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 <fcntl.h> /* open(), O_WRONLY */
35 #include <sys/ioctl.h> /* ioctl() */
36 #include <unistd.h> /* write(), close() */
38 #include <vlc_common.h>
39 #include <vlc_plugin.h>
44 /* SNDCTL_DSP_RESET, SNDCTL_DSP_SETFMT, SNDCTL_DSP_STEREO, SNDCTL_DSP_SPEED,
45 * SNDCTL_DSP_GETOSPACE */
46 #ifdef HAVE_SOUNDCARD_H
47 # include <soundcard.h>
48 #elif defined( HAVE_SYS_SOUNDCARD_H )
49 # include <sys/soundcard.h>
52 /* Patches for ignorant OSS versions */
54 # define AFMT_AC3 0x00000400 /* Dolby Digital AC3 */
58 # ifdef WORDS_BIGENDIAN
59 # define AFMT_S16_NE AFMT_S16_BE
61 # define AFMT_S16_NE AFMT_S16_LE
65 /*****************************************************************************
66 * aout_sys_t: OSS 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 *****************************************************************************/
74 int b_workaround_buggy_driver
;
76 mtime_t max_buffer_duration
;
79 /* This must be a power of 2. */
80 #define FRAME_SIZE 1024
81 #define FRAME_COUNT 32
83 /*****************************************************************************
85 *****************************************************************************/
86 static int Open ( vlc_object_t
* );
87 static void Close ( vlc_object_t
* );
89 static void Play ( aout_instance_t
* );
90 static void* OSSThread ( vlc_object_t
* );
92 static mtime_t
BufferDuration( aout_instance_t
* p_aout
);
94 /*****************************************************************************
96 *****************************************************************************/
97 #define BUGGY_TEXT N_("Try to work around buggy OSS drivers")
98 #define BUGGY_LONGTEXT N_( \
99 "Some buggy OSS drivers just don't like when their internal buffers " \
100 "are completely filled (the sound gets heavily hashed). If you have one " \
101 "of these drivers, then you need to enable this option." )
104 set_shortname( "OSS" )
105 set_description( N_("UNIX OSS audio output") )
107 set_category( CAT_AUDIO
)
108 set_subcategory( SUBCAT_AUDIO_AOUT
)
109 add_file( "oss-audio-device", "/dev/dsp", aout_FindAndRestart
,
110 N_("OSS DSP device"), NULL
, false )
111 add_deprecated_alias( "dspdev" ) /* deprecated since 0.9.3 */
112 add_bool( "oss-buggy", false, NULL
, BUGGY_TEXT
, BUGGY_LONGTEXT
, true )
114 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
= (char*) "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
= _("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
= _("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
= _("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
= _("A/52 over S/PDIF");
247 var_Change( p_aout
, "audio-device",
248 VLC_VAR_ADDCHOICE
, &val
, &text
);
249 if( var_InheritBool( p_aout
, "spdif" ) )
250 var_Set( p_aout
, "audio-device", val
);
252 else if( var_InheritBool( p_aout
, "spdif" ) )
254 msg_Warn( p_aout
, "S/PDIF not supported by card" );
258 var_AddCallback( p_aout
, "audio-device", aout_ChannelsRestart
,
262 /*****************************************************************************
263 * Open: open the audio device (the digital sound processor)
264 *****************************************************************************
265 * This function opens the DSP as a usual non-blocking write-only file, and
266 * modifies the p_aout->p_sys->i_fd with the file's descriptor.
267 *****************************************************************************/
268 static int Open( vlc_object_t
*p_this
)
270 aout_instance_t
* p_aout
= (aout_instance_t
*)p_this
;
271 struct aout_sys_t
* p_sys
;
275 /* Allocate structure */
276 p_aout
->output
.p_sys
= p_sys
= malloc( sizeof( aout_sys_t
) );
280 /* Get device name */
281 if( (psz_device
= var_InheritString( p_aout
, "oss-audio-device" )) == NULL
)
283 msg_Err( p_aout
, "no audio device specified (maybe /dev/dsp?)" );
288 /* Open the sound device in non-blocking mode, because ALSA's OSS
289 * emulation and some broken OSS drivers would make a blocking call
290 * wait forever until the device is available. Since this breaks the
291 * OSS spec, we immediately put it back to blocking mode if the
292 * operation was successful. */
293 p_sys
->i_fd
= vlc_open( psz_device
, O_WRONLY
| O_NDELAY
);
294 if( p_sys
->i_fd
< 0 )
296 msg_Err( p_aout
, "cannot open audio device (%s)", psz_device
);
302 /* if the opening was ok, put the device back in blocking mode */
303 fcntl( p_sys
->i_fd
, F_SETFL
,
304 fcntl( p_sys
->i_fd
, F_GETFL
) &~ FNDELAY
);
308 p_aout
->output
.pf_play
= Play
;
310 if ( var_Type( p_aout
, "audio-device" ) == 0 )
315 if ( var_Get( p_aout
, "audio-device", &val
) < 0 )
317 /* Probe() has failed. */
318 close( p_sys
->i_fd
);
323 if ( val
.i_int
== AOUT_VAR_SPDIF
)
325 p_aout
->output
.output
.i_format
= VLC_CODEC_SPDIFL
;
327 else if ( val
.i_int
== AOUT_VAR_5_1
)
329 p_aout
->output
.output
.i_format
= VLC_CODEC_S16N
;
330 p_aout
->output
.output
.i_physical_channels
331 = AOUT_CHAN_LEFT
| AOUT_CHAN_RIGHT
| AOUT_CHAN_CENTER
332 | AOUT_CHAN_REARLEFT
| AOUT_CHAN_REARRIGHT
335 else if ( val
.i_int
== AOUT_VAR_2F2R
)
337 p_aout
->output
.output
.i_format
= VLC_CODEC_S16N
;
338 p_aout
->output
.output
.i_physical_channels
339 = AOUT_CHAN_LEFT
| AOUT_CHAN_RIGHT
340 | AOUT_CHAN_REARLEFT
| AOUT_CHAN_REARRIGHT
;
342 else if ( val
.i_int
== AOUT_VAR_STEREO
)
344 p_aout
->output
.output
.i_format
= VLC_CODEC_S16N
;
345 p_aout
->output
.output
.i_physical_channels
346 = AOUT_CHAN_LEFT
| AOUT_CHAN_RIGHT
;
348 else if ( val
.i_int
== AOUT_VAR_MONO
)
350 p_aout
->output
.output
.i_format
= VLC_CODEC_S16N
;
351 p_aout
->output
.output
.i_physical_channels
= AOUT_CHAN_CENTER
;
355 /* This should not happen ! */
356 msg_Err( p_aout
, "internal: can't find audio-device (%"PRId64
")",
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 var_InheritBool( 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
);