Enable M4A format support

- Use https://github.com/Saecki/rust-mp4ameta for M4A metadata

Resolves https://github.com/agersant/polaris/issues/70

Cargo.lock

@@ -1202,6 +1202,14 @@ dependencies = [
  "failure 0.1.8 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "mp4ameta"
+version = "0.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "byteorder 1.3.4 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "native-tls"
 version = "0.2.4"
@@ -1477,6 +1485,7 @@ dependencies = [
  "log 0.4.8 (registry+https://github.com/rust-lang/crates.io-index)",
  "metaflac 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "mp3-duration 0.1.9 (registry+https://github.com/rust-lang/crates.io-index)",
+ "mp4ameta 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "pbkdf2 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "percent-encoding 2.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "rand 0.7.3 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -2939,6 +2948,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 "checksum mio-extras 2.0.6 (registry+https://github.com/rust-lang/crates.io-index)" = "52403fe290012ce777c4626790c8951324a2b9e3316b3143779c72b029742f19"
 "checksum miow 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)" = "8c1f2f3b1cf331de6896aabf6e9d55dca90356cc9960cca7eaaf408a355ae919"
 "checksum mp3-duration 0.1.9 (registry+https://github.com/rust-lang/crates.io-index)" = "eda61ba6c266cd2c7bfcea9a2719837dc062869e24e101a93c1b0873d17c2d35"
+"checksum mp4ameta 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)" = "3538f327d5d3afbc25b3677f5bd1e917ae7e9d3eae2aa9c3b57bc77f0356e829"
 "checksum native-tls 0.2.4 (registry+https://github.com/rust-lang/crates.io-index)" = "2b0d88c06fe90d5ee94048ba40409ef1d9315d86f6f38c2efdaad4fb50c58b2d"
 "checksum net2 0.2.34 (registry+https://github.com/rust-lang/crates.io-index)" = "2ba7c918ac76704fb42afcbbb43891e72731f3dcca3bef2a19786297baf14af7"
 "checksum notify 4.0.15 (registry+https://github.com/rust-lang/crates.io-index)" = "80ae4a7688d1fab81c5bf19c64fc8db920be8d519ce6336ed4e7efe024724dbd"

Cargo.toml

@@ -28,6 +28,7 @@ lewton = "0.10.1"
 log = "0.4.5"
 metaflac = "0.2.3"
 mp3-duration = "0.1.9"
+mp4ameta = "0.2.0"
 pbkdf2 = "0.3"
 rand = "0.7"
 rayon = "1.3"

src/index/metadata.rs

@@ -8,6 +8,7 @@ use mp3_duration;
 use regex::Regex;
 use std::fs;
 use std::path::Path;
+use mp4ameta;
 
 use crate::utils;
 use crate::utils::AudioFormat;
@@ -29,6 +30,7 @@ pub fn read(path: &Path) -> Option<SongTags> {
 	let data = match utils::get_audio_format(path) {
 		Some(AudioFormat::FLAC) => Some(read_flac(path)),
 		Some(AudioFormat::MP3) => Some(read_id3(path)),
+		Some(AudioFormat::MP4) => Some(read_mp4(path)),
 		Some(AudioFormat::MPC) => Some(read_ape(path)),
 		Some(AudioFormat::OGG) => Some(read_vorbis(path)),
 		_ => None,
@@ -203,6 +205,31 @@ fn read_flac(path: &Path) -> Result<SongTags> {
 	})
 }
 
+#[cfg_attr(feature = "profile-index", flame)]
+fn read_mp4(path: &Path) -> Result<SongTags> {
+	let tag = mp4ameta::Tag::read_from_path(path)?;
+	let mut tags = SongTags {
+		artist: None,
+		album_artist: None,
+		album: None,
+		title: None,
+		duration: None,
+		disc_number: None,
+		track_number: None,
+		year: None,
+	};
+	tags.artist = Some(tag.artist().unwrap().to_string());
+	tags.album_artist = Some(tag.album_artist().unwrap().to_string());
+	tags.album = Some(tag.album().unwrap().to_string());
+	tags.title = Some(tag.title().unwrap().to_string());
+	tags.duration = Some(tag.duration().unwrap() as u32);
+	tags.disc_number = tag.disk_number().0.and_then(|d| Some(d as u32));
+	tags.track_number = tag.track_number().0.and_then(|d| Some(d as u32));
+	tags.year = tag.year().unwrap().parse::<i32>().ok();
+
+	Ok(tags)
+}
+
 #[test]
 fn test_read_metadata() {
 	let sample_tags = SongTags {