2 * This file is part of DisOrder.
3 * Copyright (C) 2009 Richard Kettlewell
5 * This program is free software: you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation, either version 3 of the License, or
8 * (at your option) any later version.
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
15 * You should have received a copy of the GNU General Public License
16 * along with this program. If not, see <http://www.gnu.org/licenses/>.
19 /** @file lib/uaudio.c
20 * @brief Uniform audio interface
28 /** @brief Options for chosen uaudio API */
29 static hash
*uaudio_options
;
31 /** @brief Sample rate (Hz) */
34 /** @brief Bits per channel */
37 /** @brief Number of channels */
40 /** @brief Whether samples are signed or unsigned */
43 /** @brief Sample size in bytes
45 * NB one sample is a single point sample; up to @c uaudio_channels samples may
46 * play at the same time through different speakers. Thus this value is
47 * independent of @ref uaudio_channels.
49 size_t uaudio_sample_size
;
51 /** @brief Set a uaudio option */
52 void uaudio_set(const char *name
, const char *value
) {
54 uaudio_options
= hash_new(sizeof(char *));
55 value
= xstrdup(value
);
56 hash_add(uaudio_options
, name
, &value
, HASH_INSERT_OR_REPLACE
);
59 /** @brief Set a uaudio option */
60 char *uaudio_get(const char *name
) {
61 const char *value
= (uaudio_options ?
62 *(char **)hash_find(uaudio_options
, name
)
64 return value ?
xstrdup(value
) : NULL
;
67 /** @brief Set sample format
68 * @param rate Sample rate in KHz
69 * @param channels Number of channels (i.e. 2 for stereo)
70 * @param bits Number of bits per channel (typically 8 or 16)
71 * @param signed_ True for signed samples, false for unsigned
73 * Sets @ref uaudio_rate, @ref uaudio_channels, @ref uaudio_bits, @ref
74 * uaudio_signed and @ref uaudio_sample_size.
76 * Currently there is no way to specify non-native endian formats even if the
77 * underlying API can conveniently handle them. Actually this would be quite
78 * convenient for playrtp, so it might be added at some point.
80 * Not all APIs can support all sample formats. Generally the @c start
81 * function will do some error checking but some may be deferred to the point
82 * the device is opened (which might be @c activate).
84 void uaudio_set_format(int rate
, int channels
, int bits
, int signed_
) {
86 uaudio_channels
= channels
;
88 uaudio_signed
= signed_
;
89 uaudio_sample_size
= bits
/ CHAR_BIT
;
92 /** @brief List of known APIs
94 * Terminated by a null pointer.
96 * The first one will be used as a default, so putting ALSA before OSS
97 * constitutes a policy decision.
99 const struct uaudio
*uaudio_apis
[] = {
100 #if HAVE_COREAUDIO_AUDIOHARDWARE_H
103 #if HAVE_ALSA_ASOUNDLIB_H
106 #if HAVE_SYS_SOUNDCARD_H || EMPEG_HOST