /* Create OSS thread and wait for its readiness. */
516 if( vlc_thread_create( p_aout, "aout", OSSThread,
517 VLC_THREAD_PRIORITY_OUTPUT ) )
519 msg_Err( p_aout, "cannot create OSS thread (%m)" );
520 close( p_sys->i_fd );
528 /*****************************************************************************
529 * Play: nothing to do
530 *****************************************************************************/
531 static void Play( aout_instance_t *p_aout )
536 /*****************************************************************************
537 * Close: close the DSP audio device
538 *****************************************************************************/
539 static void Close( vlc_object_t * p_this )
541 aout_instance_t *p_aout = (aout_instance_t *)p_this;
542 struct aout_sys_t * p_sys = p_aout->output.p_sys;
544 vlc_object_kill( p_aout );
545 vlc_thread_join( p_aout );
546 p_aout->b_die = false;
548 ioctl( p_sys->i_fd, SNDCTL_DSP_RESET, NULL );
549 close( p_sys->i_fd );
554 /*****************************************************************************
555 * BufferDuration: buffer status query
556 *****************************************************************************
557 * This function returns the duration in microseconds of the current buffer.
558 *****************************************************************************/
559 static mtime_t BufferDuration( aout_instance_t * p_aout )
561 struct aout_sys_t * p_sys = p_aout->output.p_sys;
562 audio_buf_info audio_buf;
565 /* Fill the audio_buf_info structure:
566 * - fragstotal: total number of fragments allocated
567 * - fragsize: size of a fragment in bytes
568 * - bytes: available space in bytes (includes partially used fragments)
569 * Note! 'bytes' could be more than fragments*fragsize */
570 ioctl( p_sys->i_fd, SNDCTL_DSP_GETOSPACE, &audio_buf );
572 /* calculate number of available fragments (not partially used ones) */
573 i_bytes = (audio_buf.fragstotal * audio_buf.fragsize) - audio_buf.bytes;
575 /* Return the fragment duration */
576 return (mtime_t)i_bytes * 1000000
577 / p_aout->output.output.i_bytes_per_frame
578 / p_aout->output.output.i_rate
579 * p_aout->output.output.i_frame_length;
582 /*****************************************************************************
583 * OSSThread: asynchronous thread used to DMA the data to the device
584 *****************************************************************************/
585 static void* OSSThread( vlc_object_t *p_this )
587 aout_instance_t * p_aout = (aout_instance_t*)p_this;
588 struct aout_sys_t * p_sys = p_aout->output.p_sys;
589 mtime_t next_date = 0;
590 int canc = vlc_savecancel ();
592 while ( vlc_object_alive (p_aout) )
594 aout_buffer_t * p_buffer = NULL;
598 if ( p_aout->output.output.i_format != VLC_CODEC_SPDIFL )
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 ) ) )
652 msleep( VLC_HARD_MIN_SLEEP );
657 if ( p_buffer != NULL )
659 p_bytes = p_buffer->p_buffer;
660 i_size = p_buffer->i_buffer;
661 /* This is theoretical ... we'll see next iteration whether
663 next_date += p_buffer->i_length;
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 );
691 vlc_restorecancel (canc);