initial commit of cursed encoder project

.gitignore

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+/target

Cargo.lock

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+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 4
+
+[[package]]
+name = "dpcm-encoder-decoder"
+version = "0.1.0"

Cargo.toml

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+[package]
+name = "dpcm-encoder-decoder"
+version = "0.1.0"
+edition = "2024"
+
+[dependencies]

README.md

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+# DPCM ENCODER / DECODER
+
+goal: 
+- [ ] CLI application to encode PCM_u8 audio to DPCM audo with a given step size 

src/main.rs

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+fn main() {
+    let input = include_bytes!("../sweep_short.raw");
+
+    let min = input.iter().min().unwrap();
+    let max = input.iter().max().unwrap();
+    let step_size = 0x3;
+
+    println!("len:\t\t{} samples", input.len());
+    println!("initial:\t0x{:02x}", input[0]);
+    println!("min:\t\t0x{:02x}", min);
+    println!("max:\t\t0x{:02x}", max);
+    println!("step size:\t0x{:02x}", step_size);
+
+    let mut output: Vec<u8> = Vec::new();
+
+    // let mut max_diff = 0;
+    // let prev = input[0];
+    // for byte in input {
+        
+    // }
+
+
+    let mut sample_pair: u8 = 0;
+    let mut index = 0;
+    let mut prev = input[0];
+    for byte in &input[1..] {
+        let (diff, dir) = match byte >= &prev {
+            true => ({byte - prev}, 0x1),
+            false => ({prev - byte}, 0x0),
+        };
+        let steps = (diff / step_size) & 0x0E;
+        sample_pair |=  ((steps << 1) | dir) << 4 * (index % 2);
+        if (index % 2) == 1 {
+            output.push(sample_pair);
+            sample_pair = 0;
+        }
+        // println!("0x{:01x} | {}", steps, dir);
+        prev = match dir {
+            0x1 => prev + (steps * step_size),
+            0x0 => prev - (steps * step_size),
+            _ => prev + (steps * step_size),
+        };
+        index += 1;
+    }
+
+    // for sample in &output {
+        // println!("0x{:02x}", sample);
+    // }
+
+    std::fs::write("./sweep_dpcm_u4.raw", &output).unwrap();
+}