FFT computation and value updating

Cargo.lock

@@ -1366,6 +1366,15 @@ dependencies = [
  "num-traits",
 ]
 
+[[package]]
+name = "num-complex"
+version = "0.4.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "73f88a1307638156682bada9d7604135552957b7818057dcef22705b4d509495"
+dependencies = [
+ "num-traits",
+]
+
 [[package]]
 name = "num-derive"
 version = "0.4.2"
@@ -1578,6 +1587,15 @@ dependencies = [
  "yansi",
 ]
 
+[[package]]
+name = "primal-check"
+version = "0.3.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "dc0d895b311e3af9902528fbb8f928688abbd95872819320517cc24ca6b2bd08"
+dependencies = [
+ "num-integer",
+]
+
 [[package]]
 name = "proc-macro2"
 version = "1.0.92"
@@ -1882,6 +1900,21 @@ version = "1.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "08d43f7aa6b08d49f382cde6a7982047c3426db949b1424bc4b7ec9ae12c6ce2"
 
+[[package]]
+name = "rustfft"
+version = "6.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "43806561bc506d0c5d160643ad742e3161049ac01027b5e6d7524091fd401d86"
+dependencies = [
+ "num-complex",
+ "num-integer",
+ "num-traits",
+ "primal-check",
+ "strength_reduce",
+ "transpose",
+ "version_check",
+]
+
 [[package]]
 name = "rustix"
 version = "0.38.41"
@@ -2131,6 +2164,12 @@ version = "1.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "a2eb9349b6444b326872e140eb1cf5e7c522154d69e7a0ffb0fb81c06b37543f"
 
+[[package]]
+name = "strength_reduce"
+version = "0.2.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "fe895eb47f22e2ddd4dabc02bce419d2e643c8e3b585c78158b349195bc24d82"
+
 [[package]]
 name = "strsim"
 version = "0.11.1"
@@ -2166,11 +2205,13 @@ dependencies = [
  "crossterm",
  "image",
  "md5",
+ "num-complex",
  "pipewire",
  "rand",
  "ratatui",
  "ratatui-image",
  "reqwest",
+ "rustfft",
  "serde",
  "serde_json",
  "toml",
@@ -2415,6 +2456,16 @@ dependencies = [
  "once_cell",
 ]
 
+[[package]]
+name = "transpose"
+version = "0.2.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1ad61aed86bc3faea4300c7aee358b4c6d0c8d6ccc36524c96e4c92ccf26e77e"
+dependencies = [
+ "num-integer",
+ "strength_reduce",
+]
+
 [[package]]
 name = "try-lock"
 version = "0.2.5"
@@ -2508,6 +2559,12 @@ version = "0.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "852e951cb7832cb45cb1169900d19760cfa39b82bc0ea9c0e5a14ae88411c98b"
 
+[[package]]
+name = "version_check"
+version = "0.9.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0b928f33d975fc6ad9f86c8f283853ad26bdd5b10b7f1542aa2fa15e2289105a"
+
 [[package]]
 name = "want"
 version = "0.3.1"

Cargo.toml

@@ -7,11 +7,13 @@ edition = "2021"
 crossterm = "0.28.1"
 image = "0.25.5"
 md5 = "0.7.0"
+num-complex = "0.4.6"
 pipewire = "0.8.0"
 rand = "0.8.5"
 ratatui = "0.29.0"
 ratatui-image = "3.0.0"
 reqwest = { version = "0.12.9", features = ["blocking", "json"] }
+rustfft = "6.2.0"
 serde = { version = "1.0.215", features = ["derive"] }
 serde_json = "1.0.133"
 toml = "0.8.19"

src/audio/fft.rs

@@ -1,29 +1,78 @@
+use num_complex::{Complex, Complex64};
+use rustfft::{Fft, FftPlanner};
+
 use crate::utils::FFTResult;
-use std::collections::VecDeque;
+use std::{collections::VecDeque, sync::Arc};
+
+const FFT_WINDOW: usize = 5;
+const FFT_FRAME_SIZE: usize = FFT_WINDOW * 480;
 
 pub struct FFTFrame {
-    buffer: VecDeque<[[i16; 480]; 2]>,
+    buffer: VecDeque<[[Complex<f64>; 480]; 2]>,
+    planner: FftPlanner<f64>,
+    fft_instance: Arc<dyn Fft<f64>>,
+    n_iter: usize,
 }
 
 impl FFTFrame {
     pub fn new() -> FFTFrame {
+        let mut planner = FftPlanner::new();
+        let plan = planner.plan_fft_forward(FFT_FRAME_SIZE);
         let mut frame = FFTFrame {
             buffer: VecDeque::new(),
+            planner,
+            fft_instance: plan,
+            n_iter: 0,
         };
-        for _ in 0..5 {
-            frame.push([[0; 480]; 2]);
+        for _ in 0..FFT_WINDOW {
+            frame.push([[Complex { re: 0.0, im: 0.0 }; 480]; 2]);
         }
         frame
     }
 
-    pub fn push(&mut self, new_samples: [[i16; 480]; 2]) {
-        if self.buffer.len() == 5 {
+    pub fn push(&mut self, new_samples: [[Complex<f64>; 480]; 2]) {
+        if self.buffer.len() == FFT_WINDOW {
             self.buffer.pop_front();
         }
         self.buffer.push_back(new_samples);
+        self.n_iter = (self.n_iter + 1) % FFT_WINDOW;
     }
 
-    pub fn compute(&self) -> FFTResult {
-        unimplemented!()
+    pub fn compute(&mut self) -> Option<FFTResult> {
+        if self.n_iter != 0 {
+            return None;
+        }
+        let mut FFTResult = FFTResult {
+            bins_l: [0.0; 20],
+            bins_r: [0.0; 20],
+        };
+        let (mut buff_l, mut buff_r) = (
+            [Complex {
+                re: 0.0f64,
+                im: 0.0f64,
+            }; FFT_FRAME_SIZE],
+            [Complex {
+                re: 0.0f64,
+                im: 0.0f64,
+            }; FFT_FRAME_SIZE],
+        );
+        for i in 0..FFT_WINDOW {
+            let [l, r] = self.buffer.pop_front().unwrap();
+            buff_l[i..i + 480].copy_from_slice(&l);
+            buff_r[i..i + 480].copy_from_slice(&r);
+        }
+        self.fft_instance.process(&mut buff_l);
+        self.fft_instance.process(&mut buff_r);
+
+        let (mut bins_l, mut bins_r) = ([0.0; 20], [0.0; 20]);
+        for i in 0..20 {
+            for j in 0..120 {
+                bins_l[i] += buff_l[120 * i + j].re;
+                bins_r[i] += buff_r[120 * i + j].re;
+            }
+            bins_l[i] /= 20.0;
+            bins_r[i] /= 20.0;
+        }
+        Some(FFTResult { bins_l, bins_r })
     }
 }

src/audio/sound_mgr.rs

@@ -8,6 +8,8 @@ use std::{
     time::{Duration, SystemTime},
 };
 
+use num_complex::Complex;
+
 use crate::{
     config::Settings,
     player::PlayerEvent,
@@ -83,13 +85,16 @@ impl SoundManager {
         }
     }
 
-    fn fft_compute(&mut self, frame: &[u8]) -> FFTResult {
-        let mut samples = [[0; 480]; 2];
+    fn fft_compute(&mut self, frame: &[u8]) -> Option<FFTResult> {
+        let mut samples = [[Complex {
+            re: 0.0f64,
+            im: 0.0f64,
+        }; 480]; 2];
         for i in 0..frame.len() / 4 {
             for j in 0..2 {
                 let mut val_buff = [0; 2];
                 val_buff.copy_from_slice(&frame[4 * i + 2 * j..4 * i + 2 * j + 2]);
-                samples[i][j] = i16::from_le_bytes(val_buff);
+                samples[j][i].re = i16::from_le_bytes(val_buff) as f64 / 32767.0;
             }
         }
         self.fft_frame.push(samples);
@@ -98,8 +103,9 @@ impl SoundManager {
 
     fn push_samples(&mut self) -> Result<(), Error> {
         let (mut frame, fetch_more) = self.decoder_context.next_sample();
-        let bins = self.fft_compute(frame.as_slice());
-        self.player_chan.send(PlayerEvent::FFTBins(bins))?;
+        if let Some(bins) = self.fft_compute(frame.as_slice()) {
+            self.player_chan.send(PlayerEvent::FFTBins(bins))?;
+        }
         self.adjust_volume(frame.as_mut_slice());
         self.sample_in.send(frame)?;
         match fetch_more {

src/player/current.rs

@@ -1,6 +1,9 @@
 use image::DynamicImage;
 
-use crate::{ssonic::response::Song, utils::default_cover};
+use crate::{
+    ssonic::response::Song,
+    utils::{default_cover, FFTResult},
+};
 
 pub struct Metadata {
     pub id: String,
@@ -12,6 +15,7 @@ pub struct Metadata {
     pub size: u32,
     pub bytes_received: u32,
     pub last_byte_range_start: u32,
+    pub spectrogram: FFTResult,
 }
 
 impl Metadata {
@@ -26,6 +30,10 @@ impl Metadata {
             size: 0,
             bytes_received: 0,
             last_byte_range_start: 0,
+            spectrogram: FFTResult {
+                bins_l: [0.0; 20],
+                bins_r: [0.0; 20],
+            },
         }
     }
 
@@ -49,4 +57,8 @@ impl Metadata {
         self.bytes_received = 0;
         self.size = song.size;
     }
+
+    pub fn update_spectrogram(&mut self, bins: FFTResult) {
+        self.spectrogram = bins;
+    }
 }

src/player/player.rs

@@ -10,7 +10,7 @@ use image::DynamicImage;
 use crate::{
     audio::AudioEvent,
     ssonic::{response::Song, APIEvent, MAX_CHUNK_SIZE},
-    utils::{default_cover, time_rem, Error},
+    utils::{default_cover, time_rem, Error, FFTResult},
 };
 
 use super::{errors::PlayerError, Player, PlayerEvent};
@@ -53,6 +53,7 @@ impl Player {
                 PlayerEvent::UpdateCover(cover) => self.tui_root.update_cover(cover),
                 PlayerEvent::AddAudioChunk(chunk_len) => self.recv_chunk(chunk_len)?,
                 PlayerEvent::FetchChunk => self.fetch_audio_chunk(false)?,
+                PlayerEvent::FFTBins(bins) => self.tui_root.metadata.update_spectrogram(bins),
                 _ => unimplemented!(),
             }
         }
@@ -90,7 +91,6 @@ impl Player {
     }
 
     fn play_next(&mut self) -> Result<(), Error> {
-        dbg!("playing next");
         let song = match self.playlist.get_next() {
             None => {
                 // no song exists, requeue the event

src/utils.rs

@@ -76,4 +76,7 @@ pub fn time_rem(start_time: SystemTime, target_dur: Duration) -> Result<Duration
     Ok(target_dur.saturating_sub(time_since))
 }
 
-pub struct FFTResult {}
+pub struct FFTResult {
+    pub bins_l: [f64; 20],
+    pub bins_r: [f64; 20],
+}