rubato 2.0.0

Asynchronous resampling library intended for audio data
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
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214

extern crate rubato;
use audioadapter_buffers::direct::InterleavedSlice;
use rubato::{
    calculate_cutoff, Async, FixedAsync, Indexing, PolynomialDegree, Resampler,
    SincInterpolationParameters, SincInterpolationType, WindowFunction,
};
#[cfg(feature = "fft_resampler")]
use rubato::{Fft, FixedSync};
use std::convert::TryInto;
use std::env;
use std::fs::File;
use std::io::prelude::{Read, Seek, Write};
use std::io::{BufReader, BufWriter};
use std::time::Instant;

extern crate env_logger;
extern crate log;
use env_logger::Builder;
use log::LevelFilter;
const BYTE_PER_SAMPLE: usize = 8;

// A resampler app that reads a raw file of little-endian 64 bit floats, and writes the output in the same format.
// The command line arguments are resampler type, input filename, output filename, input samplerate, output samplerate, number of channels
// To use a sinc resampler with fixed input size to resample the file `sine_f64_2ch.raw` from 44.1kHz to 192kHz, and assuming the file has two channels, the command is:
// ```
// cargo run --release --example process_f64 SincFixedInput sine_f64_2ch.raw test.raw 44100 192000 2
// ```
// There are two helper python scripts for testing.
//  - `makesineraw.py` to generate test files in raw format.
//    Run it with the `-h` flag for instructions.
//  - `analyze_result.py` to analyze the result.
//    This takes three arguments: number of channels, samplerate, and sample format.
//    Example, to analyze the file created above:
//    ```
//    python examples/analyze_result.py test.raw 2 192000 f64
//    ```

/// Helper to read an entire file to memory as f64 values
fn read_file<R: Read + Seek>(inbuffer: &mut R) -> Vec<f64> {
    let mut buffer = vec![0u8; BYTE_PER_SAMPLE];
    let mut data = Vec::new();
    loop {
        let bytes_read = inbuffer.read(&mut buffer).unwrap();
        if bytes_read == 0 {
            break;
        }
        let value = f64::from_le_bytes(buffer.as_slice().try_into().unwrap());
        data.push(value);
    }
    data
}

/// Helper to write all frames to a file
fn write_file<W: Write + Seek>(
    data: &[f64],
    output: &mut W,
    values_to_skip: usize,
    values_to_write: usize,
) {
    for value in data.iter().skip(values_to_skip).take(values_to_write) {
        let bytes = value.to_le_bytes();
        output.write_all(&bytes).unwrap();
    }
}

fn main() {
    // init logger
    let mut builder = Builder::from_default_env();
    builder.filter(None, LevelFilter::Debug).init();

    let resampler_type = env::args()
        .nth(1)
        .expect("Please specify a resampler type, one of:\nSincFixedIn\nSincFixedOut\nFastFixedIn\nFastFixedOut\nFftFixedIn\nFftFixedOut\nFftFixedInOut");

    let file_in = env::args().nth(2).expect("Please specify an input file.");
    let file_out = env::args().nth(3).expect("Please specify an output file.");
    println!("Opening files: {}, {}", file_in, file_out);

    let fs_in_str = env::args()
        .nth(4)
        .expect("Please specify an input sample rate");
    let fs_out_str = env::args()
        .nth(5)
        .expect("Please specify an output sample rate");
    let fs_in = fs_in_str.parse::<usize>().unwrap();
    let fs_out = fs_out_str.parse::<usize>().unwrap();
    println!("Resampling from {} to {}", fs_in, fs_out);

    let channels_str = env::args()
        .nth(6)
        .expect("Please specify number of channels");
    let channels = channels_str.parse::<usize>().unwrap();

    println!("Copy input file to buffer");
    let file_in_disk = File::open(file_in).expect("Can't open file");
    let mut file_in_reader = BufReader::new(file_in_disk);
    let indata = read_file(&mut file_in_reader);
    let nbr_input_frames = indata.len() / channels;

    let f_ratio = fs_out as f64 / fs_in as f64;

    // Create buffer for storing output
    let mut outdata = vec![0.0; 2 * channels * (nbr_input_frames as f64 * f_ratio) as usize];

    println!("Creating resampler");
    // Create resampler
    let mut resampler: Box<dyn Resampler<f64>> = match resampler_type.as_str() {
        "SincFixedInput" => {
            let sinc_len = 128;
            let oversampling_factor = 256;
            let interpolation = SincInterpolationType::Quadratic;
            let window = WindowFunction::Blackman2;

            let f_cutoff = calculate_cutoff(sinc_len, window);
            let params = SincInterpolationParameters {
                sinc_len,
                f_cutoff,
                interpolation,
                oversampling_factor,
                window,
            };
            Box::new(Async::<f64>::new_sinc(f_ratio, 1.1, &params, 1024, channels, FixedAsync::Input).unwrap())
        }
        "SincFixedOutput" => {
            let sinc_len = 128;
            let oversampling_factor = 512;
            let interpolation = SincInterpolationType::Cubic;
            let window = WindowFunction::Blackman2;

            let f_cutoff = calculate_cutoff(sinc_len, window);
            let params = SincInterpolationParameters {
                sinc_len,
                f_cutoff,
                interpolation,
                oversampling_factor,
                window,
            };
            Box::new(Async::<f64>::new_sinc(f_ratio, 1.1, &params, 1024, channels, FixedAsync::Output).unwrap())
        }
        "PolyFixedInput" => {
            Box::new(Async::<f64>::new_poly(f_ratio, 1.1, PolynomialDegree::Septic, 1024, channels, FixedAsync::Input).unwrap())
        }
        "PolyFixedOutput" => {
            Box::new(Async::<f64>::new_poly(f_ratio, 1.1, PolynomialDegree::Septic, 1024, channels, FixedAsync::Output).unwrap())
        }
        #[cfg(feature = "fft_resampler")]
        "FftFixedInput" => {
            Box::new(Fft::<f64>::new(fs_in, fs_out, 1024, 2, channels, FixedSync::Input).unwrap())
        }
        #[cfg(feature = "fft_resampler")]
        "FftFixedOutput" => {
            Box::new(Fft::<f64>::new(fs_in, fs_out, 1024, 2, channels, FixedSync::Output).unwrap())
        }
        #[cfg(feature = "fft_resampler")]
        "FftFixedBoth" => {
            Box::new(Fft::<f64>::new(fs_in, fs_out, 1024, 1, channels, FixedSync::Both).unwrap())
        }
        _ => panic!("Unknown resampler type {}\nMust be one of SincFixedInput, SincFixedOutput, PolyFixedInput, PolyFixedOutput, FftFixedInput, FftFixedOutput, FftFixedBoth", resampler_type),
    };

    // Prepare
    let mut input_frames_next = resampler.input_frames_next();
    let resampler_delay = resampler.output_delay();

    let input_adapter = InterleavedSlice::new(&indata, channels, nbr_input_frames).unwrap();
    let outdata_capacity = outdata.len() / channels;
    let mut output_adapter =
        InterleavedSlice::new_mut(&mut outdata, channels, outdata_capacity).unwrap();

    println!("Process all full chunks");
    let start = Instant::now();
    let mut indexing = Indexing {
        input_offset: 0,
        output_offset: 0,
        active_channels_mask: None,
        partial_len: None,
    };
    let mut input_frames_left = nbr_input_frames;

    while input_frames_left >= input_frames_next {
        let (nbr_in, nbr_out) = resampler
            .process_into_buffer(&input_adapter, &mut output_adapter, Some(&indexing))
            .unwrap();

        indexing.input_offset += nbr_in;
        indexing.output_offset += nbr_out;
        input_frames_left -= nbr_in;
        input_frames_next = resampler.input_frames_next();
    }

    println!("Process a partial chunk with the last frames.");
    indexing.partial_len = Some(input_frames_left);
    let (_nbr_in, _nbr_out) = resampler
        .process_into_buffer(&input_adapter, &mut output_adapter, Some(&indexing))
        .unwrap();

    let duration = start.elapsed();
    println!("Resampling took: {:?}", duration);

    let nbr_output_frames = (nbr_input_frames as f32 * fs_out as f32 / fs_in as f32) as usize;
    println!(
        "Processed {} input frames into {} output frames",
        nbr_input_frames, nbr_output_frames
    );

    println!("Write output to file, trimming off the silent frames from both ends.");
    let mut file_out_disk = BufWriter::new(File::create(file_out).unwrap());
    write_file(
        &outdata,
        &mut file_out_disk,
        resampler_delay * channels,
        nbr_output_frames * channels,
    );
}