1 /*****************************************************************************
2 * aout_pcm.c: PCM audio output functions
3 *****************************************************************************
4 * Copyright (C) 1999-2002 VideoLAN
5 * $Id: aout_pcm.c,v 1.8 2002/06/01 12:32:01 sam Exp $
7 * Authors: Michel Kaempf <maxx@via.ecp.fr>
8 * Cyril Deguet <asmax@via.ecp.fr>
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; either version 2 of the License, or
13 * (at your option) any later version.
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 * GNU General Public License for more details.
20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, write to the Free Software
22 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111, USA.
23 *****************************************************************************/
25 /*****************************************************************************
27 *****************************************************************************/
28 #include <stdlib.h> /* calloc(), malloc(), free() */
33 #include "audio_output.h"
36 /* Biggest difference allowed between scheduled playing date and actual date
38 #define MAX_DELTA 50000
40 /*****************************************************************************
42 *****************************************************************************/
43 static void FillBuffer( aout_thread_t * p_aout, aout_fifo_t * p_fifo );
44 static int NextFrame ( aout_thread_t * p_aout, aout_fifo_t * p_fifo,
47 /*****************************************************************************
49 *****************************************************************************/
50 void aout_PCMThread( aout_thread_t * p_aout )
53 int i_buffer, i_buffer_limit, i_units = 0;
56 if( !SetThreadPriority(GetCurrentThread(), THREAD_PRIORITY_ABOVE_NORMAL) )
57 msg_Warn( p_aout, "could not change priority of aout_PCMThread()" );
60 /* As the s32_buffer was created with calloc(), we don't have to set this
61 * memory to zero and we can immediately jump into the thread's loop */
62 while ( ! p_aout->b_die )
64 vlc_mutex_lock( &p_aout->fifos_lock );
65 for ( i_fifo = 0; i_fifo < AOUT_MAX_FIFOS; i_fifo++ )
67 if( p_aout->fifo[i_fifo].b_die )
69 aout_FreeFifo( &p_aout->fifo[i_fifo] );
73 FillBuffer( p_aout, &p_aout->fifo[i_fifo] );
76 vlc_mutex_unlock( &p_aout->fifos_lock );
78 i_buffer_limit = p_aout->i_units * p_aout->i_channels;
80 switch ( p_aout->i_format )
83 for ( i_buffer = 0; i_buffer < i_buffer_limit; i_buffer++ )
85 ((u8*)p_aout->buffer)[i_buffer] = (u8)(
86 (p_aout->s32_buffer[i_buffer] / AOUT_MAX_FIFOS / 256 + 128)
87 * p_aout->i_volume / 256);
88 p_aout->s32_buffer[i_buffer] = 0;
93 for ( i_buffer = 0; i_buffer < i_buffer_limit; i_buffer++ )
95 ((s8*)p_aout->buffer)[i_buffer] = (s8)(
96 p_aout->s32_buffer[i_buffer] / AOUT_MAX_FIFOS / 256
97 * p_aout->i_volume / 256);
98 p_aout->s32_buffer[i_buffer] = 0;
102 case AOUT_FMT_U16_LE:
103 case AOUT_FMT_U16_BE:
104 for ( i_buffer = 0; i_buffer < i_buffer_limit; i_buffer++ )
106 ((u16*)p_aout->buffer)[i_buffer] = (u16)(
107 (p_aout->s32_buffer[i_buffer] / AOUT_MAX_FIFOS + 128)
108 * p_aout->i_volume / 256);
109 p_aout->s32_buffer[i_buffer] = 0;
113 case AOUT_FMT_S16_LE:
114 case AOUT_FMT_S16_BE:
115 for ( i_buffer = 0; i_buffer < i_buffer_limit; i_buffer++ )
117 ((s16*)p_aout->buffer)[i_buffer] = (s16)(
118 p_aout->s32_buffer[i_buffer] / AOUT_MAX_FIFOS
119 * p_aout->i_volume / 256);
120 p_aout->s32_buffer[i_buffer] = 0;
125 switch ( p_aout->i_format )
129 i_units = p_aout->pf_getbufinfo( p_aout, i_buffer_limit );
131 p_aout->date = mdate() + ((((mtime_t)((i_units +
132 p_aout->i_latency) / p_aout->i_channels)) * 1000000) /
133 ((mtime_t)p_aout->i_rate)) + p_aout->p_vlc->i_desync;
135 p_aout->pf_play( p_aout, (byte_t *)p_aout->buffer,
139 case AOUT_FMT_U16_LE:
140 case AOUT_FMT_U16_BE:
141 case AOUT_FMT_S16_LE:
142 case AOUT_FMT_S16_BE:
143 i_units = p_aout->pf_getbufinfo( p_aout, i_buffer_limit * 2 ) / 2;
145 p_aout->date = mdate() + ((((mtime_t)((i_units +
146 p_aout->i_latency / 2) / p_aout->i_channels)) * 1000000) /
147 ((mtime_t)p_aout->i_rate)) + p_aout->p_vlc->i_desync;
149 p_aout->pf_play( p_aout, (byte_t *)p_aout->buffer,
150 i_buffer_limit * 2 );
154 /* Sleep until there is only AOUT_BUFFER_DURATION/2 worth of audio
155 * left to play in the aout plugin, then we can start refill the
157 if( i_units > (i_buffer_limit/2) )
158 msleep( (i_units - i_buffer_limit/2) * AOUT_BUFFER_DURATION
162 vlc_mutex_lock( &p_aout->fifos_lock );
163 for ( i_fifo = 0; i_fifo < AOUT_MAX_FIFOS; i_fifo++ )
165 aout_FreeFifo( &p_aout->fifo[i_fifo] );
167 vlc_mutex_unlock( &p_aout->fifos_lock );
170 /* Following functions are local */
172 /*****************************************************************************
173 * InitializeIncrement: change i_x/i_y to i_a+i_b/i_c
174 *****************************************************************************/
175 static inline void InitializeIncrement( aout_increment_t *p_inc,
191 /*****************************************************************************
193 *****************************************************************************/
194 static inline void UpdateIncrement( aout_increment_t *p_inc, int *pi_integer )
196 if( (p_inc->i_r += p_inc->i_b) >= 0 )
198 *pi_integer += p_inc->i_a + 1;
199 p_inc->i_r -= p_inc->i_c;
203 *pi_integer += p_inc->i_a;
207 /*****************************************************************************
208 * FillBuffer: Read data from decoder fifo, and put it in S32_buffer
209 *****************************************************************************/
210 static void FillBuffer( aout_thread_t * p_aout, aout_fifo_t * p_fifo )
213 int i_buffer_limit, i_units;
215 switch ( p_fifo->i_format )
219 i_units = p_aout->i_units;
221 /* While there are empty frames in the buffer, fill them */
222 while ( i_units > 0 )
224 /* If there is no next frame, wait for one */
225 if( !p_fifo->b_next_frame )
227 if( NextFrame(p_aout, p_fifo, p_aout->date +
228 ((((mtime_t)(i_buffer >> 1)) * 1000000) /
229 ((mtime_t)p_aout->i_rate))) )
235 i_buffer_limit = p_aout->i_units * p_aout->i_channels;
237 while ( i_buffer < i_buffer_limit )
239 /* FIXME: make this more generic */
240 if( p_aout->i_channels == 2 )
242 p_aout->s32_buffer[i_buffer++] +=
243 (s32)( ((s16 *)p_fifo->buffer)[2*p_fifo->i_unit] );
244 p_aout->s32_buffer[i_buffer++] +=
245 (s32)( ((s16 *)p_fifo->buffer)[2*p_fifo->i_unit+1] );
247 else if( p_aout->i_channels == 1 )
249 p_aout->s32_buffer[i_buffer++] +=
250 (s32)( ((s16 *)p_fifo->buffer)[p_fifo->i_unit] );
254 msg_Err( p_aout, "unsupported number of channels" );
257 UpdateIncrement(&p_fifo->unit_increment, &p_fifo->i_unit);
259 if( p_fifo->i_unit >= p_fifo->i_unit_limit )
261 p_fifo->i_unit -= p_fifo->i_unit_limit;
265 if( p_fifo->i_units > i_units )
267 p_fifo->i_units -= i_units;
272 i_units -= p_fifo->i_units;
274 vlc_mutex_lock( &p_fifo->data_lock );
275 p_fifo->i_start_frame = p_fifo->i_next_frame;
276 /* p_fifo->b_start_frame = 1; */
277 p_fifo->i_next_frame = AOUT_FIFO_INC( p_fifo->i_next_frame );
278 p_fifo->b_next_frame = 0;
279 vlc_cond_signal( &p_fifo->data_wait );
280 vlc_mutex_unlock( &p_fifo->data_lock );
291 static int NextFrame( aout_thread_t * p_aout, aout_fifo_t * p_fifo,
294 int i_units, i_units_dist, i_rate;
297 /* We take the lock */
298 vlc_mutex_lock( &p_fifo->data_lock );
301 vlc_mutex_unlock( &p_fifo->data_lock );
305 /* Are we looking for a dated start frame ? */
306 if ( !p_fifo->b_start_frame )
308 while ( p_fifo->i_start_frame != p_fifo->i_end_frame )
310 if ( p_fifo->date[p_fifo->i_start_frame] != LAST_MDATE )
312 p_fifo->b_start_frame = 1;
313 p_fifo->i_next_frame = AOUT_FIFO_INC( p_fifo->i_start_frame );
314 p_fifo->i_unit = p_fifo->i_start_frame *
315 (p_fifo->i_frame_size / p_fifo->i_channels);
318 p_fifo->i_start_frame = AOUT_FIFO_INC( p_fifo->i_start_frame );
321 if ( p_fifo->i_start_frame == p_fifo->i_end_frame )
323 vlc_mutex_unlock( &p_fifo->data_lock );
328 /* We are looking for the next dated frame */
329 /* FIXME : is the output fifo full ?? -- pretty unlikely given its size */
330 while ( !p_fifo->b_next_frame )
332 while ( p_fifo->i_next_frame != p_fifo->i_end_frame )
334 if ( p_fifo->date[p_fifo->i_next_frame] != LAST_MDATE )
336 p_fifo->b_next_frame = 1;
339 p_fifo->i_next_frame = AOUT_FIFO_INC( p_fifo->i_next_frame );
342 while ( p_fifo->i_next_frame == p_fifo->i_end_frame )
344 vlc_cond_wait( &p_fifo->data_wait, &p_fifo->data_lock );
347 vlc_mutex_unlock( &p_fifo->data_lock );
353 i_units = ((p_fifo->i_next_frame - p_fifo->i_start_frame) & AOUT_FIFO_SIZE)
354 * (p_fifo->i_frame_size / p_fifo->i_channels);
356 i_delta = aout_date - p_fifo->date[p_fifo->i_start_frame];
358 /* Resample if delta is too long */
359 if( abs(i_delta) > MAX_DELTA )
361 i_rate = p_fifo->i_rate + (i_delta / 256);
365 i_rate = p_fifo->i_rate;
368 InitializeIncrement( &p_fifo->unit_increment, i_rate, p_aout->i_rate );
370 /* Calculate how many units we're going to write */
371 i_units_dist = p_fifo->i_unit - p_fifo->i_start_frame
372 * (p_fifo->i_frame_size / p_fifo->i_channels);
374 /* Manage the fifo wrapping */
375 if( i_units_dist > p_fifo->i_unit_limit / 2 )
377 i_units -= (i_units_dist - p_fifo->i_unit_limit);
379 else if( i_units_dist < - p_fifo->i_unit_limit / 2 )
381 i_units -= (i_units_dist + p_fifo->i_unit_limit);
385 i_units -= i_units_dist;
388 p_fifo->i_units = 1 + ( i_units * p_aout->i_rate / i_rate );
390 /* We release the lock before leaving */
391 vlc_mutex_unlock( &p_fifo->data_lock );