1 /*****************************************************************************
2 * audio_output.c : audio output instance miscellaneous functions
3 *****************************************************************************
4 * Copyright (C) 2002 VideoLAN
5 * $Id: audio_output.c,v 1.102 2002/09/16 20:46:38 massiot Exp $
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., 59 Temple Place - Suite 330, Boston, MA 02111, USA.
22 *****************************************************************************/
24 /*****************************************************************************
26 *****************************************************************************/
27 #include <stdlib.h> /* calloc(), malloc(), free() */
36 #include "audio_output.h"
37 #include "aout_internal.h"
40 * Instances management (see also input.c:aout_InputNew())
43 /*****************************************************************************
44 * aout_NewInstance: initialize aout structure
45 *****************************************************************************/
46 aout_instance_t * __aout_NewInstance( vlc_object_t * p_parent )
48 aout_instance_t * p_aout;
50 /* Allocate descriptor. */
51 p_aout = vlc_object_create( p_parent, VLC_OBJECT_AOUT );
57 /* Initialize members. */
58 vlc_mutex_init( p_parent, &p_aout->input_fifos_lock );
59 vlc_mutex_init( p_parent, &p_aout->mixer_lock );
60 vlc_mutex_init( p_parent, &p_aout->output_fifo_lock );
61 p_aout->i_nb_inputs = 0;
62 p_aout->mixer.f_multiplier = 1.0;
64 vlc_object_attach( p_aout, p_parent->p_vlc );
69 /*****************************************************************************
70 * aout_DeleteInstance: destroy aout structure
71 *****************************************************************************/
72 void aout_DeleteInstance( aout_instance_t * p_aout )
74 vlc_mutex_destroy( &p_aout->input_fifos_lock );
75 vlc_mutex_destroy( &p_aout->mixer_lock );
76 vlc_mutex_destroy( &p_aout->output_fifo_lock );
79 vlc_object_destroy( p_aout );
84 * Buffer management (interface to the decoders)
87 /*****************************************************************************
88 * aout_BufferNew : ask for a new empty buffer
89 *****************************************************************************/
90 aout_buffer_t * aout_BufferNew( aout_instance_t * p_aout,
91 aout_input_t * p_input,
94 aout_buffer_t * p_buffer;
95 mtime_t duration = (1000000 * (mtime_t)i_nb_samples)
96 / p_input->input.i_rate;
98 /* This necessarily allocates in the heap. */
99 aout_BufferAlloc( &p_input->input_alloc, duration, NULL, p_buffer );
100 p_buffer->i_nb_samples = i_nb_samples;
101 p_buffer->i_nb_bytes = i_nb_samples * p_input->input.i_bytes_per_frame
102 / p_input->input.i_frame_length;
104 if ( p_buffer == NULL )
106 msg_Err( p_aout, "NULL buffer !" );
110 p_buffer->start_date = p_buffer->end_date = 0;
116 /*****************************************************************************
117 * aout_BufferDelete : destroy an undecoded buffer
118 *****************************************************************************/
119 void aout_BufferDelete( aout_instance_t * p_aout, aout_input_t * p_input,
120 aout_buffer_t * p_buffer )
122 aout_BufferFree( p_buffer );
125 /*****************************************************************************
126 * aout_BufferPlay : filter & mix the decoded buffer
127 *****************************************************************************/
128 void aout_BufferPlay( aout_instance_t * p_aout, aout_input_t * p_input,
129 aout_buffer_t * p_buffer )
131 if ( p_buffer->start_date == 0 )
133 msg_Warn( p_aout, "non-dated buffer received" );
134 aout_BufferFree( p_buffer );
138 p_buffer->end_date = p_buffer->start_date
139 + (mtime_t)(p_buffer->i_nb_samples * 1000000)
140 / p_input->input.i_rate;
143 /* If the buffer is too early, wait a while. */
144 mwait( p_buffer->start_date - AOUT_MAX_PREPARE_TIME );
146 aout_InputPlay( p_aout, p_input, p_buffer );
148 /* Run the mixer if it is able to run. */
149 aout_MixerRun( p_aout );
157 /*****************************************************************************
158 * aout_FormatNbChannels : return the number of channels
159 *****************************************************************************/
160 int aout_FormatNbChannels( audio_sample_format_t * p_format )
164 switch ( p_format->i_channels & AOUT_CHAN_MASK )
166 case AOUT_CHAN_CHANNEL1:
167 case AOUT_CHAN_CHANNEL2:
172 case AOUT_CHAN_CHANNEL:
173 case AOUT_CHAN_STEREO:
174 case AOUT_CHAN_DOLBY:
196 if ( p_format->i_channels & AOUT_CHAN_LFE )
202 /*****************************************************************************
203 * aout_FormatPrepare : compute the number of bytes per frame & frame length
204 *****************************************************************************/
205 void aout_FormatPrepare( audio_sample_format_t * p_format )
209 switch ( p_format->i_format )
216 case AOUT_FMT_U16_LE:
217 case AOUT_FMT_U16_BE:
218 case AOUT_FMT_S16_LE:
219 case AOUT_FMT_S16_BE:
223 case AOUT_FMT_FLOAT32:
224 case AOUT_FMT_FIXED32:
231 /* For these formats the caller has to indicate the parameters
236 i_result = 0; /* will segfault much sooner... */
239 p_format->i_bytes_per_frame = i_result * aout_FormatNbChannels( p_format );
240 p_format->i_frame_length = 1;
245 * FIFO management (internal) - please understand that solving race conditions
246 * is _your_ job, ie. in the audio output you should own the mixer lock
247 * before calling any of these functions.
250 /*****************************************************************************
251 * aout_FifoInit : initialize the members of a FIFO
252 *****************************************************************************/
253 void aout_FifoInit( aout_instance_t * p_aout, aout_fifo_t * p_fifo,
256 p_fifo->p_first = NULL;
257 p_fifo->pp_last = &p_fifo->p_first;
258 aout_DateInit( &p_fifo->end_date, i_rate );
261 /*****************************************************************************
262 * aout_FifoPush : push a packet into the FIFO
263 *****************************************************************************/
264 void aout_FifoPush( aout_instance_t * p_aout, aout_fifo_t * p_fifo,
265 aout_buffer_t * p_buffer )
267 *p_fifo->pp_last = p_buffer;
268 p_fifo->pp_last = &p_buffer->p_next;
269 *p_fifo->pp_last = NULL;
270 /* Enforce the continuity of the stream. */
271 if ( aout_DateGet( &p_fifo->end_date ) )
273 p_buffer->start_date = aout_DateGet( &p_fifo->end_date );
274 p_buffer->end_date = aout_DateIncrement( &p_fifo->end_date,
275 p_buffer->i_nb_samples );
279 aout_DateSet( &p_fifo->end_date, p_buffer->end_date );
283 /*****************************************************************************
284 * aout_FifoSet : set end_date and trash all buffers (because they aren't
286 *****************************************************************************/
287 void aout_FifoSet( aout_instance_t * p_aout, aout_fifo_t * p_fifo,
290 aout_buffer_t * p_buffer;
292 aout_DateSet( &p_fifo->end_date, date );
293 p_buffer = p_fifo->p_first;
294 while ( p_buffer != NULL )
296 aout_buffer_t * p_next = p_buffer->p_next;
297 aout_BufferFree( p_buffer );
300 p_fifo->p_first = NULL;
301 p_fifo->pp_last = &p_fifo->p_first;
304 /*****************************************************************************
305 * aout_FifoMoveDates : Move forwards or backwards all dates in the FIFO
306 *****************************************************************************/
307 void aout_FifoMoveDates( aout_instance_t * p_aout, aout_fifo_t * p_fifo,
310 aout_buffer_t * p_buffer;
312 aout_DateMove( &p_fifo->end_date, difference );
313 p_buffer = p_fifo->p_first;
314 while ( p_buffer != NULL )
316 p_buffer->start_date += difference;
317 p_buffer->end_date += difference;
318 p_buffer = p_buffer->p_next;
322 /*****************************************************************************
323 * aout_FifoNextStart : return the current end_date
324 *****************************************************************************/
325 mtime_t aout_FifoNextStart( aout_instance_t * p_aout, aout_fifo_t * p_fifo )
327 return aout_DateGet( &p_fifo->end_date );
330 /*****************************************************************************
331 * aout_FifoPop : get the next buffer out of the FIFO
332 *****************************************************************************/
333 aout_buffer_t * aout_FifoPop( aout_instance_t * p_aout, aout_fifo_t * p_fifo )
335 aout_buffer_t * p_buffer;
336 p_buffer = p_fifo->p_first;
337 if ( p_buffer == NULL ) return NULL;
338 p_fifo->p_first = p_buffer->p_next;
339 if ( p_fifo->p_first == NULL )
341 p_fifo->pp_last = &p_fifo->p_first;
347 /*****************************************************************************
348 * aout_FifoDestroy : destroy a FIFO and its buffers
349 *****************************************************************************/
350 void aout_FifoDestroy( aout_instance_t * p_aout, aout_fifo_t * p_fifo )
352 aout_buffer_t * p_buffer;
354 p_buffer = p_fifo->p_first;
355 while ( p_buffer != NULL )
357 aout_buffer_t * p_next = p_buffer->p_next;
358 aout_BufferFree( p_buffer );
365 * Date management (internal and external)
368 /*****************************************************************************
369 * aout_DateInit : set the divider of an audio_date_t
370 *****************************************************************************/
371 void aout_DateInit( audio_date_t * p_date, u32 i_divider )
374 p_date->i_divider = i_divider;
375 p_date->i_remainder = 0;
378 /*****************************************************************************
379 * aout_DateSet : set the date of an audio_date_t
380 *****************************************************************************/
381 void aout_DateSet( audio_date_t * p_date, mtime_t new_date )
383 p_date->date = new_date;
384 p_date->i_remainder = 0;
387 /*****************************************************************************
388 * aout_DateMove : move forwards or backwards the date of an audio_date_t
389 *****************************************************************************/
390 void aout_DateMove( audio_date_t * p_date, mtime_t difference )
392 p_date->date += difference;
395 /*****************************************************************************
396 * aout_DateGet : get the date of an audio_date_t
397 *****************************************************************************/
398 mtime_t aout_DateGet( const audio_date_t * p_date )
403 /*****************************************************************************
404 * aout_DateIncrement : increment the date and return the result, taking
405 * into account rounding errors
406 *****************************************************************************/
407 mtime_t aout_DateIncrement( audio_date_t * p_date, u32 i_nb_samples )
409 mtime_t i_dividend = (mtime_t)i_nb_samples * 1000000;
410 p_date->date += i_dividend / p_date->i_divider;
411 p_date->i_remainder += i_dividend % p_date->i_divider;
412 if ( p_date->i_remainder >= p_date->i_divider )
414 /* This is Bresenham algorithm. */
416 p_date->i_remainder -= p_date->i_divider;