Add BGI Audio extract support

src/scripts/bgi/archive/v1.rs

@@ -489,6 +489,10 @@ fn detect_script_type(buf: &[u8], buf_len: usize, filename: &str) -> Option<&'st
     if buf_len >= 16 && buf.starts_with(b"CompressedBG___") {
         return Some(&ScriptType::BGICbg);
     }
+    #[cfg(feature = "bgi-audio")]
+    if buf_len >= 8 && buf[4..].starts_with(b"bw  ") {
+        return Some(&ScriptType::BGIAudio);
+    }
     let filename = filename.to_lowercase();
     if filename.ends_with("._bp") {
         return Some(&ScriptType::BGIBp);

src/scripts/bgi/archive/v2.rs

@@ -491,6 +491,10 @@ fn detect_script_type(buf: &[u8], buf_len: usize, filename: &str) -> Option<&'st
     if buf_len >= 16 && buf.starts_with(b"CompressedBG___") {
         return Some(&ScriptType::BGICbg);
     }
+    #[cfg(feature = "bgi-audio")]
+    if buf_len >= 8 && buf[4..].starts_with(b"bw  ") {
+        return Some(&ScriptType::BGIAudio);
+    }
     let filename = filename.to_lowercase();
     if filename.ends_with("._bp") {
         return Some(&ScriptType::BGIBp);

src/scripts/bgi/audio/audio.rs

@@ -0,0 +1,127 @@
+use crate::ext::io::*;
+use crate::scripts::base::*;
+use crate::types::*;
+use anyhow::Result;
+use std::io::{Read, Seek, SeekFrom, Write};
+
+#[derive(Debug)]
+pub struct BgiAudioBuilder {}
+
+impl BgiAudioBuilder {
+    pub fn new() -> Self {
+        Self {}
+    }
+}
+
+impl ScriptBuilder for BgiAudioBuilder {
+    fn default_encoding(&self) -> Encoding {
+        Encoding::Utf8
+    }
+
+    fn build_script(
+        &self,
+        buf: Vec<u8>,
+        _filename: &str,
+        _encoding: Encoding,
+        _archive_encoding: Encoding,
+        config: &ExtraConfig,
+        _archive: Option<&Box<dyn Script>>,
+    ) -> Result<Box<dyn Script>> {
+        Ok(Box::new(BgiAudio::new(MemReader::new(buf), config)?))
+    }
+
+    fn build_script_from_file(
+        &self,
+        filename: &str,
+        _encoding: Encoding,
+        _archive_encoding: Encoding,
+        config: &ExtraConfig,
+        _archive: Option<&Box<dyn Script>>,
+    ) -> Result<Box<dyn Script>> {
+        let file = std::fs::File::open(filename)?;
+        let f = std::io::BufReader::new(file);
+        Ok(Box::new(BgiAudio::new(f, config)?))
+    }
+
+    fn build_script_from_reader(
+        &self,
+        reader: Box<dyn ReadSeek>,
+        _filename: &str,
+        _encoding: Encoding,
+        _archive_encoding: Encoding,
+        config: &ExtraConfig,
+        _archive: Option<&Box<dyn Script>>,
+    ) -> Result<Box<dyn Script>> {
+        Ok(Box::new(BgiAudio::new(reader, config)?))
+    }
+
+    fn extensions(&self) -> &'static [&'static str] {
+        &[]
+    }
+
+    fn script_type(&self) -> &'static ScriptType {
+        &ScriptType::BGIAudio
+    }
+
+    fn is_this_format(&self, _filename: &str, buf: &[u8], buf_len: usize) -> Option<u8> {
+        if buf_len >= 8 && buf[4..].starts_with(b"bw  ") {
+            Some(10)
+        } else {
+            None
+        }
+    }
+}
+
+#[derive(Debug)]
+pub struct BgiAudio {
+    data: MemReader,
+}
+
+impl BgiAudio {
+    pub fn new<R: Read + Seek>(mut reader: R, _config: &ExtraConfig) -> Result<Self> {
+        let offset = reader.read_u32()?;
+        let len = reader.stream_length()?;
+        if (offset as u64) > len {
+            return Err(anyhow::anyhow!("Invalid offset in BGI audio file"));
+        }
+        let mut magic = [0; 4];
+        reader.read_exact(&mut magic)?;
+        if magic != *b"bw  " {
+            return Err(anyhow::anyhow!(
+                "Invalid magic in BGI audio file: {:?}",
+                magic
+            ));
+        }
+        reader.seek(SeekFrom::Start(offset as u64))?;
+        let mut data = Vec::new();
+        reader.read_to_end(&mut data)?;
+        Ok(Self {
+            data: MemReader::new(data),
+        })
+    }
+}
+
+impl Script for BgiAudio {
+    fn default_output_script_type(&self) -> OutputScriptType {
+        OutputScriptType::Custom
+    }
+
+    fn default_format_type(&self) -> FormatOptions {
+        FormatOptions::None
+    }
+
+    fn is_output_supported(&self, output: OutputScriptType) -> bool {
+        matches!(output, OutputScriptType::Custom)
+    }
+
+    fn custom_output_extension<'a>(&'a self) -> &'a str {
+        "ogg"
+    }
+
+    fn custom_export(&self, filename: &std::path::Path, _encoding: Encoding) -> Result<()> {
+        let mut writer = std::fs::File::create(filename)?;
+        writer.write_all(&self.data.data)?;
+        writer.flush()?;
+        Ok(())
+    }
+}

src/scripts/bgi/audio/mod.rs

@@ -0,0 +1 @@
+pub mod audio;

src/scripts/bgi/mod.rs

@@ -1,5 +1,7 @@
 #[cfg(feature = "bgi-arc")]
 pub mod archive;
+#[cfg(feature = "bgi-audio")]
+pub mod audio;
 pub mod bp;
 pub mod bsi;
 #[cfg(feature = "bgi-img")]