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//! Constants and routines for volume handling. // This file is part of the PulseAudio Rust language binding. // // Copyright (c) 2017 Lyndon Brown // // This library is free software; you can redistribute it and/or modify it under the terms of the // GNU Lesser General Public License as published by the Free Software Foundation; either version // 2.1 of the License, or (at your option) any later version. // // This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without // even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU // Lesser General Public License for more details. // // You should have received a copy of the GNU Lesser General Public License along with this library; // if not, see <http://www.gnu.org/licenses/>. //! # Overview //! //! Sinks, sources, sink inputs, source outputs and samples can all have their own volumes. To deal //! with these, The PulseAudio library contains a number of functions that ease handling. //! //! The basic volume type in PulseAudio is the [`Volume`] type. Most of the time, applications will //! use the aggregated [`ChannelVolumes`] structure that can store the volume of all channels at //! once. //! //! Volumes commonly span between muted (0%), and normal (100%). It is possible to set volumes to //! higher than 100%, but clipping might occur. //! //! There is no single well-defined meaning attached to the 100% volume for a sink input. In fact, //! it depends on the server configuration. With flat volumes enabled, it means the maximum volume //! that the sound hardware is capable of, which is usually so high that you absolutely must not set //! sink input volume to 100% unless the the user explicitly requests that (note that usually you //! shouldn't set the volume anyway if the user doesn't explicitly request it, instead, let //! PulseAudio decide the volume for the sink input). With flat volumes disabled the sink input //! volume is relative to the sink volume, so 100% sink input volume means that the sink input is //! played at the current sink volume level. In this case 100% is often a good default volume for a //! sink input, although you still should let PulseAudio decide the default volume. It is possible //! to figure out whether flat volume mode is in effect for a given sink by calling //! [`::context::introspect::Introspector::get_sink_info_by_name`]. //! //! # Calculations //! //! The [`Volume`]s in PulseAudio are cubic in nature and applications should not perform //! calculations with them directly. Instead, they should be converted to and from either dB or a //! linear scale. //! //! The [`VolumeDB`] type represents decibel (dB) converted values, and [`VolumeLinear`], linear. //! The `From` trait has been implemented for your convenience, allowing such conversions. //! //! For simple multiplication, [`Volume::multiply`] and [`ChannelVolumes::sw_multiply`] can be used. //! //! It's often unknown what scale hardware volumes relate to. Don't use the above functions on sink //! and source volumes, unless the sink or source in question has the //! [`::def::sink_flags::DECIBEL_VOLUME`] or [`::def::source_flags::DECIBEL_VOLUME`] flag set. The //! conversion functions are rarely needed anyway, most of the time it's sufficient to treat all //! volumes as opaque with a range from [`VOLUME_MUTED`] \(0%) to [`VOLUME_NORM`] \(100%). //! //! [`Volume`]: struct.Volume.html //! [`VolumeDB`]: struct.VolumeDB.html //! [`VolumeLinear`]: struct.VolumeLinear.html //! [`ChannelVolumes`]: struct.ChannelVolumes.html //! [`::context::introspect::Introspector::get_sink_info_by_name`]: //! ../context/introspect/struct.Introspector.html#method.get_sink_info_by_name //! [`Volume::multiply`]: struct.Volume.html#method.multiply //! [`ChannelVolumes::sw_multiply`]: struct.ChannelVolumes.html#method.sw_multiply //! [`VOLUME_MUTED`]: constant.VOLUME_MUTED.html //! [`VOLUME_NORM`]: constant.VOLUME_NORM.html //! [`::def::sink_flags::DECIBEL_VOLUME`]: ../def/sink_flags/constant.DECIBEL_VOLUME.html //! [`::def::source_flags::DECIBEL_VOLUME`]: ../def/source_flags/constant.DECIBEL_VOLUME.html use std; use capi; use std::ffi::CStr; use std::ptr::null; pub const VOLUME_NORM: Volume = Volume(capi::PA_VOLUME_NORM); pub const VOLUME_MUTED: Volume = Volume(capi::PA_VOLUME_MUTED); pub const VOLUME_MAX: Volume = Volume(capi::PA_VOLUME_MAX); pub const VOLUME_INVALID: Volume = Volume(capi::PA_VOLUME_INVALID); /// Minus Infinity. This floor value is used / can be used, when using converting between integer /// software volume and decibel (dB, floating point) software volume. pub const DECIBEL_MINUS_INFINITY: VolumeDB = VolumeDB(capi::PA_DECIBEL_MININFTY); /// Software volume expressed as an integer #[derive(Debug, Copy, Clone, PartialEq, Eq, PartialOrd, Ord)] pub struct Volume(pub capi::pa_volume_t); impl Default for Volume { fn default() -> Self { VOLUME_NORM } } /// Software volume expressed in decibels (dBs) #[derive(Debug, Copy, Clone, PartialEq, PartialOrd)] pub struct VolumeDB(pub f64); impl Default for VolumeDB { fn default() -> Self { VolumeDB(0.0) } } /// Software volume expressed as linear factor #[derive(Debug, Copy, Clone, PartialEq, PartialOrd)] pub struct VolumeLinear(pub f64); impl Default for VolumeLinear { fn default() -> Self { VolumeLinear(0.0) } } /// A structure encapsulating a per-channel volume #[repr(C)] #[derive(Debug, Copy, Clone, Default)] pub struct ChannelVolumes { /// Number of channels. pub channels: u8, /// Per-channel volume. pub values: [Volume; ::sample::CHANNELS_MAX], } impl PartialEq for ChannelVolumes { fn eq(&self, other: &Self) -> bool { match self.channels == other.channels { true => self.values[..self.channels as usize] == other.values[..other.channels as usize], false => false, } } } /// Convert a decibel value to a volume (amplitude, not power). /// This is only valid for software volumes! impl From<VolumeDB> for Volume { fn from(v: VolumeDB) -> Self { Volume(unsafe { capi::pa_sw_volume_from_dB(v.0) }) } } /// Convert a volume to a decibel value (amplitude, not power). /// This is only valid for software volumes! impl From<Volume> for VolumeDB { fn from(v: Volume) -> Self { VolumeDB(unsafe { capi::pa_sw_volume_to_dB(v.0) }) } } /// Convert a linear factor to a volume. /// `0.0` and less is muted while `1.0` is [`VOLUME_NORM`](constant.VOLUME_NORM.html). /// This is only valid for software volumes! impl From<VolumeLinear> for Volume { fn from(v: VolumeLinear) -> Self { Volume(unsafe { capi::pa_sw_volume_from_linear(v.0) }) } } /// Convert a volume to a linear factor. /// This is only valid for software volumes! impl From<Volume> for VolumeLinear { fn from(v: Volume) -> Self { VolumeLinear(unsafe { capi::pa_sw_volume_to_linear(v.0) }) } } /// Convert a linear factor to a decibel value (amplitude, not power). /// `0.0` and less is muted while `1.0` is [`VOLUME_NORM`](constant.VOLUME_NORM.html). /// This is only valid for software volumes! impl From<VolumeLinear> for VolumeDB { fn from(v: VolumeLinear) -> Self { VolumeDB::from(Volume::from(v)) } } /// Convert a decibel value (amplitude, not power) to a linear factor. /// This is only valid for software volumes! impl From<VolumeDB> for VolumeLinear { fn from(v: VolumeDB) -> Self { VolumeLinear::from(Volume::from(v)) } } impl VolumeLinear { pub fn is_muted(&self) -> bool { self.0 <= 0.0 } pub fn is_normal(&self) -> bool { self.0 == 1.0 } } impl Volume { pub fn is_muted(&self) -> bool { *self == VOLUME_MUTED } pub fn is_normal(&self) -> bool { *self == VOLUME_NORM } pub fn is_max(&self) -> bool { *self == VOLUME_MAX } /// Recommended maximum volume to show in user facing UIs. /// Note: UIs should deal gracefully with volumes greater than this value and not cause feedback /// loops etc. - i.e. if the volume is more than this, the UI should not limit it and push the /// limited value back to the server. pub fn ui_max() -> Self { Volume(capi::pa_volume_ui_max()) } /// Check if volume is valid. pub fn is_valid(&self) -> bool { capi::pa_volume_is_valid(self.0) } /// Clamp volume to the permitted range. pub fn clamp(&mut self) { self.0 = capi::pa_clamp_volume(self.0) } /// Multiply two software volumes, return the result. /// This uses [`VOLUME_NORM`](constant.VOLUME_NORM.html) as neutral element of multiplication. /// This is only valid for software volumes! pub fn multiply(a: Self, b: Self) -> Self { Volume(unsafe { capi::pa_sw_volume_multiply(a.0, b.0) }) } /// Divide two software volumes, return the result. /// /// This uses [`VOLUME_NORM`](constant.VOLUME_NORM.html) as neutral element of division. This is /// only valid for software volumes! If a division by zero is tried the result will be `0`. pub fn divide(a: Self, b: Self) -> Self { Volume(unsafe { capi::pa_sw_volume_divide(a.0, b.0) }) } /// Pretty print a volume pub fn print(&self) -> String { const PRINT_MAX: usize = capi::PA_VOLUME_SNPRINT_MAX; let mut tmp = Vec::with_capacity(PRINT_MAX); unsafe { capi::pa_volume_snprint(tmp.as_mut_ptr(), PRINT_MAX, self.0); CStr::from_ptr(tmp.as_mut_ptr()).to_string_lossy().into_owned() } } /// Pretty print a volume but show dB values. pub fn print_db(&self) -> String { const PRINT_DB_MAX: usize = capi::PA_SW_VOLUME_SNPRINT_DB_MAX; let mut tmp = Vec::with_capacity(PRINT_DB_MAX); unsafe { capi::pa_sw_volume_snprint_dB(tmp.as_mut_ptr(), PRINT_DB_MAX, self.0); CStr::from_ptr(tmp.as_mut_ptr()).to_string_lossy().into_owned() } } /// Pretty print a volume in a verbose way. /// /// The volume is printed in several formats: the raw volume value, percentage, and if /// `print_db` is true, also the dB value. pub fn print_verbose(&self, print_db: bool) -> String { const PRINT_VERBOSE_MAX: usize = capi::PA_VOLUME_SNPRINT_VERBOSE_MAX; let mut tmp = Vec::with_capacity(PRINT_VERBOSE_MAX); unsafe { capi::pa_volume_snprint_verbose(tmp.as_mut_ptr(), PRINT_VERBOSE_MAX, self.0, print_db as i32); CStr::from_ptr(tmp.as_mut_ptr()).to_string_lossy().into_owned() } } } impl std::fmt::Display for Volume { fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result { write!(f, "{}", &self.print()) } } impl ChannelVolumes { /// Initialize the specified volume and return a pointer to it. The sample spec will have a /// defined state but [`is_valid`](#method.is_valid) will fail for it. pub fn init(&mut self) -> &Self { unsafe { capi::pa_cvolume_init(std::mem::transmute(&self)) }; self } /// Set the volume of the specified number of channels to the supplied volume pub fn set(&mut self, channels: u32, v: Volume) -> &Self { unsafe { capi::pa_cvolume_set(std::mem::transmute(&self), channels, v.0) }; self } /// Set the volume of the first n channels to [`VOLUME_NORM`](constant.VOLUME_NORM.html). pub fn reset(&mut self, channels: u32) -> &Self { self.set(channels, VOLUME_NORM) } /// Set the volume of the first n channels to [`VOLUME_MUTED`](constant.VOLUME_MUTED.html). pub fn mute(&mut self, channels: u32) -> &Self { self.set(channels, VOLUME_MUTED) } /// Returns `true` when self is equal to `to`. /// /// This checks that the number of channels in self equals the number in `to` and that the /// channels volumes in self equal those in `to`. pub fn equal_to(&self, to: &Self) -> bool { unsafe { capi::pa_cvolume_equal(std::mem::transmute(self), std::mem::transmute(to)) != 0 } } /// Returns `true` if all channels are muted pub fn is_muted(&self) -> bool { self.channels_equal_to(VOLUME_MUTED) } /// Returns `true` if all channels are at normal volume level pub fn is_norm(&self) -> bool { self.channels_equal_to(VOLUME_NORM) } /// Returns the average volume of all channels pub fn avg(&self) -> Volume { Volume(unsafe { capi::pa_cvolume_avg(std::mem::transmute(self)) }) } /// Returns the average volume of all channels that are included in the specified channel map /// with the specified channel position mask. /// /// If no channel is selected the returned value will be /// [`VOLUME_MUTED`](constant.VOLUME_MUTED.html). If `mask` is `None`, has the same effect as /// passing [`::channelmap::POSITION_MASK_ALL`](../channelmap/constant.POSITION_MASK_ALL.html). pub fn avg_mask(&self, cm: &::channelmap::Map, mask: Option<::channelmap::PositionMask> ) -> Volume { let mask_actual = mask.unwrap_or(::channelmap::POSITION_MASK_ALL); Volume(unsafe { capi::pa_cvolume_avg_mask(std::mem::transmute(self), std::mem::transmute(cm), mask_actual) }) } /// Return the maximum volume of all channels. pub fn max(&self) -> Volume { Volume(unsafe { capi::pa_cvolume_max(std::mem::transmute(self)) }) } /// Return the maximum volume of all channels that are included in the specified channel map /// with the specified channel position mask. /// /// If no channel is selected the returned value will be /// [`VOLUME_MUTED`](constant.VOLUME_MUTED.html). If `mask` is `None`, has the same effect as /// passing [`::channelmap::POSITION_MASK_ALL`](../channelmap/constant.POSITION_MASK_ALL.html). pub fn max_mask(&self, cm: &::channelmap::Map, mask: Option<::channelmap::PositionMask> ) -> Volume { let mask_actual = mask.unwrap_or(::channelmap::POSITION_MASK_ALL); Volume(unsafe { capi::pa_cvolume_max_mask(std::mem::transmute(self), std::mem::transmute(cm), mask_actual) }) } /// Return the minimum volume of all channels. pub fn min(&self) -> Volume { Volume(unsafe { capi::pa_cvolume_min(std::mem::transmute(self)) }) } /// Return the minimum volume of all channels that are included in the specified channel map /// with the specified channel position mask. /// /// If no channel is selected the returned value will be /// [`VOLUME_MUTED`](constant.VOLUME_MUTED.html). If `mask` is `None`, has the same effect as /// passing [`::channelmap::POSITION_MASK_ALL`](../channelmap/constant.POSITION_MASK_ALL.html). pub fn min_mask(&self, cm: &::channelmap::Map, mask: Option<::channelmap::PositionMask> ) -> Volume { let mask_actual = mask.unwrap_or(::channelmap::POSITION_MASK_ALL); Volume(unsafe { capi::pa_cvolume_min_mask(std::mem::transmute(self), std::mem::transmute(cm), mask_actual) }) } /// Returns `true` when the `ChannelVolumes` structure is valid. pub fn is_valid(&self) -> bool { unsafe { capi::pa_cvolume_valid(std::mem::transmute(self)) != 0 } } /// Returns `true` if the volume of all channels are equal to the specified value. pub fn channels_equal_to(&self, v: Volume) -> bool { unsafe { capi::pa_cvolume_channels_equal_to(std::mem::transmute(self), v.0) != 0 } } /// Multiply two per-channel volumes. /// /// If `with` is `None`, multiplies with itself. This is only valid for software volumes! /// Returns pointer to self. pub fn sw_multiply(&mut self, with: Option<&Self>) -> &mut Self { match with { Some(with) => unsafe { capi::pa_sw_cvolume_multiply(std::mem::transmute(&self), std::mem::transmute(&self), std::mem::transmute(with)) }, None => unsafe { capi::pa_sw_cvolume_multiply(std::mem::transmute(&self), std::mem::transmute(&self), std::mem::transmute(&self)) }, }; self } /// Multiply a per-channel volume with a scalar volume. /// /// This is only valid for software volumes! Returns pointer to self. pub fn sw_multiply_scalar(&mut self, with: Volume) -> &mut Self { unsafe { capi::pa_sw_cvolume_multiply_scalar(std::mem::transmute(&self), std::mem::transmute(&self), with.0) }; self } /// Divide two per-channel volumes. /// /// If `with` is `None`, divides with itself. This is only valid for software volumes! Returns /// pointer to self. pub fn sw_divide(&mut self, with: Option<&Self>) -> &mut Self { match with { Some(with) => unsafe { capi::pa_sw_cvolume_divide(std::mem::transmute(&self), std::mem::transmute(&self), std::mem::transmute(with)) }, None => unsafe { capi::pa_sw_cvolume_divide(std::mem::transmute(&self), std::mem::transmute(&self), std::mem::transmute(&self)) }, }; self } /// Divide a per-channel volume by a scalar volume. /// /// This is only valid for software volumes! Returns pointer to self. pub fn sw_divide_scalar(&mut self, with: Volume) -> &mut Self { unsafe { capi::pa_sw_cvolume_divide_scalar(std::mem::transmute(&self), std::mem::transmute(&self), with.0) }; self } /// Remap a volume from one channel mapping to a different channel mapping. /// /// Returns pointer to self. pub fn remap(&mut self, from: &::channelmap::Map, to: &::channelmap::Map) -> &mut Self { unsafe { capi::pa_cvolume_remap(std::mem::transmute(&self), std::mem::transmute(from), std::mem::transmute(to)) }; self } /// Returns `true` if the specified volume is compatible with the specified sample spec. pub fn is_compatible_with_ss(&self, ss: &::sample::Spec) -> bool { unsafe { capi::pa_cvolume_compatible(std::mem::transmute(self), std::mem::transmute(ss)) != 0 } } /// Returns `true` if the specified volume is compatible with the specified channel map. pub fn is_compatible_with_cm(&self, cm: &::channelmap::Map) -> bool { unsafe { capi::pa_cvolume_compatible_with_channel_map(std::mem::transmute(self), std::mem::transmute(cm)) != 0 } } /// Calculate a 'balance' value for the specified volume with the specified channel map. /// /// The return value will range from `-1.0` (left) to `+1.0` (right). If no balance value is /// applicable to this channel map the return value will always be `0.0`. See /// [`::channelmap::Map::can_balance`]. /// /// [`::channelmap::Map::can_balance`]: ../channelmap/struct.Map.html#method.can_balance pub fn get_balance(&self, map: &::channelmap::Map) -> f32 { unsafe { capi::pa_cvolume_get_balance(std::mem::transmute(self), std::mem::transmute(map)) } } /// Adjust the 'balance' value for the specified volume with the specified channel map. /// /// The balance is a value between `-1.0` and `+1.0`. This operation might not be reversible! /// Also, after this call [`get_balance`] is not guaranteed to actually return the requested /// balance value (e.g. when the input volume was zero anyway for all channels). If no balance /// value is applicable to this channel map the volume will not be modified. See /// [`::channelmap::Map::can_balance`]. /// /// Returns pointer to self, or `None` on error. /// /// [`get_balance`]: #method.get_balance /// [`::channelmap::Map::can_balance`]: ../channelmap/struct.Map.html#method.can_balance pub fn set_balance(&mut self, map: &::channelmap::Map, new_balance: f32) -> Option<&mut Self> { let ptr = unsafe { capi::pa_cvolume_set_balance(std::mem::transmute(&self), std::mem::transmute(map), new_balance) }; if ptr.is_null() { return None; } Some(self) } /// Calculate a 'fade' value (i.e. 'balance' between front and rear) for the specified volume /// with the specified channel map. /// /// The return value will range from -1.0f (rear) to +1.0f (left). If no fade value is /// applicable to this channel map the return value will always be `0.0`. See /// [`::channelmap::Map::can_fade`]. /// /// [`::channelmap::Map::can_fade`]: ../channelmap/struct.Map.html#method.can_fade pub fn get_fade(&self, map: &::channelmap::Map) -> f32 { unsafe { capi::pa_cvolume_get_fade(std::mem::transmute(self), std::mem::transmute(map)) } } /// Adjust the 'fade' value (i.e. 'balance' between front and rear) for the specified volume /// with the specified channel map. /// /// The balance is a value between `-1.0` and `+1.0`. This operation might not be reversible! /// Also, after this call [`get_fade`] is not guaranteed to actually return the requested fade /// value (e.g. when the input volume was zero anyway for all channels). If no fade value is /// applicable to this channel map the volume will not be modified. See /// [`::channelmap::Map::can_fade`]. /// /// Returns pointer to self, or `None` on error. /// /// [`get_fade`]: #method.get_fade /// [`::channelmap::Map::can_fade`]: ../channelmap/struct.Map.html#method.can_fade pub fn set_fade(&mut self, map: &::channelmap::Map, new_fade: f32) -> Option<&mut Self>{ let ptr = unsafe { capi::pa_cvolume_set_fade(std::mem::transmute(&self), std::mem::transmute(map), new_fade) }; if ptr.is_null() { return None; } Some(self) } /// Calculate a 'lfe balance' value for the specified volume with the specified channel map. /// /// The return value will range from `-1.0` (no lfe) to `+1.0` (only lfe), where `0.0` is /// balanced. If no value is applicable to this channel map the return value will always be /// `0.0`. See [`::channelmap::Map::can_lfe_balance`]. /// /// [`::channelmap::Map::can_lfe_balance`]: /// ../channelmap/struct.Map.html#method.can_lfe_balance pub fn get_lfe_balance(&self, map: &::channelmap::Map) -> f32 { unsafe { capi::pa_cvolume_get_lfe_balance(std::mem::transmute(self), std::mem::transmute(map)) } } /// Adjust the 'LFE balance' value for the specified volume with the specified channel map. /// /// The balance is a value between `-1.0` (no lfe) and `+1.0` (only lfe). This operation might /// not be reversible! Also, after this call [`get_lfe_balance`] is not guaranteed to actually /// return the requested value (e.g. when the input volume was zero anyway for all channels). If /// no lfe balance value is applicable to this channel map the volume will not be modified. See /// [`::channelmap::Map::can_lfe_balance`]. /// /// Returns pointer to self, or `None` on error. /// /// [`get_lfe_balance`]: #method.get_lfe_balance /// [`::channelmap::Map::can_lfe_balance`]: ../channelmap/struct.Map.html#method.can_lfe_balance pub fn set_lfe_balance(&mut self, map: &::channelmap::Map, new_balance: f32 ) -> Option<&mut Self> { let ptr = unsafe { capi::pa_cvolume_set_lfe_balance(std::mem::transmute(&self), std::mem::transmute(map), new_balance) }; if ptr.is_null() { return None; } Some(self) } /// Scale so that the maximum volume of all channels equals `max`. /// /// The proportions between the channel volumes are kept. /// Returns pointer to self, or `None` on error. pub fn scale(&mut self, max: Volume) -> Option<&mut Self> { let ptr = unsafe { capi::pa_cvolume_scale(std::mem::transmute(&self), max.0) }; if ptr.is_null() { return None; } Some(self) } /// Scale so that the maximum volume of all channels selected via `cm`/`mask` equals `max`. /// /// This also modifies the volume of those channels that are unmasked. The proportions between /// the channel volumes are kept. /// /// If `mask` is `None`, has the same effect as passing /// [`::channelmap::POSITION_MASK_ALL`](../channelmap/constant.POSITION_MASK_ALL.html). /// /// Returns pointer to self, or `None` on error. pub fn scale_mask(&mut self, max: Volume, cm: &mut ::channelmap::Map, mask: Option<::channelmap::PositionMask>) -> Option<&mut Self> { let mask_actual = mask.unwrap_or(::channelmap::POSITION_MASK_ALL); let ptr = unsafe { capi::pa_cvolume_scale_mask(std::mem::transmute(&self), max.0, std::mem::transmute(cm), mask_actual) }; if ptr.is_null() { return None; } Some(self) } /// Set the passed volume to all channels at the specified channel position. /// /// Returns `None` if either invalid data was provided, or if there is no channel at the /// position specified. You can check if a channel map includes a specific position by calling /// [`::channelmap::Map::has_position`]. On success, returns pointer to self. /// /// [`::channelmap::Map::has_position`]: ../channelmap/struct.Map.html#method.has_position pub fn set_position(&mut self, map: &::channelmap::Map, t: ::channelmap::Position, v: Volume ) -> Option<&mut Self> { // Note: C function returns NULL on invalid data or no channel at position specified (no // change needed). We could ignore failure and always return self ptr, but it does not seem // ideal to leave callers unaware should they be passing in invalid data. let ptr = unsafe { capi::pa_cvolume_set_position(std::mem::transmute(&self), std::mem::transmute(map), t.into(), v.0) }; if ptr.is_null() { return None; } Some(self) } /// Get the maximum volume of all channels at the specified channel position. /// /// Will return `0` if there is no channel at the position specified. You can check if a channel /// map includes a specific position by calling [`::channelmap::Map::has_position`]. /// /// [`::channelmap::Map::has_position`]: ../channelmap/struct.Map.html#method.has_position pub fn get_position(&self, map: &::channelmap::Map, t: ::channelmap::Position) -> Volume { Volume(unsafe { capi::pa_cvolume_get_position(std::mem::transmute(self), std::mem::transmute(map), t.into()) }) } /// Merges one set of channel volumes with another. /// /// The channel count is set to the minimum between that of self and that of `with`. Only this /// number of channels are processed. For each channel processed, volume is set to the greatest /// of the values from self and from `with`. I.e if one set has three channels and the other has /// two, the number of channels will be set to two, and only the first two channels will be /// compared, with the greatest values of these two channels being stored. The third channel in /// the one set will be ignored. /// /// Returns pointer to self, or `None` on error. pub fn merge(&mut self, with: &Self) -> Option<&mut Self> { let ptr = unsafe { capi::pa_cvolume_merge(std::mem::transmute(&self), std::mem::transmute(&self), std::mem::transmute(with)) }; if ptr.is_null() { return None; } Some(self) } /// Increase the volume passed in by `inc`, but not exceeding `limit`. /// The proportions between the channels are kept. /// Returns pointer to self, or `None` on error. pub fn inc_clamp(&mut self, inc: Volume, limit: Volume) -> Option<&mut Self> { let ptr = unsafe { capi::pa_cvolume_inc_clamp(std::mem::transmute(&self), inc.0, limit.0) }; if ptr.is_null() { return None; } Some(self) } /// Increase the volume passed in by `inc`. /// The proportions between the channels are kept. /// Returns pointer to self, or `None` on error. pub fn increase(&mut self, inc: Volume) -> Option<&mut Self> { let ptr = unsafe { capi::pa_cvolume_inc(std::mem::transmute(&self), inc.0) }; if ptr.is_null() { return None; } Some(self) } /// Decrease the volume passed in by `dec`. /// The proportions between the channels are kept. /// Returns pointer to self, or `None` on error. pub fn decrease(&mut self, dec: Volume) -> Option<&mut Self> { let ptr = unsafe { capi::pa_cvolume_dec(std::mem::transmute(&self), dec.0) }; if ptr.is_null() { return None; } Some(self) } /// Pretty print a volume structure pub fn print(&self) -> String { const PRINT_MAX: usize = capi::PA_CVOLUME_SNPRINT_MAX; let mut tmp = Vec::with_capacity(PRINT_MAX); unsafe { capi::pa_cvolume_snprint(tmp.as_mut_ptr(), PRINT_MAX, std::mem::transmute(self)); CStr::from_ptr(tmp.as_mut_ptr()).to_string_lossy().into_owned() } } /// Pretty print a volume structure but show dB values. pub fn print_db(&self) -> String { const PRINT_DB_MAX: usize = capi::PA_SW_CVOLUME_SNPRINT_DB_MAX; let mut tmp = Vec::with_capacity(PRINT_DB_MAX); unsafe { capi::pa_sw_cvolume_snprint_dB(tmp.as_mut_ptr(), PRINT_DB_MAX, std::mem::transmute(self)); CStr::from_ptr(tmp.as_mut_ptr()).to_string_lossy().into_owned() } } /// Pretty print a volume structure in a verbose way. /// /// The volume for each channel is printed in several formats: the raw volume value, /// percentage, and if `print_db` is non-zero, also the dB value. If `map` is provided, the /// channel names will be printed. pub fn print_verbose(&self, map: Option<&::channelmap::Map>, print_db: bool) -> String { const PRINT_VERBOSE_MAX: usize = capi::PA_CVOLUME_SNPRINT_VERBOSE_MAX; let p_map: *const capi::pa_channel_map = match map { Some(map) => unsafe { std::mem::transmute(map) }, None => null::<capi::pa_channel_map>(), }; let mut tmp = Vec::with_capacity(PRINT_VERBOSE_MAX); unsafe { capi::pa_cvolume_snprint_verbose(tmp.as_mut_ptr(), PRINT_VERBOSE_MAX, std::mem::transmute(self), p_map, print_db as i32); CStr::from_ptr(tmp.as_mut_ptr()).to_string_lossy().into_owned() } } } impl std::fmt::Display for ChannelVolumes { fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result { write!(f, "{}", &self.print()) } }