Reorganized source, comments

src/bext.rs

@@ -0,0 +1,82 @@
+
+pub type LU = f32;
+pub type LUFS = f32;
+pub type Decibels = f32;
+
+/**
+ * Broadcast-WAV metadata record.
+ * 
+ * The `bext` record contains information about the original recording of the 
+ * Wave file, including a longish (256 ASCII chars) description field, 
+ * originator identification fields, creation calendar date and time, a 
+ * sample-accurate recording time field, and a SMPTE UMID. 
+ * 
+ * For a Wave file to be a complaint "Broadcast-WAV" file, it must contain
+ * a `bext` metadata record.
+ * 
+ * For reference on the structure and use of the BEXT record
+ * check out [EBU Tech 3285](https://tech.ebu.ch/docs/tech/tech3285.pdf).
+ */
+#[derive(Debug)]
+pub struct Bext {
+
+    /// 256 ASCII character field with free text.
+    pub description: String,
+
+    /// Originating application.
+    pub originator: String,
+
+    /// Application-specific UID.
+    pub originator_reference: String,
+
+    /// Creation date in format `YYYY-MM-DD`.
+    pub origination_date: String,
+
+    /// Creation time in format `HH:MM:SS`.
+    pub origination_time: String,
+
+    /// Time of the start of this wave file, expressed as the number of samples
+    /// since local midnight.
+    pub time_reference: u64,
+
+    /// Bext chunk version.
+    /// 
+    /// Version 1 contains a UMID, version 2 contains a UMID and 
+    /// loudness metadata.
+    pub version: u16,
+
+    /// SMPTE 330M UMID
+    /// 
+    /// 
+    /// This field is `None` if the version is less than 1.
+    pub umid: Option<[u8; 64]>,
+
+    /// Integrated loudness in LUFS.
+    /// 
+    /// This field is `None` if the version is less than 2.
+    pub loudness_value: Option<LUFS>,
+
+    /// Loudness range in LU.
+    /// 
+    /// This field is `None` if the version is less than 2.
+    pub loudness_range: Option<LU>,
+
+    /// Maximum True Peak Level in decibels True Peak.
+    ///
+    /// This field is `None` if the version is less than 2.
+    pub max_true_peak_level: Option<Decibels>,
+
+    /// Maximum momentary loudness in LUFS.
+    ///
+    /// This field is `None` if the version is less than 2.
+    pub max_momentary_loudness: Option<LUFS>,
+
+    /// Maximum short-term loudness in LUFS.
+    /// 
+    /// This field is `None` if the version is less than 2.
+    pub max_short_term_loudness: Option<LUFS>,
+    // 180 bytes of nothing
+
+    /// Coding History.
+    pub coding_history: String
+}