1 /*****************************************************************************
2 * aout_pcm.c: PCM audio output functions
3 *****************************************************************************
4 * Copyright (C) 1999-2002 VideoLAN
5 * $Id: aout_pcm.c,v 1.3 2002/03/04 22:18:25 gbazin 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 <stdio.h> /* "intf_msg.h" */
29 #include <stdlib.h> /* calloc(), malloc(), free() */
32 #include <videolan/vlc.h>
34 #include "audio_output.h"
37 /* Biggest difference allowed between scheduled playing date and actual date
39 #define MAX_DELTA 10000
41 /*****************************************************************************
43 *****************************************************************************/
44 static void FillBuffer( aout_thread_t * p_aout, aout_fifo_t * p_fifo );
45 static int NextFrame ( aout_thread_t * p_aout, aout_fifo_t * p_fifo,
48 /*****************************************************************************
50 *****************************************************************************/
51 void aout_PCMThread( aout_thread_t * p_aout )
54 int i_buffer, i_buffer_limit, i_units = 0;
56 /* As the s32_buffer was created with calloc(), we don't have to set this
57 * memory to zero and we can immediately jump into the thread's loop */
58 while ( ! p_aout->b_die )
60 vlc_mutex_lock( &p_aout->fifos_lock );
61 for ( i_fifo = 0; i_fifo < AOUT_MAX_FIFOS; i_fifo++ )
63 if( p_aout->fifo[i_fifo].b_die )
65 aout_FreeFifo( &p_aout->fifo[i_fifo] );
69 FillBuffer( p_aout, &p_aout->fifo[i_fifo] );
72 vlc_mutex_unlock( &p_aout->fifos_lock );
74 i_buffer_limit = p_aout->i_units * p_aout->i_channels;
76 switch ( p_aout->i_format )
79 for ( i_buffer = 0; i_buffer < i_buffer_limit; i_buffer++ )
81 ((u8*)p_aout->buffer)[i_buffer] = (u8)(
82 (p_aout->s32_buffer[i_buffer] / AOUT_MAX_FIFOS / 256 + 128)
83 * p_aout->i_volume / 256);
84 p_aout->s32_buffer[i_buffer] = 0;
89 for ( i_buffer = 0; i_buffer < i_buffer_limit; i_buffer++ )
91 ((s8*)p_aout->buffer)[i_buffer] = (s8)(
92 p_aout->s32_buffer[i_buffer] / AOUT_MAX_FIFOS / 256
93 * p_aout->i_volume / 256);
94 p_aout->s32_buffer[i_buffer] = 0;
100 for ( i_buffer = 0; i_buffer < i_buffer_limit; i_buffer++ )
102 ((u16*)p_aout->buffer)[i_buffer] = (u16)(
103 (p_aout->s32_buffer[i_buffer] / AOUT_MAX_FIFOS + 128)
104 * p_aout->i_volume / 256);
105 p_aout->s32_buffer[i_buffer] = 0;
109 case AOUT_FMT_S16_LE:
110 case AOUT_FMT_S16_BE:
111 for ( i_buffer = 0; i_buffer < i_buffer_limit; i_buffer++ )
113 ((s16*)p_aout->buffer)[i_buffer] = (s16)(
114 p_aout->s32_buffer[i_buffer] / AOUT_MAX_FIFOS
115 * p_aout->i_volume / 256);
116 p_aout->s32_buffer[i_buffer] = 0;
121 switch ( p_aout->i_format )
125 i_units = p_aout->pf_getbufinfo( p_aout, i_buffer_limit );
127 p_aout->date = mdate() + ((((mtime_t)((i_units + 4 *
128 p_aout->i_latency) / p_aout->i_channels)) * 1000000) /
129 ((mtime_t)p_aout->i_rate)) + p_main->i_desync;
131 p_aout->pf_play( p_aout, (byte_t *)p_aout->buffer,
135 case AOUT_FMT_U16_LE:
136 case AOUT_FMT_U16_BE:
137 case AOUT_FMT_S16_LE:
138 case AOUT_FMT_S16_BE:
139 i_units = p_aout->pf_getbufinfo( p_aout, i_buffer_limit * 2 ) / 2;
141 p_aout->date = mdate() + ((((mtime_t)((i_units + 4 *
142 p_aout->i_latency) / (2 * p_aout->i_channels))) * 1000000) /
143 ((mtime_t)p_aout->i_rate)) + p_main->i_desync;
145 p_aout->pf_play( p_aout, (byte_t *)p_aout->buffer,
146 i_buffer_limit * 2 );
150 /* Sleep until there is only AOUT_BUFFER_DURATION/2 worth of audio
151 * left to play in the aout plugin, then we can start refill the
153 if( i_units > (i_buffer_limit/2) )
154 msleep( (i_units - i_buffer_limit/2) * AOUT_BUFFER_DURATION
159 vlc_mutex_lock( &p_aout->fifos_lock );
160 for ( i_fifo = 0; i_fifo < AOUT_MAX_FIFOS; i_fifo++ )
162 aout_FreeFifo( &p_aout->fifo[i_fifo] );
164 vlc_mutex_unlock( &p_aout->fifos_lock );
167 /* Following functions are local */
169 /*****************************************************************************
170 * InitializeIncrement: change i_x/i_y to i_a+i_b/i_c
171 *****************************************************************************/
172 static __inline__ void InitializeIncrement( aout_increment_t * p_inc,
188 /*****************************************************************************
190 *****************************************************************************/
191 static __inline__ void UpdateIncrement( aout_increment_t * p_inc,
194 if( (p_inc->i_r += p_inc->i_b) >= 0 )
196 *pi_integer += p_inc->i_a + 1;
197 p_inc->i_r -= p_inc->i_c;
201 *pi_integer += p_inc->i_a;
205 /*****************************************************************************
206 * FillBuffer: Read data from decoder fifo, and put it in S32_buffer
207 *****************************************************************************/
208 static void FillBuffer( aout_thread_t * p_aout, aout_fifo_t * p_fifo )
211 int i_buffer_limit, i_units;
213 switch ( p_fifo->i_format )
217 i_units = p_aout->i_units;
219 /* While there are empty frames in the buffer, fill them */
220 while ( i_units > 0 )
222 /* If there is no next frame, wait for one */
223 if( !p_fifo->b_next_frame )
225 if( NextFrame(p_aout, p_fifo, p_aout->date +
226 ((((mtime_t)(i_buffer >> 1)) * 1000000) /
227 ((mtime_t)p_aout->i_rate))) )
233 i_buffer_limit = p_aout->i_units * p_aout->i_channels;
235 while ( i_buffer < i_buffer_limit )
237 /* FIXME: make this more generic */
238 if( p_aout->i_channels == 2 )
240 p_aout->s32_buffer[i_buffer++] +=
241 (s32)( ((s16 *)p_fifo->buffer)[2*p_fifo->i_unit] );
242 p_aout->s32_buffer[i_buffer++] +=
243 (s32)( ((s16 *)p_fifo->buffer)[2*p_fifo->i_unit+1] );
245 else if( p_aout->i_channels == 1 )
247 p_aout->s32_buffer[i_buffer++] +=
248 (s32)( ((s16 *)p_fifo->buffer)[p_fifo->i_unit] );
252 intf_ErrMsg( "aout error: unsupported number of channels" );
255 UpdateIncrement(&p_fifo->unit_increment, &p_fifo->i_unit);
257 if( p_fifo->i_unit >= p_fifo->i_unit_limit )
259 p_fifo->i_unit -= p_fifo->i_unit_limit;
263 if( p_fifo->i_units > i_units )
265 p_fifo->i_units -= i_units;
270 i_units -= p_fifo->i_units;
272 vlc_mutex_lock( &p_fifo->data_lock );
273 p_fifo->i_start_frame = p_fifo->i_next_frame;
274 /* p_fifo->b_start_frame = 1; */
275 p_fifo->i_next_frame = AOUT_FIFO_INC( p_fifo->i_next_frame );
276 p_fifo->b_next_frame = 0;
277 vlc_cond_signal( &p_fifo->data_wait );
278 vlc_mutex_unlock( &p_fifo->data_lock );
289 static int NextFrame( aout_thread_t * p_aout, aout_fifo_t * p_fifo,
292 int i_units, i_units_dist, i_rate;
295 /* We take the lock */
296 vlc_mutex_lock( &p_fifo->data_lock );
298 /* Are we looking for a dated start frame ? */
299 if ( !p_fifo->b_start_frame )
301 while ( p_fifo->i_start_frame != p_fifo->i_end_frame )
303 if ( p_fifo->date[p_fifo->i_start_frame] != LAST_MDATE )
305 p_fifo->b_start_frame = 1;
306 p_fifo->i_next_frame = AOUT_FIFO_INC( p_fifo->i_start_frame );
307 p_fifo->i_unit = p_fifo->i_start_frame *
308 (p_fifo->i_frame_size / p_fifo->i_channels);
311 p_fifo->i_start_frame = AOUT_FIFO_INC( p_fifo->i_start_frame );
314 if ( p_fifo->i_start_frame == p_fifo->i_end_frame )
316 vlc_mutex_unlock( &p_fifo->data_lock );
321 /* We are looking for the next dated frame */
322 /* FIXME : is the output fifo full ?? -- pretty unlikely given its size */
323 while ( !p_fifo->b_next_frame )
325 while ( p_fifo->i_next_frame != p_fifo->i_end_frame )
327 if ( p_fifo->date[p_fifo->i_next_frame] != LAST_MDATE )
329 p_fifo->b_next_frame = 1;
332 p_fifo->i_next_frame = AOUT_FIFO_INC( p_fifo->i_next_frame );
335 while ( p_fifo->i_next_frame == p_fifo->i_end_frame )
337 vlc_cond_wait( &p_fifo->data_wait, &p_fifo->data_lock );
340 vlc_mutex_unlock( &p_fifo->data_lock );
346 i_units = ((p_fifo->i_next_frame - p_fifo->i_start_frame) & AOUT_FIFO_SIZE)
347 * (p_fifo->i_frame_size / p_fifo->i_channels);
349 i_delta = aout_date - p_fifo->date[p_fifo->i_start_frame];
351 /* Resample if delta is too long */
352 if( abs(i_delta) > MAX_DELTA )
354 i_rate = p_fifo->i_rate + (i_delta / 256);
358 i_rate = p_fifo->i_rate;
361 InitializeIncrement( &p_fifo->unit_increment, i_rate, p_aout->i_rate );
363 /* Calculate how many units we're going to write */
364 i_units_dist = p_fifo->i_unit - p_fifo->i_start_frame
365 * (p_fifo->i_frame_size / p_fifo->i_channels);
367 /* Manage the fifo wrapping */
368 if( i_units_dist > p_fifo->i_unit_limit / 2 )
370 i_units -= (i_units_dist - p_fifo->i_unit_limit);
372 else if( i_units_dist < - p_fifo->i_unit_limit / 2 )
374 i_units -= (i_units_dist + p_fifo->i_unit_limit);
378 i_units -= i_units_dist;
381 p_fifo->i_units = 1 + ( i_units * p_aout->i_rate / i_rate );
383 /* We release the lock before leaving */
384 vlc_mutex_unlock( &p_fifo->data_lock );