alsa/
chmap.rs

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1use crate::alsa;
2use std::{fmt, mem, slice};
3use super::error::*;
4
5alsa_enum!(
6    /// [SND_CHMAP_TYPE_xxx](http://www.alsa-project.org/alsa-doc/alsa-lib/group___p_c_m.html) constants
7    ChmapType, ALL_CHMAP_TYPES[4],
8
9    None = SND_CHMAP_TYPE_NONE,
10    Fixed = SND_CHMAP_TYPE_FIXED,
11    Var = SND_CHMAP_TYPE_VAR,
12    Paired = SND_CHMAP_TYPE_PAIRED,
13);
14
15alsa_enum!(
16    /// [SND_CHMAP_xxx](http://www.alsa-project.org/alsa-doc/alsa-lib/group___p_c_m.html) constants
17    ChmapPosition, ALL_CHMAP_POSITIONS[33],
18
19    Unknown = SND_CHMAP_UNKNOWN,
20    NA = SND_CHMAP_NA,
21    Mono = SND_CHMAP_MONO,
22    FL = SND_CHMAP_FL,
23    FR = SND_CHMAP_FR,
24    RL = SND_CHMAP_RL,
25    SR = SND_CHMAP_SR,
26    RC = SND_CHMAP_RC,
27    FLC = SND_CHMAP_FLC,
28    FRC = SND_CHMAP_FRC,
29    RLC = SND_CHMAP_RLC,
30    RRC = SND_CHMAP_RRC,
31    FLW = SND_CHMAP_FLW,
32    FRW = SND_CHMAP_FRW,
33    FLH = SND_CHMAP_FLH,
34    FCH = SND_CHMAP_FCH,
35    FRH = SND_CHMAP_FRH,
36    TC = SND_CHMAP_TC,
37    TFL = SND_CHMAP_TFL,
38    TFR = SND_CHMAP_TFR,
39    TFC = SND_CHMAP_TFC,
40    TRL = SND_CHMAP_TRL,
41    TRR = SND_CHMAP_TRR,
42    TRC = SND_CHMAP_TRC,
43    TFLC = SND_CHMAP_TFLC,
44    TFRC = SND_CHMAP_TFRC,
45    TSL = SND_CHMAP_TSL,
46    TSR = SND_CHMAP_TSR,
47    LLFE = SND_CHMAP_LLFE,
48    RLFE = SND_CHMAP_RLFE,
49    BC = SND_CHMAP_BC,
50    BLC = SND_CHMAP_BLC,
51    BRC = SND_CHMAP_BRC,
52);
53
54impl fmt::Display for ChmapPosition {
55    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
56        let s = unsafe { alsa::snd_pcm_chmap_long_name(*self as libc::c_uint) };
57        let s = from_const("snd_pcm_chmap_long_name", s)?;
58        write!(f, "{}", s)
59    }
60}
61
62
63/// [snd_pcm_chmap_t](http://www.alsa-project.org/alsa-doc/alsa-lib/group___p_c_m.html) wrapper
64pub struct Chmap(*mut alsa::snd_pcm_chmap_t, bool);
65
66impl Drop for Chmap {
67    fn drop(&mut self) { if self.1 { unsafe { libc::free(self.0 as *mut libc::c_void) }}}
68}
69
70impl Chmap {
71    fn set_channels(&mut self, c: libc::c_uint) { unsafe { (*self.0) .channels = c }}
72    fn as_slice_mut(&mut self) -> &mut [libc::c_uint] {
73        unsafe { slice::from_raw_parts_mut((*self.0).pos.as_mut_ptr(), (*self.0).channels as usize) }
74    }
75    fn as_slice(&self) -> &[libc::c_uint] {
76        unsafe { slice::from_raw_parts((*self.0).pos.as_ptr(), (*self.0).channels as usize) }
77    }
78}
79
80impl fmt::Display for Chmap {
81    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
82        let mut buf: Vec<libc::c_char> = vec![0; 512];
83        acheck!(snd_pcm_chmap_print(self.0, buf.len() as libc::size_t, buf.as_mut_ptr()))?;
84        let s = from_const("snd_pcm_chmap_print", buf.as_mut_ptr())?;
85        write!(f, "{}", s)
86    }
87}
88
89impl<'a> From<&'a [ChmapPosition]> for Chmap {
90    fn from(a: &'a [ChmapPosition]) -> Chmap {
91        let p = unsafe { libc::malloc((mem::size_of::<alsa::snd_pcm_chmap_t>() + mem::size_of::<libc::c_uint>() * a.len()) as libc::size_t) };
92        if p.is_null() { panic!("Out of memory") }
93        let mut r = Chmap(p as *mut alsa::snd_pcm_chmap_t, true);
94        r.set_channels(a.len() as libc::c_uint);
95        for (i,v) in r.as_slice_mut().iter_mut().enumerate() { *v = a[i] as libc::c_uint }
96        r
97    }
98}
99
100impl<'a> From<&'a Chmap> for Vec<ChmapPosition> {
101    fn from(a: &'a Chmap) -> Vec<ChmapPosition> {
102        a.as_slice().iter().map(|&v| ChmapPosition::from_c_int(v as libc::c_int, "").unwrap()).collect()
103    }
104}
105
106pub fn chmap_new(a: *mut alsa::snd_pcm_chmap_t) -> Chmap { Chmap(a, true) }
107pub fn chmap_handle(a: &Chmap) -> *mut alsa::snd_pcm_chmap_t { a.0 }
108
109
110/// Iterator over available channel maps - see [snd_pcm_chmap_query_t](http://www.alsa-project.org/alsa-doc/alsa-lib/group___p_c_m.html)
111pub struct ChmapsQuery(*mut *mut alsa::snd_pcm_chmap_query_t, isize);
112
113impl Drop for ChmapsQuery {
114    fn drop(&mut self) { unsafe { alsa::snd_pcm_free_chmaps(self.0) }}
115}
116
117pub fn chmaps_query_new(a: *mut *mut alsa::snd_pcm_chmap_query_t) -> ChmapsQuery { ChmapsQuery(a, 0) }
118
119impl Iterator for ChmapsQuery {
120    type Item = (ChmapType, Chmap);
121    fn next(&mut self) -> Option<Self::Item> {
122        if self.0.is_null() { return None; }
123        let p = unsafe { *self.0.offset(self.1) };
124        if p.is_null() { return None; }
125        self.1 += 1;
126        let t = ChmapType::from_c_int(unsafe { (*p).type_ } as libc::c_int, "snd_pcm_query_chmaps").unwrap();
127        let m = Chmap(unsafe { &mut (*p).map }, false);
128        Some((t, m))
129    }
130}
131
132
133#[test]
134fn chmap_for_first_pcm() {
135    use super::*;
136    use std::ffi::CString;
137    use crate::device_name::HintIter;
138    let i = HintIter::new(None, &*CString::new("pcm").unwrap()).unwrap();
139    for p in i.map(|n| n.name.unwrap()) {
140        println!("Chmaps for {:?}:", p);
141        match PCM::open(&CString::new(p).unwrap(),  Direction::Playback, false) {
142            Ok(a) => for c in a.query_chmaps() {
143               println!("  {:?}, {}", c.0, c.1);
144            },
145            Err(a) => println!("  {}", a) // It's okay to have entries in the name hint array that can't be opened
146        }
147    }
148}
alsa/chmap.rs

alsa/
chmap.rs
