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 Play ( audio_output_t *, block_t * );
91 static void* OSSThread ( void * );
93 static mtime_t BufferDuration( audio_output_t * p_aout );
95 /*****************************************************************************
97 *****************************************************************************/
99 set_shortname( "OSS" )
100 set_description( N_("Open Sound System") )
102 set_category( CAT_AUDIO )
103 set_subcategory( SUBCAT_AUDIO_AOUT )
104 add_loadfile( "oss-audio-device", "/dev/dsp",
105 N_("OSS DSP device"), NULL, false )
107 set_capability( "audio output", 100 )
108 add_shortcut( "oss" )
109 set_callbacks( Open, Close )
112 /*****************************************************************************
113 * Probe: probe the audio device for available formats and channels
114 *****************************************************************************/
115 static void Probe( audio_output_t * p_aout )
117 struct aout_sys_t * p_sys = p_aout->sys;
118 vlc_value_t val, text;
119 int i_format, i_nb_channels;
121 var_Create( p_aout, "audio-device", VLC_VAR_INTEGER | VLC_VAR_HASCHOICE );
122 text.psz_string = _("Audio Device");
123 var_Change( p_aout, "audio-device", VLC_VAR_SETTEXT, &text, NULL );
125 /* Test for multi-channel. */
126 #ifdef SNDCTL_DSP_GETCHANNELMASK
127 if ( aout_FormatNbChannels( &p_aout->format ) > 2 )
129 /* Check that the device supports this. */
134 i_format = AFMT_S16_NE;
135 if( ioctl( p_sys->i_fd, SNDCTL_DSP_RESET, NULL ) < 0 ||
136 ioctl( p_sys->i_fd, SNDCTL_DSP_SETFMT, &i_format ) < 0 )
138 msg_Err( p_aout, "cannot reset OSS audio device" );
139 var_Destroy( p_aout, "audio-device" );
143 if ( ioctl( p_sys->i_fd, SNDCTL_DSP_GETCHANNELMASK,
146 if ( !(i_chanmask & DSP_BIND_FRONT) )
148 msg_Err( p_aout, "no front channels! (%x)",
153 if ( (i_chanmask & (DSP_BIND_SURR | DSP_BIND_CENTER_LFE))
154 && (p_aout->format.i_physical_channels ==
155 (AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_CENTER
156 | AOUT_CHAN_REARLEFT | AOUT_CHAN_REARRIGHT
159 val.i_int = AOUT_VAR_5_1;
160 text.psz_string = (char*) "5.1";
161 var_Change( p_aout, "audio-device",
162 VLC_VAR_ADDCHOICE, &val, &text );
165 if ( (i_chanmask & DSP_BIND_SURR)
166 && (p_aout->format.i_physical_channels &
167 (AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT
168 | AOUT_CHAN_REARLEFT | AOUT_CHAN_REARRIGHT)) )
170 val.i_int = AOUT_VAR_2F2R;
171 text.psz_string = _("2 Front 2 Rear");
172 var_Change( p_aout, "audio-device",
173 VLC_VAR_ADDCHOICE, &val, &text );
180 i_format = AFMT_S16_NE;
181 if( ioctl( p_sys->i_fd, SNDCTL_DSP_RESET, NULL ) < 0 ||
182 ioctl( p_sys->i_fd, SNDCTL_DSP_SETFMT, &i_format ) < 0 )
184 msg_Err( p_aout, "cannot reset OSS audio device" );
185 var_Destroy( p_aout, "audio-device" );
189 /* Test for stereo. */
191 if( ioctl( p_sys->i_fd, SNDCTL_DSP_CHANNELS, &i_nb_channels ) >= 0
192 && i_nb_channels == 2 )
194 val.i_int = AOUT_VAR_STEREO;
195 text.psz_string = _("Stereo");
196 var_Change( p_aout, "audio-device", VLC_VAR_ADDCHOICE, &val, &text );
200 i_format = AFMT_S16_NE;
201 if( ioctl( p_sys->i_fd, SNDCTL_DSP_RESET, NULL ) < 0 ||
202 ioctl( p_sys->i_fd, SNDCTL_DSP_SETFMT, &i_format ) < 0 )
204 msg_Err( p_aout, "cannot reset OSS audio device" );
205 var_Destroy( p_aout, "audio-device" );
211 if( ioctl( p_sys->i_fd, SNDCTL_DSP_CHANNELS, &i_nb_channels ) >= 0
212 && i_nb_channels == 1 )
214 val.i_int = AOUT_VAR_MONO;
215 text.psz_string = _("Mono");
216 var_Change( p_aout, "audio-device", VLC_VAR_ADDCHOICE, &val, &text );
217 if ( p_aout->format.i_physical_channels == AOUT_CHAN_CENTER )
219 var_Set( p_aout, "audio-device", val );
223 if( ioctl( p_sys->i_fd, SNDCTL_DSP_RESET, NULL ) < 0 )
225 msg_Err( p_aout, "cannot reset OSS audio device" );
226 var_Destroy( p_aout, "audio-device" );
230 /* Test for spdif. */
231 if ( AOUT_FMT_SPDIF( &p_aout->format ) )
235 if( ioctl( p_sys->i_fd, SNDCTL_DSP_SETFMT, &i_format ) >= 0
236 && i_format == AFMT_AC3 )
238 val.i_int = AOUT_VAR_SPDIF;
239 text.psz_string = _("A/52 over S/PDIF");
240 var_Change( p_aout, "audio-device",
241 VLC_VAR_ADDCHOICE, &val, &text );
242 if( var_InheritBool( p_aout, "spdif" ) )
243 var_Set( p_aout, "audio-device", val );
245 else if( var_InheritBool( p_aout, "spdif" ) )
247 msg_Warn( p_aout, "S/PDIF not supported by card" );
251 var_AddCallback( p_aout, "audio-device", aout_ChannelsRestart,
255 /*****************************************************************************
256 * Open: open the audio device (the digital sound processor)
257 *****************************************************************************
258 * This function opens the DSP as a usual non-blocking write-only file, and
259 * modifies the p_aout->p_sys->i_fd with the file's descriptor.
260 *****************************************************************************/
261 static int Open( vlc_object_t *p_this )
263 audio_output_t * p_aout = (audio_output_t *)p_this;
264 struct aout_sys_t * p_sys;
268 /* Allocate structure */
269 p_aout->sys = p_sys = malloc( sizeof( aout_sys_t ) );
273 /* Get device name */
274 if( (psz_device = var_InheritString( p_aout, "oss-audio-device" )) == NULL )
276 msg_Err( p_aout, "no audio device specified (maybe /dev/dsp?)" );
281 /* Open the sound device in non-blocking mode, because ALSA's OSS
282 * emulation and some broken OSS drivers would make a blocking call
283 * wait forever until the device is available. Since this breaks the
284 * OSS spec, we immediately put it back to blocking mode if the
285 * operation was successful. */
286 p_sys->i_fd = vlc_open( psz_device, O_WRONLY | O_NDELAY );
287 if( p_sys->i_fd < 0 )
289 msg_Err( p_aout, "cannot open audio device (%s)", psz_device );
295 /* if the opening was ok, put the device back in blocking mode */
296 fcntl( p_sys->i_fd, F_SETFL,
297 fcntl( p_sys->i_fd, F_GETFL ) &~ FNDELAY );
301 p_aout->pf_play = aout_PacketPlay;
302 p_aout->pf_pause = aout_PacketPause;
303 p_aout->pf_flush = aout_PacketFlush;
305 if ( var_Type( p_aout, "audio-device" ) == 0 )
310 if ( var_Get( p_aout, "audio-device", &val ) < 0 )
312 /* Probe() has failed. */
313 close( p_sys->i_fd );
318 if ( val.i_int == AOUT_VAR_SPDIF )
320 p_aout->format.i_format = VLC_CODEC_SPDIFL;
322 else if ( val.i_int == AOUT_VAR_5_1 )
324 p_aout->format.i_format = VLC_CODEC_S16N;
325 p_aout->format.i_physical_channels
326 = AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_CENTER
327 | AOUT_CHAN_REARLEFT | AOUT_CHAN_REARRIGHT
330 else if ( val.i_int == AOUT_VAR_2F2R )
332 p_aout->format.i_format = VLC_CODEC_S16N;
333 p_aout->format.i_physical_channels
334 = AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT
335 | AOUT_CHAN_REARLEFT | AOUT_CHAN_REARRIGHT;
337 else if ( val.i_int == AOUT_VAR_STEREO )
339 p_aout->format.i_format = VLC_CODEC_S16N;
340 p_aout->format.i_physical_channels
341 = AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT;
343 else if ( val.i_int == AOUT_VAR_MONO )
345 p_aout->format.i_format = VLC_CODEC_S16N;
346 p_aout->format.i_physical_channels = AOUT_CHAN_CENTER;
350 /* This should not happen ! */
351 msg_Err( p_aout, "internal: can't find audio-device (%"PRId64")",
353 close( p_sys->i_fd );
358 var_TriggerCallback( p_aout, "intf-change" );
360 /* Reset the DSP device */
361 if( ioctl( p_sys->i_fd, SNDCTL_DSP_RESET, NULL ) < 0 )
363 msg_Err( p_aout, "cannot reset OSS audio device" );
364 close( p_sys->i_fd );
369 /* Set the output format */
370 if ( AOUT_FMT_SPDIF( &p_aout->format ) )
372 int i_format = AFMT_AC3;
374 if( ioctl( p_sys->i_fd, SNDCTL_DSP_SETFMT, &i_format ) < 0
375 || i_format != AFMT_AC3 )
377 msg_Err( p_aout, "cannot reset OSS audio device" );
378 close( p_sys->i_fd );
383 p_aout->format.i_format = VLC_CODEC_SPDIFL;
384 p_aout->format.i_bytes_per_frame = AOUT_SPDIF_SIZE;
385 p_aout->format.i_frame_length = A52_FRAME_NB;
387 aout_PacketInit( p_aout, &p_sys->packet, A52_FRAME_NB );
388 aout_VolumeNoneInit( p_aout );
392 unsigned int i_format = AFMT_S16_NE;
393 unsigned int i_frame_size, i_fragments;
395 unsigned int i_nb_channels;
396 audio_buf_info audio_buf;
398 if( ioctl( p_sys->i_fd, SNDCTL_DSP_SETFMT, &i_format ) < 0 )
400 msg_Err( p_aout, "cannot set audio output format" );
401 close( p_sys->i_fd );
409 p_aout->format.i_format = VLC_CODEC_U8;
412 p_aout->format.i_format = VLC_CODEC_S8;
415 p_aout->format.i_format = VLC_CODEC_U16L;
418 p_aout->format.i_format = VLC_CODEC_S16L;
421 p_aout->format.i_format = VLC_CODEC_U16B;
424 p_aout->format.i_format = VLC_CODEC_S16B;
427 msg_Err( p_aout, "OSS fell back to an unknown format (%d)",
429 close( p_sys->i_fd );
434 i_nb_channels = aout_FormatNbChannels( &p_aout->format );
436 /* Set the number of channels */
437 if( ioctl( p_sys->i_fd, SNDCTL_DSP_CHANNELS, &i_nb_channels ) < 0 ||
438 i_nb_channels != aout_FormatNbChannels( &p_aout->format ) )
440 msg_Err( p_aout, "cannot set number of audio channels (%s)",
441 aout_FormatPrintChannels( &p_aout->format) );
442 close( p_sys->i_fd );
447 /* Set the output rate */
448 i_rate = p_aout->format.i_rate;
449 if( ioctl( p_sys->i_fd, SNDCTL_DSP_SPEED, &i_rate ) < 0 )
451 msg_Err( p_aout, "cannot set audio output rate (%i)",
452 p_aout->format.i_rate );
453 close( p_sys->i_fd );
458 if( i_rate != p_aout->format.i_rate )
460 p_aout->format.i_rate = i_rate;
463 /* Set the fragment size */
464 aout_FormatPrepare( &p_aout->format );
466 /* i_fragment = xxxxyyyy where: xxxx is fragtotal
467 * 1 << yyyy is fragsize */
468 i_frame_size = ((uint64_t)p_aout->format.i_bytes_per_frame * p_aout->format.i_rate * 65536) / (48000 * 2 * 2) / FRAME_COUNT;
470 while( i_fragments < 12 && (1U << i_fragments) < i_frame_size )
474 i_fragments |= FRAME_COUNT << 16;
475 if( ioctl( p_sys->i_fd, SNDCTL_DSP_SETFRAGMENT, &i_fragments ) < 0 )
477 msg_Warn( p_aout, "cannot set fragment size (%.8x)", i_fragments );
480 if( ioctl( p_sys->i_fd, SNDCTL_DSP_GETOSPACE, &audio_buf ) < 0 )
482 msg_Err( p_aout, "cannot get fragment size" );
483 close( p_sys->i_fd );
488 /* Number of fragments actually allocated */
489 p_aout->sys->i_fragstotal = audio_buf.fragstotal;
491 /* Maximum duration the soundcard's buffer can hold */
492 p_aout->sys->max_buffer_duration =
493 (mtime_t)audio_buf.fragstotal * audio_buf.fragsize * 1000000
494 / p_aout->format.i_bytes_per_frame
495 / p_aout->format.i_rate
496 * p_aout->format.i_frame_length;
498 aout_PacketInit( p_aout, &p_sys->packet,
499 audio_buf.fragsize/p_aout->format.i_bytes_per_frame );
500 aout_VolumeSoftInit( p_aout );
503 /* Create OSS thread and wait for its readiness. */
504 if( vlc_clone( &p_sys->thread, OSSThread, p_aout,
505 VLC_THREAD_PRIORITY_OUTPUT ) )
507 msg_Err( p_aout, "cannot create OSS thread (%m)" );
508 close( p_sys->i_fd );
509 aout_PacketDestroy( p_aout );
517 /*****************************************************************************
518 * Close: close the DSP audio device
519 *****************************************************************************/
520 static void Close( vlc_object_t * p_this )
522 audio_output_t *p_aout = (audio_output_t *)p_this;
523 struct aout_sys_t * p_sys = p_aout->sys;
525 vlc_cancel( p_sys->thread );
526 vlc_join( p_sys->thread, NULL );
527 p_aout->b_die = false;
529 ioctl( p_sys->i_fd, SNDCTL_DSP_RESET, NULL );
530 close( p_sys->i_fd );
532 aout_PacketDestroy( p_aout );
536 /*****************************************************************************
537 * BufferDuration: buffer status query
538 *****************************************************************************
539 * This function returns the duration in microseconds of the current buffer.
540 *****************************************************************************/
541 static mtime_t BufferDuration( audio_output_t * p_aout )
543 struct aout_sys_t * p_sys = p_aout->sys;
544 audio_buf_info audio_buf;
547 #ifdef SNDCTL_DSP_GETODELAY
548 if ( ioctl( p_sys->i_fd, SNDCTL_DSP_GETODELAY, &i_bytes ) < 0 )
551 /* Fall back to GETOSPACE and approximate latency. */
553 /* Fill the audio_buf_info structure:
554 * - fragstotal: total number of fragments allocated
555 * - fragsize: size of a fragment in bytes
556 * - bytes: available space in bytes (includes partially used fragments)
557 * Note! 'bytes' could be more than fragments*fragsize */
558 ioctl( p_sys->i_fd, SNDCTL_DSP_GETOSPACE, &audio_buf );
560 /* calculate number of available fragments (not partially used ones) */
561 i_bytes = (audio_buf.fragstotal * audio_buf.fragsize) - audio_buf.bytes;
564 /* Return the fragment duration */
565 return (mtime_t)i_bytes * 1000000
566 / p_aout->format.i_bytes_per_frame
567 / p_aout->format.i_rate
568 * p_aout->format.i_frame_length;
573 aout_buffer_t *p_buffer;
577 static void OSSThreadCleanup( void *data )
579 oss_thread_ctx_t *p_ctx = data;
580 if( p_ctx->p_buffer )
581 aout_BufferFree( p_ctx->p_buffer );
583 free( p_ctx->p_bytes );
586 /*****************************************************************************
587 * OSSThread: asynchronous thread used to DMA the data to the device
588 *****************************************************************************/
589 static void* OSSThread( void *obj )
591 audio_output_t * p_aout = (audio_output_t*)obj;
592 struct aout_sys_t * p_sys = p_aout->sys;
593 mtime_t next_date = 0;
597 aout_buffer_t * p_buffer = NULL;
599 int canc = vlc_savecancel ();
600 if ( p_aout->format.i_format != VLC_CODEC_SPDIFL )
602 mtime_t buffered = BufferDuration( p_aout );
604 /* Next buffer will be played at mdate() + buffered */
605 p_buffer = aout_PacketNext( p_aout, mdate() + buffered );
607 if( p_buffer == NULL &&
608 buffered > ( p_aout->sys->max_buffer_duration
609 / p_aout->sys->i_fragstotal ) )
611 vlc_restorecancel (canc);
612 /* If we have at least a fragment full, then we can wait a
613 * little and retry to get a new audio buffer instead of
614 * playing a blank sample */
615 msleep( ( p_aout->sys->max_buffer_duration
616 / p_aout->sys->i_fragstotal / 2 ) );
622 vlc_restorecancel (canc);
624 /* emu10k1 driver does not report Buffer Duration correctly in
625 * passthrough mode so we have to cheat */
632 mtime_t delay = next_date - mdate();
633 if( delay > AOUT_MAX_PTS_ADVANCE )
641 canc = vlc_savecancel ();
642 p_buffer = aout_PacketNext( p_aout, next_date );
645 vlc_restorecancel (canc);
647 msleep( VLC_HARD_MIN_SLEEP );
654 if ( p_buffer != NULL )
656 p_bytes = p_buffer->p_buffer;
657 i_size = p_buffer->i_buffer;
658 /* This is theoretical ... we'll see next iteration whether
660 next_date += p_buffer->i_length;
664 i_size = FRAME_SIZE / p_aout->format.i_frame_length
665 * p_aout->format.i_bytes_per_frame;
666 p_bytes = malloc( i_size );
667 memset( p_bytes, 0, i_size );
671 oss_thread_ctx_t ctx = {
672 .p_buffer = p_buffer,
676 vlc_cleanup_push( OSSThreadCleanup, &ctx );
677 vlc_restorecancel( canc );
679 int i_tmp = write( p_sys->i_fd, p_bytes, i_size );
683 msg_Err( p_aout, "write failed (%m)" );