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 *****************************************************************************/
29 #include <errno.h> /* ENOMEM */
30 #include <fcntl.h> /* open(), O_WRONLY */
31 #include <sys/ioctl.h> /* ioctl() */
32 #include <unistd.h> /* write(), close() */
42 /* SNDCTL_DSP_RESET, SNDCTL_DSP_SETFMT, SNDCTL_DSP_STEREO, SNDCTL_DSP_SPEED,
43 * SNDCTL_DSP_GETOSPACE */
44 #ifdef HAVE_SOUNDCARD_H
45 # include <soundcard.h>
46 #elif defined( HAVE_SYS_SOUNDCARD_H )
47 # include <sys/soundcard.h>
48 #elif defined( HAVE_MACHINE_SOUNDCARD_H )
49 # include <machine/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 int OSSThread ( aout_instance_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( _("UNIX OSS audio output") );
107 set_category( CAT_AUDIO );
108 set_subcategory( SUBCAT_AUDIO_AOUT );
109 add_file( "dspdev", "/dev/dsp", aout_FindAndRestart,
110 N_("OSS DSP device"), NULL, VLC_FALSE );
111 add_bool( "oss-buggy", 0, NULL, BUGGY_TEXT, BUGGY_LONGTEXT, VLC_TRUE );
113 set_capability( "audio output", 100 );
114 add_shortcut( "oss" );
115 set_callbacks( Open, Close );
118 /*****************************************************************************
119 * Probe: probe the audio device for available formats and channels
120 *****************************************************************************/
121 static void Probe( aout_instance_t * p_aout )
123 struct aout_sys_t * p_sys = p_aout->output.p_sys;
124 vlc_value_t val, text;
125 int i_format, i_nb_channels;
127 var_Create( p_aout, "audio-device", VLC_VAR_INTEGER | VLC_VAR_HASCHOICE );
128 text.psz_string = _("Audio Device");
129 var_Change( p_aout, "audio-device", VLC_VAR_SETTEXT, &text, NULL );
131 /* Test for multi-channel. */
132 #ifdef SNDCTL_DSP_GETCHANNELMASK
133 if ( aout_FormatNbChannels( &p_aout->output.output ) > 2 )
135 /* Check that the device supports this. */
140 i_format = AFMT_S16_NE;
141 if( ioctl( p_sys->i_fd, SNDCTL_DSP_RESET, NULL ) < 0 ||
142 ioctl( p_sys->i_fd, SNDCTL_DSP_SETFMT, &i_format ) < 0 )
144 msg_Err( p_aout, "cannot reset OSS audio device" );
145 var_Destroy( p_aout, "audio-device" );
149 if ( ioctl( p_sys->i_fd, SNDCTL_DSP_GETCHANNELMASK,
152 if ( !(i_chanmask & DSP_BIND_FRONT) )
154 msg_Err( p_aout, "no front channels! (%x)",
159 if ( (i_chanmask & (DSP_BIND_SURR | DSP_BIND_CENTER_LFE))
160 && (p_aout->output.output.i_physical_channels ==
161 (AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_CENTER
162 | AOUT_CHAN_REARLEFT | AOUT_CHAN_REARRIGHT
165 val.i_int = AOUT_VAR_5_1;
166 text.psz_string = "5.1";
167 var_Change( p_aout, "audio-device",
168 VLC_VAR_ADDCHOICE, &val, &text );
171 if ( (i_chanmask & DSP_BIND_SURR)
172 && (p_aout->output.output.i_physical_channels &
173 (AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT
174 | AOUT_CHAN_REARLEFT | AOUT_CHAN_REARRIGHT)) )
176 val.i_int = AOUT_VAR_2F2R;
177 text.psz_string = N_("2 Front 2 Rear");
178 var_Change( p_aout, "audio-device",
179 VLC_VAR_ADDCHOICE, &val, &text );
186 i_format = AFMT_S16_NE;
187 if( ioctl( p_sys->i_fd, SNDCTL_DSP_RESET, NULL ) < 0 ||
188 ioctl( p_sys->i_fd, SNDCTL_DSP_SETFMT, &i_format ) < 0 )
190 msg_Err( p_aout, "cannot reset OSS audio device" );
191 var_Destroy( p_aout, "audio-device" );
195 /* Test for stereo. */
197 if( ioctl( p_sys->i_fd, SNDCTL_DSP_CHANNELS, &i_nb_channels ) >= 0
198 && i_nb_channels == 2 )
200 val.i_int = AOUT_VAR_STEREO;
201 text.psz_string = N_("Stereo");
202 var_Change( p_aout, "audio-device", VLC_VAR_ADDCHOICE, &val, &text );
206 i_format = AFMT_S16_NE;
207 if( ioctl( p_sys->i_fd, SNDCTL_DSP_RESET, NULL ) < 0 ||
208 ioctl( p_sys->i_fd, SNDCTL_DSP_SETFMT, &i_format ) < 0 )
210 msg_Err( p_aout, "cannot reset OSS audio device" );
211 var_Destroy( p_aout, "audio-device" );
217 if( ioctl( p_sys->i_fd, SNDCTL_DSP_CHANNELS, &i_nb_channels ) >= 0
218 && i_nb_channels == 1 )
220 val.i_int = AOUT_VAR_MONO;
221 text.psz_string = N_("Mono");
222 var_Change( p_aout, "audio-device", VLC_VAR_ADDCHOICE, &val, &text );
223 if ( p_aout->output.output.i_physical_channels == AOUT_CHAN_CENTER )
225 var_Set( p_aout, "audio-device", val );
229 if( ioctl( p_sys->i_fd, SNDCTL_DSP_RESET, NULL ) < 0 )
231 msg_Err( p_aout, "cannot reset OSS audio device" );
232 var_Destroy( p_aout, "audio-device" );
236 /* Test for spdif. */
237 if ( AOUT_FMT_NON_LINEAR( &p_aout->output.output ) )
241 if( ioctl( p_sys->i_fd, SNDCTL_DSP_SETFMT, &i_format ) >= 0
242 && i_format == AFMT_AC3 )
244 val.i_int = AOUT_VAR_SPDIF;
245 text.psz_string = N_("A/52 over S/PDIF");
246 var_Change( p_aout, "audio-device",
247 VLC_VAR_ADDCHOICE, &val, &text );
248 if( config_GetInt( p_aout, "spdif" ) )
249 var_Set( p_aout, "audio-device", val );
251 else if( config_GetInt( p_aout, "spdif" ) )
253 msg_Warn( p_aout, "S/PDIF not supported by card" );
257 var_AddCallback( p_aout, "audio-device", aout_ChannelsRestart,
261 /*****************************************************************************
262 * Open: open the audio device (the digital sound processor)
263 *****************************************************************************
264 * This function opens the DSP as a usual non-blocking write-only file, and
265 * modifies the p_aout->p_sys->i_fd with the file's descriptor.
266 *****************************************************************************/
267 static int Open( vlc_object_t *p_this )
269 aout_instance_t * p_aout = (aout_instance_t *)p_this;
270 struct aout_sys_t * p_sys;
274 /* Allocate structure */
275 p_aout->output.p_sys = p_sys = malloc( sizeof( aout_sys_t ) );
278 msg_Err( p_aout, "out of memory" );
282 /* Get device name */
283 if( (psz_device = config_GetPsz( p_aout, "dspdev" )) == NULL )
285 msg_Err( p_aout, "no audio device specified (maybe /dev/dsp?)" );
290 /* Open the sound device in non-blocking mode, because ALSA's OSS
291 * emulation and some broken OSS drivers would make a blocking call
292 * wait forever until the device is available. Since this breaks the
293 * OSS spec, we immediately put it back to blocking mode if the
294 * operation was successful. */
295 p_sys->i_fd = open( psz_device, O_WRONLY | O_NDELAY );
296 if( p_sys->i_fd < 0 )
298 msg_Err( p_aout, "cannot open audio device (%s)", psz_device );
303 /* if the opening was ok, put the device back in blocking mode */
304 fcntl( p_sys->i_fd, F_SETFL,
305 fcntl( p_sys->i_fd, F_GETFL ) &~ FNDELAY );
309 p_aout->output.pf_play = Play;
311 if ( var_Type( p_aout, "audio-device" ) == 0 )
316 if ( var_Get( p_aout, "audio-device", &val ) < 0 )
318 /* Probe() has failed. */
323 if ( val.i_int == AOUT_VAR_SPDIF )
325 p_aout->output.output.i_format = VLC_FOURCC('s','p','d','i');
327 else if ( val.i_int == AOUT_VAR_5_1 )
329 p_aout->output.output.i_format = AOUT_FMT_S16_NE;
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 = AOUT_FMT_S16_NE;
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 = AOUT_FMT_S16_NE;
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 = AOUT_FMT_S16_NE;
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 (%i)", val.i_int );
361 val.b_bool = VLC_TRUE;
362 var_Set( p_aout, "intf-change", val );
364 /* Reset the DSP device */
365 if( ioctl( p_sys->i_fd, SNDCTL_DSP_RESET, NULL ) < 0 )
367 msg_Err( p_aout, "cannot reset OSS audio device" );
368 close( p_sys->i_fd );
373 /* Set the output format */
374 if ( AOUT_FMT_NON_LINEAR( &p_aout->output.output ) )
376 int i_format = AFMT_AC3;
378 if( ioctl( p_sys->i_fd, SNDCTL_DSP_SETFMT, &i_format ) < 0
379 || i_format != AFMT_AC3 )
381 msg_Err( p_aout, "cannot reset OSS audio device" );
382 close( p_sys->i_fd );
387 p_aout->output.output.i_format = VLC_FOURCC('s','p','d','i');
388 p_aout->output.i_nb_samples = A52_FRAME_NB;
389 p_aout->output.output.i_bytes_per_frame = AOUT_SPDIF_SIZE;
390 p_aout->output.output.i_frame_length = A52_FRAME_NB;
392 aout_VolumeNoneInit( p_aout );
395 if ( !AOUT_FMT_NON_LINEAR( &p_aout->output.output ) )
397 unsigned int i_format = AFMT_S16_NE;
398 unsigned int i_frame_size, i_fragments;
400 unsigned int i_nb_channels;
401 audio_buf_info audio_buf;
403 if( ioctl( p_sys->i_fd, SNDCTL_DSP_SETFMT, &i_format ) < 0 )
405 msg_Err( p_aout, "cannot set audio output format" );
406 close( p_sys->i_fd );
414 p_aout->output.output.i_format = VLC_FOURCC('u','8',' ',' ');
417 p_aout->output.output.i_format = VLC_FOURCC('s','8',' ',' ');
420 p_aout->output.output.i_format = VLC_FOURCC('u','1','6','l');
423 p_aout->output.output.i_format = VLC_FOURCC('s','1','6','l');
426 p_aout->output.output.i_format = VLC_FOURCC('u','1','6','b');
429 p_aout->output.output.i_format = VLC_FOURCC('s','1','6','b');
432 msg_Err( p_aout, "OSS fell back to an unknown format (%d)",
434 close( p_sys->i_fd );
439 i_nb_channels = aout_FormatNbChannels( &p_aout->output.output );
441 /* Set the number of channels */
442 if( ioctl( p_sys->i_fd, SNDCTL_DSP_CHANNELS, &i_nb_channels ) < 0 ||
443 i_nb_channels != aout_FormatNbChannels( &p_aout->output.output ) )
445 msg_Err( p_aout, "cannot set number of audio channels (%s)",
446 aout_FormatPrintChannels( &p_aout->output.output) );
447 close( p_sys->i_fd );
452 /* Set the output rate */
453 i_rate = p_aout->output.output.i_rate;
454 if( ioctl( p_sys->i_fd, SNDCTL_DSP_SPEED, &i_rate ) < 0 )
456 msg_Err( p_aout, "cannot set audio output rate (%i)",
457 p_aout->output.output.i_rate );
458 close( p_sys->i_fd );
463 if( i_rate != p_aout->output.output.i_rate )
465 p_aout->output.output.i_rate = i_rate;
468 /* Set the fragment size */
469 aout_FormatPrepare( &p_aout->output.output );
471 /* i_fragment = xxxxyyyy where: xxxx is fragtotal
472 * 1 << yyyy is fragsize */
473 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;
475 while( i_fragments < 12 && (1U << i_fragments) < i_frame_size )
479 i_fragments |= FRAME_COUNT << 16;
480 if( ioctl( p_sys->i_fd, SNDCTL_DSP_SETFRAGMENT, &i_fragments ) < 0 )
482 msg_Warn( p_aout, "cannot set fragment size (%.8x)", i_fragments );
485 if( ioctl( p_sys->i_fd, SNDCTL_DSP_GETOSPACE, &audio_buf ) < 0 )
487 msg_Err( p_aout, "cannot get fragment size" );
488 close( p_sys->i_fd );
494 /* Number of fragments actually allocated */
495 p_aout->output.p_sys->i_fragstotal = audio_buf.fragstotal;
497 /* Maximum duration the soundcard's buffer can hold */
498 p_aout->output.p_sys->max_buffer_duration =
499 (mtime_t)audio_buf.fragstotal * audio_buf.fragsize * 1000000
500 / p_aout->output.output.i_bytes_per_frame
501 / p_aout->output.output.i_rate
502 * p_aout->output.output.i_frame_length;
504 p_aout->output.i_nb_samples = audio_buf.fragsize /
505 p_aout->output.output.i_bytes_per_frame;
508 aout_VolumeSoftInit( p_aout );
511 p_aout->output.p_sys->b_workaround_buggy_driver =
512 config_GetInt( p_aout, "oss-buggy" );
514 /* Create OSS thread and wait for its readiness. */
515 if( vlc_thread_create( p_aout, "aout", OSSThread,
516 VLC_THREAD_PRIORITY_OUTPUT, VLC_FALSE ) )
518 msg_Err( p_aout, "cannot create OSS thread (%m)" );
519 close( p_sys->i_fd );
527 /*****************************************************************************
528 * Play: nothing to do
529 *****************************************************************************/
530 static void Play( aout_instance_t *p_aout )
534 /*****************************************************************************
535 * Close: close the DSP audio device
536 *****************************************************************************/
537 static void Close( vlc_object_t * p_this )
539 aout_instance_t *p_aout = (aout_instance_t *)p_this;
540 struct aout_sys_t * p_sys = p_aout->output.p_sys;
542 vlc_object_kill( p_aout );
543 vlc_thread_join( p_aout );
544 p_aout->b_die = VLC_FALSE;
546 ioctl( p_sys->i_fd, SNDCTL_DSP_RESET, NULL );
547 close( p_sys->i_fd );
552 /*****************************************************************************
553 * BufferDuration: buffer status query
554 *****************************************************************************
555 * This function returns the duration in microseconds of the current buffer.
556 *****************************************************************************/
557 static mtime_t BufferDuration( aout_instance_t * p_aout )
559 struct aout_sys_t * p_sys = p_aout->output.p_sys;
560 audio_buf_info audio_buf;
563 /* Fill the audio_buf_info structure:
564 * - fragstotal: total number of fragments allocated
565 * - fragsize: size of a fragment in bytes
566 * - bytes: available space in bytes (includes partially used fragments)
567 * Note! 'bytes' could be more than fragments*fragsize */
568 ioctl( p_sys->i_fd, SNDCTL_DSP_GETOSPACE, &audio_buf );
570 /* calculate number of available fragments (not partially used ones) */
571 i_bytes = (audio_buf.fragstotal * audio_buf.fragsize) - audio_buf.bytes;
573 /* Return the fragment duration */
574 return (mtime_t)i_bytes * 1000000
575 / p_aout->output.output.i_bytes_per_frame
576 / p_aout->output.output.i_rate
577 * p_aout->output.output.i_frame_length;
580 /*****************************************************************************
581 * OSSThread: asynchronous thread used to DMA the data to the device
582 *****************************************************************************/
583 static int OSSThread( aout_instance_t * p_aout )
585 struct aout_sys_t * p_sys = p_aout->output.p_sys;
586 mtime_t next_date = 0;
588 while ( !p_aout->b_die )
590 aout_buffer_t * p_buffer = NULL;
594 if ( p_aout->output.output.i_format != VLC_FOURCC('s','p','d','i') )
596 mtime_t buffered = BufferDuration( p_aout );
598 if( p_aout->output.p_sys->b_workaround_buggy_driver )
600 #define i_fragstotal p_aout->output.p_sys->i_fragstotal
601 /* Wait a bit - we don't want our buffer to be full */
602 if( buffered > (p_aout->output.p_sys->max_buffer_duration
603 / i_fragstotal * (i_fragstotal - 1)) )
605 msleep((p_aout->output.p_sys->max_buffer_duration
607 buffered = BufferDuration( p_aout );
612 /* Next buffer will be played at mdate() + buffered */
613 p_buffer = aout_OutputNextBuffer( p_aout, mdate() + buffered,
616 if( p_buffer == NULL &&
617 buffered > ( p_aout->output.p_sys->max_buffer_duration
618 / p_aout->output.p_sys->i_fragstotal ) )
620 /* If we have at least a fragment full, then we can wait a
621 * little and retry to get a new audio buffer instead of
622 * playing a blank sample */
623 msleep( ( p_aout->output.p_sys->max_buffer_duration
624 / p_aout->output.p_sys->i_fragstotal / 2 ) );
630 /* emu10k1 driver does not report Buffer Duration correctly in
631 * passthrough mode so we have to cheat */
638 mtime_t delay = next_date - mdate();
639 if( delay > AOUT_PTS_TOLERANCE )
645 while( !p_aout->b_die && ! ( p_buffer =
646 aout_OutputNextBuffer( p_aout, next_date, VLC_TRUE ) ) )
653 if ( p_buffer != NULL )
655 p_bytes = p_buffer->p_buffer;
656 i_size = p_buffer->i_nb_bytes;
657 /* This is theoretical ... we'll see next iteration whether
659 next_date += p_buffer->end_date - p_buffer->start_date;
663 i_size = FRAME_SIZE / p_aout->output.output.i_frame_length
664 * p_aout->output.output.i_bytes_per_frame;
665 p_bytes = malloc( i_size );
666 memset( p_bytes, 0, i_size );
670 i_tmp = write( p_sys->i_fd, p_bytes, i_size );
674 msg_Err( p_aout, "write failed (%m)" );
677 if ( p_buffer != NULL )
679 aout_BufferFree( p_buffer );