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" );
252 /*****************************************************************************
253 * Open: open the audio device (the digital sound processor)
254 *****************************************************************************
255 * This function opens the DSP as a usual non-blocking write-only file, and
256 * modifies the p_aout->p_sys->i_fd with the file's descriptor.
257 *****************************************************************************/
258 static int Open( vlc_object_t *p_this )
260 audio_output_t * p_aout = (audio_output_t *)p_this;
261 struct aout_sys_t * p_sys;
265 /* Allocate structure */
266 p_aout->sys = p_sys = malloc( sizeof( aout_sys_t ) );
270 /* Get device name */
271 if( (psz_device = var_InheritString( p_aout, "oss-audio-device" )) == NULL )
273 msg_Err( p_aout, "no audio device specified (maybe /dev/dsp?)" );
278 /* Open the sound device in non-blocking mode, because ALSA's OSS
279 * emulation and some broken OSS drivers would make a blocking call
280 * wait forever until the device is available. Since this breaks the
281 * OSS spec, we immediately put it back to blocking mode if the
282 * operation was successful. */
283 p_sys->i_fd = vlc_open( psz_device, O_WRONLY | O_NDELAY );
284 if( p_sys->i_fd < 0 )
286 msg_Err( p_aout, "cannot open audio device (%s)", psz_device );
292 /* if the opening was ok, put the device back in blocking mode */
293 fcntl( p_sys->i_fd, F_SETFL,
294 fcntl( p_sys->i_fd, F_GETFL ) &~ FNDELAY );
298 p_aout->pf_play = aout_PacketPlay;
299 p_aout->pf_pause = aout_PacketPause;
300 p_aout->pf_flush = aout_PacketFlush;
302 if ( var_Type( p_aout, "audio-device" ) == 0 )
304 var_AddCallback( p_aout, "audio-device", aout_ChannelsRestart, NULL );
306 if ( var_Get( p_aout, "audio-device", &val ) < 0 )
307 /* Probe() has failed. */
310 if ( val.i_int == AOUT_VAR_SPDIF )
312 p_aout->format.i_format = VLC_CODEC_SPDIFL;
314 else if ( val.i_int == AOUT_VAR_5_1 )
316 p_aout->format.i_format = VLC_CODEC_S16N;
317 p_aout->format.i_physical_channels
318 = AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_CENTER
319 | AOUT_CHAN_REARLEFT | AOUT_CHAN_REARRIGHT
322 else if ( val.i_int == AOUT_VAR_2F2R )
324 p_aout->format.i_format = VLC_CODEC_S16N;
325 p_aout->format.i_physical_channels
326 = AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT
327 | AOUT_CHAN_REARLEFT | AOUT_CHAN_REARRIGHT;
329 else if ( val.i_int == AOUT_VAR_STEREO )
331 p_aout->format.i_format = VLC_CODEC_S16N;
332 p_aout->format.i_physical_channels
333 = AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT;
335 else if ( val.i_int == AOUT_VAR_MONO )
337 p_aout->format.i_format = VLC_CODEC_S16N;
338 p_aout->format.i_physical_channels = AOUT_CHAN_CENTER;
342 /* This should not happen ! */
343 msg_Err( p_aout, "internal: can't find audio-device (%"PRId64")",
348 var_TriggerCallback( p_aout, "intf-change" );
350 /* Reset the DSP device */
351 if( ioctl( p_sys->i_fd, SNDCTL_DSP_RESET, NULL ) < 0 )
353 msg_Err( p_aout, "cannot reset OSS audio device" );
357 /* Set the output format */
358 if ( AOUT_FMT_SPDIF( &p_aout->format ) )
360 int i_format = AFMT_AC3;
362 if( ioctl( p_sys->i_fd, SNDCTL_DSP_SETFMT, &i_format ) < 0
363 || i_format != AFMT_AC3 )
365 msg_Err( p_aout, "cannot reset OSS audio device" );
369 p_aout->format.i_format = VLC_CODEC_SPDIFL;
370 p_aout->format.i_bytes_per_frame = AOUT_SPDIF_SIZE;
371 p_aout->format.i_frame_length = A52_FRAME_NB;
373 aout_PacketInit( p_aout, &p_sys->packet, A52_FRAME_NB );
374 aout_VolumeNoneInit( p_aout );
378 unsigned int i_format = AFMT_S16_NE;
379 unsigned int i_frame_size, i_fragments;
381 unsigned int i_nb_channels;
382 audio_buf_info audio_buf;
384 if( ioctl( p_sys->i_fd, SNDCTL_DSP_SETFMT, &i_format ) < 0 )
386 msg_Err( p_aout, "cannot set audio output format" );
393 p_aout->format.i_format = VLC_CODEC_U8;
396 p_aout->format.i_format = VLC_CODEC_S8;
399 p_aout->format.i_format = VLC_CODEC_U16L;
402 p_aout->format.i_format = VLC_CODEC_S16L;
405 p_aout->format.i_format = VLC_CODEC_U16B;
408 p_aout->format.i_format = VLC_CODEC_S16B;
411 msg_Err( p_aout, "OSS fell back to an unknown format (%d)",
416 i_nb_channels = aout_FormatNbChannels( &p_aout->format );
418 /* Set the number of channels */
419 if( ioctl( p_sys->i_fd, SNDCTL_DSP_CHANNELS, &i_nb_channels ) < 0 ||
420 i_nb_channels != aout_FormatNbChannels( &p_aout->format ) )
422 msg_Err( p_aout, "cannot set number of audio channels (%s)",
423 aout_FormatPrintChannels( &p_aout->format) );
427 /* Set the output rate */
428 i_rate = p_aout->format.i_rate;
429 if( ioctl( p_sys->i_fd, SNDCTL_DSP_SPEED, &i_rate ) < 0 )
431 msg_Err( p_aout, "cannot set audio output rate (%i)",
432 p_aout->format.i_rate );
436 if( i_rate != p_aout->format.i_rate )
438 p_aout->format.i_rate = i_rate;
441 /* Set the fragment size */
442 aout_FormatPrepare( &p_aout->format );
444 /* i_fragment = xxxxyyyy where: xxxx is fragtotal
445 * 1 << yyyy is fragsize */
446 i_frame_size = ((uint64_t)p_aout->format.i_bytes_per_frame * p_aout->format.i_rate * 65536) / (48000 * 2 * 2) / FRAME_COUNT;
448 while( i_fragments < 12 && (1U << i_fragments) < i_frame_size )
452 i_fragments |= FRAME_COUNT << 16;
453 if( ioctl( p_sys->i_fd, SNDCTL_DSP_SETFRAGMENT, &i_fragments ) < 0 )
455 msg_Warn( p_aout, "cannot set fragment size (%.8x)", i_fragments );
458 if( ioctl( p_sys->i_fd, SNDCTL_DSP_GETOSPACE, &audio_buf ) < 0 )
460 msg_Err( p_aout, "cannot get fragment size" );
464 /* Number of fragments actually allocated */
465 p_aout->sys->i_fragstotal = audio_buf.fragstotal;
467 /* Maximum duration the soundcard's buffer can hold */
468 p_aout->sys->max_buffer_duration =
469 (mtime_t)audio_buf.fragstotal * audio_buf.fragsize * 1000000
470 / p_aout->format.i_bytes_per_frame
471 / p_aout->format.i_rate
472 * p_aout->format.i_frame_length;
474 aout_PacketInit( p_aout, &p_sys->packet,
475 audio_buf.fragsize/p_aout->format.i_bytes_per_frame );
476 aout_VolumeSoftInit( p_aout );
479 /* Create OSS thread and wait for its readiness. */
480 if( vlc_clone( &p_sys->thread, OSSThread, p_aout,
481 VLC_THREAD_PRIORITY_OUTPUT ) )
483 msg_Err( p_aout, "cannot create OSS thread (%m)" );
484 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)" );