Revert "started working on my own libflac decoder"

This reverts commit 715b53059b73d762348b8c1f54d9aa5f65f5262f.

1 files changed, 281 insertions, 0 deletions

diff --git a/src/flac.rs b/src/flac.rs
new file mode 100644
index 0000000..05d915f
--- /dev/null
+++ b/src/flac.rs
@@ -0,0 +1,281 @@
+use anyhow::{Result, anyhow};
+use flac_bound::{FlacEncoder, WriteWrapper};
+use md5::{Digest, Md5};
+use metaflac::{Block, Tag};
+use std::{
+    fs::File,
+    path::{Path, PathBuf},
+};
+use symphonia::core::{
+    audio::{Audio, GenericAudioBufferRef},
+    codecs::audio::AudioDecoder,
+    formats::{FormatOptions, FormatReader, TrackType, probe::Hint},
+    io::MediaSourceStream,
+    meta::MetadataOptions,
+};
+
+pub const CURRENT_VENDOR: &str = "reference libFLAC 1.5.0 20250211";
+
+type BoxedFormatReader = Box<dyn FormatReader>;
+type BoxedAudioDecoder = Box<dyn AudioDecoder + 'static>;
+
+struct StreamConfig {
+    channels: u32,
+    bits_per_sample: Bps,
+    sample_rate: u32,
+}
+
+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,
+        }
+    }
+}
+
+struct FileEncoder {
+    filename: PathBuf,
+    streamdata: StreamConfig,
+    format: BoxedFormatReader,
+    decoder: BoxedAudioDecoder,
+}
+
+impl FileEncoder {
+    fn new(file: impl AsRef<Path>) -> Result<Self> {
+        let (format, decoder, config) = init_decoder(&file)?;
+        Ok(FileEncoder {
+            filename: file.as_ref().to_path_buf(),
+            streamdata: config,
+            format,
+            decoder,
+        })
+    }
+
+    fn temp_name(&self) -> PathBuf {
+        self.filename.clone().with_extension("tmp")
+    }
+
+    fn encode(&mut self, mut encoder: FlacEncoder) -> Result<Vec<u8>> {
+        let mut buffer: Vec<i32> = Vec::new();
+        let mut hasher = Md5::new();
+        let track_id = self.format.default_track(TrackType::Audio).unwrap().id;
+        let offset = self.streamdata.bits_per_sample.value();
+
+        loop {
+            let packet = match self.format.next_packet() {
+                Ok(Some(packet)) => packet,
+                Ok(None) => break,
+                Err(error) => return Err(error.into()),
+            };
+
+            if packet.track_id() != track_id {
+                continue;
+            }
+
+            if let GenericAudioBufferRef::S32(buf) = self.decoder.decode(&packet)? {
+                for sample in buf.iter_interleaved() {
+                    let real_sample = sample >> (32 - offset);
+                    hasher.update(real_sample.to_le_bytes());
+                    buffer.push(real_sample);
+                }
+                encoder
+                    .process_interleaved(&buffer, buf.samples_planar() as u32)
+                    .unwrap();
+                buffer.clear();
+            } else {
+                return Err(anyhow!("unsupported codec"));
+            }
+        }
+
+        if let Err(enc) = encoder.finish() {
+            return Err(anyhow!("Encoding failed:\t{:?}", enc.state()));
+        }
+
+        Ok(hasher.finalize().to_vec())
+    }
+
+    fn write_tags(&self, hash: Vec<u8>) -> Result<()> {
+        let tags = Tag::read_from_path(&self.filename)?;
+        let mut output = Tag::read_from_path(self.temp_name())?;
+
+        let mut streaminfo = tags.get_streaminfo().unwrap().clone();
+
+        streaminfo.md5 = hash;
+        output.set_streaminfo(streaminfo);
+
+        for block in tags.blocks() {
+            match block {
+                Block::VorbisComment(comment) => {
+                    for (key, val) in comment.comments.clone() {
+                        if key != "ENCODER" {
+                            output.set_vorbis(key, val);
+                        }
+                    }
+                }
+                Block::StreamInfo(_) | Block::Padding(_) => {}
+                _ => output.push_block(block.clone()),
+            }
+        }
+
+        output.write_to_path(self.temp_name())?;
+        Ok(())
+    }
+}
+
+fn init_decoder(
+    filename: impl AsRef<Path>,
+) -> Result<(BoxedFormatReader, BoxedAudioDecoder, StreamConfig)> {
+    let src = std::fs::File::open(filename)?;
+    let mss = MediaSourceStream::new(Box::new(src), Default::default());
+    let mut hint = Hint::new();
+    hint.with_extension("flac");
+
+    let format_opts: FormatOptions = Default::default();
+    let metadata_opts: MetadataOptions = Default::default();
+
+    let format = symphonia::default::get_probe()
+        .probe(&hint, mss, format_opts, metadata_opts)
+        .unwrap();
+
+    let track = format.default_track(TrackType::Audio).unwrap();
+
+    let decoder = symphonia::default::get_codecs()
+        .make_audio_decoder(
+            track.codec_params.as_ref().unwrap().audio().unwrap(),
+            &Default::default(),
+        )
+        .unwrap();
+
+    let params = track.codec_params.as_ref().unwrap().audio().unwrap();
+
+    let config = StreamConfig {
+        channels: u32::try_from(params.channels.as_ref().unwrap().count()).unwrap(),
+        bits_per_sample: Bps::new(params.bits_per_sample.unwrap())?,
+        sample_rate: params.sample_rate.unwrap(),
+    };
+
+    Ok((format, decoder, config))
+}
+
+pub fn encode_file(filename: impl AsRef<Path>) -> Result<()> {
+    let mut filencoder = FileEncoder::new(filename)?;
+    let temp_name = filencoder.temp_name();
+
+    if temp_name.exists() {
+        std::fs::remove_file(&temp_name)?;
+    }
+
+    let mut outf = File::create(temp_name)?;
+    let mut outw = WriteWrapper(&mut outf);
+    let enc = FlacEncoder::new()
+        .unwrap()
+        .channels(filencoder.streamdata.channels)
+        .bits_per_sample(filencoder.streamdata.bits_per_sample.value())
+        .sample_rate(filencoder.streamdata.sample_rate)
+        .compression_level(8)
+        .verify(false)
+        .init_write(&mut outw)
+        .unwrap();
+
+    let hash = filencoder.encode(enc)?;
+    filencoder.write_tags(hash)?;
+    std::fs::rename(filencoder.temp_name(), filencoder.filename)?;
+    Ok(())
+}
+
+pub fn get_vendor(file: impl AsRef<Path>) -> Result<String> {
+    if let Some(vorbis) = Tag::read_from_path(file)?.vorbis_comments() {
+        Ok(vorbis.vendor_string.to_owned())
+    } else {
+        Err(anyhow!("Vendor string not found"))
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use metaflac::Tag;
+
+    #[test]
+    fn bit16() {
+        let name = "16bit.flac";
+        let tempname = "16bit.flac.temp";
+        std::fs::copy(name, tempname).unwrap();
+        encode_file(name).unwrap();
+        let target_md5 = Tag::read_from_path(tempname)
+            .unwrap()
+            .get_streaminfo()
+            .unwrap()
+            .md5
+            .clone();
+        let encoded_md5 = Tag::read_from_path(name)
+            .unwrap()
+            .get_streaminfo()
+            .unwrap()
+            .md5
+            .clone();
+        std::fs::remove_file(tempname).unwrap();
+        assert_eq!(target_md5, encoded_md5);
+    }
+
+    #[test]
+    fn bit24() {
+        let name = "24bit.flac";
+        let tempname = "24bit.flac.temp";
+        std::fs::copy(name, tempname).unwrap();
+        encode_file(name).unwrap();
+        let target_md5 = Tag::read_from_path(tempname)
+            .unwrap()
+            .get_streaminfo()
+            .unwrap()
+            .md5
+            .clone();
+        let encoded_md5 = Tag::read_from_path(name)
+            .unwrap()
+            .get_streaminfo()
+            .unwrap()
+            .md5
+            .clone();
+        std::fs::remove_file(tempname).unwrap();
+        assert_eq!(target_md5, encoded_md5);
+    }
+
+    #[test]
+    fn bit32() {
+        let name = "32bit.flac";
+        let tempname = "32bit.flac.temp";
+        std::fs::copy(name, tempname).unwrap();
+        encode_file(name).unwrap();
+        let target_md5 = Tag::read_from_path(tempname)
+            .unwrap()
+            .get_streaminfo()
+            .unwrap()
+            .md5
+            .clone();
+        let encoded_md5 = Tag::read_from_path(name)
+            .unwrap()
+            .get_streaminfo()
+            .unwrap()
+            .md5
+            .clone();
+        std::fs::remove_file(tempname).unwrap();
+        assert_eq!(target_md5, encoded_md5);
+    }
+}