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 )
106 add_deprecated_alias( "dspdev" ) /* deprecated since 0.9.3 */
108 set_capability( "audio output", 100 )
109 add_shortcut( "oss" )
110 set_callbacks( Open, Close )
113 /*****************************************************************************
114 * Probe: probe the audio device for available formats and channels
115 *****************************************************************************/
116 static void Probe( audio_output_t * p_aout )
118 struct aout_sys_t * p_sys = p_aout->sys;
119 vlc_value_t val, text;
120 int i_format, i_nb_channels;
122 var_Create( p_aout, "audio-device", VLC_VAR_INTEGER | VLC_VAR_HASCHOICE );
123 text.psz_string = _("Audio Device");
124 var_Change( p_aout, "audio-device", VLC_VAR_SETTEXT, &text, NULL );
126 /* Test for multi-channel. */
127 #ifdef SNDCTL_DSP_GETCHANNELMASK
128 if ( aout_FormatNbChannels( &p_aout->format ) > 2 )
130 /* Check that the device supports this. */
135 i_format = AFMT_S16_NE;
136 if( ioctl( p_sys->i_fd, SNDCTL_DSP_RESET, NULL ) < 0 ||
137 ioctl( p_sys->i_fd, SNDCTL_DSP_SETFMT, &i_format ) < 0 )
139 msg_Err( p_aout, "cannot reset OSS audio device" );
140 var_Destroy( p_aout, "audio-device" );
144 if ( ioctl( p_sys->i_fd, SNDCTL_DSP_GETCHANNELMASK,
147 if ( !(i_chanmask & DSP_BIND_FRONT) )
149 msg_Err( p_aout, "no front channels! (%x)",
154 if ( (i_chanmask & (DSP_BIND_SURR | DSP_BIND_CENTER_LFE))
155 && (p_aout->format.i_physical_channels ==
156 (AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_CENTER
157 | AOUT_CHAN_REARLEFT | AOUT_CHAN_REARRIGHT
160 val.i_int = AOUT_VAR_5_1;
161 text.psz_string = (char*) "5.1";
162 var_Change( p_aout, "audio-device",
163 VLC_VAR_ADDCHOICE, &val, &text );
166 if ( (i_chanmask & DSP_BIND_SURR)
167 && (p_aout->format.i_physical_channels &
168 (AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT
169 | AOUT_CHAN_REARLEFT | AOUT_CHAN_REARRIGHT)) )
171 val.i_int = AOUT_VAR_2F2R;
172 text.psz_string = _("2 Front 2 Rear");
173 var_Change( p_aout, "audio-device",
174 VLC_VAR_ADDCHOICE, &val, &text );
181 i_format = AFMT_S16_NE;
182 if( ioctl( p_sys->i_fd, SNDCTL_DSP_RESET, NULL ) < 0 ||
183 ioctl( p_sys->i_fd, SNDCTL_DSP_SETFMT, &i_format ) < 0 )
185 msg_Err( p_aout, "cannot reset OSS audio device" );
186 var_Destroy( p_aout, "audio-device" );
190 /* Test for stereo. */
192 if( ioctl( p_sys->i_fd, SNDCTL_DSP_CHANNELS, &i_nb_channels ) >= 0
193 && i_nb_channels == 2 )
195 val.i_int = AOUT_VAR_STEREO;
196 text.psz_string = _("Stereo");
197 var_Change( p_aout, "audio-device", VLC_VAR_ADDCHOICE, &val, &text );
201 i_format = AFMT_S16_NE;
202 if( ioctl( p_sys->i_fd, SNDCTL_DSP_RESET, NULL ) < 0 ||
203 ioctl( p_sys->i_fd, SNDCTL_DSP_SETFMT, &i_format ) < 0 )
205 msg_Err( p_aout, "cannot reset OSS audio device" );
206 var_Destroy( p_aout, "audio-device" );
212 if( ioctl( p_sys->i_fd, SNDCTL_DSP_CHANNELS, &i_nb_channels ) >= 0
213 && i_nb_channels == 1 )
215 val.i_int = AOUT_VAR_MONO;
216 text.psz_string = _("Mono");
217 var_Change( p_aout, "audio-device", VLC_VAR_ADDCHOICE, &val, &text );
218 if ( p_aout->format.i_physical_channels == AOUT_CHAN_CENTER )
220 var_Set( p_aout, "audio-device", val );
224 if( ioctl( p_sys->i_fd, SNDCTL_DSP_RESET, NULL ) < 0 )
226 msg_Err( p_aout, "cannot reset OSS audio device" );
227 var_Destroy( p_aout, "audio-device" );
231 /* Test for spdif. */
232 if ( AOUT_FMT_NON_LINEAR( &p_aout->format ) )
236 if( ioctl( p_sys->i_fd, SNDCTL_DSP_SETFMT, &i_format ) >= 0
237 && i_format == AFMT_AC3 )
239 val.i_int = AOUT_VAR_SPDIF;
240 text.psz_string = _("A/52 over S/PDIF");
241 var_Change( p_aout, "audio-device",
242 VLC_VAR_ADDCHOICE, &val, &text );
243 if( var_InheritBool( p_aout, "spdif" ) )
244 var_Set( p_aout, "audio-device", val );
246 else if( var_InheritBool( p_aout, "spdif" ) )
248 msg_Warn( p_aout, "S/PDIF not supported by card" );
252 var_AddCallback( p_aout, "audio-device", aout_ChannelsRestart,
256 /*****************************************************************************
257 * Open: open the audio device (the digital sound processor)
258 *****************************************************************************
259 * This function opens the DSP as a usual non-blocking write-only file, and
260 * modifies the p_aout->p_sys->i_fd with the file's descriptor.
261 *****************************************************************************/
262 static int Open( vlc_object_t *p_this )
264 audio_output_t * p_aout = (audio_output_t *)p_this;
265 struct aout_sys_t * p_sys;
269 /* Allocate structure */
270 p_aout->sys = p_sys = malloc( sizeof( aout_sys_t ) );
274 /* Get device name */
275 if( (psz_device = var_InheritString( p_aout, "oss-audio-device" )) == NULL )
277 msg_Err( p_aout, "no audio device specified (maybe /dev/dsp?)" );
282 /* Open the sound device in non-blocking mode, because ALSA's OSS
283 * emulation and some broken OSS drivers would make a blocking call
284 * wait forever until the device is available. Since this breaks the
285 * OSS spec, we immediately put it back to blocking mode if the
286 * operation was successful. */
287 p_sys->i_fd = vlc_open( psz_device, O_WRONLY | O_NDELAY );
288 if( p_sys->i_fd < 0 )
290 msg_Err( p_aout, "cannot open audio device (%s)", psz_device );
296 /* if the opening was ok, put the device back in blocking mode */
297 fcntl( p_sys->i_fd, F_SETFL,
298 fcntl( p_sys->i_fd, F_GETFL ) &~ FNDELAY );
302 p_aout->pf_play = aout_PacketPlay;
303 p_aout->pf_pause = aout_PacketPause;
304 p_aout->pf_flush = aout_PacketFlush;
306 if ( var_Type( p_aout, "audio-device" ) == 0 )
311 if ( var_Get( p_aout, "audio-device", &val ) < 0 )
313 /* Probe() has failed. */
314 close( p_sys->i_fd );
319 if ( val.i_int == AOUT_VAR_SPDIF )
321 p_aout->format.i_format = VLC_CODEC_SPDIFL;
323 else if ( val.i_int == AOUT_VAR_5_1 )
325 p_aout->format.i_format = VLC_CODEC_S16N;
326 p_aout->format.i_physical_channels
327 = AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_CENTER
328 | AOUT_CHAN_REARLEFT | AOUT_CHAN_REARRIGHT
331 else if ( val.i_int == AOUT_VAR_2F2R )
333 p_aout->format.i_format = VLC_CODEC_S16N;
334 p_aout->format.i_physical_channels
335 = AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT
336 | AOUT_CHAN_REARLEFT | AOUT_CHAN_REARRIGHT;
338 else if ( val.i_int == AOUT_VAR_STEREO )
340 p_aout->format.i_format = VLC_CODEC_S16N;
341 p_aout->format.i_physical_channels
342 = AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT;
344 else if ( val.i_int == AOUT_VAR_MONO )
346 p_aout->format.i_format = VLC_CODEC_S16N;
347 p_aout->format.i_physical_channels = AOUT_CHAN_CENTER;
351 /* This should not happen ! */
352 msg_Err( p_aout, "internal: can't find audio-device (%"PRId64")",
354 close( p_sys->i_fd );
359 var_TriggerCallback( p_aout, "intf-change" );
361 /* Reset the DSP device */
362 if( ioctl( p_sys->i_fd, SNDCTL_DSP_RESET, NULL ) < 0 )
364 msg_Err( p_aout, "cannot reset OSS audio device" );
365 close( p_sys->i_fd );
370 /* Set the output format */
371 if ( AOUT_FMT_NON_LINEAR( &p_aout->format ) )
373 int i_format = AFMT_AC3;
375 if( ioctl( p_sys->i_fd, SNDCTL_DSP_SETFMT, &i_format ) < 0
376 || i_format != AFMT_AC3 )
378 msg_Err( p_aout, "cannot reset OSS audio device" );
379 close( p_sys->i_fd );
384 p_aout->format.i_format = VLC_CODEC_SPDIFL;
385 p_aout->format.i_bytes_per_frame = AOUT_SPDIF_SIZE;
386 p_aout->format.i_frame_length = A52_FRAME_NB;
388 aout_PacketInit( p_aout, &p_sys->packet, A52_FRAME_NB );
389 aout_VolumeNoneInit( p_aout );
392 if ( !AOUT_FMT_NON_LINEAR( &p_aout->format ) )
394 unsigned int i_format = AFMT_S16_NE;
395 unsigned int i_frame_size, i_fragments;
397 unsigned int i_nb_channels;
398 audio_buf_info audio_buf;
400 if( ioctl( p_sys->i_fd, SNDCTL_DSP_SETFMT, &i_format ) < 0 )
402 msg_Err( p_aout, "cannot set audio output format" );
403 close( p_sys->i_fd );
411 p_aout->format.i_format = VLC_CODEC_U8;
414 p_aout->format.i_format = VLC_CODEC_S8;
417 p_aout->format.i_format = VLC_CODEC_U16L;
420 p_aout->format.i_format = VLC_CODEC_S16L;
423 p_aout->format.i_format = VLC_CODEC_U16B;
426 p_aout->format.i_format = VLC_CODEC_S16B;
429 msg_Err( p_aout, "OSS fell back to an unknown format (%d)",
431 close( p_sys->i_fd );
436 i_nb_channels = aout_FormatNbChannels( &p_aout->format );
438 /* Set the number of channels */
439 if( ioctl( p_sys->i_fd, SNDCTL_DSP_CHANNELS, &i_nb_channels ) < 0 ||
440 i_nb_channels != aout_FormatNbChannels( &p_aout->format ) )
442 msg_Err( p_aout, "cannot set number of audio channels (%s)",
443 aout_FormatPrintChannels( &p_aout->format) );
444 close( p_sys->i_fd );
449 /* Set the output rate */
450 i_rate = p_aout->format.i_rate;
451 if( ioctl( p_sys->i_fd, SNDCTL_DSP_SPEED, &i_rate ) < 0 )
453 msg_Err( p_aout, "cannot set audio output rate (%i)",
454 p_aout->format.i_rate );
455 close( p_sys->i_fd );
460 if( i_rate != p_aout->format.i_rate )
462 p_aout->format.i_rate = i_rate;
465 /* Set the fragment size */
466 aout_FormatPrepare( &p_aout->format );
468 /* i_fragment = xxxxyyyy where: xxxx is fragtotal
469 * 1 << yyyy is fragsize */
470 i_frame_size = ((uint64_t)p_aout->format.i_bytes_per_frame * p_aout->format.i_rate * 65536) / (48000 * 2 * 2) / FRAME_COUNT;
472 while( i_fragments < 12 && (1U << i_fragments) < i_frame_size )
476 i_fragments |= FRAME_COUNT << 16;
477 if( ioctl( p_sys->i_fd, SNDCTL_DSP_SETFRAGMENT, &i_fragments ) < 0 )
479 msg_Warn( p_aout, "cannot set fragment size (%.8x)", i_fragments );
482 if( ioctl( p_sys->i_fd, SNDCTL_DSP_GETOSPACE, &audio_buf ) < 0 )
484 msg_Err( p_aout, "cannot get fragment size" );
485 close( p_sys->i_fd );
490 /* Number of fragments actually allocated */
491 p_aout->sys->i_fragstotal = audio_buf.fragstotal;
493 /* Maximum duration the soundcard's buffer can hold */
494 p_aout->sys->max_buffer_duration =
495 (mtime_t)audio_buf.fragstotal * audio_buf.fragsize * 1000000
496 / p_aout->format.i_bytes_per_frame
497 / p_aout->format.i_rate
498 * p_aout->format.i_frame_length;
500 aout_PacketInit( p_aout, &p_sys->packet,
501 audio_buf.fragsize/p_aout->format.i_bytes_per_frame );
502 aout_VolumeSoftInit( p_aout );
505 /* Create OSS thread and wait for its readiness. */
506 if( vlc_clone( &p_sys->thread, OSSThread, p_aout,
507 VLC_THREAD_PRIORITY_OUTPUT ) )
509 msg_Err( p_aout, "cannot create OSS thread (%m)" );
510 close( p_sys->i_fd );
518 /*****************************************************************************
519 * Close: close the DSP audio device
520 *****************************************************************************/
521 static void Close( vlc_object_t * p_this )
523 audio_output_t *p_aout = (audio_output_t *)p_this;
524 struct aout_sys_t * p_sys = p_aout->sys;
526 vlc_cancel( p_sys->thread );
527 vlc_join( p_sys->thread, NULL );
528 p_aout->b_die = false;
530 ioctl( p_sys->i_fd, SNDCTL_DSP_RESET, NULL );
531 close( p_sys->i_fd );
533 aout_PacketDestroy( p_aout );
537 /*****************************************************************************
538 * BufferDuration: buffer status query
539 *****************************************************************************
540 * This function returns the duration in microseconds of the current buffer.
541 *****************************************************************************/
542 static mtime_t BufferDuration( audio_output_t * p_aout )
544 struct aout_sys_t * p_sys = p_aout->sys;
545 audio_buf_info audio_buf;
548 #ifdef SNDCTL_DSP_GETODELAY
549 if ( ioctl( p_sys->i_fd, SNDCTL_DSP_GETODELAY, &i_bytes ) < 0 )
552 /* Fall back to GETOSPACE and approximate latency. */
554 /* Fill the audio_buf_info structure:
555 * - fragstotal: total number of fragments allocated
556 * - fragsize: size of a fragment in bytes
557 * - bytes: available space in bytes (includes partially used fragments)
558 * Note! 'bytes' could be more than fragments*fragsize */
559 ioctl( p_sys->i_fd, SNDCTL_DSP_GETOSPACE, &audio_buf );
561 /* calculate number of available fragments (not partially used ones) */
562 i_bytes = (audio_buf.fragstotal * audio_buf.fragsize) - audio_buf.bytes;
565 /* Return the fragment duration */
566 return (mtime_t)i_bytes * 1000000
567 / p_aout->format.i_bytes_per_frame
568 / p_aout->format.i_rate
569 * p_aout->format.i_frame_length;
574 aout_buffer_t *p_buffer;
578 static void OSSThreadCleanup( void *data )
580 oss_thread_ctx_t *p_ctx = data;
581 if( p_ctx->p_buffer )
582 aout_BufferFree( p_ctx->p_buffer );
584 free( p_ctx->p_bytes );
587 /*****************************************************************************
588 * OSSThread: asynchronous thread used to DMA the data to the device
589 *****************************************************************************/
590 static void* OSSThread( void *obj )
592 audio_output_t * p_aout = (audio_output_t*)obj;
593 struct aout_sys_t * p_sys = p_aout->sys;
594 mtime_t next_date = 0;
598 aout_buffer_t * p_buffer = NULL;
600 int canc = vlc_savecancel ();
601 if ( p_aout->format.i_format != VLC_CODEC_SPDIFL )
603 mtime_t buffered = BufferDuration( p_aout );
605 /* Next buffer will be played at mdate() + buffered */
606 p_buffer = aout_OutputNextBuffer( p_aout, mdate() + buffered,
609 if( p_buffer == NULL &&
610 buffered > ( p_aout->sys->max_buffer_duration
611 / p_aout->sys->i_fragstotal ) )
613 vlc_restorecancel (canc);
614 /* If we have at least a fragment full, then we can wait a
615 * little and retry to get a new audio buffer instead of
616 * playing a blank sample */
617 msleep( ( p_aout->sys->max_buffer_duration
618 / p_aout->sys->i_fragstotal / 2 ) );
624 vlc_restorecancel (canc);
626 /* emu10k1 driver does not report Buffer Duration correctly in
627 * passthrough mode so we have to cheat */
634 mtime_t delay = next_date - mdate();
635 if( delay > AOUT_MAX_PTS_ADVANCE )
643 canc = vlc_savecancel ();
644 p_buffer = aout_OutputNextBuffer( p_aout, next_date, true );
647 vlc_restorecancel (canc);
649 msleep( VLC_HARD_MIN_SLEEP );
656 if ( p_buffer != NULL )
658 p_bytes = p_buffer->p_buffer;
659 i_size = p_buffer->i_buffer;
660 /* This is theoretical ... we'll see next iteration whether
662 next_date += p_buffer->i_length;
666 i_size = FRAME_SIZE / p_aout->format.i_frame_length
667 * p_aout->format.i_bytes_per_frame;
668 p_bytes = malloc( i_size );
669 memset( p_bytes, 0, i_size );
673 oss_thread_ctx_t ctx = {
674 .p_buffer = p_buffer,
678 vlc_cleanup_push( OSSThreadCleanup, &ctx );
679 vlc_restorecancel( canc );
681 int i_tmp = write( p_sys->i_fd, p_bytes, i_size );
685 msg_Err( p_aout, "write failed (%m)" );