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// Copyright 2017 Lyndon Brown // // This file is part of the PulseAudio Rust language binding. // // 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/>. //! PulseAudio Rust language binding library for the ‘simple’ component. //! //! PulseAudio ‘simple’ provides a simple but limited synchronous playback and recording API. This //! is a synchronous, simplified wrapper around the standard asynchronous API. //! //! # About //! //! This library is a binding that allows Rust code to connect to the PulseAudio sound server via //! PulseAudio’s existing C API. This binding provides a safe(r) Rust interface which might be //! preferred over the raw C API provided by the underlying `sys` linking crate. //! //! This crate provides an interface to PulseAudio’s ‘simple’ component, and should be used in //! addition to the general `libpulse_binding` crate. //! //! # Introduction //! //! The simple API is designed for applications with very basic sound playback or capture needs. It //! can only support a single stream per connection and has no support for handling of complex //! features like events, channel mappings and volume control. It is, however, very simple to use //! and quite sufficient for many programs. //! //! # Usage //! //! Firstly, add a dependency on the crate in your program’s `Cargo.toml` file. Secondly, import the //! crate along with the general `libpulse_binding` crate to the root of your program: //! //! ```rust,ignore //! extern crate libpulse_binding as pulse; //! extern crate libpulse_simple_binding as psimple; //! ``` //! //! Finally, establish a connection, as below. //! //! # Connecting //! //! The first step before using the sound system is to connect to the server. This is normally done //! this way: //! //! ```rust //! # extern crate libpulse_binding as pulse; //! # extern crate libpulse_simple_binding as psimple; //! # //! use psimple::Simple; //! use pulse::stream::Direction; //! use pulse::sample; //! //! # fn main() { //! let spec = sample::Spec { //! format: sample::SAMPLE_S16NE, //! channels: 2, //! rate: 44100, //! }; //! assert!(spec.is_valid()); //! //! let s = Simple::new( //! None, // Use the default server //! "FooApp", // Our application’s name //! Direction::Playback, // We want a playback stream //! None, // Use the default device //! "Music", // Description of our stream //! &spec, // Our sample format //! None, // Use default channel map //! None // Use default buffering attributes //! ).unwrap(); //! # } //! ``` //! //! # Transferring data //! //! Once the connection is established to the server, data can start flowing. Using the connection //! is very similar to the normal read() and write() system calls using [`read`] and [`write`] //! methods of the [`Simple`] object. Note that these operations always block. //! //! # Buffer control //! //! * [`Simple::get_latency`]: Will return the total latency of the playback or record pipeline, //! respectively. //! * [`Simple::flush`]: Will throw away all data currently in buffers. //! //! If a playback stream is used then the following operation is available: //! //! * [`Simple::drain`]: Will wait for all sent data to finish playing. //! //! # Cleanup //! //! Once playback or capture is complete, the connection should be closed and resources freed. This //! is done automatically once the object is dropped. //! //! [`Simple`]: struct.Simple.html //! [`read`]: struct.Simple.html#method.read //! [`write`]: struct.Simple.html#method.write //! [`Simple::get_latency`]: struct.Simple.html#method.get_latency //! [`Simple::flush`]: struct.Simple.html#method.flush //! [`Simple::drain`]: struct.Simple.html#method.drain #![doc(html_logo_url = "https://github.com/jnqnfe/pulse-binding-rust/raw/master/logo.png", html_favicon_url = "https://github.com/jnqnfe/pulse-binding-rust/raw/master/favicon.ico")] extern crate libpulse_binding as pulse; extern crate libpulse_sys as pcapi; extern crate libpulse_simple_sys as capi; use std::os::raw::{c_char, c_void}; use std::{ffi::CString, ptr::null}; use std::mem; use pulse::{error::PAErr, time::MicroSeconds}; use pulse::{stream, sample, channelmap, def}; use capi::pa_simple as SimpleInternal; /// An opaque simple connection object. pub struct Simple { /// The actual C object. ptr: *mut SimpleInternal, } unsafe impl Send for Simple {} unsafe impl Sync for Simple {} impl Simple { /// Creates a new connection to the server. /// /// # Params /// /// * `server`: Server name, or `None` for default. /// * `name`: A descriptive name for this client (application name, ...). /// * `dir`: Open this stream for recording or playback? /// * `dev`: Sink (resp. source) name, or `None` for default. /// * `stream_name`: A descriptive name for this stream (application name, song title, ...). /// * `ss`: The sample type to use. /// * `map`: The channel map to use, or `None` for default. /// * `attr`: Buffering attributes, or `None` for default. pub fn new(server: Option<&str>, name: &str, dir: stream::Direction, dev: Option<&str>, stream_name: &str, ss: &sample::Spec, map: Option<&channelmap::Map>, attr: Option<&def::BufferAttr>) -> Result<Self, PAErr> { // Warning: New CStrings will be immediately freed if not bound to a variable, leading to // as_ptr() giving dangling pointers! let c_server = match server { Some(server) => CString::new(server.clone()).unwrap(), None => CString::new("").unwrap(), }; let c_dev = match dev { Some(dev) => CString::new(dev.clone()).unwrap(), None => CString::new("").unwrap(), }; let p_map = map.map_or(null::<pcapi::pa_channel_map>(), |m| m.as_ref()); let p_attr = attr.map_or(null::<pcapi::pa_buffer_attr>(), |a| a.as_ref()); let p_server = server.map_or(null::<c_char>(), |_| c_server.as_ptr() as *const c_char); let p_dev = dev.map_or(null::<c_char>(), |_| c_dev.as_ptr() as *const c_char); let c_name = CString::new(name.clone()).unwrap(); let c_stream_name = CString::new(stream_name.clone()).unwrap(); let mut error: i32 = 0; let ptr = unsafe { capi::pa_simple_new( p_server, c_name.as_ptr(), dir, p_dev, c_stream_name.as_ptr(), mem::transmute(ss), p_map, p_attr, &mut error ) }; match ptr.is_null() { false => Ok(Self::from_raw(ptr)), true => Err(PAErr(error)), } } /// Creates a new `Simple` from an existing [`SimpleInternal`](capi/enum.pa_simple.html) pointer. fn from_raw(ptr: *mut SimpleInternal) -> Self { assert_eq!(false, ptr.is_null()); Self { ptr } } /// Writes some data to the server. pub fn write(&self, data: &[u8]) -> Result<(), PAErr> { let mut error: i32 = 0; match unsafe { capi::pa_simple_write(self.ptr, data.as_ptr() as *mut c_void, data.len(), &mut error) } { 0 => Ok(()), _ => Err(PAErr(error)), } } /// Waits until all data already written is played by the daemon. pub fn drain(&self) -> Result<(), PAErr> { let mut error: i32 = 0; match unsafe { capi::pa_simple_drain(self.ptr, &mut error) } { 0 => Ok(()), _ => Err(PAErr(error)), } } /// Reads some data from the server. /// /// This function blocks until `data.len()` amount of data has been received from the server, /// or until an error occurs. pub fn read(&self, data: &mut [u8]) -> Result<(), PAErr> { let mut error: i32 = 0; match unsafe { capi::pa_simple_read(self.ptr, data.as_mut_ptr() as *mut c_void, data.len(), &mut error) } { 0 => Ok(()), _ => Err(PAErr(error)), } } /// Gets the playback or record latency. pub fn get_latency(&self) -> Option<MicroSeconds> { let mut error: i32 = 0; let ret = unsafe { capi::pa_simple_get_latency(self.ptr, &mut error) }; if error != 0 { return None; } Some(MicroSeconds(ret)) } /// Flushes the playback or record buffer. /// /// This discards any audio in the buffer. pub fn flush(&self) -> Result<(), PAErr> { let mut error: i32 = 0; match unsafe { capi::pa_simple_flush(self.ptr, &mut error) } { 0 => Ok(()), _ => Err(PAErr(error)), } } } impl Drop for Simple { fn drop(&mut self) { // Close and free the connection to the server. unsafe { capi::pa_simple_free(self.ptr) }; self.ptr = null::<SimpleInternal>() as *mut SimpleInternal; } }