1 /*****************************************************************************
2 * mixer.c : audio output mixing operations
3 *****************************************************************************
4 * Copyright (C) 2002 VideoLAN
5 * $Id: mixer.c,v 1.11 2002/08/30 22:22:24 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"
39 /*****************************************************************************
40 * aout_MixerNew: prepare a mixer plug-in
41 *****************************************************************************
42 * Please note that you must hold the mixer lock.
43 *****************************************************************************/
44 int aout_MixerNew( aout_instance_t * p_aout )
46 p_aout->mixer.p_module = module_Need( p_aout, "audio mixer", NULL );
47 if ( p_aout->mixer.p_module == NULL )
49 msg_Err( p_aout, "no suitable aout mixer" );
55 /*****************************************************************************
56 * aout_MixerDelete: delete the mixer
57 *****************************************************************************
58 * Please note that you must hold the mixer lock.
59 *****************************************************************************/
60 void aout_MixerDelete( aout_instance_t * p_aout )
62 module_Unneed( p_aout, p_aout->mixer.p_module );
65 /*****************************************************************************
66 * MixBuffer: try to prepare one output buffer
67 *****************************************************************************/
68 static int MixBuffer( aout_instance_t * p_aout )
71 aout_buffer_t * p_output_buffer;
72 mtime_t start_date, end_date;
73 audio_date_t exact_start_date;
75 vlc_mutex_lock( &p_aout->mixer_lock );
76 vlc_mutex_lock( &p_aout->output_fifo_lock );
77 vlc_mutex_lock( &p_aout->input_fifos_lock );
79 /* Retrieve the date of the next buffer. */
80 memcpy( &exact_start_date, &p_aout->output.fifo.end_date,
81 sizeof(audio_date_t) );
82 start_date = aout_DateGet( &exact_start_date );
84 if ( start_date != 0 && start_date < mdate() )
86 /* The output is _very_ late. This can only happen if the user
87 * pauses the stream (or if the decoder is buggy, which cannot
89 msg_Warn( p_aout, "Output PTS is out of range (%lld), clearing out",
91 aout_FifoSet( p_aout, &p_aout->output.fifo, 0 );
92 aout_DateSet( &exact_start_date, 0 );
96 vlc_mutex_unlock( &p_aout->output_fifo_lock );
98 /* See if we have enough data to prepare a new buffer for the audio
99 * output. First : start date. */
102 /* Find the latest start date available. */
103 for ( i = 0; i < p_aout->i_nb_inputs; i++ )
105 aout_input_t * p_input = p_aout->pp_inputs[i];
106 aout_fifo_t * p_fifo = &p_input->fifo;
107 aout_buffer_t * p_buffer;
109 p_buffer = p_fifo->p_first;
110 if ( p_buffer == NULL )
115 if ( !start_date || start_date < p_buffer->start_date )
117 aout_DateSet( &exact_start_date, p_buffer->start_date );
118 start_date = p_buffer->start_date;
122 if ( i < p_aout->i_nb_inputs )
124 /* Interrupted before the end... We can't run. */
125 vlc_mutex_unlock( &p_aout->input_fifos_lock );
126 vlc_mutex_unlock( &p_aout->mixer_lock );
130 aout_DateIncrement( &exact_start_date, p_aout->output.i_nb_samples );
131 end_date = aout_DateGet( &exact_start_date );
133 /* Check that start_date and end_date are available for all input
135 for ( i = 0; i < p_aout->i_nb_inputs; i++ )
137 aout_input_t * p_input = p_aout->pp_inputs[i];
138 aout_fifo_t * p_fifo = &p_input->fifo;
139 aout_buffer_t * p_buffer;
141 vlc_bool_t b_drop_buffers;
143 p_buffer = p_fifo->p_first;
144 if ( p_buffer == NULL )
149 /* Check for the continuity of start_date */
150 while ( p_buffer != NULL && p_buffer->end_date < start_date )
152 aout_buffer_t * p_next = p_buffer->p_next;
153 msg_Err( p_aout, "the mixer got a packet in the past (%lld)",
154 start_date - p_buffer->end_date );
155 aout_BufferFree( p_buffer );
156 p_fifo->p_first = p_buffer = p_next;
157 p_input->p_first_byte_to_mix = NULL;
159 if ( p_buffer == NULL )
161 p_fifo->pp_last = &p_fifo->p_first;
165 if ( !AOUT_FMT_NON_LINEAR( &p_aout->mixer.mixer ) )
167 /* Additionally check that p_first_byte_to_mix is well
169 unsigned long i_nb_bytes = (start_date - p_buffer->start_date)
170 * p_aout->mixer.mixer.i_bytes_per_frame
171 * p_aout->mixer.mixer.i_rate
172 / p_aout->mixer.mixer.i_frame_length
174 ptrdiff_t mixer_nb_bytes;
176 if ( p_input->p_first_byte_to_mix == NULL )
178 p_input->p_first_byte_to_mix = p_buffer->p_buffer;
180 mixer_nb_bytes = p_input->p_first_byte_to_mix
181 - p_buffer->p_buffer;
183 if ( !((i_nb_bytes + p_aout->mixer.mixer.i_bytes_per_frame
185 (i_nb_bytes < p_aout->mixer.mixer.i_bytes_per_frame
189 "mixer start isn't output start (%d)",
190 i_nb_bytes - mixer_nb_bytes );
192 /* Round to the nearest multiple */
193 i_nb_bytes /= p_aout->mixer.mixer.i_bytes_per_frame;
194 i_nb_bytes *= p_aout->mixer.mixer.i_bytes_per_frame;
195 p_input->p_first_byte_to_mix = p_buffer->p_buffer
200 /* Check that we have enough samples. */
203 p_buffer = p_fifo->p_first;
204 if ( p_buffer == NULL ) break;
205 if ( p_buffer->end_date >= end_date ) break;
207 /* Check that all buffers are contiguous. */
208 prev_date = p_fifo->p_first->end_date;
209 p_buffer = p_buffer->p_next;
211 for ( ; p_buffer != NULL; p_buffer = p_buffer->p_next )
213 if ( prev_date != p_buffer->start_date )
216 "buffer hole, dropping packets (%lld)",
217 p_buffer->start_date - prev_date );
221 if ( p_buffer->end_date >= end_date ) break;
222 prev_date = p_buffer->end_date;
224 if ( b_drop_buffers )
226 aout_buffer_t * p_deleted = p_fifo->p_first;
227 while ( p_deleted != NULL && p_deleted != p_buffer )
229 aout_buffer_t * p_next = p_deleted->p_next;
230 aout_BufferFree( p_deleted );
233 p_fifo->p_first = p_deleted; /* == p_buffer */
237 if ( p_buffer == NULL ) break;
240 if ( i < p_aout->i_nb_inputs )
242 /* Interrupted before the end... We can't run. */
243 vlc_mutex_unlock( &p_aout->input_fifos_lock );
244 vlc_mutex_unlock( &p_aout->mixer_lock );
249 aout_BufferAlloc( &p_aout->mixer.output_alloc,
250 ((u64)p_aout->output.i_nb_samples * 1000000)
251 / p_aout->output.output.i_rate,
252 /* This is a bit kludgy, but is actually only used
253 * for the S/PDIF dummy mixer : */
254 p_aout->pp_inputs[0]->fifo.p_first,
256 if ( p_output_buffer == NULL )
258 msg_Err( p_aout, "out of memory" );
259 vlc_mutex_unlock( &p_aout->input_fifos_lock );
260 vlc_mutex_unlock( &p_aout->mixer_lock );
263 /* This is again a bit kludgy - for the S/PDIF mixer. */
264 if ( p_aout->mixer.output_alloc.i_alloc_type != AOUT_ALLOC_NONE )
266 p_output_buffer->i_nb_samples = p_aout->output.i_nb_samples;
267 p_output_buffer->i_nb_bytes = p_aout->output.i_nb_samples
268 * p_aout->mixer.mixer.i_bytes_per_frame
269 / p_aout->mixer.mixer.i_frame_length;
271 p_output_buffer->start_date = start_date;
272 p_output_buffer->end_date = end_date;
274 p_aout->mixer.pf_do_work( p_aout, p_output_buffer );
276 vlc_mutex_unlock( &p_aout->input_fifos_lock );
278 aout_OutputPlay( p_aout, p_output_buffer );
280 vlc_mutex_unlock( &p_aout->mixer_lock );
285 /*****************************************************************************
286 * aout_MixerRun: entry point for the mixer & post-filters processing
287 *****************************************************************************/
288 void aout_MixerRun( aout_instance_t * p_aout )
290 while( MixBuffer( p_aout ) != -1 );