android builds (#9)

This adds android builds to the CI infrastructure. These builds generate an `apk` file that you can download and install.
- Adds a new container build job that builds a container with all the required android dependencies
- Adds a new release build that builds an android apk
- Updated the imp module to split out mobile and desktop behavior
- Adds logic to request microphone permissions
- Added a custom android manifest that declares the required permissions

Reviewed-on: #9

gui/src/imp/native_audio.rs

@@ -0,0 +1,209 @@
+use crate::effects::{AudioProcessor, AudioProcessorSender};
+use color_eyre::eyre::{eyre, Error};
+use cpal::traits::{DeviceTrait, HostTrait, StreamTrait as _};
+use futures::io::{AsyncRead, AsyncWrite};
+use std::mem::replace;
+use std::sync::Arc;
+use std::sync::Mutex;
+use tracing::{error, info, warn};
+
+pub trait ImpRead: AsyncRead + Unpin + Send + 'static {}
+impl<T: AsyncRead + Unpin + Send + 'static> ImpRead for T {}
+
+pub trait ImpWrite: AsyncWrite + Unpin + Send + 'static {}
+impl<T: AsyncWrite + Unpin + Send + 'static> ImpWrite for T {}
+
+pub struct AudioSystem {
+    output: cpal::Device,
+    input: cpal::Device,
+    processors: AudioProcessorSender,
+    recording_stream: Option<cpal::Stream>,
+}
+
+const SAMPLE_RATE: u32 = 48_000;
+const PACKET_SAMPLES: u32 = 960;
+
+type Buffer = Arc<Mutex<dasp_ring_buffer::Bounded<Vec<i16>>>>;
+
+impl AudioSystem {
+    pub async fn new() -> Result<Self, Error> {
+        // TODO
+        let host = cpal::default_host();
+        let name = host.id();
+        let processors = AudioProcessorSender::default();
+        Ok(AudioSystem {
+            output: host
+                .default_output_device()
+                .ok_or(eyre!("no output devices from {name:?}"))?,
+            input: host
+                .default_input_device()
+                .ok_or(eyre!("no input devices from {name:?}"))?,
+            processors,
+            recording_stream: None,
+        })
+    }
+
+    pub fn set_processor(&self, processor: AudioProcessor) {
+        self.processors.store(Some(processor))
+    }
+
+    fn choose_config(
+        &self,
+        configs: impl Iterator<Item = cpal::SupportedStreamConfigRange>,
+    ) -> Result<cpal::StreamConfig, Error> {
+        let mut supported_configs: Vec<_> = configs
+            .filter_map(|cfg| cfg.try_with_sample_rate(cpal::SampleRate(SAMPLE_RATE)))
+            .filter(|cfg| cfg.sample_format() == cpal::SampleFormat::I16)
+            .map(|cfg| cpal::StreamConfig {
+                buffer_size: cpal::BufferSize::Fixed(match *cfg.buffer_size() {
+                    cpal::SupportedBufferSize::Range { min, max } => 480.clamp(min, max),
+                    cpal::SupportedBufferSize::Unknown => 480,
+                }),
+                ..cfg.config()
+            })
+            .collect();
+        supported_configs.sort_by(|a, b| {
+            let cpal::BufferSize::Fixed(a_buf) = a.buffer_size else {
+                unreachable!()
+            };
+            let cpal::BufferSize::Fixed(b_buf) = b.buffer_size else {
+                unreachable!()
+            };
+            Ord::cmp(&a.channels, &b.channels).then(Ord::cmp(&a_buf, &b_buf))
+        });
+        supported_configs
+            .get(0)
+            .cloned()
+            .ok_or(eyre!("no supported stream configs"))
+    }
+
+    pub fn start_recording(
+        &mut self,
+        mut each: impl FnMut(Vec<u8>) + Send + 'static,
+    ) -> Result<(), Error> {
+        let config = self.choose_config(self.input.supported_input_configs()?)?;
+        info!(
+            "creating recording on {:?} with {:#?}",
+            self.input.name()?,
+            config
+        );
+        let mut encoder =
+            opus::Encoder::new(SAMPLE_RATE, opus::Channels::Mono, opus::Application::Voip)?;
+        let mut current_processor = AudioProcessor::new_plain();
+        let mut output_buffer = Vec::new();
+        let processors = self.processors.clone();
+        let error_callback = move |e: cpal::StreamError| error!("error recording: {e:?}");
+        let data_callback = move |frame: &[f32], _: &cpal::InputCallbackInfo| {
+            if let Some(new_processor) = processors.take() {
+                current_processor = new_processor;
+            }
+            current_processor.process(frame, config.channels as usize, &mut output_buffer);
+            if output_buffer.len() < PACKET_SAMPLES as usize {
+                return;
+            }
+            let remainder = output_buffer.split_off(PACKET_SAMPLES as usize);
+            let frame = replace(&mut output_buffer, remainder);
+            match encoder.encode_vec_float(&frame, frame.len() * 2) {
+                Ok(buf) => {
+                    each(buf);
+                }
+                Err(e) => {
+                    error!("error encoding {} samples: {e:?}", frame.len());
+                }
+            }
+        };
+
+        match self
+            .input
+            .build_input_stream(&config, data_callback, error_callback, None)
+        {
+            Ok(stream) => {
+                stream.play()?;
+                self.recording_stream = Some(stream);
+                Ok(())
+            }
+            Err(err) => {
+                self.recording_stream = None;
+                Err(err.into())
+            }
+        }
+    }
+
+    pub fn create_player(&mut self) -> Result<AudioPlayer, Error> {
+        let config = self.choose_config(self.output.supported_output_configs()?)?;
+        info!(
+            "creating player on {:?} with {:#?}",
+            self.output.name().ok(),
+            &config
+        );
+        let buffer = Arc::new(Mutex::new(dasp_ring_buffer::Bounded::from_raw_parts(
+            0,
+            0,
+            vec![
+            0;
+            SAMPLE_RATE as usize/4 // 250ms of buffer
+        ],
+        )));
+        let decoder = opus::Decoder::new(SAMPLE_RATE, opus::Channels::Mono)?;
+        let stream = {
+            let buffer = buffer.clone();
+            self.output.build_output_stream(
+                &config,
+                move |frame, _info| {
+                    let mut buffer = buffer.lock().unwrap();
+                    for x in frame.chunks_mut(config.channels as usize) {
+                        match buffer.pop() {
+                            Some(y) => {
+                                x.fill(y);
+                            }
+                            None => {
+                                x.fill(0);
+                            }
+                        }
+                    }
+                },
+                move |err| error!("could not create output stream {err:?}"),
+                None,
+            )?
+        };
+        stream.play()?;
+        Ok(AudioPlayer {
+            decoder,
+            stream,
+            buffer,
+            tmp: vec![0; 2400],
+        })
+    }
+}
+
+pub struct AudioPlayer {
+    decoder: opus::Decoder,
+    stream: cpal::Stream,
+    buffer: Buffer,
+    tmp: Vec<i16>,
+}
+
+impl AudioPlayer {
+    pub fn play_opus(&mut self, payload: &[u8]) {
+        let len = loop {
+            match self.decoder.decode(payload, &mut self.tmp, false) {
+                Ok(l) => break l,
+                Err(e) => {
+                    error!("opus decode error {e:?}");
+                    return;
+                }
+            }
+        };
+
+        let mut buffer = self.buffer.lock().unwrap();
+        let mut overrun = 0;
+        for x in &self.tmp[..len] {
+            if let Some(_) = buffer.push(*x) {
+                overrun += 1;
+            }
+        }
+        if overrun > 0 {
+            warn!("playback overrun by {overrun} samples");
+        }
+    }
+}