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 *****************************************************************************/
76 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* OSSThread ( void * );
92 static mtime_t BufferDuration( audio_output_t * p_aout );
94 /*****************************************************************************
96 *****************************************************************************/
98 set_shortname( "OSS" )
99 set_description( N_("Open Sound System") )
101 set_category( CAT_AUDIO )
102 set_subcategory( SUBCAT_AUDIO_AOUT )
103 add_loadfile( "oss-audio-device", "/dev/dsp",
104 N_("OSS DSP device"), NULL, false )
106 set_capability( "audio output", 100 )
107 add_shortcut( "oss" )
108 set_callbacks( Open, Close )
111 /*****************************************************************************
112 * Probe: probe the audio device for available formats and channels
113 *****************************************************************************/
114 static void Probe( audio_output_t * p_aout )
116 struct aout_sys_t * p_sys = p_aout->sys;
117 vlc_value_t val, text;
118 int i_format, i_nb_channels;
120 var_Create( p_aout, "audio-device", VLC_VAR_INTEGER | VLC_VAR_HASCHOICE );
121 text.psz_string = _("Audio Device");
122 var_Change( p_aout, "audio-device", VLC_VAR_SETTEXT, &text, NULL );
124 /* Test for multi-channel. */
125 #ifdef SNDCTL_DSP_GETCHANNELMASK
126 if ( aout_FormatNbChannels( &p_aout->format ) > 2 )
128 /* Check that the device supports this. */
133 i_format = AFMT_S16_NE;
134 if( ioctl( p_sys->i_fd, SNDCTL_DSP_RESET, NULL ) < 0 ||
135 ioctl( p_sys->i_fd, SNDCTL_DSP_SETFMT, &i_format ) < 0 )
137 msg_Err( p_aout, "cannot reset OSS audio device" );
138 var_Destroy( p_aout, "audio-device" );
142 if ( ioctl( p_sys->i_fd, SNDCTL_DSP_GETCHANNELMASK,
145 if ( !(i_chanmask & DSP_BIND_FRONT) )
147 msg_Err( p_aout, "no front channels! (%x)",
152 if ( (i_chanmask & (DSP_BIND_SURR | DSP_BIND_CENTER_LFE))
153 && (p_aout->format.i_physical_channels ==
154 (AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_CENTER
155 | AOUT_CHAN_REARLEFT | AOUT_CHAN_REARRIGHT
158 val.i_int = AOUT_VAR_5_1;
159 text.psz_string = (char*) "5.1";
160 var_Change( p_aout, "audio-device",
161 VLC_VAR_ADDCHOICE, &val, &text );
164 if ( (i_chanmask & DSP_BIND_SURR)
165 && (p_aout->format.i_physical_channels &
166 (AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT
167 | AOUT_CHAN_REARLEFT | AOUT_CHAN_REARRIGHT)) )
169 val.i_int = AOUT_VAR_2F2R;
170 text.psz_string = _("2 Front 2 Rear");
171 var_Change( p_aout, "audio-device",
172 VLC_VAR_ADDCHOICE, &val, &text );
179 i_format = AFMT_S16_NE;
180 if( ioctl( p_sys->i_fd, SNDCTL_DSP_RESET, NULL ) < 0 ||
181 ioctl( p_sys->i_fd, SNDCTL_DSP_SETFMT, &i_format ) < 0 )
183 msg_Err( p_aout, "cannot reset OSS audio device" );
184 var_Destroy( p_aout, "audio-device" );
188 /* Test for stereo. */
190 if( ioctl( p_sys->i_fd, SNDCTL_DSP_CHANNELS, &i_nb_channels ) >= 0
191 && i_nb_channels == 2 )
193 val.i_int = AOUT_VAR_STEREO;
194 text.psz_string = _("Stereo");
195 var_Change( p_aout, "audio-device", VLC_VAR_ADDCHOICE, &val, &text );
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.i_int = AOUT_VAR_MONO;
214 text.psz_string = _("Mono");
215 var_Change( p_aout, "audio-device", VLC_VAR_ADDCHOICE, &val, &text );
216 if ( p_aout->format.i_physical_channels == AOUT_CHAN_CENTER )
218 var_Set( p_aout, "audio-device", val );
222 if( ioctl( p_sys->i_fd, SNDCTL_DSP_RESET, NULL ) < 0 )
224 msg_Err( p_aout, "cannot reset OSS audio device" );
225 var_Destroy( p_aout, "audio-device" );
229 /* Test for spdif. */
230 if ( AOUT_FMT_SPDIF( &p_aout->format ) )
234 if( ioctl( p_sys->i_fd, SNDCTL_DSP_SETFMT, &i_format ) >= 0
235 && i_format == AFMT_AC3 )
237 val.i_int = AOUT_VAR_SPDIF;
238 text.psz_string = _("A/52 over S/PDIF");
239 var_Change( p_aout, "audio-device",
240 VLC_VAR_ADDCHOICE, &val, &text );
241 if( var_InheritBool( p_aout, "spdif" ) )
242 var_Set( p_aout, "audio-device", val );
244 else if( var_InheritBool( p_aout, "spdif" ) )
246 msg_Warn( p_aout, "S/PDIF not supported by card" );
251 /*****************************************************************************
252 * Open: open the audio device (the digital sound processor)
253 *****************************************************************************
254 * This function opens the DSP as a usual non-blocking write-only file, and
255 * modifies the p_aout->p_sys->i_fd with the file's descriptor.
256 *****************************************************************************/
257 static int Open( vlc_object_t *p_this )
259 audio_output_t * p_aout = (audio_output_t *)p_this;
260 struct aout_sys_t * p_sys;
264 /* Allocate structure */
265 p_aout->sys = p_sys = malloc( sizeof( aout_sys_t ) );
269 /* Get device name */
270 if( (psz_device = var_InheritString( p_aout, "oss-audio-device" )) == NULL )
272 msg_Err( p_aout, "no audio device specified (maybe /dev/dsp?)" );
277 /* Open the sound device in non-blocking mode, because ALSA's OSS
278 * emulation and some broken OSS drivers would make a blocking call
279 * wait forever until the device is available. Since this breaks the
280 * OSS spec, we immediately put it back to blocking mode if the
281 * operation was successful. */
282 p_sys->i_fd = vlc_open( psz_device, O_WRONLY | O_NDELAY );
283 if( p_sys->i_fd < 0 )
285 msg_Err( p_aout, "cannot open audio device (%s)", psz_device );
291 /* if the opening was ok, put the device back in blocking mode */
292 fcntl( p_sys->i_fd, F_SETFL,
293 fcntl( p_sys->i_fd, F_GETFL ) &~ FNDELAY );
297 p_aout->pf_play = aout_PacketPlay;
298 p_aout->pf_pause = aout_PacketPause;
299 p_aout->pf_flush = aout_PacketFlush;
301 if ( var_Type( p_aout, "audio-device" ) == 0 )
303 var_AddCallback( p_aout, "audio-device", aout_ChannelsRestart, NULL );
305 if ( var_Get( p_aout, "audio-device", &val ) < 0 )
306 /* Probe() has failed. */
309 if ( val.i_int == AOUT_VAR_SPDIF )
311 p_aout->format.i_format = VLC_CODEC_SPDIFL;
313 else if ( val.i_int == AOUT_VAR_5_1 )
315 p_aout->format.i_format = VLC_CODEC_S16N;
316 p_aout->format.i_physical_channels
317 = AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_CENTER
318 | AOUT_CHAN_REARLEFT | AOUT_CHAN_REARRIGHT
321 else if ( val.i_int == AOUT_VAR_2F2R )
323 p_aout->format.i_format = VLC_CODEC_S16N;
324 p_aout->format.i_physical_channels
325 = AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT
326 | AOUT_CHAN_REARLEFT | AOUT_CHAN_REARRIGHT;
328 else if ( val.i_int == AOUT_VAR_STEREO )
330 p_aout->format.i_format = VLC_CODEC_S16N;
331 p_aout->format.i_physical_channels
332 = AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT;
334 else if ( val.i_int == AOUT_VAR_MONO )
336 p_aout->format.i_format = VLC_CODEC_S16N;
337 p_aout->format.i_physical_channels = AOUT_CHAN_CENTER;
341 /* This should not happen ! */
342 msg_Err( p_aout, "internal: can't find audio-device (%"PRId64")",
347 var_TriggerCallback( p_aout, "intf-change" );
349 /* Reset the DSP device */
350 if( ioctl( p_sys->i_fd, SNDCTL_DSP_RESET, NULL ) < 0 )
352 msg_Err( p_aout, "cannot reset OSS audio device" );
356 /* Set the output format */
357 if ( AOUT_FMT_SPDIF( &p_aout->format ) )
359 int i_format = AFMT_AC3;
361 if( ioctl( p_sys->i_fd, SNDCTL_DSP_SETFMT, &i_format ) < 0
362 || i_format != AFMT_AC3 )
364 msg_Err( p_aout, "cannot reset OSS audio device" );
368 p_aout->format.i_format = VLC_CODEC_SPDIFL;
369 p_aout->format.i_bytes_per_frame = AOUT_SPDIF_SIZE;
370 p_aout->format.i_frame_length = A52_FRAME_NB;
372 aout_PacketInit( p_aout, &p_sys->packet, A52_FRAME_NB );
373 aout_VolumeNoneInit( p_aout );
377 unsigned int i_format = AFMT_S16_NE;
378 unsigned int i_frame_size, i_fragments;
380 unsigned int i_nb_channels;
381 audio_buf_info audio_buf;
383 if( ioctl( p_sys->i_fd, SNDCTL_DSP_SETFMT, &i_format ) < 0 )
385 msg_Err( p_aout, "cannot set audio output format" );
392 p_aout->format.i_format = VLC_CODEC_U8;
395 p_aout->format.i_format = VLC_CODEC_S8;
398 p_aout->format.i_format = VLC_CODEC_U16L;
401 p_aout->format.i_format = VLC_CODEC_S16L;
404 p_aout->format.i_format = VLC_CODEC_U16B;
407 p_aout->format.i_format = VLC_CODEC_S16B;
410 msg_Err( p_aout, "OSS fell back to an unknown format (%d)",
415 i_nb_channels = aout_FormatNbChannels( &p_aout->format );
417 /* Set the number of channels */
418 if( ioctl( p_sys->i_fd, SNDCTL_DSP_CHANNELS, &i_nb_channels ) < 0 ||
419 i_nb_channels != aout_FormatNbChannels( &p_aout->format ) )
421 msg_Err( p_aout, "cannot set number of audio channels (%s)",
422 aout_FormatPrintChannels( &p_aout->format) );
426 /* Set the output rate */
427 i_rate = p_aout->format.i_rate;
428 if( ioctl( p_sys->i_fd, SNDCTL_DSP_SPEED, &i_rate ) < 0 )
430 msg_Err( p_aout, "cannot set audio output rate (%i)",
431 p_aout->format.i_rate );
435 if( i_rate != p_aout->format.i_rate )
437 p_aout->format.i_rate = i_rate;
440 /* Set the fragment size */
441 aout_FormatPrepare( &p_aout->format );
443 /* i_fragment = xxxxyyyy where: xxxx is fragtotal
444 * 1 << yyyy is fragsize */
445 i_frame_size = ((uint64_t)p_aout->format.i_bytes_per_frame * p_aout->format.i_rate * 65536) / (48000 * 2 * 2) / FRAME_COUNT;
447 while( i_fragments < 12 && (1U << i_fragments) < i_frame_size )
451 i_fragments |= FRAME_COUNT << 16;
452 if( ioctl( p_sys->i_fd, SNDCTL_DSP_SETFRAGMENT, &i_fragments ) < 0 )
454 msg_Warn( p_aout, "cannot set fragment size (%.8x)", i_fragments );
457 if( ioctl( p_sys->i_fd, SNDCTL_DSP_GETOSPACE, &audio_buf ) < 0 )
459 msg_Err( p_aout, "cannot get fragment size" );
463 /* Number of fragments actually allocated */
464 p_aout->sys->i_fragstotal = audio_buf.fragstotal;
466 /* Maximum duration the soundcard's buffer can hold */
467 p_aout->sys->max_buffer_duration =
468 (mtime_t)audio_buf.fragstotal * audio_buf.fragsize * 1000000
469 / p_aout->format.i_bytes_per_frame
470 / p_aout->format.i_rate
471 * p_aout->format.i_frame_length;
473 aout_PacketInit( p_aout, &p_sys->packet,
474 audio_buf.fragsize/p_aout->format.i_bytes_per_frame );
475 aout_VolumeSoftInit( p_aout );
478 /* Create OSS thread and wait for its readiness. */
479 if( vlc_clone( &p_sys->thread, OSSThread, p_aout,
480 VLC_THREAD_PRIORITY_OUTPUT ) )
482 msg_Err( p_aout, "cannot create OSS thread (%m)" );
483 aout_PacketDestroy( p_aout );
490 var_DelCallback( p_aout, "audio-device", aout_ChannelsRestart, NULL );
491 close( p_sys->i_fd );
496 /*****************************************************************************
497 * Close: close the DSP audio device
498 *****************************************************************************/
499 static void Close( vlc_object_t * p_this )
501 audio_output_t *p_aout = (audio_output_t *)p_this;
502 struct aout_sys_t * p_sys = p_aout->sys;
504 vlc_cancel( p_sys->thread );
505 vlc_join( p_sys->thread, NULL );
506 p_aout->b_die = false;
507 var_DelCallback( p_aout, "audio-device", aout_ChannelsRestart, NULL );
509 ioctl( p_sys->i_fd, SNDCTL_DSP_RESET, NULL );
510 close( p_sys->i_fd );
512 aout_PacketDestroy( p_aout );
516 /*****************************************************************************
517 * BufferDuration: buffer status query
518 *****************************************************************************
519 * This function returns the duration in microseconds of the current buffer.
520 *****************************************************************************/
521 static mtime_t BufferDuration( audio_output_t * p_aout )
523 struct aout_sys_t * p_sys = p_aout->sys;
524 audio_buf_info audio_buf;
527 #ifdef SNDCTL_DSP_GETODELAY
528 if ( ioctl( p_sys->i_fd, SNDCTL_DSP_GETODELAY, &i_bytes ) < 0 )
531 /* Fall back to GETOSPACE and approximate latency. */
533 /* Fill the audio_buf_info structure:
534 * - fragstotal: total number of fragments allocated
535 * - fragsize: size of a fragment in bytes
536 * - bytes: available space in bytes (includes partially used fragments)
537 * Note! 'bytes' could be more than fragments*fragsize */
538 ioctl( p_sys->i_fd, SNDCTL_DSP_GETOSPACE, &audio_buf );
540 /* calculate number of available fragments (not partially used ones) */
541 i_bytes = (audio_buf.fragstotal * audio_buf.fragsize) - audio_buf.bytes;
544 /* Return the fragment duration */
545 return (mtime_t)i_bytes * 1000000
546 / p_aout->format.i_bytes_per_frame
547 / p_aout->format.i_rate
548 * p_aout->format.i_frame_length;
553 aout_buffer_t *p_buffer;
557 static void OSSThreadCleanup( void *data )
559 oss_thread_ctx_t *p_ctx = data;
560 if( p_ctx->p_buffer )
561 aout_BufferFree( p_ctx->p_buffer );
563 free( p_ctx->p_bytes );
566 /*****************************************************************************
567 * OSSThread: asynchronous thread used to DMA the data to the device
568 *****************************************************************************/
569 static void* OSSThread( void *obj )
571 audio_output_t * p_aout = (audio_output_t*)obj;
572 struct aout_sys_t * p_sys = p_aout->sys;
573 mtime_t next_date = 0;
577 aout_buffer_t * p_buffer = NULL;
579 int canc = vlc_savecancel ();
580 if ( p_aout->format.i_format != VLC_CODEC_SPDIFL )
582 mtime_t buffered = BufferDuration( p_aout );
584 /* Next buffer will be played at mdate() + buffered */
585 p_buffer = aout_PacketNext( p_aout, mdate() + buffered );
587 if( p_buffer == NULL &&
588 buffered > ( p_aout->sys->max_buffer_duration
589 / p_aout->sys->i_fragstotal ) )
591 vlc_restorecancel (canc);
592 /* If we have at least a fragment full, then we can wait a
593 * little and retry to get a new audio buffer instead of
594 * playing a blank sample */
595 msleep( ( p_aout->sys->max_buffer_duration
596 / p_aout->sys->i_fragstotal / 2 ) );
602 vlc_restorecancel (canc);
604 /* emu10k1 driver does not report Buffer Duration correctly in
605 * passthrough mode so we have to cheat */
612 mtime_t delay = next_date - mdate();
613 if( delay > AOUT_MAX_PTS_ADVANCE )
621 canc = vlc_savecancel ();
622 p_buffer = aout_PacketNext( p_aout, next_date );
625 vlc_restorecancel (canc);
627 msleep( VLC_HARD_MIN_SLEEP );
634 if ( p_buffer != NULL )
636 p_bytes = p_buffer->p_buffer;
637 i_size = p_buffer->i_buffer;
638 /* This is theoretical ... we'll see next iteration whether
640 next_date += p_buffer->i_length;
644 i_size = FRAME_SIZE / p_aout->format.i_frame_length
645 * p_aout->format.i_bytes_per_frame;
646 p_bytes = malloc( i_size );
647 memset( p_bytes, 0, i_size );
651 oss_thread_ctx_t ctx = {
652 .p_buffer = p_buffer,
656 vlc_cleanup_push( OSSThreadCleanup, &ctx );
657 vlc_restorecancel( canc );
659 int i_tmp = write( p_sys->i_fd, p_bytes, i_size );
663 msg_Err( p_aout, "write failed (%m)" );