Updated readme

Need to clean up zero-terminated strings in adtl

Cargo.lock

@@ -2,7 +2,7 @@
 # It is not intended for manual editing.
 [[package]]
 name = "bwavfile"
-version = "0.1.6"
+version = "0.1.7"
 dependencies = [
  "byteorder",
  "encoding",

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "bwavfile"
-version = "0.1.6"
+version = "0.1.7"
 authors = ["Jamie Hardt <jamiehardt@me.com>"]
 edition = "2018"
 license = "MIT"

README.md

@@ -6,22 +6,22 @@
 # bwavfile
 Rust Wave File Reader/Writer with Broadcast-WAV, MBWF and RF64 Support
 
-This is currently a work-in-progress!
-
 ### Features
 
-- Read standard WAV, Broadcast-Wave, and 64-bit RF64 and BW64 wave files with one interface for 
+This is currently a work-in-progress! However many features presently work:
+
+- [x] Read standard WAV, Broadcast-Wave, and 64-bit RF64 and BW64 wave files with one interface for 
   all types with transparent format detection.
-- Unified format definition interface for standard and extended-format wave files.
+- [ ] Wave/RF64 file writing with transparent promotion from WAV to RF64.
-- Read channel/speaker map metadata.
+- [x] Unified format definition interface for standard and extended-format wave files.
-- Read standard EBU Broadcast-Wave metadata and decode to fields, including timestamp and SMPTE UMID.
+- [x] Read channel/speaker map metadata.
-- Validate the compatibility of a given wave file for certain regimes.
+- [x] Read standard EBU Broadcast-Wave metadata and decode to fields, including timestamp and SMPTE UMID.
-- Metadata support for ambisonic B-format.
+- [x] iXML and ADM XML metadata.
-
+- [ ] Broadcast-WAV Level and Quality metadata.
-### In Progress
+- [x] Cue list metadata.
-
+- [ ] Sampler and instrument metadata.
-- Wave/RF64 file writing.
+- [x] Validate the compatibility of a given wave file for certain regimes.
-- iXML and ADM XML metadata reading/writing.
+- [x] Metadata support for ambisonic B-format.
 
 
 ## Use Examples
@@ -46,6 +46,21 @@ This is currently a work-in-progress!
  assert_eq!(read, 1);
 ```
 
+### Accessing Channel Descriptions
+
+```rust
+ use bwavfile::{WaveReader, ChannelMask};
+ 
+ let mut f = WaveReader::open("tests/media/pt_24bit_51.wav").unwrap();
+    
+ let chans = f.channels().unwrap();
+ assert_eq!(chans[0].index, 0);
+ assert_eq!(chans[0].speaker, ChannelMask::FrontLeft);
+ assert_eq!(chans[3].index, 3);
+ assert_eq!(chans[3].speaker, ChannelMask::LowFrequency);
+ assert_eq!(chans[4].speaker, ChannelMask::BackLeft);
+```
+
 ## Note on Testing
 
 All of the media for the integration tests is committed to the respository

src/cue.rs

@@ -0,0 +1,258 @@
+use super::fourcc::{FourCC,ReadFourCC, LABL_SIG, NOTE_SIG, LTXT_SIG};
+use super::list_form::collect_list_form;
+
+use byteorder::{ReadBytesExt, LittleEndian};
+
+use encoding::{DecoderTrap};
+use encoding::{Encoding};
+use encoding::all::ASCII;
+
+use std::io::{Cursor, Error, Read};
+
+#[derive(Copy,Clone, Debug)]
+struct RawCue {
+    cue_point_id : u32,
+    frame : u32,
+    chunk_id : FourCC,
+    chunk_start : u32,
+    block_start : u32,
+    frame_offset : u32
+}
+
+impl RawCue {
+    fn read_from(data : &[u8]) -> Result<Vec<Self>,Error> {
+        let mut rdr = Cursor::new(data);
+        let count = rdr.read_u32::<LittleEndian>()?;
+        let mut retval : Vec<Self> = vec![];
+
+        for _ in 0..count {
+            retval.push( Self {
+                cue_point_id : rdr.read_u32::<LittleEndian>()?,
+                frame : rdr.read_u32::<LittleEndian>()?,
+                chunk_id : rdr.read_fourcc()?,
+                chunk_start : rdr.read_u32::<LittleEndian>()?,
+                block_start : rdr.read_u32::<LittleEndian>()?,
+                frame_offset : rdr.read_u32::<LittleEndian>()?
+            })
+        }
+
+        Ok( retval )
+    }
+}
+
+#[derive(Clone, Debug)]
+struct RawLabel {
+    cue_point_id : u32,
+    text : Vec<u8>
+}
+
+impl RawLabel {
+    fn read_from(data : &[u8]) -> Result<Self, Error> {
+        let mut rdr = Cursor::new(data);
+        let length = data.len();
+
+        Ok( Self {
+            cue_point_id : rdr.read_u32::<LittleEndian>()?,
+            text : {
+                let mut buf = vec![0u8; (length - 4) as usize ];
+                rdr.read_exact(&mut buf)?;
+                buf
+            }
+        })
+    }
+}
+
+#[derive(Clone, Debug)]
+struct RawNote {
+    cue_point_id : u32,
+    text : Vec<u8>
+}
+
+impl RawNote {
+    fn read_from(data : &[u8]) -> Result<Self, Error> {
+        let mut rdr = Cursor::new(data);
+        let length = data.len();
+
+        Ok( Self {
+            cue_point_id : rdr.read_u32::<LittleEndian>()?,
+            text : {
+                let mut buf = vec![0u8; (length - 4) as usize ];
+                rdr.read_exact(&mut buf)?;
+                buf
+            }
+        })
+    }
+}
+
+#[derive(Clone, Debug)]
+struct RawLtxt { 
+    cue_point_id : u32,
+    frame_length : u32,
+    purpose : FourCC,
+    country : u16,
+    language : u16,
+    dialect : u16,
+    code_page : u16,
+    text: Option<Vec<u8>>
+}
+
+impl RawLtxt {
+    fn read_from(data : &[u8]) -> Result<Self, Error> {
+        let mut rdr = Cursor::new(data);
+        let length = data.len();
+
+        Ok( Self {
+            cue_point_id : rdr.read_u32::<LittleEndian>()?,
+            frame_length : rdr.read_u32::<LittleEndian>()?,
+            purpose : rdr.read_fourcc()?,
+            country : rdr.read_u16::<LittleEndian>()?,
+            language : rdr.read_u16::<LittleEndian>()?,
+            dialect : rdr.read_u16::<LittleEndian>()?,
+            code_page : rdr.read_u16::<LittleEndian>()?,
+            text : {
+                if length - 20 > 0 {
+                    let mut buf = vec![0u8; (length - 20) as usize];
+                    rdr.read_exact(&mut buf)?;
+                    Some( buf )
+                } else {
+                    None
+                }
+            }
+        })
+    }
+}
+
+#[derive(Clone, Debug)]
+enum RawAdtlMember {
+    Label(RawLabel),
+    Note(RawNote),
+    LabeledText(RawLtxt),
+    Unrecognized(FourCC)
+}
+
+impl RawAdtlMember {
+    fn collect_from(chunk : &[u8]) -> Result<Vec<RawAdtlMember>,Error> {
+        let chunks = collect_list_form(chunk)?;
+        let mut retval : Vec<RawAdtlMember> = vec![];
+
+        for chunk in chunks.iter() {
+            retval.push( 
+                match chunk.signature {
+                    LABL_SIG => RawAdtlMember::Label( RawLabel::read_from(&chunk.contents)? ),
+                    NOTE_SIG => RawAdtlMember::Note( RawNote::read_from(&chunk.contents)? ),
+                    LTXT_SIG => RawAdtlMember::LabeledText( RawLtxt::read_from(&chunk.contents)? ),
+                    x => RawAdtlMember::Unrecognized(x)
+                }
+            )
+        }
+        Ok( retval )
+    }
+}
+
+trait AdtlMemberSearch {
+    fn labels_for_cue_point(&self, id: u32) -> Vec<&RawLabel>;
+    fn notes_for_cue_point(&self, id : u32) -> Vec<&RawNote>;
+    fn ltxt_for_cue_point(&self, id: u32) -> Vec<&RawLtxt>;
+}
+
+impl AdtlMemberSearch for Vec<RawAdtlMember> {
+
+    fn labels_for_cue_point(&self, id: u32) -> Vec<&RawLabel> {
+        self.iter().filter_map(|item| {
+            match item {
+                RawAdtlMember::Label(x) if x.cue_point_id == id => Some(x),
+                _ => None
+            }
+        })
+        .collect()
+    }
+    
+    fn notes_for_cue_point(&self, id: u32) -> Vec<&RawNote> { 
+        self.iter().filter_map(|item| {
+            match item {
+                RawAdtlMember::Note(x) if x.cue_point_id == id => Some(x),
+                _ => None
+            }
+        })
+        .collect()  
+    }
+
+    fn ltxt_for_cue_point(&self, id: u32) -> Vec<&RawLtxt> {
+        self.iter().filter_map(|item| {
+            match item {
+                RawAdtlMember::LabeledText(x) if x.cue_point_id == id => Some(x),
+                _ => None
+            }
+        })
+        .collect()
+    }
+}
+
+/// A cue point recorded in the `cue` and `adtl` metadata.
+/// 
+/// 
+pub struct Cue {
+
+    /// Unique numeric identifier for this cue
+    pub ident : u32,
+
+    /// The time of this marker
+    pub frame : u32,
+
+    /// The length of this marker, if it is a range
+    pub length : Option<u32>,
+
+    /// The text "label"/name of this marker if provided
+    pub label : Option<String>,
+
+    /// The text "note"/comment of this marker if provided
+    pub note : Option<String>
+}
+
+
+fn convert_to_cue_string(buffer : &[u8]) -> String {
+    let trimmed : Vec<u8> = buffer.iter().take_while(|c| **c != 0 as u8).cloned().collect();
+    ASCII.decode(&trimmed, DecoderTrap::Ignore).expect("Error decoding text")
+}
+
+impl Cue {
+
+    pub fn collect_from(cue_chunk : &[u8], adtl_chunk : Option<&[u8]>) -> Result<Vec<Cue>, Error> {
+        let raw_cues = RawCue::read_from(cue_chunk)?;
+        let raw_adtl : Vec<RawAdtlMember>;
+
+        if let Some(adtl) = adtl_chunk {
+            raw_adtl = RawAdtlMember::collect_from(adtl)?;
+        } else {
+            raw_adtl = vec![];
+        }
+        
+
+        Ok( 
+            raw_cues.iter()
+            .map(|i| {
+                Cue {
+                    ident : i.cue_point_id,
+                    frame : i.frame,
+                    length: {
+                        raw_adtl.ltxt_for_cue_point(i.cue_point_id).first()
+                        .filter(|x| x.purpose == FourCC::make(b"rgn "))
+                        .map(|x| x.frame_length)
+                    },
+                    label: {
+                        raw_adtl.labels_for_cue_point(i.cue_point_id).iter()
+                            .map(|s| convert_to_cue_string(&s.text))
+                            .next()
+                    },
+                    note : {
+                        raw_adtl.notes_for_cue_point(i.cue_point_id).iter()
+                            //.filter_map(|x| str::from_utf8(&x.text).ok())
+                            .map(|s| convert_to_cue_string(&s.text))
+                            .next()
+                    }
+                }
+            }).collect() 
+        )
+    }
+
+}

src/fourcc.rs

@@ -105,6 +105,14 @@ pub const BEXT_SIG: FourCC = FourCC::make(b"bext");
 
 pub const JUNK_SIG: FourCC = FourCC::make(b"JUNK");
 pub const FLLR_SIG: FourCC = FourCC::make(b"FLLR");
+pub const LIST_SIG: FourCC = FourCC::make(b"LIST");
+
+pub const CUE__SIG: FourCC = FourCC::make(b"cue ");
+pub const ADTL_SIG: FourCC = FourCC::make(b"adtl");
+pub const LABL_SIG: FourCC = FourCC::make(b"labl");
+pub const NOTE_SIG: FourCC = FourCC::make(b"note");
+pub const LTXT_SIG: FourCC = FourCC::make(b"ltxt");
+
 
 #[cfg(test)]
 mod tests {

src/lib.rs

@@ -15,6 +15,7 @@ production.
 
 Apps we test against:
 - Avid Pro Tools
+- iZotope RX Audio Editor
 - FFMpeg
 - Audacity
 
@@ -66,7 +67,9 @@ Things that are _not_ necessarily in the scope of this package:
 
 
 ### Other resources
-- [RFC 3261][rfc3261] (June 1998) "WAVE and AVI Codec Registries" 
+- [RFC 3261][rfc3261] (June 1998) "WAVE and AVI Codec Registries"
+- [Sampler Metadata](http://www.piclist.com/techref/io/serial/midi/wave.html)
+- [Cue list, label and other metadata](https://sites.google.com/site/musicgapi/technical-documents/wav-file-format#smpl)
 - [Peter Kabal, McGill University](http://www-mmsp.ece.mcgill.ca/Documents/AudioFormats/WAVE/WAVE.html)
  - [Multimedia Programming Interface and Data Specifications 1.0](http://www-mmsp.ece.mcgill.ca/Documents/AudioFormats/WAVE/Docs/riffmci.pdf) 
     (August 1991), IBM Corporation and Microsoft Corporation
@@ -111,7 +114,10 @@ mod parser;
 
 mod raw_chunk_reader;
 mod audio_frame_reader;
+mod list_form;
+
 mod chunks;
+mod cue;
 mod bext;
 mod fmt;
 
@@ -124,4 +130,5 @@ pub use wavewriter::WaveWriter;
 pub use bext::Bext;
 pub use fmt::{WaveFmt, WaveFmtExtended, ChannelDescriptor, ChannelMask};
 pub use common_format::CommonFormat;
-pub use audio_frame_reader::AudioFrameReader;
+pub use audio_frame_reader::AudioFrameReader;
+pub use cue::Cue;

src/list_form.rs

@@ -0,0 +1,40 @@
+use super::fourcc::{FourCC, ReadFourCC};
+use byteorder::{ReadBytesExt, LittleEndian};
+use std::io::{Cursor, Error, Read};
+
+pub struct ListFormItem {
+    pub signature : FourCC,
+    pub contents : Vec<u8>
+}
+
+/// A helper that will accept a LIST chunk as a [u8]
+/// and give you back each segment
+/// 
+pub fn collect_list_form(list_contents :& [u8]) -> Result<Vec<ListFormItem>, Error> {
+    let mut cursor = Cursor::new(list_contents);
+    let mut remain = list_contents.len();
+    let _ = cursor.read_fourcc()?; // skip signature
+
+    remain -= 4;
+    let mut retval : Vec<ListFormItem> = vec![];
+
+    while remain > 0 {
+        let this_sig = cursor.read_fourcc()?;
+        let this_size = cursor.read_u32::<LittleEndian>()? as usize;
+        remain -= 8;
+        let mut content_buf = vec![0u8; this_size];
+        cursor.read_exact(&mut content_buf)?;
+        remain -= this_size;
+        
+        retval.push( ListFormItem { signature : this_sig, contents : content_buf } );
+        
+        if this_size % 2 == 1 {
+            cursor.read_u8()?;
+            //panic!("Got this far!");
+            remain -= 1;
+        }
+    }
+    
+
+    Ok( retval )
+}

src/raw_chunk_reader.rs

@@ -28,7 +28,7 @@ impl<'a,R: Read + Seek> RawChunkReader<'a, R> {
 impl<'a, R:Read + Seek> Read for RawChunkReader<'_, R> {
     fn read(&mut self, buf: &mut [u8]) -> Result<usize, Error> { 
         if self.position >= self.length {
-            Err(Error::new(ErrorKind::UnexpectedEof, "RawChunkReader encountered end-of-file"))
+            Ok(0)
         } else {
             self.reader.seek(Start(self.start + self.position))?;
             let to_read = min(self.length - self.position, buf.len() as u64);

src/wavereader.rs

@@ -2,15 +2,16 @@
 use std::fs::File;
 
 use super::parser::Parser;
-use super::fourcc::{FourCC, FMT__SIG,DATA_SIG, BEXT_SIG, JUNK_SIG, FLLR_SIG};
+use super::fourcc::{FourCC, ReadFourCC, FMT__SIG,DATA_SIG, BEXT_SIG, LIST_SIG, JUNK_SIG, FLLR_SIG, CUE__SIG, ADTL_SIG};
 use super::errors::Error as ParserError;
 use super::raw_chunk_reader::RawChunkReader;
 use super::fmt::{WaveFmt, ChannelDescriptor, ChannelMask};
 use super::bext::Bext;
 use super::audio_frame_reader::AudioFrameReader;
 use super::chunks::ReadBWaveChunks;
+use super::cue::Cue;
 
-
+use std::io::Cursor;
 use std::io::{Read, Seek};
 
 
@@ -118,18 +119,26 @@ impl<R: Read + Seek> WaveReader<R> {
         Ok( data_length / (format.block_alignment as u64) )
     } 
 
-    /**
+    
-     * Sample and frame format of this wave file.
+    /// Sample and frame format of this wave file.
-     */
+    ///
     pub fn format(&mut self) -> Result<WaveFmt, ParserError> {
         self.chunk_reader(FMT__SIG, 0)?.read_wave_fmt()
     }
 
-    /**
+    ///
-     * The Broadcast-WAV metadata record for this file.
+    /// The Broadcast-WAV metadata record for this file, if present.
-     */
+    /// 
-    pub fn broadcast_extension(&mut self) -> Result<Bext, ParserError> {
+    pub fn broadcast_extension(&mut self) -> Result<Option<Bext>, ParserError> {
-        self.chunk_reader(BEXT_SIG, 0)?.read_bext()
+        let mut bext_buff : Vec<u8> = vec![ ];
+        let result = self.read_chunk(BEXT_SIG, 0, &mut bext_buff)?;
+        if result > 0 {
+            let mut bext_cursor = Cursor::new(bext_buff);
+            Ok( Some( bext_cursor.read_bext()? ) )
+        } else {
+            Ok( None)
+        }
+
     }
 
     /// Describe the channels in this file
@@ -137,8 +146,9 @@ impl<R: Read + Seek> WaveReader<R> {
     /// Returns a vector of channel descriptors, one for each channel
     /// 
     /// ```rust
-    /// # use bwavfile::WaveReader;
+    /// use bwavfile::WaveReader;
-    /// # use bwavfile::ChannelMask;
+    /// use bwavfile::ChannelMask;
+    ///
     /// let mut f = WaveReader::open("tests/media/pt_24bit_51.wav").unwrap();
     /// 
     /// let chans = f.channels().unwrap();
@@ -163,38 +173,72 @@ impl<R: Read + Seek> WaveReader<R> {
             .collect() )
     }
 
+    /// Read cue points.
+    /// 
+    /// ```rust
+    /// use bwavfile::WaveReader;
+    /// use bwavfile::Cue;
+    /// 
+    /// let mut f = WaveReader::open("tests/media/izotope_test.wav").unwrap();
+    /// let cue_points = f.cue_points().unwrap();
+    /// 
+    /// assert_eq!(cue_points.len(), 3);
+    /// assert_eq!(cue_points[0].ident, 1);
+    /// assert_eq!(cue_points[0].frame, 12532);
+    /// assert_eq!(cue_points[0].length, None);
+    /// assert_eq!(cue_points[0].label, Some(String::from("Marker 1")));
+    /// assert_eq!(cue_points[0].note, Some(String::from("Marker 1 Comment")));
+    /// 
+    /// assert_eq!(cue_points[1].ident, 2);
+    /// assert_eq!(cue_points[1].frame, 20997);
+    /// assert_eq!(cue_points[1].length, None);
+    /// assert_eq!(cue_points[1].label, Some(String::from("Marker 2")));
+    /// assert_eq!(cue_points[1].note, Some(String::from("Marker 2 Comment"))); 
+    /// 
+    /// assert_eq!(cue_points[2].ident, 3);
+    /// assert_eq!(cue_points[2].frame, 26711);
+    /// assert_eq!(cue_points[2].length, Some(6465));
+    /// assert_eq!(cue_points[2].label, Some(String::from("Timed Region")));
+    /// assert_eq!(cue_points[2].note, Some(String::from("Region Comment"))); 
+    /// 
+    /// ```
+    pub fn cue_points(&mut self) -> Result<Vec<Cue>,ParserError> {
+        let mut cue_buffer : Vec<u8> = vec![];
+        let mut adtl_buffer : Vec<u8> = vec![];
+
+        let cue_read = self.read_chunk(CUE__SIG, 0, &mut cue_buffer)?;
+        let adtl_read = self.read_list(ADTL_SIG, &mut adtl_buffer)?;
+
+        match (cue_read, adtl_read) {
+            (0,_) => Ok( vec![] ),
+            (_,0) => Ok( Cue::collect_from(&cue_buffer, None)? ),
+            (_,_) => Ok( Cue::collect_from(&cue_buffer, Some(&adtl_buffer) )? )
+        }
+    }
+
     /// Read iXML data.
     /// 
+    /// The iXML data will be appended to `buffer`.
     /// If there are no iXML metadata present in the file, 
-    /// Err(Error::ChunkMissing { "iXML" } will be returned.
+    /// Ok(0) will be returned.
-    pub fn ixml(&mut self, buffer: &mut Vec<u8>) -> Result<usize, ParserError> {
+    pub fn read_ixml(&mut self, buffer: &mut Vec<u8>) -> Result<usize, ParserError> {
-        let ixml_sig: FourCC = FourCC::make(b"iXML");
+        let ixml_fourcc = FourCC::make(b"iXML");
-        let mut chunk = self.chunk_reader(ixml_sig, 0)?;
+        self.read_chunk(ixml_fourcc, 0, buffer) 
-
-        match chunk.read_to_end(buffer) {
-            Ok(read) => Ok(read),
-            Err(error) => Err(error.into())
-        }
     }
 
     /// Read AXML data.
     /// 
-    /// By convention this will generally be ADM metadata. 
+    /// The axml data will be appended to `buffer`. By convention this will 
+    /// generally be ADM metadata.
     /// 
-    /// If there are no iXML metadata present in the file, 
+    /// If there are no axml metadata present in the file, 
-    /// Err(Error::ChunkMissing { "axml" } will be returned. 
+    /// Ok(0) will be returned
-    pub fn axml(&mut self, buffer: &mut Vec<u8>) -> Result<usize, ParserError> {
+    pub fn read_axml(&mut self, buffer: &mut Vec<u8>) -> Result<usize, ParserError> {
-        let axml_sig: FourCC = FourCC::make(b"axml");
+        let axml_fourcc = FourCC::make(b"axml");
-        let mut chunk = self.chunk_reader(axml_sig, 0)?;
+        self.read_chunk(axml_fourcc, 0, buffer)
-
-        match chunk.read_to_end(buffer) {
-            Ok(read) => Ok(read),
-            Err(error) => Err(error.into())
-        }
     }
 
 
-
     /**
     * Validate file is readable.
     * 
@@ -220,6 +264,8 @@ impl<R: Read + Seek> WaveReader<R> {
      * `Ok(())` if the source is `validate_readable()` AND
      * 
      *   - Contains _only_ a `fmt` chunk and `data` chunk, with no other chunks present
+     *   - `fmt` chunk is exactly 16 bytes long and begins _exactly_ at file offset 12
+     *   - `data` content begins _exactly_ at file offset 36
      *   - is not an RF64/BW64
      * 
      * Some clients require a WAVE file to only contain format and data without any other
@@ -248,7 +294,7 @@ impl<R: Read + Seek> WaveReader<R> {
             .into_chunk_list()?.iter().map(|c| c.signature ).collect();
 
         if chunk_fourccs == vec![FMT__SIG, DATA_SIG] {
-            Ok(())
+            Ok(()) /* FIXME: finish implementation */
         } else {
             Err( ParserError::NotMinimalWaveFile )
         }
@@ -332,21 +378,78 @@ impl<R: Read + Seek> WaveReader<R> {
     }
 }
 
-impl<R:Read+Seek> WaveReader<R> { /* Private Implementation */
+impl<R:Read+Seek> WaveReader<R> {
+
+    // Private implementation
+    //
+    // As time passes thi get smore obnoxious because I haven't implemented recursive chunk 
+    // parsing in the raw parser and I'm working around it
 
     fn chunk_reader(&mut self, signature: FourCC, at_index: u32) -> Result<RawChunkReader<R>, ParserError> {
         let (start, length) = self.get_chunk_extent_at_index(signature, at_index)?;
         Ok( RawChunkReader::new(&mut self.inner, start, length) )
     } 
 
-    fn get_chunk_extent_at_index(&mut self, fourcc: FourCC, index: u32) -> Result<(u64,u64), ParserError> {
+    fn read_list(&mut self, ident: FourCC, buffer: &mut Vec<u8>) -> Result<usize, ParserError> {
+        if let Some(index) = self.get_list_form(ident)? {
+            self.read_chunk(LIST_SIG, index, buffer)
+        } else {
+            Ok( 0 )
+        }
+    }
+
+    fn read_chunk(&mut self, ident: FourCC, at: u32, buffer: &mut Vec<u8>) -> Result<usize, ParserError> {
+        let result = self.chunk_reader(ident, at);
+
+        match result {
+            Ok(mut chunk) => {
+                match chunk.read_to_end(buffer) {
+                    Ok(read) => Ok(read),
+                    Err(err) => Err(err.into())
+                }
+            },
+            Err(ParserError::ChunkMissing { signature : _} ) => Ok(0),
+            Err( any ) => Err(any.into())
+        }
+    }
+
+    /// Extent of every chunk with the given fourcc
+    fn get_chunks_extents(&mut self, fourcc: FourCC) -> Result<Vec<(u64,u64)>, ParserError> {
         let p = Parser::make(&mut self.inner)?.into_chunk_list()?;
 
-        if let Some(chunk) = p.iter().filter(|item| item.signature == fourcc).nth(index as usize) {
+        Ok( p.iter().filter(|item| item.signature == fourcc)
-            Ok ((chunk.start, chunk.length))
+            .map(|item| (item.start, item.length)).collect() )
+    }
+
+    /// Index of first LIST for with the given FORM fourcc
+    fn get_list_form(&mut self, fourcc: FourCC) -> Result<Option<u32>, ParserError> {
+        for (n, (start, length)) in self.get_chunks_extents(LIST_SIG)?.iter().enumerate() {
+            let mut reader = RawChunkReader::new(&mut self.inner, *start, *length);
+            let this_fourcc = reader.read_fourcc()?;
+            if this_fourcc == fourcc {
+                return Ok( Some( n as u32 ) );
+            }
+        }
+
+        Ok( None )
+    }
+
+    fn get_chunk_extent_at_index(&mut self, fourcc: FourCC, index: u32) -> Result<(u64,u64), ParserError> {
+        if let Some((start, length)) = self.get_chunks_extents(fourcc)?.iter().nth(index as usize) {
+            Ok ((*start, *length))
         } else {
-            Err( ParserError::ChunkMissing { signature : fourcc })
+            Err( ParserError::ChunkMissing { signature : fourcc } )
         }
     }
 }
 
+#[test]
+fn test_list_form() {
+    let mut f = WaveReader::open("tests/media/izotope_test.wav").unwrap();
+    let mut buf : Vec<u8> = vec![];
+    
+    f.read_list(ADTL_SIG, &mut buf).unwrap();
+
+    assert_ne!(buf.len(),  0);
+
+}

tests/Untitled.txt

@@ -0,0 +1,5 @@
+Marker file version: 1
+Time format: Time
+Marker 1	00:00:00.28417234		Marker 1 Comment
+Marker 2	00:00:00.47612245		Marker 2 Comment
+Timed Region	00:00:00.60569161	00:00:00.75226757	Region Comment