| 1 | /* |
| 2 | * This file is part of DisOrder. |
| 3 | * Copyright (C) 2009 Richard Kettlewell |
| 4 | * |
| 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. |
| 9 | * |
| 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. |
| 14 | * |
| 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/>. |
| 17 | */ |
| 18 | |
| 19 | /** @file lib/uaudio.c |
| 20 | * @brief Uniform audio interface |
| 21 | */ |
| 22 | |
| 23 | #include "common.h" |
| 24 | #include "uaudio.h" |
| 25 | #include "hash.h" |
| 26 | #include "mem.h" |
| 27 | #include "log.h" |
| 28 | |
| 29 | /** @brief Options for chosen uaudio API */ |
| 30 | static hash *uaudio_options; |
| 31 | |
| 32 | /** @brief Sample rate (Hz) */ |
| 33 | int uaudio_rate; |
| 34 | |
| 35 | /** @brief Bits per channel */ |
| 36 | int uaudio_bits; |
| 37 | |
| 38 | /** @brief Number of channels */ |
| 39 | int uaudio_channels; |
| 40 | |
| 41 | /** @brief Whether samples are signed or unsigned */ |
| 42 | int uaudio_signed; |
| 43 | |
| 44 | /** @brief Sample size in bytes |
| 45 | * |
| 46 | * NB one sample is a single point sample; up to @c uaudio_channels samples may |
| 47 | * play at the same time through different speakers. Thus this value is |
| 48 | * independent of @ref uaudio_channels. |
| 49 | */ |
| 50 | size_t uaudio_sample_size; |
| 51 | |
| 52 | /** @brief Set a uaudio option */ |
| 53 | void uaudio_set(const char *name, const char *value) { |
| 54 | if(!value) { |
| 55 | if(uaudio_options) |
| 56 | hash_remove(uaudio_options, name); |
| 57 | return; |
| 58 | } |
| 59 | if(!uaudio_options) |
| 60 | uaudio_options = hash_new(sizeof(char *)); |
| 61 | value = xstrdup(value); |
| 62 | hash_add(uaudio_options, name, &value, HASH_INSERT_OR_REPLACE); |
| 63 | } |
| 64 | |
| 65 | /** @brief Get a uaudio option */ |
| 66 | char *uaudio_get(const char *name, const char *default_value) { |
| 67 | if(!uaudio_options) |
| 68 | return default_value ? xstrdup(default_value) : 0; |
| 69 | char **valuep = hash_find(uaudio_options, name); |
| 70 | if(!valuep) |
| 71 | return default_value ? xstrdup(default_value) : 0; |
| 72 | return xstrdup(*valuep); |
| 73 | } |
| 74 | |
| 75 | /** @brief Set sample format |
| 76 | * @param rate Sample rate in KHz |
| 77 | * @param channels Number of channels (i.e. 2 for stereo) |
| 78 | * @param bits Number of bits per channel (typically 8 or 16) |
| 79 | * @param signed_ True for signed samples, false for unsigned |
| 80 | * |
| 81 | * Sets @ref uaudio_rate, @ref uaudio_channels, @ref uaudio_bits, @ref |
| 82 | * uaudio_signed and @ref uaudio_sample_size. |
| 83 | * |
| 84 | * Currently there is no way to specify non-native endian formats even if the |
| 85 | * underlying API can conveniently handle them. Actually this would be quite |
| 86 | * convenient for playrtp, so it might be added at some point. |
| 87 | * |
| 88 | * Not all APIs can support all sample formats. Generally the @c start |
| 89 | * function will do some error checking but some may be deferred to the point |
| 90 | * the device is opened (which might be @c activate). |
| 91 | */ |
| 92 | void uaudio_set_format(int rate, int channels, int bits, int signed_) { |
| 93 | uaudio_rate = rate; |
| 94 | uaudio_channels = channels; |
| 95 | uaudio_bits = bits; |
| 96 | uaudio_signed = signed_; |
| 97 | uaudio_sample_size = bits / CHAR_BIT; |
| 98 | } |
| 99 | |
| 100 | /* |
| 101 | Local Variables: |
| 102 | c-basic-offset:2 |
| 103 | comment-column:40 |
| 104 | fill-column:79 |
| 105 | indent-tabs-mode:nil |
| 106 | End: |
| 107 | */ |