1 /*****************************************************************************
2 * aout_spdif: ac3 passthrough output
3 *****************************************************************************
4 * Copyright (C) 2001 VideoLAN
5 * $Id: aout_spdif.c,v 1.21 2001/12/30 07:09:56 sam Exp $
7 * Authors: Michel Kaempf <maxx@via.ecp.fr>
8 * Stéphane Borel <stef@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() */
30 #include <string.h> /* memset() */
32 #include <videolan/vlc.h>
34 #include "audio_output.h"
35 #include "aout_common.h"
37 /*****************************************************************************
38 * aout_SpdifThread: audio output thread that sends raw spdif data
39 * to an external decoder
40 *****************************************************************************
41 * This output thread is quite specific as it can only handle one fifo now.
43 * Note: spdif can demux up to 8 ac3 streams, and can even take
44 * care of time stamps (cf ac3 spec) but I'm not sure all decoders
46 *****************************************************************************/
47 void aout_SpdifThread( aout_thread_t * p_aout )
50 mtime_t m_frame_time = 0;
55 intf_DbgMsg( "aout debug: starting spdif output loop" );
57 while( !p_aout->b_die )
59 for( i_fifo = 0 ; i_fifo < AOUT_MAX_FIFOS ; i_fifo++ )
61 /* the loop read each fifo so that we can change the stream
62 * on the fly but mulitplexing is not handled yet so
63 * the sound will be broken is more than one fifo has data */
64 /* TODO: write the muliplexer :) */
65 if( p_aout->fifo[i_fifo].i_type == AOUT_ADEC_SPDIF_FIFO )
67 vlc_mutex_lock( &p_aout->fifo[i_fifo].data_lock );
68 if( p_aout->fifo[i_fifo].b_die )
70 vlc_mutex_unlock( &p_aout->fifo[i_fifo].data_lock );
72 vlc_mutex_lock( &p_aout->fifos_lock );
73 aout_FreeFifo( &p_aout->fifo[i_fifo] );
74 vlc_mutex_unlock( &p_aout->fifos_lock );
76 else if( !AOUT_FIFO_ISEMPTY( p_aout->fifo[i_fifo] ) )
78 /* Copy data from fifo to buffer to release the lock earlier */
79 memcpy( p_aout->buffer,
80 (byte_t *)p_aout->fifo[i_fifo].buffer
81 + p_aout->fifo[i_fifo].l_start_frame
85 m_play = p_aout->fifo[i_fifo].date[p_aout->fifo[i_fifo].
88 p_aout->fifo[i_fifo].l_start_frame =
89 (p_aout->fifo[i_fifo].l_start_frame + 1 )
92 /* Compute the theorical duration of an ac3 frame */
93 m_frame_time = 1000000 * AC3_FRAME_SIZE
94 / p_aout->fifo[i_fifo].l_rate;
96 vlc_mutex_unlock( &p_aout->fifo[i_fifo].data_lock );
98 /* play spdif frame to the external decoder
99 * the kernel driver will sleep until the
100 * dsp buffer is empty enough to accept the data */
101 if( m_play > ( mdate() - m_frame_time ) )
103 /* check continuity */
104 if( (m_play - m_old) != m_frame_time )
106 intf_DbgMsg( "aout debug: malformed frame ? (%lld)",
108 mwait( m_play - m_frame_time );
112 mwait( m_play - 2 * m_frame_time );
116 p_aout->pf_play( p_aout,
117 (byte_t *)p_aout->buffer,
122 intf_DbgMsg( "aout debug: late spdif frame" );
127 vlc_mutex_unlock( &p_aout->fifo[i_fifo].data_lock );
128 msleep( m_frame_time );
129 intf_WarnMsg( 3, "aout warning: empty spdif fifo" );
135 intf_DbgMsg( "aout debug: exiting spdif loop" );
136 vlc_mutex_lock( &p_aout->fifos_lock );
138 for ( i_fifo = 0; i_fifo < AOUT_MAX_FIFOS; i_fifo++ )
140 aout_FreeFifo( &p_aout->fifo[i_fifo] );
143 vlc_mutex_unlock( &p_aout->fifos_lock );