pxdct 0.3.5

Discrete cosine transform
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80

/*
 * // Copyright (c) Radzivon Bartoshyk 1/2026. All rights reserved.
 * //
 * // Redistribution and use in source and binary forms, with or without modification,
 * // are permitted provided that the following conditions are met:
 * //
 * // 1.  Redistributions of source code must retain the above copyright notice, this
 * // list of conditions and the following disclaimer.
 * //
 * // 2.  Redistributions in binary form must reproduce the above copyright notice,
 * // this list of conditions and the following disclaimer in the documentation
 * // and/or other materials provided with the distribution.
 * //
 * // 3.  Neither the name of the copyright holder nor the names of its
 * // contributors may be used to endorse or promote products derived from
 * // this software without specific prior written permission.
 * //
 * // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * // AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * // IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * // DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
 * // FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * // DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * // SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
 * // CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * // OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
use crate::util::DctSample;
use crate::{PxdctError, PxdctExecutor};
use num_traits::AsPrimitive;

#[derive(Debug, Clone)]
pub(crate) struct DctIdentity<T: DctSample> {
    _phantom: std::marker::PhantomData<T>,
}

impl<T: DctSample> Default for DctIdentity<T> {
    fn default() -> Self {
        DctIdentity {
            _phantom: std::marker::PhantomData,
        }
    }
}

impl<T: DctSample> PxdctExecutor<T> for DctIdentity<T>
where
    f64: AsPrimitive<T>,
{
    fn execute(&self, _: &mut [T]) -> Result<(), PxdctError> {
        Ok(())
    }

    fn execute_with_scratch(&self, _: &mut [T], _: &mut [T]) -> Result<(), PxdctError> {
        Ok(())
    }

    fn execute_into(&self, input: &[T], output: &mut [T]) -> Result<(), PxdctError> {
        output.copy_from_slice(input);
        Ok(())
    }

    fn execute_into_with_scratch(
        &self,
        input: &[T],
        output: &mut [T],
        _: &mut [T],
    ) -> Result<(), PxdctError> {
        output.copy_from_slice(input);
        Ok(())
    }

    fn length(&self) -> usize {
        1
    }

    fn scratch_size(&self) -> usize {
        0
    }
}