pub const MAX_FIXED_ORDER: usize = 4;

pub struct SubFrame {
  pub data: Data,
  pub wasted_bits: u32,
}

pub enum Data {
  Constant(i32),
  Verbatim(Vec<i32>),
  Fixed(Fixed),
}

pub struct Fixed {
  pub entropy_coding_method: EntropyCodingMethod,
  pub order: u8,
  pub warmup: [i32; MAX_FIXED_ORDER],
  pub residual: Vec<i32>,
}

pub struct EntropyCodingMethod {
  pub method_type: CodingMethod,
  pub data: PartitionedRice,
}

#[derive(Debug, PartialEq, Eq, Clone, Copy)]
pub enum CodingMethod {
  PartitionedRice,
  PartitionedRice2,
}

pub struct PartitionedRice {
  pub order: u32,
  pub contents: PartitionedRiceContents,
}

pub struct PartitionedRiceContents {
  pub parameters: Vec<u32>,
  pub raw_bits: Vec<u32>,
  pub capacity_by_order: u32,
}

impl PartitionedRiceContents {
  pub fn new(capacity_by_order: u32) -> PartitionedRiceContents {
    let capacity       = 2_usize.pow(capacity_by_order);
    let mut parameters = Vec::with_capacity(capacity);
    let mut raw_bits   = Vec::with_capacity(capacity);

    unsafe {
      parameters.set_len(capacity);
      raw_bits.set_len(capacity);
    }

    PartitionedRiceContents {
      parameters: parameters,
      raw_bits: raw_bits,
      capacity_by_order: capacity_by_order,
    }
  }
}

pub const MAX_FIXED_ORDER: usize = 4;

pub struct SubFrame {
  pub data: Data,
  pub wasted_bits: u32,
}

pub enum Data {
  Constant(i32),
  Verbatim(Vec<i32>),
  Fixed(Fixed),
}

pub struct Fixed {
  pub entropy_coding_method: EntropyCodingMethod,
  pub order: u8,
  pub warmup: [i32; MAX_FIXED_ORDER],
  pub residual: Vec<i32>,
}

pub struct EntropyCodingMethod {
  pub method_type: CodingMethod,
  pub data: PartitionedRice,
}

#[derive(Debug, PartialEq, Eq, Clone, Copy)]
pub enum CodingMethod {
  PartitionedRice,
  PartitionedRice2,
}

pub struct PartitionedRice {
  pub order: u32,
  pub contents: PartitionedRiceContents,
}

pub struct PartitionedRiceContents {
  pub parameters: Vec<u32>,
  pub raw_bits: Vec<u32>,
  pub capacity_by_order: u32,
}

--- 
+++ 
@@ -39,3 +39,22 @@
   pub raw_bits: Vec<u32>,
   pub capacity_by_order: u32,
 }
+
+impl PartitionedRiceContents {
+  pub fn new(capacity_by_order: u32) -> PartitionedRiceContents {
+    let capacity       = 2_usize.pow(capacity_by_order);
+    let mut parameters = Vec::with_capacity(capacity);
+    let mut raw_bits   = Vec::with_capacity(capacity);
+
+    unsafe {
+      parameters.set_len(capacity);
+      raw_bits.set_len(capacity);
+    }
+
+    PartitionedRiceContents {
+      parameters: parameters,
+      raw_bits: raw_bits,
+      capacity_by_order: capacity_by_order,
+    }
+  }
+}
Add new initializer for `PartitionedRiceContents`
