1 /*****************************************************************************
2 * audio_output.h : audio output thread interface
3 *****************************************************************************
4 * Copyright (C) 1999, 2000 VideoLAN
5 * $Id: audio_output.h,v 1.34 2001/05/06 04:32:02 sam Exp $
7 * Authors: Michel Kaempf <maxx@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 /*****************************************************************************
25 * aout_bank_t, p_aout_bank (global variable)
26 *****************************************************************************
27 * This global variable is accessed by any function using the audio output.
28 *****************************************************************************/
31 /* Array to all the audio outputs */
32 struct aout_thread_s *pp_aout[ AOUT_MAX_THREADS ];
35 vlc_mutex_t lock; /* Global lock */
39 extern aout_bank_t *p_aout_bank;
41 /*****************************************************************************
43 *****************************************************************************
44 * This structure is used to keep the progression of an index up-to-date, in
45 * order to avoid rounding problems and heavy computations, as the function
46 * that handles this structure only uses additions.
47 *****************************************************************************/
48 typedef struct aout_increment_s
50 /* The remainder is used to keep track of the fractional part of the
55 * The increment structure is initialized with the result of an euclidean
58 * l_euclidean_numerator l_euclidean_remainder
59 * ----------------------- = l_euclidean_integer + -----------------------
60 * l_euclidean_denominator l_euclidean_denominator
63 long l_euclidean_integer;
64 long l_euclidean_remainder;
65 long l_euclidean_denominator;
69 /*****************************************************************************
71 *****************************************************************************/
72 typedef struct aout_fifo_s
74 /* See the fifo types below */
77 int i_fifo; /* Just to keep track of the fifo index */
83 vlc_mutex_t data_lock;
89 /* The start frame is the first frame in the buffer that contains decoded
90 * audio data. It it also the first frame in the current timestamped frame
91 * area, ie the first dated frame in the decoded part of the buffer. :-p */
93 boolean_t b_start_frame;
94 /* The next frame is the end frame of the current timestamped frame area,
95 * ie the first dated frame after the start frame. */
97 boolean_t b_next_frame;
98 /* The end frame is the first frame, after the start frame, that doesn't
99 * contain decoded audio data. That's why the end frame is the first frame
100 * where the audio decoder can store its decoded audio frames. */
104 aout_increment_t unit_increment;
105 /* The following variable is used to store the number of remaining audio
106 * units in the current timestamped frame area. */
111 #define AOUT_FIFO_ISEMPTY( fifo ) \
112 ( (fifo).l_end_frame == (fifo).l_start_frame )
114 #define AOUT_FIFO_ISFULL( fifo ) \
115 ( ((((fifo).l_end_frame + 1) - (fifo).l_start_frame) & AOUT_FIFO_SIZE) == 0 )
117 #define AOUT_EMPTY_FIFO 0
118 #define AOUT_INTF_MONO_FIFO 1
119 #define AOUT_INTF_STEREO_FIFO 2
120 #define AOUT_ADEC_MONO_FIFO 3
121 #define AOUT_ADEC_STEREO_FIFO 4
122 #define AOUT_ADEC_SPDIF_FIFO 5
124 /*****************************************************************************
125 * aout_thread_t : audio output thread descriptor
126 *****************************************************************************/
127 typedef struct aout_thread_s
129 vlc_thread_t thread_id;
133 vlc_mutex_t fifos_lock;
134 aout_fifo_t fifo[ AOUT_MAX_FIFOS ];
136 /* Plugin used and shortcuts to access its capabilities */
137 struct module_s * p_module;
138 int ( *pf_open ) ( p_aout_thread_t );
139 int ( *pf_setformat ) ( p_aout_thread_t );
140 long ( *pf_getbufinfo ) ( p_aout_thread_t, long );
141 void ( *pf_play ) ( p_aout_thread_t, byte_t *, int );
142 void ( *pf_close ) ( p_aout_thread_t );
145 /* The s32 buffer is used to mix all the audio fifos together before
146 * converting them and storing them in the audio output buffer */
149 /* The size of the audio output buffer is kept in audio units, as this is
150 * the only unit that is common with every audio decoder and audio fifo */
154 /* date is the moment where the first audio unit of the output buffer
158 /* Path to the audio output device (default is set to "/dev/dsp") */
162 /* The current volume */
165 /* Format of the audio output samples */
167 /* Number of channels */
169 /* Mono or Stereo sound */
171 /* Rate and gain of the audio output sound (in Hz) */
175 /* there might be some useful private structure, such as audio_buf_info
176 * for the OSS output */
181 /* Those are from <linux/soundcard.h> but are needed because of formats
182 * on other platforms */
183 #define AOUT_FMT_U8 0x00000008
184 #define AOUT_FMT_S16_LE 0x00000010 /* Little endian signed 16 */
185 #define AOUT_FMT_S16_BE 0x00000020 /* Big endian signed 16 */
186 #define AOUT_FMT_S8 0x00000040
187 #define AOUT_FMT_U16_LE 0x00000080 /* Little endian U16 */
188 #define AOUT_FMT_U16_BE 0x00000100 /* Big endian U16 */
189 #define AOUT_FMT_AC3 0x00000400 /* Dolby Digital AC3 */
192 #ifdef WORDS_BIGENDIAN
193 #define AOUT_FMT_S16_NE AOUT_FMT_S16_BE
195 #define AOUT_FMT_S16_NE AOUT_FMT_S16_LE
198 /*****************************************************************************
200 *****************************************************************************/
201 void aout_InitBank ( void );
202 void aout_EndBank ( void );
204 aout_thread_t * aout_CreateThread ( int *pi_status );
205 void aout_DestroyThread ( aout_thread_t *, int * );
207 aout_fifo_t * aout_CreateFifo ( int, int, long, long, long, void * );
208 void aout_DestroyFifo ( aout_fifo_t *p_fifo );
209 void aout_FreeFifo ( aout_fifo_t *p_fifo );