rustdct/mdct/
mod.rs

1use rustfft::Length;
2
3mod mdct_naive;
4mod mdct_via_dct4;
5
6pub mod window_fn;
7
8/// An umbrella trait for algorithms which compute the Modified Discrete Cosine Transform (MDCT)
9pub trait Mdct<T: DctNum>: RequiredScratch + Length + Sync + Send {
10    /// Computes the MDCT on the `input` buffer and places the result in the `output` buffer.
11    /// Uses `input_a` for the first half of the input, and `input_b` for the second half of the input
12    ///
13    /// To make overlapping array segments easier, this method DOES NOT modify the input buffer.
14    ///
15    /// Normalization depends on which window function was chosen when planning the mdct --
16    /// each built-in window function documents whether it does normalization or not.
17    fn process_mdct_with_scratch(
18        &self,
19        input_a: &[T],
20        input_b: &[T],
21        output: &mut [T],
22        scratch: &mut [T],
23    );
24
25    /// Computes the IMDCT on the `input` buffer and places the result in the `output` buffer.
26    /// Puts the first half of the output in `output_a`, and puts the first half of the output in `output_b`.
27    ///
28    /// Since the IMDCT is designed with overlapping output segments in mind, this method DOES NOT zero
29    /// out the output buffer before writing like most other DCT algorithms. Instead, it sums
30    /// the result of the IMDCT with what's already in the output buffer.
31    ///
32    /// Normalization depends on which window function was chosen when planning the mdct --
33    /// each built-in window function documents whether it does normalization or not.
34    fn process_imdct_with_scratch(
35        &self,
36        input: &[T],
37        output_a: &mut [T],
38        output_b: &mut [T],
39        scratch: &mut [T],
40    );
41}
42
43use crate::{DctNum, RequiredScratch};
44
45pub use self::mdct_naive::MdctNaive;
46pub use self::mdct_via_dct4::MdctViaDct4;
rustdct/mdct/mod.rs

rustdct/mdct/
mod.rs
