1 /*****************************************************************************
2 * audio_output.h : audio output interface
3 *****************************************************************************
4 * Copyright (C) 2002 VideoLAN
5 * $Id: audio_output.h,v 1.58 2002/08/14 00:23:59 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 /*****************************************************************************
25 * audio_sample_format_t
26 *****************************************************************************
27 * This structure defines a format for audio samples.
28 *****************************************************************************/
29 struct audio_sample_format_t
34 /* Optional - for A52, SPDIF and DTS types */
38 #define AOUT_FMT_MU_LAW 0x00000001
39 #define AOUT_FMT_A_LAW 0x00000002
40 #define AOUT_FMT_IMA_ADPCM 0x00000004
41 #define AOUT_FMT_U8 0x00000008
42 #define AOUT_FMT_S16_LE 0x00000010 /* Little endian signed 16 */
43 #define AOUT_FMT_S16_BE 0x00000020 /* Big endian signed 16 */
44 #define AOUT_FMT_S8 0x00000040
45 #define AOUT_FMT_U16_LE 0x00000080 /* Little endian U16 */
46 #define AOUT_FMT_U16_BE 0x00000100 /* Big endian U16 */
47 #define AOUT_FMT_SPDIF 0x00000400 /* S/PDIF hardware support */
48 #define AOUT_FMT_FLOAT32 0x00010000
49 #define AOUT_FMT_FIXED32 0x00020000
50 #define AOUT_FMT_A52 0x00100000
51 #define AOUT_FMT_DTS 0x00200000
53 #define AOUT_FMTS_IDENTICAL( p_first, p_second ) ( \
54 ((p_first)->i_format == (p_second)->i_format) \
55 && ((p_first)->i_rate == (p_second)->i_rate) \
56 && ((p_first)->i_channels == (p_second)->i_channels \
57 || (p_first)->i_channels == -1 || (p_second)->i_channels == -1) )
59 #ifdef WORDS_BIGENDIAN
60 # define AOUT_FMT_S16_NE AOUT_FMT_S16_BE
61 # define AOUT_FMT_U16_NE AOUT_FMT_U16_BE
63 # define AOUT_FMT_S16_NE AOUT_FMT_S16_LE
64 # define AOUT_FMT_U16_NE AOUT_FMT_U16_LE
67 #define AOUT_FMT_NON_LINEAR( p_format ) \
68 ( ((p_format)->i_format == AOUT_FMT_SPDIF) \
69 || ((p_format)->i_format == AOUT_FMT_A52) \
70 || ((p_format)->i_format == AOUT_FMT_DTS) )
72 /* This is heavily borrowed from libmad, by Robert Leslie <rob@mars.org> */
74 * Fixed-point format: 0xABBBBBBB
75 * A == whole part (sign + 3 bits)
76 * B == fractional part (28 bits)
78 * Values are signed two's complement, so the effective range is:
79 * 0x80000000 to 0x7fffffff
80 * -8.0 to +7.9999999962747097015380859375
82 * The smallest representable value is:
83 * 0x00000001 == 0.0000000037252902984619140625 (i.e. about 3.725e-9)
85 * 28 bits of fractional accuracy represent about
86 * 8.6 digits of decimal accuracy.
88 * Fixed-point numbers can be added or subtracted as normal
89 * integers, but multiplication requires shifting the 64-bit result
90 * from 56 fractional bits back to 28 (and rounding.)
92 typedef s32 vlc_fixed_t;
93 #define FIXED32_FRACBITS 28
94 #define FIXED32_MIN ((vlc_fixed_t) -0x80000000L)
95 #define FIXED32_MAX ((vlc_fixed_t) +0x7fffffffL)
96 #define FIXED32_ONE ((vlc_fixed_t) 0x10000000)
99 /*****************************************************************************
100 * aout_buffer_t : audio output buffer
101 *****************************************************************************/
106 /* i_size is the real size of the buffer (normally unused), i_nb_bytes
107 * is the number of significative bytes in it. */
108 size_t i_size, i_nb_bytes;
110 mtime_t start_date, end_date;
112 struct aout_buffer_t * p_next;
115 /* Size of a frame for S/PDIF output. */
116 #define AOUT_SPDIF_SIZE 6144
118 /*****************************************************************************
120 *****************************************************************************/
121 /* From audio_output.c : */
122 #define aout_NewInstance(a) __aout_NewInstance(VLC_OBJECT(a))
123 VLC_EXPORT( aout_instance_t *, __aout_NewInstance, ( vlc_object_t * ) );
124 VLC_EXPORT( void, aout_DeleteInstance, ( aout_instance_t * ) );
125 VLC_EXPORT( aout_buffer_t *, aout_BufferNew, ( aout_instance_t *, aout_input_t *, size_t ) );
126 VLC_EXPORT( void, aout_BufferDelete, ( aout_instance_t *, aout_input_t *, aout_buffer_t * ) );
127 VLC_EXPORT( void, aout_BufferPlay, ( aout_instance_t *, aout_input_t *, aout_buffer_t * ) );
128 VLC_EXPORT( int, aout_FormatToByterate, ( audio_sample_format_t * p_format ) );
131 #define aout_InputNew(a,b,c) __aout_InputNew(VLC_OBJECT(a),b,c)
132 VLC_EXPORT( aout_input_t *, __aout_InputNew, ( vlc_object_t *, aout_instance_t **, audio_sample_format_t * ) );
133 VLC_EXPORT( void, aout_InputDelete, ( aout_instance_t *, aout_input_t * ) );
135 /* From output.c : */
136 VLC_EXPORT( aout_buffer_t *, aout_OutputNextBuffer, ( aout_instance_t *, mtime_t ) );