ears 0.7.0

// The MIT License (MIT)
//
// Copyright (c) 2013 Jeremy Letang (letang.jeremy@gmail.com)
//
// Permission is hereby granted, free of charge, to any person obtaining a copy of
// this software and associated documentation files (the "Software"), to deal in
// the Software without restriction, including without limitation the rights to
// use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
// the Software, and to permit persons to whom the Software is furnished to do so,
// subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in all
// copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
// FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
// COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
// IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
// CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

//! Record audio

use std::{thread, mem};
use std::vec::Vec;
use std::sync::mpsc::{channel, Sender, Receiver};

use record_context::RecordContext;
use record_context;
use openal::ffi;
use sndfile::{SndInfo, SndFile};
use sndfile::OpenMode::Write;
use sndfile::FormatType::{FormatWav, FormatPcm16};
use std::intrinsics::transmute;

/**
 * Record audio
 *
 * This class provide easy audio recording using. The Recorder allow the user
 * to record sound, then save it in a file, or create a SoundData object to play the
 * recorded sound in the same program.
 * A special context, RecordContext is needed to create the Recorder object.
 * The Recorder work in it's own task.
 *
 * # Examples
 * ```no_run
 * use ears::Recorder;
 *
 * fn main() -> () {
 *     // Create a new context to record audio
 *     let context = ears::init_in().unwrap();
 *     // Create the recorder
 *     let mut recorder = Recorder::new(context);
 *     // Start to record something
 *     recorder.start();
 *
 *     // Do some other stuff here
 *
 *     // Stop the recorder
 *     recorder.stop();
 *     // Then store the recorded data in a file
 *     recorder.save_to_file("hello_file");
 * }
 * ```
 */
pub struct Recorder {
    ctxt: RecordContext,
    stop_sender: Option<Sender<bool>>,
    data_receiver: Option<Receiver<Vec<i16>>>,
    samples: Vec<i16>
}

impl Recorder {
    /// Create a new audio recorder
    pub fn new(record_context: RecordContext) -> Recorder {
        Recorder {
            ctxt: record_context,
            stop_sender: None,
            data_receiver: None,
            samples: Vec::new()

        }
    }

    pub fn start(&mut self) {
        let (stop_sender, stop_receiver) = channel();
        let (data_sender, data_receiver) = channel();
        let r_c = self.ctxt.clone();

        self.stop_sender = Some(stop_sender);
        self.data_receiver = Some(data_receiver);

        thread::spawn(move || {
            let mut terminate = false;
            let ctxt = record_context::get(r_c);
            unsafe { ffi::alcCaptureStart(ctxt); }
            let mut available_samples = 0;
            let mut samples: Vec<i16> = Vec::new();

            while !terminate {
                unsafe {
                    ffi::alcGetIntegerv(ctxt,
                                        ffi::ALC_CAPTURE_SAMPLES,
                                        1,
                                        &mut available_samples)
                };

                if available_samples != 0 {
                    let tmp_buf = vec![0i16; available_samples as usize];
                    unsafe {
                        ffi::alcCaptureSamples(ctxt,
                                               transmute(&tmp_buf[0]),
                                               available_samples);
                    }
                    samples.extend(tmp_buf.into_iter());
                }

                match stop_receiver.try_recv() {
                    Ok(_) => {
                        unsafe { ffi::alcCaptureStop(ctxt); }
                        terminate = true;
                    },
                    _ => {}
                }
            }
            data_sender.send(samples);
        });
    }

    pub fn stop(&mut self) -> bool {
        match self.stop_sender {
            Some(ref s_c) => {
                s_c.send(true);
                match self.data_receiver {
                    Some(ref d_p) => {
                        self.samples = d_p.recv().ok().unwrap();
                        true
                    },
                    None          => false
                }
            },
            None      => false
        }
    }

    pub fn save_to_file(&mut self, filename: &str) -> bool {
        if self.samples.len() == 0 {
            false
        } else {
            let infos = Box::new(SndInfo {
                frames : self.samples.len() as i64,
                samplerate : 44100,
                channels : 1,
                format : (FormatPcm16 | FormatWav) as i32,
                sections : 0,
                seekable : 0
            });


            let mut file_ext = String::new();
            file_ext.push_str(filename);
            file_ext.push_str(".wav");
            match SndFile::new_with_info(file_ext.as_ref(), Write, infos) {
                Ok(mut f) => {
                    let len = self.samples.len() as i64;
                    f.write_i16(&mut self.samples[..], len);
                    f.close();
                    true
                },
                Err(e) => { println!("{}", e); false }
            }
        }
    }
}