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// Copyright 2017 Lyndon Brown
//
// This file is part of the PulseAudio Rust language binding.
//
// Licensed under the MIT license or the Apache license (version 2.0), at your option. You may not
// copy, modify, or distribute this file except in compliance with said license. You can find copies
// of these licenses either in the LICENSE-MIT and LICENSE-APACHE files, or alternatively at
// <http://opensource.org/licenses/MIT> and <http://www.apache.org/licenses/LICENSE-2.0>
// respectively.
//
// Portions of documentation are copied from the LGPL 2.1+ licensed PulseAudio C headers on a
// fair-use basis, as discussed in the overall project readme (available in the git repository).
//! Constants and routines for sample type handling.
//!
//! # Overview
//!
//! PulseAudio is capable of handling a multitude of sample formats, rates and channels,
//! transparently converting and mixing them as needed.
//!
//! # Sample Formats
//!
//! PulseAudio supports the following sample formats:
//!
//! * `U8` - Unsigned 8 bit integer PCM.
//! * `S16LE` - Signed 16 integer bit PCM, little endian.
//! * `S16BE` - Signed 16 integer bit PCM, big endian.
//! * `FLOAT32LE` - 32 bit IEEE floating point PCM, little endian.
//! * `FLOAT32BE` - 32 bit IEEE floating point PCM, big endian.
//! * `ALAW` - 8 bit a-Law.
//! * `ULAW` - 8 bit mu-Law.
//! * `S32LE` - Signed 32 bit integer PCM, little endian.
//! * `S32BE` - Signed 32 bit integer PCM, big endian.
//! * `S24LE` - Signed 24 bit integer PCM packed, little endian.
//! * `S24BE` - Signed 24 bit integer PCM packed, big endian.
//! * `S24_32LE` - Signed 24 bit integer PCM in LSB of 32 bit words, little endian.
//! * `S24_32BE` - Signed 24 bit integer PCM in LSB of 32 bit words, big endian.
//!
//! The floating point sample formats have the range from `-1.0` to `1.0`.
//!
//! # Sample Rates
//!
//! PulseAudio supports any sample rate between 1 Hz and 192000 Hz. There is no point trying to
//! exceed the sample rate of the output device though as the signal will only get downsampled,
//! consuming CPU on the machine running the server.
//!
//! # Channels
//!
//! PulseAudio supports up to 32 individual channels. The order of the channels is up to the
//! application, but they must be continuous. To map channels to speakers, see
//! [`channelmap`](mod@crate::channelmap).
//!
//! # Calculations
//!
//! The PulseAudio library contains a number of convenience functions to do calculations on sample
//! formats:
//!
//! * [`Spec::bytes_per_second()`]: The number of bytes one second of audio will take given a sample
//! format.
//! * [`Spec::frame_size()`]: The size, in bytes, of one frame (i.e. one set of samples, one for
//! each channel).
//! * [`Spec::sample_size()`]: The size, in bytes, of one sample.
//! * [`Spec::bytes_to_usec()`]: Calculate the time it would take to play a buffer of a certain
//! size.
use std::ffi::{CStr, CString};
use std::borrow::Cow;
use num_derive::{FromPrimitive, ToPrimitive};
use crate::time::MicroSeconds;
/// Maximum number of allowed channels.
#[deprecated(since = "2.20.0", note = "use associated constants on structs instead")]
pub const CHANNELS_MAX: u8 = capi::PA_CHANNELS_MAX;
/// Maximum allowed sample rate.
#[deprecated(since = "2.20.0", note = "use the associated constant on `Spec` instead")]
pub const RATE_MAX: u32 = capi::PA_RATE_MAX;
/// Sample format.
///
/// Note, native-endian (endian-independent) associated constants are available on this type which
/// should be preferred over direct use of the endian-specific variants, for improved flexibility
/// and avoidance of mistakes.
#[repr(C)]
#[derive(Debug, Copy, Clone, PartialEq, Eq)]
#[derive(FromPrimitive, ToPrimitive)]
#[allow(non_camel_case_types)]
pub enum Format {
/* NOTE: This enum’s variants and variant values **must** remain identical to the `sys` crate
(C API) equivalent */
/// Unsigned 8 Bit PCM.
U8,
/// 8 Bit a-Law.
ALaw,
/// 8 Bit mu-Law.
ULaw,
/// Signed 16 Bit PCM, little endian (PC).
S16le,
/// Signed 16 Bit PCM, big endian.
S16be,
/// 32 Bit IEEE floating point, little endian (PC), range -1.0 to 1.0.
F32le,
/// 32 Bit IEEE floating point, big endian, range -1.0 to 1.0.
F32be,
/// Signed 32 Bit PCM, little endian (PC).
S32le,
/// Signed 32 Bit PCM, big endian.
S32be,
/// Signed 24 Bit PCM packed, little endian (PC).
S24le,
/// Signed 24 Bit PCM packed, big endian.
S24be,
/// Signed 24 Bit PCM in LSB of 32 Bit words, little endian (PC).
S24_32le,
/// Signed 24 Bit PCM in LSB of 32 Bit words, big endian.
S24_32be,
/// An invalid value.
Invalid = -1,
}
/// Check is equal to `sys` equivalent
#[test]
fn format_compare_capi() {
assert_eq!(std::mem::size_of::<Format>(), std::mem::size_of::<capi::pa_sample_format_t>());
assert_eq!(std::mem::align_of::<Format>(), std::mem::align_of::<capi::pa_sample_format_t>());
// Check order and value of variants match
// No point checking conversions in both directions since both are a transmute
assert_eq!(Format::U8, Format::from(capi::pa_sample_format_t::U8));
assert_eq!(Format::ALaw, Format::from(capi::pa_sample_format_t::ALaw));
assert_eq!(Format::ULaw, Format::from(capi::pa_sample_format_t::ULaw));
assert_eq!(Format::S16le, Format::from(capi::pa_sample_format_t::S16le));
assert_eq!(Format::S16be, Format::from(capi::pa_sample_format_t::S16be));
assert_eq!(Format::F32le, Format::from(capi::pa_sample_format_t::F32le));
assert_eq!(Format::F32be, Format::from(capi::pa_sample_format_t::F32be));
assert_eq!(Format::S32le, Format::from(capi::pa_sample_format_t::S32le));
assert_eq!(Format::S32be, Format::from(capi::pa_sample_format_t::S32be));
assert_eq!(Format::S24le, Format::from(capi::pa_sample_format_t::S24le));
assert_eq!(Format::S24be, Format::from(capi::pa_sample_format_t::S24be));
assert_eq!(Format::S24_32le, Format::from(capi::pa_sample_format_t::S24_32le));
assert_eq!(Format::S24_32be, Format::from(capi::pa_sample_format_t::S24_32be));
assert_eq!(Format::Invalid, Format::from(capi::pa_sample_format_t::Invalid));
}
impl From<Format> for capi::pa_sample_format_t {
#[inline]
fn from(f: Format) -> Self {
unsafe { std::mem::transmute(f) }
}
}
impl From<capi::pa_sample_format_t> for Format {
#[inline]
fn from(f: capi::pa_sample_format_t) -> Self {
unsafe { std::mem::transmute(f) }
}
}
impl Default for Format {
#[inline(always)]
fn default() -> Self {
Format::Invalid
}
}
// The following are endian-independant format references.
/// A shortcut for [`SAMPLE_FLOAT32NE`].
#[allow(deprecated)]
#[deprecated(since = "2.20.0", note = "use the `FLOAT32NE` associated constant on `Format` instead")]
pub const SAMPLE_FLOAT32: Format = SAMPLE_FLOAT32NE;
/// Signed 16-bit PCM, native endian.
#[deprecated(since = "2.20.0", note = "use the associated constant on `Format` instead")]
pub const SAMPLE_S16NE: Format = self::ei_formats::SAMPLE_S16NE;
/// 32-bit IEEE floating point, native endian.
#[deprecated(since = "2.20.0", note = "use the associated constant on `Format` instead")]
pub const SAMPLE_FLOAT32NE: Format = self::ei_formats::SAMPLE_FLOAT32NE;
/// Signed 32-bit PCM, native endian.
#[deprecated(since = "2.20.0", note = "use the associated constant on `Format` instead")]
pub const SAMPLE_S32NE: Format = self::ei_formats::SAMPLE_S32NE;
/// Signed 24-bit PCM packed, native endian.
#[deprecated(since = "2.20.0", note = "use the associated constant on `Format` instead")]
pub const SAMPLE_S24NE: Format = self::ei_formats::SAMPLE_S24NE;
/// Signed 24-bit PCM in LSB of 32-bit words, native endian.
#[deprecated(since = "2.20.0", note = "use the associated constant on `Format` instead")]
pub const SAMPLE_S24_32NE: Format = self::ei_formats::SAMPLE_S24_32NE;
/// Signed 16-bit PCM reverse endian.
#[deprecated(since = "2.20.0", note = "use the associated constant on `Format` instead")]
pub const SAMPLE_S16RE: Format = self::ei_formats::SAMPLE_S16RE;
/// 32-bit IEEE floating point, reverse endian.
#[deprecated(since = "2.20.0", note = "use the associated constant on `Format` instead")]
pub const SAMPLE_FLOAT32RE: Format = self::ei_formats::SAMPLE_FLOAT32RE;
/// Signed 32-bit PCM, reverse endian.
#[deprecated(since = "2.20.0", note = "use the associated constant on `Format` instead")]
pub const SAMPLE_S32RE: Format = self::ei_formats::SAMPLE_S32RE;
/// Signed 24-bit PCM, packed reverse endian.
#[deprecated(since = "2.20.0", note = "use the associated constant on `Format` instead")]
pub const SAMPLE_S24RE: Format = self::ei_formats::SAMPLE_S24RE;
/// Signed 24-bit PCM, in LSB of 32-bit words, reverse endian.
#[deprecated(since = "2.20.0", note = "use the associated constant on `Format` instead")]
pub const SAMPLE_S24_32RE: Format = self::ei_formats::SAMPLE_S24_32RE;
/// Endian-independent format identifiers, for big-endian systems.
#[cfg(target_endian = "big")]
mod ei_formats {
use super::Format;
pub const SAMPLE_S16NE: Format = Format::S16be;
pub const SAMPLE_FLOAT32NE: Format = Format::F32be;
pub const SAMPLE_S32NE: Format = Format::S32be;
pub const SAMPLE_S24NE: Format = Format::S24be;
pub const SAMPLE_S24_32NE: Format = Format::S24_32be;
pub const SAMPLE_S16RE: Format = Format::S16le;
pub const SAMPLE_FLOAT32RE: Format = Format::F32le;
pub const SAMPLE_S32RE: Format = Format::S32le;
pub const SAMPLE_S24RE: Format = Format::S24le;
pub const SAMPLE_S24_32RE: Format = Format::S24_32le;
}
/// Endian-independent format identifiers, for little-endian systems.
#[cfg(target_endian = "little")]
mod ei_formats {
use super::Format;
pub const SAMPLE_S16NE: Format = Format::S16le;
pub const SAMPLE_FLOAT32NE: Format = Format::F32le;
pub const SAMPLE_S32NE: Format = Format::S32le;
pub const SAMPLE_S24NE: Format = Format::S24le;
pub const SAMPLE_S24_32NE: Format = Format::S24_32le;
pub const SAMPLE_S16RE: Format = Format::S16be;
pub const SAMPLE_FLOAT32RE: Format = Format::F32be;
pub const SAMPLE_S32RE: Format = Format::S32be;
pub const SAMPLE_S24RE: Format = Format::S24be;
pub const SAMPLE_S24_32RE: Format = Format::S24_32be;
}
/// A sample format and attribute specification.
#[repr(C)]
#[derive(Debug, Copy, Clone, Eq)]
pub struct Spec {
/* NOTE: This struct must be directly usable by the C API, thus same attributes/layout/etc */
/// The sample format.
pub format: Format,
/// The sample rate. (e.g. 44100).
pub rate: u32,
/// Audio channels. (1 for mono, 2 for stereo, ...).
pub channels: u8,
}
/// Test size is equal to `sys` equivalent
#[test]
fn spec_compare_capi() {
assert_eq!(std::mem::size_of::<Spec>(), std::mem::size_of::<capi::pa_sample_spec>());
assert_eq!(std::mem::align_of::<Spec>(), std::mem::align_of::<capi::pa_sample_spec>());
}
impl AsRef<capi::pa_sample_spec> for Spec {
#[inline]
fn as_ref(&self) -> &capi::pa_sample_spec {
unsafe { &*(self as *const Self as *const capi::pa_sample_spec) }
}
}
impl AsMut<capi::pa_sample_spec> for Spec {
#[inline]
fn as_mut(&mut self) -> &mut capi::pa_sample_spec {
unsafe { &mut *(self as *mut Self as *mut capi::pa_sample_spec) }
}
}
impl AsRef<Spec> for capi::pa_sample_spec {
#[inline]
fn as_ref(&self) -> &Spec {
unsafe { &*(self as *const Self as *const Spec) }
}
}
impl From<capi::pa_sample_spec> for Spec {
#[inline]
fn from(s: capi::pa_sample_spec) -> Self {
unsafe { std::mem::transmute(s) }
}
}
impl PartialEq for Spec {
#[inline]
fn eq(&self, other: &Self) -> bool {
unsafe { capi::pa_sample_spec_equal(self.as_ref(), other.as_ref()) != 0 }
}
}
impl Spec {
/// Maximum number of allowed channels.
pub const CHANNELS_MAX: u8 = capi::PA_CHANNELS_MAX;
/// Maximum allowed sample rate.
pub const RATE_MAX: u32 = capi::PA_RATE_MAX;
/// Initializes the specified sample spec.
///
/// The sample spec will have a defined state but [`is_valid()`](Self::is_valid) will fail for
/// it.
#[inline]
pub fn init(&mut self) {
unsafe { capi::pa_sample_spec_init(self.as_mut()); }
}
/// Checks if the whole sample type specification is valid.
#[inline]
pub fn is_valid(&self) -> bool {
unsafe { capi::pa_sample_spec_valid(self.as_ref()) != 0 }
}
/// Checks only if the format attribute is valid.
///
/// Or in other words that the client library running on the end user system accepts it.
#[inline]
pub fn format_is_valid(&self) -> bool {
unsafe { capi::pa_sample_format_valid(self.format as u32) != 0 }
}
/// Checks only if the rate is within the supported range.
#[inline]
pub fn rate_is_valid(&self) -> bool {
unsafe { capi::pa_sample_rate_valid(self.rate) != 0 }
}
/// Checks only if the channel count is within the supported range.
#[inline]
pub fn channels_are_valid(&self) -> bool {
unsafe { capi::pa_channels_valid(self.channels) != 0 }
}
/// Gets the amount of bytes that constitute playback of one second of audio, with the specified
/// sample type.
#[inline]
pub fn bytes_per_second(&self) -> usize {
unsafe { capi::pa_bytes_per_second(self.as_ref()) }
}
/// Gets the size of a frame.
#[inline]
pub fn frame_size(&self) -> usize {
unsafe { capi::pa_frame_size(self.as_ref()) }
}
/// Gets the size of a sample.
#[inline]
pub fn sample_size(&self) -> usize {
unsafe { capi::pa_sample_size(self.as_ref()) }
}
/// Calculates the time it would take to play a buffer of the specified size.
///
/// The return value will always be rounded down for non-integral return values.
///
/// Note, the underlying calculation may overflow for very large values.
#[inline]
pub fn bytes_to_usec(&self, length: u64) -> MicroSeconds {
MicroSeconds(unsafe { capi::pa_bytes_to_usec(length, self.as_ref()) })
}
/// Calculates the size of a buffer required, for playback duration of the time specified.
///
/// The return value will always be rounded down for non-integral return values.
///
/// Note, the underlying calculation may overflow for very large values.
#[inline]
pub fn usec_to_bytes(&self, t: MicroSeconds) -> usize {
unsafe { capi::pa_usec_to_bytes(t.0, self.as_ref()) }
}
/// Pretty prints a sample type specification to a string.
pub fn print(&self) -> String {
const PRINT_MAX: usize = capi::PA_SAMPLE_SPEC_SNPRINT_MAX;
let mut tmp = Vec::with_capacity(PRINT_MAX);
unsafe {
capi::pa_sample_spec_snprint(tmp.as_mut_ptr(), PRINT_MAX, self.as_ref());
CStr::from_ptr(tmp.as_mut_ptr()).to_string_lossy().into_owned()
}
}
}
/// Pretty print a byte size value (i.e. “2.5 MiB”).
pub fn bytes_print(bytes: u32) -> String {
const PRINT_MAX: usize = capi::PA_BYTES_SNPRINT_MAX;
let mut tmp = Vec::with_capacity(PRINT_MAX);
unsafe {
capi::pa_bytes_snprint(tmp.as_mut_ptr(), PRINT_MAX, bytes);
CStr::from_ptr(tmp.as_mut_ptr()).to_string_lossy().into_owned()
}
}
impl Format {
/// Signed 16-bit PCM, native endian.
pub const S16NE: Self = self::ei_formats::SAMPLE_S16NE;
/// 32-bit IEEE floating point, native endian.
pub const FLOAT32NE: Self = self::ei_formats::SAMPLE_FLOAT32NE;
/// Signed 32-bit PCM, native endian.
pub const S32NE: Self = self::ei_formats::SAMPLE_S32NE;
/// Signed 24-bit PCM packed, native endian.
pub const S24NE: Self = self::ei_formats::SAMPLE_S24NE;
/// Signed 24-bit PCM in LSB of 32-bit words, native endian.
pub const S24_32NE: Self = self::ei_formats::SAMPLE_S24_32NE;
/// Signed 16-bit PCM reverse endian.
pub const S16RE: Self = self::ei_formats::SAMPLE_S16RE;
/// 32-bit IEEE floating point, reverse endian.
pub const FLOAT32RE: Self = self::ei_formats::SAMPLE_FLOAT32RE;
/// Signed 32-bit PCM, reverse endian.
pub const S32RE: Self = self::ei_formats::SAMPLE_S32RE;
/// Signed 24-bit PCM, packed reverse endian.
pub const S24RE: Self = self::ei_formats::SAMPLE_S24RE;
/// Signed 24-bit PCM, in LSB of 32-bit words, reverse endian.
pub const S24_32RE: Self = self::ei_formats::SAMPLE_S24_32RE;
/// Similar to [`Spec::sample_size()`] but take a sample format instead of full sample spec.
#[inline]
pub fn size(&self) -> usize {
unsafe { capi::pa_sample_size_of_format((*self).into()) }
}
/// Gets a descriptive string for the specified sample format.
pub fn to_string(&self) -> Option<Cow<'static, str>> {
let ptr = unsafe { capi::pa_sample_format_to_string((*self).into()) };
match ptr.is_null() {
false => Some(unsafe { CStr::from_ptr(ptr).to_string_lossy() }),
true => None,
}
}
/// Parses a sample format text. Inverse of [`to_string()`](Self::to_string).
pub fn parse(format: &str) -> Self {
// Warning: New CStrings will be immediately freed if not bound to a variable, leading to
// as_ptr() giving dangling pointers!
let c_format = CString::new(format.clone()).unwrap();
unsafe { capi::pa_parse_sample_format(c_format.as_ptr()).into() }
}
/// Checks if format is little endian.
///
/// Returns `true` when the specified format is little endian, `false` if big endian. Returns
/// `None` when endianness does not apply to this format, or if unknown.
pub fn is_le(&self) -> Option<bool> {
match unsafe { capi::pa_sample_format_is_le((*self).into()) } {
0 => Some(false),
1 => Some(true),
_ => None,
}
}
/// Checks if format is big endian.
///
/// Returns `true` when the specified format is big endian, `false` if little endian. Returns
/// `None` when endianness does not apply to this format, or if unknown.
pub fn is_be(&self) -> Option<bool> {
match unsafe { capi::pa_sample_format_is_be((*self).into()) } {
0 => Some(false),
1 => Some(true),
_ => None,
}
}
/// Checks if format is native endian.
///
/// Returns `true` when the specified format is native endian, `false` when not. Returns `None`
/// when endianness does not apply to the specified format, or endianness is unknown.
#[inline]
pub fn is_ne(&self) -> Option<bool> {
#[cfg(target_endian = "big")]
{ Format::is_be(self) }
#[cfg(target_endian = "little")]
{ Format::is_le(self) }
}
/// Checks if format is reverse of native endian.
///
/// Returns `true` when the specified format is reverse endian, `false` when not. Returns `None`
/// when endianness does not apply to the specified format, or endianness is unknown.
#[inline]
pub fn is_re(&self) -> Option<bool> {
self.is_ne().and_then(|b| Some(!b))
}
}