1 /*****************************************************************************
2 * common.c : audio output management of common data structures
3 *****************************************************************************
4 * Copyright (C) 2002-2007 the VideoLAN team
7 * Authors: Christophe Massiot <massiot@via.ecp.fr>
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 of the License, or
12 * (at your option) any later version.
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Public License for more details.
19 * You should have received a copy of the GNU General Public License
20 * along with this program; if not, write to the Free Software
21 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
22 *****************************************************************************/
24 /*****************************************************************************
26 *****************************************************************************/
33 #include <vlc_common.h>
35 #include "aout_internal.h"
39 * Instances management (internal and external)
42 #define AOUT_ASSERT_FIFO_LOCKED aout_assert_fifo_locked(p_aout, p_fifo)
43 static inline void aout_assert_fifo_locked( aout_instance_t * p_aout, aout_fifo_t * p_fifo )
46 if( p_fifo == &p_aout->output.fifo )
47 vlc_assert_locked( &p_aout->output_fifo_lock );
51 for( i = 0; i < p_aout->i_nb_inputs; i++ )
53 if( p_fifo == &p_aout->pp_inputs[i]->fifo)
55 vlc_assert_locked( &p_aout->input_fifos_lock );
59 if( i == p_aout->i_nb_inputs )
60 vlc_assert_locked( &p_aout->mixer_lock );
69 static void aout_Destructor( vlc_object_t * p_this );
71 /*****************************************************************************
72 * aout_New: initialize aout structure
73 *****************************************************************************/
74 aout_instance_t * __aout_New( vlc_object_t * p_parent )
76 aout_instance_t * p_aout;
79 /* Allocate descriptor. */
80 p_aout = vlc_object_create( p_parent, VLC_OBJECT_AOUT );
86 /* Initialize members. */
87 vlc_mutex_init( &p_aout->input_fifos_lock );
88 vlc_mutex_init( &p_aout->mixer_lock );
89 vlc_mutex_init( &p_aout->output_fifo_lock );
90 p_aout->i_nb_inputs = 0;
91 p_aout->mixer.f_multiplier = 1.0;
92 p_aout->mixer.b_error = 1;
93 p_aout->output.b_error = 1;
94 p_aout->output.b_starving = 1;
96 var_Create( p_aout, "intf-change", VLC_VAR_BOOL );
98 var_Set( p_aout, "intf-change", val );
100 vlc_object_set_destructor( p_aout, aout_Destructor );
105 /*****************************************************************************
106 * aout_Destructor: destroy aout structure
107 *****************************************************************************/
108 static void aout_Destructor( vlc_object_t * p_this )
110 aout_instance_t * p_aout = (aout_instance_t *)p_this;
111 vlc_mutex_destroy( &p_aout->input_fifos_lock );
112 vlc_mutex_destroy( &p_aout->mixer_lock );
113 vlc_mutex_destroy( &p_aout->output_fifo_lock );
118 * Formats management (internal and external)
121 /*****************************************************************************
122 * aout_FormatNbChannels : return the number of channels
123 *****************************************************************************/
124 unsigned int aout_FormatNbChannels( const audio_sample_format_t * p_format )
126 static const uint32_t pi_channels[] =
127 { AOUT_CHAN_CENTER, AOUT_CHAN_LEFT, AOUT_CHAN_RIGHT,
128 AOUT_CHAN_REARCENTER, AOUT_CHAN_REARLEFT, AOUT_CHAN_REARRIGHT,
129 AOUT_CHAN_MIDDLELEFT, AOUT_CHAN_MIDDLERIGHT, AOUT_CHAN_LFE };
130 unsigned int i_nb = 0, i;
132 for ( i = 0; i < sizeof(pi_channels)/sizeof(uint32_t); i++ )
134 if ( p_format->i_physical_channels & pi_channels[i] ) i_nb++;
140 /*****************************************************************************
141 * aout_BitsPerSample : get the number of bits per sample
142 *****************************************************************************/
143 unsigned int aout_BitsPerSample( vlc_fourcc_t i_format )
173 /* For these formats the caller has to indicate the parameters
179 /*****************************************************************************
180 * aout_FormatPrepare : compute the number of bytes per frame & frame length
181 *****************************************************************************/
182 void aout_FormatPrepare( audio_sample_format_t * p_format )
184 p_format->i_bitspersample = aout_BitsPerSample( p_format->i_format );
185 if( p_format->i_bitspersample > 0 )
187 p_format->i_bytes_per_frame = ( p_format->i_bitspersample / 8 )
188 * aout_FormatNbChannels( p_format );
189 p_format->i_frame_length = 1;
193 /*****************************************************************************
194 * aout_FormatPrintChannels : print a channel in a human-readable form
195 *****************************************************************************/
196 const char * aout_FormatPrintChannels( const audio_sample_format_t * p_format )
198 switch ( p_format->i_physical_channels & AOUT_CHAN_PHYSMASK )
201 case AOUT_CHAN_RIGHT:
202 case AOUT_CHAN_CENTER:
203 if ( (p_format->i_original_channels & AOUT_CHAN_CENTER)
204 || (p_format->i_original_channels
205 & (AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT)) )
207 else if ( p_format->i_original_channels & AOUT_CHAN_LEFT )
210 case AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT:
211 if ( p_format->i_original_channels & AOUT_CHAN_REVERSESTEREO )
213 if ( p_format->i_original_channels & AOUT_CHAN_DOLBYSTEREO )
214 return "Dolby/Reverse";
215 return "Stereo/Reverse";
219 if ( p_format->i_original_channels & AOUT_CHAN_DOLBYSTEREO )
221 else if ( p_format->i_original_channels & AOUT_CHAN_DUALMONO )
223 else if ( p_format->i_original_channels == AOUT_CHAN_CENTER )
224 return "Stereo/Mono";
225 else if ( !(p_format->i_original_channels & AOUT_CHAN_RIGHT) )
226 return "Stereo/Left";
227 else if ( !(p_format->i_original_channels & AOUT_CHAN_LEFT) )
228 return "Stereo/Right";
231 case AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_CENTER:
233 case AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_REARCENTER:
235 case AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_CENTER
236 | AOUT_CHAN_REARCENTER:
238 case AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT
239 | AOUT_CHAN_REARLEFT | AOUT_CHAN_REARRIGHT:
241 case AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT
242 | AOUT_CHAN_MIDDLELEFT | AOUT_CHAN_MIDDLERIGHT:
244 case AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_CENTER
245 | AOUT_CHAN_REARLEFT | AOUT_CHAN_REARRIGHT:
247 case AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_CENTER
248 | AOUT_CHAN_MIDDLELEFT | AOUT_CHAN_MIDDLERIGHT:
251 case AOUT_CHAN_CENTER | AOUT_CHAN_LFE:
252 if ( (p_format->i_original_channels & AOUT_CHAN_CENTER)
253 || (p_format->i_original_channels
254 & (AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT)) )
256 else if ( p_format->i_original_channels & AOUT_CHAN_LEFT )
259 case AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_LFE:
260 if ( p_format->i_original_channels & AOUT_CHAN_DOLBYSTEREO )
262 else if ( p_format->i_original_channels & AOUT_CHAN_DUALMONO )
263 return "Dual-mono/LFE";
264 else if ( p_format->i_original_channels == AOUT_CHAN_CENTER )
266 else if ( !(p_format->i_original_channels & AOUT_CHAN_RIGHT) )
267 return "Stereo/Left/LFE";
268 else if ( !(p_format->i_original_channels & AOUT_CHAN_LEFT) )
269 return "Stereo/Right/LFE";
271 case AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_CENTER | AOUT_CHAN_LFE:
273 case AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_REARCENTER
276 case AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_CENTER
277 | AOUT_CHAN_REARCENTER | AOUT_CHAN_LFE:
279 case AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT
280 | AOUT_CHAN_REARLEFT | AOUT_CHAN_REARRIGHT | AOUT_CHAN_LFE:
282 case AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT
283 | AOUT_CHAN_MIDDLELEFT | AOUT_CHAN_MIDDLERIGHT | AOUT_CHAN_LFE:
285 case AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_CENTER
286 | AOUT_CHAN_REARLEFT | AOUT_CHAN_REARRIGHT | AOUT_CHAN_LFE:
288 case AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_CENTER
289 | AOUT_CHAN_MIDDLELEFT | AOUT_CHAN_MIDDLERIGHT | AOUT_CHAN_LFE:
291 case AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_CENTER
292 | AOUT_CHAN_REARLEFT | AOUT_CHAN_REARRIGHT | AOUT_CHAN_MIDDLELEFT
293 | AOUT_CHAN_MIDDLERIGHT:
295 case AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_CENTER
296 | AOUT_CHAN_REARLEFT | AOUT_CHAN_REARRIGHT | AOUT_CHAN_MIDDLELEFT
297 | AOUT_CHAN_MIDDLERIGHT | AOUT_CHAN_LFE:
304 /*****************************************************************************
305 * aout_FormatPrint : print a format in a human-readable form
306 *****************************************************************************/
307 void aout_FormatPrint( aout_instance_t * p_aout, const char * psz_text,
308 const audio_sample_format_t * p_format )
310 msg_Dbg( p_aout, "%s '%4.4s' %d Hz %s frame=%d samples/%d bytes", psz_text,
311 (char *)&p_format->i_format, p_format->i_rate,
312 aout_FormatPrintChannels( p_format ),
313 p_format->i_frame_length, p_format->i_bytes_per_frame );
316 /*****************************************************************************
317 * aout_FormatsPrint : print two formats in a human-readable form
318 *****************************************************************************/
319 void aout_FormatsPrint( aout_instance_t * p_aout, const char * psz_text,
320 const audio_sample_format_t * p_format1,
321 const audio_sample_format_t * p_format2 )
323 msg_Dbg( p_aout, "%s '%4.4s'->'%4.4s' %d Hz->%d Hz %s->%s",
325 (char *)&p_format1->i_format, (char *)&p_format2->i_format,
326 p_format1->i_rate, p_format2->i_rate,
327 aout_FormatPrintChannels( p_format1 ),
328 aout_FormatPrintChannels( p_format2 ) );
333 * FIFO management (internal) - please understand that solving race conditions
334 * is _your_ job, ie. in the audio output you should own the mixer lock
335 * before calling any of these functions.
338 /*****************************************************************************
339 * aout_FifoInit : initialize the members of a FIFO
340 *****************************************************************************/
341 void aout_FifoInit( aout_instance_t * p_aout, aout_fifo_t * p_fifo,
344 AOUT_ASSERT_FIFO_LOCKED;
348 msg_Err( p_aout, "initialising fifo with zero divider" );
351 p_fifo->p_first = NULL;
352 p_fifo->pp_last = &p_fifo->p_first;
353 aout_DateInit( &p_fifo->end_date, i_rate );
356 /*****************************************************************************
357 * aout_FifoPush : push a packet into the FIFO
358 *****************************************************************************/
359 void aout_FifoPush( aout_instance_t * p_aout, aout_fifo_t * p_fifo,
360 aout_buffer_t * p_buffer )
363 AOUT_ASSERT_FIFO_LOCKED;
365 *p_fifo->pp_last = p_buffer;
366 p_fifo->pp_last = &p_buffer->p_next;
367 *p_fifo->pp_last = NULL;
368 /* Enforce the continuity of the stream. */
369 if ( aout_DateGet( &p_fifo->end_date ) )
371 p_buffer->start_date = aout_DateGet( &p_fifo->end_date );
372 p_buffer->end_date = aout_DateIncrement( &p_fifo->end_date,
373 p_buffer->i_nb_samples );
377 aout_DateSet( &p_fifo->end_date, p_buffer->end_date );
381 /*****************************************************************************
382 * aout_FifoSet : set end_date and trash all buffers (because they aren't
384 *****************************************************************************/
385 void aout_FifoSet( aout_instance_t * p_aout, aout_fifo_t * p_fifo,
388 aout_buffer_t * p_buffer;
390 AOUT_ASSERT_FIFO_LOCKED;
392 aout_DateSet( &p_fifo->end_date, date );
393 p_buffer = p_fifo->p_first;
394 while ( p_buffer != NULL )
396 aout_buffer_t * p_next = p_buffer->p_next;
397 aout_BufferFree( p_buffer );
400 p_fifo->p_first = NULL;
401 p_fifo->pp_last = &p_fifo->p_first;
404 /*****************************************************************************
405 * aout_FifoMoveDates : Move forwards or backwards all dates in the FIFO
406 *****************************************************************************/
407 void aout_FifoMoveDates( aout_instance_t * p_aout, aout_fifo_t * p_fifo,
410 aout_buffer_t * p_buffer;
412 AOUT_ASSERT_FIFO_LOCKED;
414 aout_DateMove( &p_fifo->end_date, difference );
415 p_buffer = p_fifo->p_first;
416 while ( p_buffer != NULL )
418 p_buffer->start_date += difference;
419 p_buffer->end_date += difference;
420 p_buffer = p_buffer->p_next;
424 /*****************************************************************************
425 * aout_FifoNextStart : return the current end_date
426 *****************************************************************************/
427 mtime_t aout_FifoNextStart( aout_instance_t * p_aout, aout_fifo_t * p_fifo )
430 AOUT_ASSERT_FIFO_LOCKED;
431 return aout_DateGet( &p_fifo->end_date );
434 /*****************************************************************************
435 * aout_FifoFirstDate : return the playing date of the first buffer in the
437 *****************************************************************************/
438 mtime_t aout_FifoFirstDate( aout_instance_t * p_aout, aout_fifo_t * p_fifo )
441 AOUT_ASSERT_FIFO_LOCKED;
442 return p_fifo->p_first ? p_fifo->p_first->start_date : 0;
445 /*****************************************************************************
446 * aout_FifoPop : get the next buffer out of the FIFO
447 *****************************************************************************/
448 aout_buffer_t * aout_FifoPop( aout_instance_t * p_aout, aout_fifo_t * p_fifo )
450 aout_buffer_t * p_buffer;
452 AOUT_ASSERT_FIFO_LOCKED;
454 p_buffer = p_fifo->p_first;
455 if ( p_buffer == NULL ) return NULL;
456 p_fifo->p_first = p_buffer->p_next;
457 if ( p_fifo->p_first == NULL )
459 p_fifo->pp_last = &p_fifo->p_first;
465 /*****************************************************************************
466 * aout_FifoDestroy : destroy a FIFO and its buffers
467 *****************************************************************************/
468 void aout_FifoDestroy( aout_instance_t * p_aout, aout_fifo_t * p_fifo )
470 aout_buffer_t * p_buffer;
472 AOUT_ASSERT_FIFO_LOCKED;
474 p_buffer = p_fifo->p_first;
475 while ( p_buffer != NULL )
477 aout_buffer_t * p_next = p_buffer->p_next;
478 aout_BufferFree( p_buffer );
482 p_fifo->p_first = NULL;
483 p_fifo->pp_last = &p_fifo->p_first;
488 * Date management (internal and external)
491 /*****************************************************************************
492 * aout_DateInit : set the divider of an audio_date_t
493 *****************************************************************************/
494 void aout_DateInit( audio_date_t * p_date, uint32_t i_divider )
497 p_date->i_divider = i_divider;
498 p_date->i_remainder = 0;
501 /*****************************************************************************
502 * aout_DateSet : set the date of an audio_date_t
503 *****************************************************************************/
504 void aout_DateSet( audio_date_t * p_date, mtime_t new_date )
506 p_date->date = new_date;
507 p_date->i_remainder = 0;
510 /*****************************************************************************
511 * aout_DateMove : move forwards or backwards the date of an audio_date_t
512 *****************************************************************************/
513 void aout_DateMove( audio_date_t * p_date, mtime_t difference )
515 p_date->date += difference;
518 /*****************************************************************************
519 * aout_DateGet : get the date of an audio_date_t
520 *****************************************************************************/
521 mtime_t aout_DateGet( const audio_date_t * p_date )
526 /*****************************************************************************
527 * aout_DateIncrement : increment the date and return the result, taking
528 * into account rounding errors
529 *****************************************************************************/
530 mtime_t aout_DateIncrement( audio_date_t * p_date, uint32_t i_nb_samples )
532 mtime_t i_dividend = INT64_C(1000000) * i_nb_samples;
533 assert( p_date->i_divider > 0 ); /* uninitialized audio_data_t ? */
534 p_date->date += i_dividend / p_date->i_divider;
535 p_date->i_remainder += (int)(i_dividend % p_date->i_divider);
536 if ( p_date->i_remainder >= p_date->i_divider )
538 /* This is Bresenham algorithm. */
540 p_date->i_remainder -= p_date->i_divider;
545 /*****************************************************************************
546 * aout_CheckChannelReorder : Check if we need to do some channel re-ordering
547 *****************************************************************************/
548 int aout_CheckChannelReorder( const uint32_t *pi_chan_order_in,
549 const uint32_t *pi_chan_order_out,
550 uint32_t i_channel_mask,
551 int i_channels, int *pi_chan_table )
553 bool b_chan_reorder = false;
556 if( i_channels > AOUT_CHAN_MAX )
559 if( pi_chan_order_in == NULL )
560 pi_chan_order_in = pi_vlc_chan_order_wg4;
561 if( pi_chan_order_out == NULL )
562 pi_chan_order_out = pi_vlc_chan_order_wg4;
564 for( i = 0, j = 0; pi_chan_order_in[i]; i++ )
566 if( !(i_channel_mask & pi_chan_order_in[i]) ) continue;
568 for( k = 0, l = 0; pi_chan_order_in[i] != pi_chan_order_out[k]; k++ )
570 if( i_channel_mask & pi_chan_order_out[k] ) l++;
573 pi_chan_table[j++] = l;
576 for( i = 0; i < i_channels; i++ )
578 if( pi_chan_table[i] != i ) b_chan_reorder = true;
581 return b_chan_reorder;
584 /*****************************************************************************
585 * aout_ChannelReorder :
586 *****************************************************************************/
587 void aout_ChannelReorder( uint8_t *p_buf, int i_buffer,
588 int i_channels, const int *pi_chan_table,
589 int i_bits_per_sample )
591 uint8_t p_tmp[AOUT_CHAN_MAX * 4];
594 if( i_bits_per_sample == 8 )
596 for( i = 0; i < i_buffer / i_channels; i++ )
598 for( j = 0; j < i_channels; j++ )
600 p_tmp[pi_chan_table[j]] = p_buf[j];
603 memcpy( p_buf, p_tmp, i_channels );
607 else if( i_bits_per_sample == 16 )
609 for( i = 0; i < i_buffer / i_channels / 2; i++ )
611 for( j = 0; j < i_channels; j++ )
613 p_tmp[2 * pi_chan_table[j]] = p_buf[2 * j];
614 p_tmp[2 * pi_chan_table[j] + 1] = p_buf[2 * j + 1];
617 memcpy( p_buf, p_tmp, 2 * i_channels );
618 p_buf += 2 * i_channels;
621 else if( i_bits_per_sample == 24 )
623 for( i = 0; i < i_buffer / i_channels / 3; i++ )
625 for( j = 0; j < i_channels; j++ )
627 p_tmp[3 * pi_chan_table[j]] = p_buf[3 * j];
628 p_tmp[3 * pi_chan_table[j] + 1] = p_buf[3 * j + 1];
629 p_tmp[3 * pi_chan_table[j] + 2] = p_buf[3 * j + 2];
632 memcpy( p_buf, p_tmp, 3 * i_channels );
633 p_buf += 3 * i_channels;
636 else if( i_bits_per_sample == 32 )
638 for( i = 0; i < i_buffer / i_channels / 4; i++ )
640 for( j = 0; j < i_channels; j++ )
642 p_tmp[4 * pi_chan_table[j]] = p_buf[4 * j];
643 p_tmp[4 * pi_chan_table[j] + 1] = p_buf[4 * j + 1];
644 p_tmp[4 * pi_chan_table[j] + 2] = p_buf[4 * j + 2];
645 p_tmp[4 * pi_chan_table[j] + 3] = p_buf[4 * j + 3];
648 memcpy( p_buf, p_tmp, 4 * i_channels );
649 p_buf += 4 * i_channels;
654 /*****************************************************************************
655 * aout_ChannelExtract:
656 *****************************************************************************/
657 static inline void ExtractChannel( uint8_t *pi_dst, int i_dst_channels,
658 const uint8_t *pi_src, int i_src_channels,
660 const int *pi_selection, int i_bytes )
662 for( int i = 0; i < i_sample_count; i++ )
664 for( int j = 0; j < i_dst_channels; j++ )
665 memcpy( &pi_dst[j * i_bytes], &pi_src[pi_selection[j] * i_bytes], i_bytes );
666 pi_dst += i_dst_channels * i_bytes;
667 pi_src += i_src_channels * i_bytes;
671 void aout_ChannelExtract( void *p_dst, int i_dst_channels,
672 const void *p_src, int i_src_channels,
673 int i_sample_count, const int *pi_selection, int i_bits_per_sample )
675 /* It does not work in place */
676 assert( p_dst != p_src );
678 /* Force the compiler to inline for the specific cases so it can optimize */
679 if( i_bits_per_sample == 8 )
680 ExtractChannel( p_dst, i_dst_channels, p_src, i_src_channels, i_sample_count, pi_selection, 1 );
681 else if( i_bits_per_sample == 16 )
682 ExtractChannel( p_dst, i_dst_channels, p_src, i_src_channels, i_sample_count, pi_selection, 2 );
683 else if( i_bits_per_sample == 24 )
684 ExtractChannel( p_dst, i_dst_channels, p_src, i_src_channels, i_sample_count, pi_selection, 3 );
685 else if( i_bits_per_sample == 32 )
686 ExtractChannel( p_dst, i_dst_channels, p_src, i_src_channels, i_sample_count, pi_selection, 4 );
687 else if( i_bits_per_sample == 64 )
688 ExtractChannel( p_dst, i_dst_channels, p_src, i_src_channels, i_sample_count, pi_selection, 8 );
691 bool aout_CheckChannelExtraction( int *pi_selection,
692 uint32_t *pi_layout, int *pi_channels,
693 const uint32_t pi_order_dst[AOUT_CHAN_MAX],
694 const uint32_t *pi_order_src, int i_channels )
696 const uint32_t pi_order_dual_mono[] = { AOUT_CHAN_LEFT, AOUT_CHAN_RIGHT };
697 uint32_t i_layout = 0;
699 int pi_index[AOUT_CHAN_MAX];
703 pi_order_dst = pi_vlc_chan_order_wg4;
705 /* Detect special dual mono case */
706 if( i_channels == 2 &&
707 pi_order_src[0] == AOUT_CHAN_CENTER && pi_order_src[1] == AOUT_CHAN_CENTER )
709 i_layout |= AOUT_CHAN_DUALMONO;
710 pi_order_src = pi_order_dual_mono;
714 for( int i = 0; i < i_channels; i++ )
716 /* Ignore unknown or duplicated channels or not present in output */
717 if( !pi_order_src[i] || (i_layout & pi_order_src[i]) )
720 for( int j = 0; j < AOUT_CHAN_MAX; j++ )
722 if( pi_order_dst[j] == pi_order_src[i] )
724 assert( i_out < AOUT_CHAN_MAX );
725 pi_index[i_out++] = i;
726 i_layout |= pi_order_src[i];
733 for( int i = 0, j = 0; i < AOUT_CHAN_MAX; i++ )
735 for( int k = 0; k < i_out; k++ )
737 if( pi_order_dst[i] == pi_order_src[pi_index[k]] )
739 pi_selection[j++] = pi_index[k];
745 *pi_layout = i_layout;
746 *pi_channels = i_out;
748 for( int i = 0; i < i_out; i++ )
750 if( pi_selection[i] != i )
753 return i_out == i_channels;