From a7615b9471dfe6fe94a3ace6e4f94e9c78844b51 Mon Sep 17 00:00:00 2001
From: jakka <jakkadoujin@gmail.com>
Date: Wed, 4 Jun 2025 21:30:40 +0300
Subject: added 16 and 24 bit md5sum calculation support

---
 src/flac.rs | 134 +++++++++++++++++++++++++++++++++++++++++++++++-------------
 1 file changed, 106 insertions(+), 28 deletions(-)

(limited to 'src/flac.rs')

diff --git a/src/flac.rs b/src/flac.rs
index 92c4b77..8653881 100644
--- a/src/flac.rs
+++ b/src/flac.rs
@@ -1,32 +1,126 @@
 use anyhow::{Result, anyhow};
+use claxon::FlacReader;
 use flac_bound::{FlacEncoder, WriteWrapper};
+use i24::i24;
 use md5::{Digest, Md5};
 use metaflac::Tag;
 use std::fs::File;
 
-#[derive(Debug)]
 struct StreamConfig {
     channels: u32,
-    bits_per_sample: u32,
+    bits_per_sample: Bps,
     sample_rate: u32,
     total_samples_estimate: u64,
 }
 
+enum Bps {
+    _16,
+    _24,
+    _32,
+}
+
+impl Bps {
+    fn new(num: u32) -> Result<Self> {
+        match num {
+            16 => Ok(Bps::_16),
+            24 => Ok(Bps::_24),
+            32 => Ok(Bps::_32),
+            _ => Err(anyhow!("Invalid BPS")),
+        }
+    }
+
+    fn value(&self) -> u32 {
+        match self {
+            Bps::_16 => 16,
+            Bps::_24 => 24,
+            Bps::_32 => 32,
+        }
+    }
+}
+
+fn process_samples_i16(
+    hasher: &mut impl Digest,
+    mut reader: FlacReader<File>,
+    enc: &mut FlacEncoder,
+    config: &StreamConfig,
+) -> Result<()> {
+    for samples in reader
+        .samples()
+        .map(|sample| sample.unwrap())
+        .collect::<Vec<_>>()
+        .chunks(4096)
+    {
+        enc.process_interleaved(samples, 4096 / config.channels)
+            .unwrap();
+        let _ = samples
+            .iter()
+            .map(|sample| hasher.update((i16::try_from(*sample)).unwrap().to_le_bytes()))
+            .collect::<Vec<_>>();
+    }
+    Ok(())
+}
+
+fn process_samples_i24(
+    hasher: &mut impl Digest,
+    mut reader: FlacReader<File>,
+    enc: &mut FlacEncoder,
+    config: &StreamConfig,
+) -> Result<()> {
+    for samples in reader
+        .samples()
+        .map(|sample| sample.unwrap())
+        .collect::<Vec<_>>()
+        .chunks(4096)
+    {
+        enc.process_interleaved(samples, 4096 / config.channels)
+            .unwrap();
+        let _ = samples
+            .iter()
+            .map(|sample| hasher.update((i24::try_from(*sample)).unwrap().to_le_bytes()))
+            .collect::<Vec<_>>();
+    }
+    Ok(())
+}
+
+fn process_samples_i32(
+    hasher: &mut impl Digest,
+    mut reader: FlacReader<File>,
+    enc: &mut FlacEncoder,
+    config: &StreamConfig,
+) -> Result<()> {
+    for samples in reader
+        .samples()
+        .map(|sample| sample.unwrap())
+        .collect::<Vec<_>>()
+        .chunks(4096)
+    {
+        enc.process_interleaved(samples, 4096 / config.channels)
+            .unwrap();
+        let _ = samples
+            .iter()
+            .map(|sample| hasher.update(sample.to_le_bytes()))
+            .collect::<Vec<_>>();
+    }
+    Ok(())
+}
+
 pub fn encode_file(file: &std::path::Path) -> Result<()> {
-    let mut reader = claxon::FlacReader::open(file)?;
+    let reader = claxon::FlacReader::open(file)?;
     let config = StreamConfig {
         channels: reader.streaminfo().channels,
-        bits_per_sample: reader.streaminfo().bits_per_sample,
+        bits_per_sample: Bps::new(reader.streaminfo().bits_per_sample)?,
         sample_rate: reader.streaminfo().sample_rate,
         total_samples_estimate: reader.streaminfo().samples.unwrap(),
     };
+
     let tempname = format!("{}.{}", file.display(), "tmp");
+
     let mut outf = File::create(&tempname)?;
     let mut outw = WriteWrapper(&mut outf);
     let mut enc = FlacEncoder::new()
         .unwrap()
         .channels(config.channels)
-        .bits_per_sample(config.bits_per_sample)
+        .bits_per_sample(config.bits_per_sample.value())
         .sample_rate(config.sample_rate)
         .total_samples_estimate(config.total_samples_estimate)
         .compression_level(8)
@@ -35,30 +129,15 @@ pub fn encode_file(file: &std::path::Path) -> Result<()> {
         .unwrap();
 
     let mut hasher = Md5::new();
-    let mut bytes = Vec::new();
 
-    for samples in reader
-        .samples()
-        .map(|sample| sample.unwrap())
-        .collect::<Vec<_>>()
-        .chunks(4096)
-    {
-        enc.process_interleaved(samples, 4096 / config.channels).unwrap();
-        let _ = samples
-            .iter()
-            .map(|sample| {
-                for byte in sample.to_le_bytes() {
-                    bytes.push(byte)
-                }
-            })
-            .collect::<Vec<_>>();
-        hasher.update(&bytes);
-        bytes.clear();
-    }
+    match config.bits_per_sample {
+        Bps::_16 => process_samples_i16(&mut hasher, reader, &mut enc, &config)?,
+        Bps::_24 => process_samples_i24(&mut hasher, reader, &mut enc, &config)?,
+        Bps::_32 => process_samples_i32(&mut hasher, reader, &mut enc, &config)?,
+    };
 
-    match enc.finish() {
-        Ok(_) => {}
-        Err(enc) => return Err(anyhow!("Encoding failed:\t{:?}", enc.state())),
+    if let Err(enc) = enc.finish() {
+        return Err(anyhow!("Encoding failed:\t{:?}", enc.state()));
     }
 
     /* let source_tags = Tag::read_from_path(file)?;
@@ -68,7 +147,6 @@ pub fn encode_file(file: &std::path::Path) -> Result<()> {
     for block in source_tags.blocks() {
         todo!()
     } */
-
     let mut tags = Tag::read_from_path(tempname)?;
     let mut streaminfo = tags.get_streaminfo().unwrap().clone();
     streaminfo.md5 = hasher.finalize()[..].to_vec();
-- 
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