Add metadata pipe support which is compatible with forked-daapd.

Cargo.lock

@@ -487,6 +487,7 @@ name = "librespot-playback"
 version = "0.1.0"
 dependencies = [
  "alsa 0.0.1 (git+https://github.com/plietar/rust-alsa)",
+ "base64 0.5.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "byteorder 1.2.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "futures 0.1.21 (registry+https://github.com/rust-lang/crates.io-index)",
  "jack 0.5.7 (registry+https://github.com/rust-lang/crates.io-index)",

playback/Cargo.toml

@@ -11,6 +11,7 @@ path = "../core"
 path = "../metadata"
 
 [dependencies]
+base64 = "0.5.0"
 futures = "0.1.8"
 log = "0.3.5"
 byteorder = "1.2.1"

playback/src/lib.rs

@@ -1,6 +1,6 @@
 #[macro_use]
 extern crate log;
-
+extern crate base64;
 extern crate byteorder;
 extern crate futures;
 

playback/src/mixer/mod.rs

@@ -9,6 +9,7 @@ pub trait Mixer: Send {
     fn get_audio_filter(&self) -> Option<Box<AudioFilter + Send>> {
         None
     }
+    fn set_metadata_pipe(&mut self, _metadata_pipe: Option<String>) {}
 }
 
 pub trait AudioFilter {
@@ -18,6 +19,9 @@ pub trait AudioFilter {
 pub mod softmixer;
 use self::softmixer::SoftMixer;
 
+pub mod pipemixer;
+use self::pipemixer::PipeMixer;
+
 fn mk_sink<M: Mixer + 'static>() -> Box<Mixer> {
     Box::new(M::open())
 }
@@ -25,6 +29,7 @@ fn mk_sink<M: Mixer + 'static>() -> Box<Mixer> {
 pub fn find<T: AsRef<str>>(name: Option<T>) -> Option<fn() -> Box<Mixer>> {
     match name.as_ref().map(AsRef::as_ref) {
         None | Some("softvol") => Some(mk_sink::<SoftMixer>),
+        Some("pipe") => Some(mk_sink::<PipeMixer>),
         _ => None,
     }
 }

playback/src/mixer/pipemixer.rs

@@ -0,0 +1,56 @@
+use base64;
+use std::f32;
+use std::fs::File;
+use std::io::Write;
+use std::sync::atomic::{AtomicUsize, Ordering};
+use std::sync::Arc;
+
+use super::Mixer;
+
+#[derive(Clone)]
+pub struct PipeMixer {
+    volume: Arc<AtomicUsize>,
+    pipe: Option<String>,
+}
+
+impl Mixer for PipeMixer {
+    fn open() -> PipeMixer {
+        PipeMixer {
+            volume: Arc::new(AtomicUsize::new(0xFFFF)),
+            pipe: None,
+        }
+    }
+    fn start(&self) {}
+    fn stop(&self) {}
+    fn volume(&self) -> u16 {
+        self.volume.load(Ordering::Relaxed) as u16
+    }
+    fn set_volume(&self, volume: u16) {
+        self.volume.store(volume as usize, Ordering::Relaxed);
+
+        if let Some(path) = self.pipe.as_ref() {
+            let vol = volume;
+            let metadata_vol = if vol == 0 {
+                -144.0f32
+            } else if vol == 1 {
+                -30.0f32
+            } else if vol == 0xFFFF {
+                0.0f32
+            } else {
+                ((vol as f32) - (0xFFFF as f32)) * 30.0f32 / (0xFFFE as f32)
+            };
+
+            let vol_string = format!("{:.*},0.00,0.00,0.00", 2, metadata_vol);
+            let vol_string_len = vol_string.chars().count();
+            let metadata_vol_string = base64::encode(&vol_string);
+            let metadata_xml = format!("<item><type>73736e63</type><code>70766f6c</code><length>{}</length>\n<data encoding=\"base64\">\n{}</data></item>", vol_string_len, metadata_vol_string);
+
+            let mut f = File::create(path).expect("Unable to open pipe");
+            f.write_all(metadata_xml.as_bytes())
+                .expect("Unable to write data");
+        }
+    }
+    fn set_metadata_pipe(&mut self, metadata_pipe: Option<String>) {
+        self.pipe = metadata_pipe;
+    }
+}

playback/src/player.rs

@@ -1,5 +1,6 @@
 use byteorder::{LittleEndian, ReadBytesExt};
 use futures;
+use base64;
 use futures::sync::oneshot;
 use futures::{future, Future};
 use std;
@@ -9,6 +10,8 @@ use std::mem;
 use std::sync::mpsc::{RecvError, RecvTimeoutError, TryRecvError};
 use std::thread;
 use std::time::Duration;
+use std::fs::File;
+use std::io::Write;
 
 use config::{Bitrate, PlayerConfig};
 use core::session::Session;
@@ -17,7 +20,7 @@ use core::spotify_id::SpotifyId;
 use audio::{AudioDecrypt, AudioFile};
 use audio::{VorbisDecoder, VorbisPacket};
 use audio_backend::Sink;
-use metadata::{FileFormat, Metadata, Track};
+use metadata::{FileFormat, Metadata, Track, Album, Artist};
 use mixer::AudioFilter;
 
 pub struct Player {
@@ -35,6 +38,8 @@ struct PlayerInternal {
     sink_running: bool,
     audio_filter: Option<Box<AudioFilter + Send>>,
     event_sender: futures::sync::mpsc::UnboundedSender<PlayerEvent>,
+
+    metadata_pipe: Option<String>,
 }
 
 enum PlayerCommand {
@@ -113,6 +118,7 @@ impl Player {
         config: PlayerConfig,
         session: Session,
         audio_filter: Option<Box<AudioFilter + Send>>,
+        metadata_pipe: Option<String>,
         sink_builder: F,
     ) -> (Player, PlayerEventChannel)
     where
@@ -133,6 +139,7 @@ impl Player {
                 sink: sink_builder(),
                 sink_running: false,
                 audio_filter: audio_filter,
+                metadata_pipe: metadata_pipe,
                 event_sender: event_sender,
             };
 
@@ -535,6 +542,39 @@ impl PlayerInternal {
             track_id.to_base62()
         );
 
+        if let Some(path) = self.metadata_pipe.as_ref() {
+            let mut f = File::create(path).expect("Unable to open pipe");
+
+            // title
+            let title = track.name.clone();
+            let title_len = title.chars().count();
+            let title_string = base64::encode(&title);
+            let title_xml = format!("<item><type>636f7265</type><code>6d696e6d</code><length>{}</length>\n<data encoding=\"base64\">\n{}</data></item>", title_len, title_string);
+            f.write_all(title_xml.as_bytes()).expect("Unable to write title");
+
+            // album
+            let album = Album::get(&self.session, track.album).wait().unwrap();
+            let album_name = album.name.clone();
+            let album_name_len = album_name.chars().count();
+            let album_name_string = base64::encode(&album_name);
+            let album_name_xml = format!("<item><type>636f7265</type><code>6173616c</code><length>{}</length>\n<data encoding=\"base64\">\n{}</data></item>", album_name_len, album_name_string);
+            f.write_all(album_name_xml.as_bytes()).expect("Unable to write album");
+
+            // artist
+            let mut artists = String::new();
+            for id in &track.artists {
+                if artists != "" {
+                    artists.push_str(" & ");
+                }
+                let artist = Artist::get(&self.session, *id).wait().unwrap();
+                artists.push_str(&artist.name);
+            }
+            let artists_len = artists.chars().count();
+            let artists_string = base64::encode(&artists);
+            let artists_xml = format!("<item><type>636f7265</type><code>61736172</code><length>{}</length>\n<data encoding=\"base64\">\n{}</data></item>", artists_len, artists_string);
+            f.write_all(artists_xml.as_bytes()).expect("Unable to write artists");
+        }
+
         let track = match self.find_available_alternative(&track) {
             Some(track) => track,
             None => {

src/main.rs

@@ -90,6 +90,7 @@ fn list_backends() {
 struct Setup {
     backend: fn(Option<String>) -> Box<Sink>,
     device: Option<String>,
+    metadata_pipe: Option<String>,
 
     mixer: fn() -> Box<Mixer>,
 
@@ -143,6 +144,7 @@ fn setup(args: &[String]) -> Setup {
             "DEVICE",
         )
         .optopt("", "mixer", "Mixer to use", "MIXER")
+        .optopt("", "metadata-pipe", "Pipe to write metadata", "METADATA_PIPE")
         .optopt(
             "",
             "initial-volume",
@@ -201,6 +203,8 @@ fn setup(args: &[String]) -> Setup {
 
     let device = matches.opt_str("device");
 
+    let metadata_pipe = matches.opt_str("metadata-pipe");
+
     let mixer_name = matches.opt_str("mixer");
     let mixer = mixer::find(mixer_name.as_ref()).expect("Invalid mixer");
 
@@ -312,6 +316,7 @@ fn setup(args: &[String]) -> Setup {
         connect_config: connect_config,
         credentials: credentials,
         device: device,
+        metadata_pipe: metadata_pipe,
         enable_discovery: enable_discovery,
         zeroconf_port: zeroconf_port,
         mixer: mixer,
@@ -326,6 +331,7 @@ struct Main {
     connect_config: ConnectConfig,
     backend: fn(Option<String>) -> Box<Sink>,
     device: Option<String>,
+    metadata_pipe: Option<String>,
     mixer: fn() -> Box<Mixer>,
     handle: Handle,
 
@@ -352,6 +358,7 @@ impl Main {
             connect_config: setup.connect_config,
             backend: setup.backend,
             device: setup.device,
+            metadata_pipe: setup.metadata_pipe,
             mixer: setup.mixer,
 
             connect: Box::new(futures::future::empty()),
@@ -414,16 +421,22 @@ impl Future for Main {
             if let Async::Ready(session) = self.connect.poll().unwrap() {
                 self.connect = Box::new(futures::future::empty());
                 let device = self.device.clone();
-                let mixer = (self.mixer)();
+                let mut mixer = (self.mixer)();
                 let player_config = self.player_config.clone();
                 let connect_config = self.connect_config.clone();
+                let metadata_pipe = self.metadata_pipe.clone();
+
+                mixer.set_metadata_pipe(metadata_pipe.clone());
 
                 let audio_filter = mixer.get_audio_filter();
                 let backend = self.backend;
-                let (player, event_channel) =
-                    Player::new(player_config, session.clone(), audio_filter, move || {
-                        (backend)(device)
-                    });
+                let (player, event_channel) = Player::new(
+                    player_config,
+                    session.clone(),
+                    audio_filter,
+                    metadata_pipe,
+                    move || (backend)(device),
+                );
 
                 let (spirc, spirc_task) = Spirc::new(connect_config, session, player, mixer);
                 self.spirc = Some(spirc);