Update to v0.9.0

To reflect changes in create_frame_buffer()

Cargo.lock

@@ -2,7 +2,7 @@
 # It is not intended for manual editing.
 [[package]]
 name = "bwavfile"
-version = "0.1.7"
+version = "0.9.0"
 dependencies = [
  "byteorder",
  "encoding",

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "bwavfile"
-version = "0.1.7"
+version = "0.9.0"
 authors = ["Jamie Hardt <jamiehardt@me.com>"]
 edition = "2018"
 license = "MIT"

README.md

@@ -10,18 +10,20 @@ Rust Wave File Reader/Writer with Broadcast-WAV, MBWF and RF64 Support
 
 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.
-- [ ] Wave/RF64 file writing with transparent promotion from WAV to RF64.
-- [x] Unified format definition interface for standard and extended-format wave files.
-- [x] Read channel/speaker map metadata.
-- [x] Read standard EBU Broadcast-Wave metadata and decode to fields, including timestamp and SMPTE UMID.
-- [x] iXML and ADM XML metadata.
-- [ ] Broadcast-WAV Level and Quality metadata.
-- [x] Cue list metadata.
-- [ ] Sampler and instrument metadata.
-- [x] Validate the compatibility of a given wave file for certain regimes.
-- [x] Metadata support for ambisonic B-format.
+| Feature                               | Read  | Write |
+|---------------------------------------|:-----:|:-----:|
+| Standard .wav files                   | ☑️   | ☑️ |
+| Transparent promotion to RF64/BW64    | ☑️   |    |
+| Unified interface for regular and extended Wave format | ☑️  |  |
+| Channel/speaker map metadata          | ☑️    |    |
+| Ambisonic B-format metadata           | ☑️    |   |
+| EBU Broadcast-WAVE metadata           | ☑️   |    |
+| Basic iXML/ADM metadata               | ☑️    |    |
+| Enhanced iXML metadata support        |        |    |
+| Broadcast-WAVE Level overview `levl` metadata         |    |    |
+| Cue list metadata                     | ☑️   |    |
+| Sampler and instrument metadata       |    |    |
+| Enhanced Wave file form validation    | ☑️   | 🚫   |
 
 
 ## Use Examples
@@ -37,8 +39,8 @@ This is currently a work-in-progress! However many features presently work:
  assert_eq!(format.sample_rate, 44100);
  assert_eq!(format.channel_count, 1);
  
+ let mut buffer = format.create_frame_buffer();
  let mut frame_reader = r.audio_frame_reader().unwrap();
- let mut buffer = frame_reader.create_frame_buffer();
  
  let read = frame_reader.read_integer_frame(&mut buffer).unwrap();
  

bwavefile.code-workspace

@@ -0,0 +1,8 @@
+{
+	"folders": [
+		{
+			"path": "."
+		}
+	],
+	"settings": {}
+}

src/audio_frame_reader.rs

@@ -62,13 +62,6 @@ impl<R: Read + Seek> AudioFrameReader<R> {
         Ok( (seek_result - self.start) / self.format.block_alignment as u64 )
     }
 
-    /// Create a frame buffer sized to hold frames of the reader
-    /// 
-    /// This is a conveneince method that creates a `Vec<i32>` with
-    /// as many elements as there are channels in the underlying stream. 
-    pub fn create_frame_buffer(&self) -> Vec<i32> {
-        vec![0i32; self.format.channel_count as usize]
-    }
 
     /// Read a frame
     /// 

src/common_format.rs

@@ -22,19 +22,19 @@ const BASIC_EXTENDED: u16   = 0xFFFE;
 
 */
 
-const UUID_PCM: Uuid =           Uuid::from_bytes([0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x10, 0x00, 
+pub const UUID_PCM: Uuid =           Uuid::from_bytes([0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x10, 0x00, 
     0x80, 0x00, 0x00, 0xaa, 0x00, 0x38, 0x9b, 0x71]);
 
-const UUID_FLOAT: Uuid =         Uuid::from_bytes([0x03, 0x00, 0x00, 0x00, 0x00, 0x00, 0x10, 0x00,
+pub const UUID_FLOAT: Uuid =         Uuid::from_bytes([0x03, 0x00, 0x00, 0x00, 0x00, 0x00, 0x10, 0x00,
     0x80, 0x00, 0x00, 0xaa, 0x00, 0x38, 0x9b, 0x71]);
 
-const UUID_MPEG: Uuid =          Uuid::from_bytes([0x50, 0x00, 0x00, 0x00, 0x00, 0x00, 0x10, 0x00,
+pub const UUID_MPEG: Uuid =          Uuid::from_bytes([0x50, 0x00, 0x00, 0x00, 0x00, 0x00, 0x10, 0x00,
     0x80, 0x00, 0x00, 0xaa, 0x00, 0x38, 0x9b, 0x71]);
 
-const UUID_BFORMAT_PCM: Uuid =   Uuid::from_bytes([0x01, 0x00, 0x00, 0x00, 0x21, 0x07, 0xd3, 0x11, 
+pub const UUID_BFORMAT_PCM: Uuid =   Uuid::from_bytes([0x01, 0x00, 0x00, 0x00, 0x21, 0x07, 0xd3, 0x11, 
     0x86, 0x44, 0xc8, 0xc1, 0xca, 0x00, 0x00, 0x00]);
 
-const UUID_BFORMAT_FLOAT: Uuid = Uuid::from_bytes([0x03, 0x00, 0x00, 0x00, 0x21, 0x07, 0xd3, 0x11,
+pub const UUID_BFORMAT_FLOAT: Uuid = Uuid::from_bytes([0x03, 0x00, 0x00, 0x00, 0x21, 0x07, 0xd3, 0x11,
     0x86, 0x44, 0xc8, 0xc1, 0xca, 0x00, 0x00, 0x00]);
 
 

src/fmt.rs

@@ -1,22 +1,22 @@
 use uuid::Uuid;
-use super::common_format::CommonFormat;
+use super::common_format::{CommonFormat, UUID_PCM};
 
 #[allow(dead_code)]
 
-/// ADM Audio ID record
+/// ADM Audio ID record.
 /// 
 /// This structure relates a channel in the wave file to either a common ADM
 /// channel definition or further definition in the WAV file's ADM metadata 
 /// chunk.
 /// 
 /// An individual channel in a WAV file can have multiple Audio IDs in an ADM 
-/// AudioProgramme.
+/// `AudioProgramme`.
 /// 
 /// See BS.2088-1 § 8, also BS.2094, also blahblahblah...
 pub struct ADMAudioID {
-    track_uid: [char; 12],
-    channel_format_ref: [char; 14],
-    pack_ref: [char; 11]
+    pub track_uid: [char; 12],
+    pub channel_format_ref: [char; 14],
+    pub pack_ref: [char; 11]
 }
 
 /// Describes a single channel in a WAV file.
@@ -35,13 +35,9 @@ pub struct ChannelDescriptor {
 }
 
 
-
-/*
-https://docs.microsoft.com/en-us/windows-hardware/drivers/audio/subformat-guids-for-compressed-audio-formats
-
-These are from http://dream.cs.bath.ac.uk/researchdev/wave-ex/mulchaud.rtf
-*/
-
+/// A bitmask indicating which channels are present in 
+/// the file.
+/// 
 #[derive(Debug, Clone, Copy, PartialEq)]
 pub enum ChannelMask {
     DirectOut        = 0x0,
@@ -204,7 +200,17 @@ impl WaveFmt {
             bytes_per_second: container_bytes_per_sample as u32 * sample_rate * channel_count as u32,
             block_alignment: container_bytes_per_sample * channel_count,
             bits_per_sample: container_bits_per_sample,
-            extended_format: None
+            extended_format: {
+                if channel_count > 2 {
+                    Some( WaveFmtExtended {
+                        channel_mask : !(0xFFFF_FFFF << channel_count),
+                        type_guid: UUID_PCM,
+                        valid_bits_per_sample: bits_per_sample
+                    })
+                } else {
+                    None
+                }
+            }
         }
     }
 
@@ -216,6 +222,15 @@ impl WaveFmt {
         CommonFormat::make( self.tag, self.extended_format.map(|ext| ext.type_guid))
     }
 
+    /// Create a frame buffer sized to hold frames for a reader or writer
+    /// 
+    /// This is a conveneince method that creates a `Vec<i32>` with
+    /// as many elements as there are channels in the underlying stream. 
+    pub fn create_frame_buffer(&self) -> Vec<i32> {
+        vec![0i32; self.channel_count as usize]
+    }
+
+
     /// Channel descriptors for each channel.
     pub fn channels(&self) -> Vec<ChannelDescriptor> {
         match self.channel_count {

src/fourcc.rs

@@ -102,9 +102,11 @@ pub const DATA_SIG: FourCC = FourCC::make(b"data");
 pub const FMT__SIG: FourCC = FourCC::make(b"fmt ");
 
 pub const BEXT_SIG: FourCC = FourCC::make(b"bext");
+//pub const FACT_SIG: FourCC = FourCC::make(b"fact");
 
 pub const JUNK_SIG: FourCC = FourCC::make(b"JUNK");
 pub const FLLR_SIG: FourCC = FourCC::make(b"FLLR");
+pub const ELM1_SIG: FourCC = FourCC::make(b"elm1");
 pub const LIST_SIG: FourCC = FourCC::make(b"LIST");
 
 pub const CUE__SIG: FourCC = FourCC::make(b"cue ");

src/lib.rs

@@ -85,7 +85,7 @@ Things that are _not_ necessarily in the scope of this package:
   - [Supplement 6](https://tech.ebu.ch/docs/tech/tech3285s6.pdf) (October 2009): Dolby Metadata 
 - [EBU Tech R099](https://tech.ebu.ch/docs/r/r099.pdf) (October 2011) "‘Unique’ Source Identifier (USID) for use in the 
   <OriginatorReference> field of the Broadcast Wave Format"
-- [EBU Tech R098](https://tech.ebu.ch/docs/r/r098.pdf) (1999) "Format for the <CodingHistory> field in Broadcast Wave Format files, BWF"
+- [EBU Tech R098](https://tech.ebu.ch/docs/r/r098.pdf) (1999) "Format for the &lt;CodingHistory&gt; field in Broadcast Wave Format files, BWF"
 
 [ebu3285]: https://tech.ebu.ch/docs/tech/tech3285.pdf
 [ebu3306v1]: https://tech.ebu.ch/docs/tech/tech3306v1_1.pdf
@@ -111,8 +111,6 @@ mod common_format;
 
 mod parser;
 
-
-mod raw_chunk_reader;
 mod audio_frame_reader;
 mod list_form;
 
@@ -128,7 +126,7 @@ pub use errors::Error;
 pub use wavereader::WaveReader;
 pub use wavewriter::WaveWriter;
 pub use bext::Bext;
-pub use fmt::{WaveFmt, WaveFmtExtended, ChannelDescriptor, ChannelMask};
+pub use fmt::{WaveFmt, WaveFmtExtended, ChannelDescriptor, ChannelMask, ADMAudioID};
 pub use common_format::CommonFormat;
 pub use audio_frame_reader::AudioFrameReader;
 pub use cue::Cue;

src/parser.rs

@@ -45,6 +45,7 @@ pub struct Parser<R: Read + Seek> {
     ds64state: HashMap<FourCC,u64>
 }
 
+#[derive(Debug, PartialEq, Eq)]
 pub struct ChunkIteratorItem {
     pub signature: FourCC,
     pub start: u64,

src/raw_chunk_reader.rs

@@ -1,69 +0,0 @@
-use std::cmp::min;
-
-use std::io::SeekFrom;
-use std::io::SeekFrom::{Start, Current, End};
-use std::io::{Seek,Read,Error,ErrorKind};
-
-// I'm not sure this hasn't already been written somewhere in
-// std but I'm just doing this here as an exercise.
-#[derive(Debug)]
-pub struct RawChunkReader<'a, R: Read + Seek> {
-    reader: &'a mut R,
-    pub start: u64,
-    pub length: u64,
-    position: u64
-}
-
-impl<'a,R: Read + Seek> RawChunkReader<'a, R> {
-    pub fn new(reader: &'a mut R, start: u64, length: u64) -> Self {
-        return Self {
-            reader: reader, 
-            start: start, 
-            length: length, 
-            position: 0
-        }
-    }
-}
-
-impl<'a, R:Read + Seek> Read for RawChunkReader<'_, R> {
-    fn read(&mut self, buf: &mut [u8]) -> Result<usize, Error> { 
-        if self.position >= self.length {
-            Ok(0)
-        } else {
-            self.reader.seek(Start(self.start + self.position))?;
-            let to_read = min(self.length - self.position, buf.len() as u64);
-            self.reader.take(to_read).read(buf)?;
-            self.position += to_read;
-            Ok(to_read as usize)
-        }
-    }
-}
-
-impl<'a, R:Read + Seek> Seek for RawChunkReader<'_, R> {
-    fn seek(&mut self, seek: SeekFrom) -> Result<u64, std::io::Error> { 
-        match seek {
-            Start(s) => {
-                self.position = s;
-                Ok(self.position)
-            },
-            Current(s) => {
-                let new_position = s + self.position as i64;
-                if new_position < 0 {
-                    Err( Error::new(ErrorKind::Other, "Attempted seek before beginning of chunk") )
-                } else {
-                    self.position = new_position as u64;
-                    Ok(self.position)
-                }
-            },
-            End(s) => {
-                let new_position = s + self.length as i64;
-                if new_position < 0 {
-                    Err( Error::new(ErrorKind::Other, "Attempted seek before beginning of chunk") )
-                } else {
-                    self.position = new_position as u64;
-                    Ok(self.position)
-                }
-            }
-        }
-    }
-}

src/wavereader.rs

@@ -1,10 +1,10 @@
 
+use std::io::SeekFrom;
 use std::fs::File;
 
 use super::parser::Parser;
 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;
@@ -27,7 +27,7 @@ use std::io::{Read, Seek};
  * assert_eq!(format.channel_count, 1);
  * 
  * let mut frame_reader = r.audio_frame_reader().unwrap();
- * let mut buffer = frame_reader.create_frame_buffer();
+ * let mut buffer = format.create_frame_buffer();
  * 
  * let read = frame_reader.read_integer_frame(&mut buffer).unwrap();
  * 
@@ -123,7 +123,9 @@ impl<R: Read + Seek> WaveReader<R> {
     /// 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()
+        let (start, _) = self.get_chunk_extent_at_index(FMT__SIG, 0)?;
+        self.inner.seek(SeekFrom::Start(start))?;
+        self.inner.read_wave_fmt()
     }
 
     ///
@@ -385,10 +387,10 @@ impl<R:Read+Seek> WaveReader<R> {
     // 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 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 read_list(&mut self, ident: FourCC, buffer: &mut Vec<u8>) -> Result<usize, ParserError> {
         if let Some(index) = self.get_list_form(ident)? {
@@ -398,15 +400,14 @@ impl<R:Read+Seek> WaveReader<R> {
         }
     }
 
-    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())
-                }
+    fn read_chunk(&mut self, ident: FourCC, at: u32, mut buffer: &mut Vec<u8>) -> Result<usize, ParserError> {
+
+        match self.get_chunk_extent_at_index(ident, at) {
+            Ok((start, length)) => {
+                buffer.resize(length as usize, 0x0);
+                self.inner.seek(SeekFrom::Start(start))?;
+                self.inner.read(&mut buffer).map_err(|e| ParserError::IOError(e))
             },
             Err(ParserError::ChunkMissing { signature : _} ) => Ok(0),
             Err( any ) => Err(any.into())
@@ -423,9 +424,9 @@ impl<R:Read+Seek> WaveReader<R> {
 
     /// 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()?;
+        for (n, (start, _)) in self.get_chunks_extents(LIST_SIG)?.iter().enumerate() {
+            self.inner.seek(SeekFrom::Start(*start as u64))?;
+            let this_fourcc = self.inner.read_fourcc()?;
             if this_fourcc == fourcc {
                 return Ok( Some( n as u32 ) );
             }

src/wavewriter.rs

@@ -1,94 +1,252 @@
-use std::io::{Write, Seek, SeekFrom};
 use std::fs::File;
-use std::io::Cursor;
+use std::io::{Write,Seek,SeekFrom};
 
-use super::errors::Error;
-use super::chunks::{WriteBWaveChunks};
-use super::bext::Bext;
-use super::fmt::{WaveFmt};
-use super::fourcc::{FourCC, RIFF_SIG, WAVE_SIG, FMT__SIG, JUNK_SIG, BEXT_SIG, DATA_SIG, WriteFourCC};
+use super::Error;
+use super::fourcc::{FourCC, WriteFourCC, RIFF_SIG, WAVE_SIG, FMT__SIG, DATA_SIG, ELM1_SIG};
+use super::fmt::WaveFmt;
+//use super::common_format::CommonFormat;
+use super::chunks::WriteBWaveChunks;
 
 use byteorder::LittleEndian;
 use byteorder::WriteBytesExt;
 
-/// This isn't working yet, do not use.
-pub struct WaveWriter<W> where W: Write + Seek {
-    inner : W
+
+pub struct AudioFrameWriter<W> where W: Write + Seek {
+    inner : WaveChunkWriter<W>
 }
 
-impl WaveWriter<File> {
-    pub fn create(path : &str, format:WaveFmt, broadcast_extension: Option<Bext>) -> Result<Self,Error> {
-        let inner = File::create(path)?;
-        Self::make(inner, format, broadcast_extension)
-    }
-}
+impl<W> AudioFrameWriter<W> where W: Write + Seek {
+    pub fn write_integer_frame(&mut self, buffer: &[i32]) -> Result<u64,Error> {
+        let format = self.inner.inner.format;
+        assert!(buffer.len() as u16 == format.channel_count, 
+            "read_integer_frame was called with a mis-sized buffer, expected {}, was {}", 
+            format.channel_count, buffer.len());
 
-impl<W:Write + Seek> WaveWriter<W> {
+        let framed_bits_per_sample = format.block_alignment * 8 / format.channel_count;
 
-    pub fn make(inner : W, format: WaveFmt, broadcast_extension: Option<Bext>) -> Result<Self, Error> {
-        let mut retval = Self { inner };
-        retval.prepare_created(format, broadcast_extension)?;
-        Ok(retval) 
-    }
-
-    fn prepare_created(&mut self, format : WaveFmt, broadcast_extension: Option<Bext>) -> Result<(),Error> {
-        self.inner.write_fourcc(RIFF_SIG)?;
-        self.inner.write_u32::<LittleEndian>(4)?;
-        self.inner.write_fourcc(WAVE_SIG)?;
-        let mut written : u64 = 4;
-
-        let ds64_reservation = [0u8; 92];
-
-        written += self.primitive_append_chunk(JUNK_SIG, &ds64_reservation)?;
-
-        let fmt_data : Vec<u8> = {
-            let mut c = Cursor::new(vec![]);
-            c.write_wave_fmt(&format)?;
-            c.into_inner()
-        };
-
-        written += self.primitive_append_chunk(FMT__SIG, &fmt_data)?;
-
-        if let Some(bext) = broadcast_extension {
-            let mut b = Cursor::new(vec![]);
-            b.write_bext(&bext)?;
-            let data = b.into_inner();
-            written += self.primitive_append_chunk(BEXT_SIG, &data)?;
+        for n in 0..(format.channel_count as usize) {
+            match (format.bits_per_sample, framed_bits_per_sample) {
+                (0..=8,8) => self.inner.write_u8((buffer[n] + 0x80) as u8 )?, // EBU 3285 §A2.2
+                (9..=16,16) => self.inner.write_i16::<LittleEndian>(buffer[n] as i16)?,
+                (10..=24,24) => self.inner.write_i24::<LittleEndian>(buffer[n])?,
+                (25..=32,32) => self.inner.write_i32::<LittleEndian>(buffer[n])?,
+                (b,_)=> panic!("Unrecognized integer format, bits per sample {}, channels {}, block_alignment {}", 
+                    b, format.channel_count, format.block_alignment)
+            }
         }
-        
-        // show our work
-        let desired_data_alignment = 0x4000;
-        let data_fourcc_start = desired_data_alignment - 8;
-        let current_position_from_start = written + 8;
-        let data_pad_length = data_fourcc_start - current_position_from_start;
 
-        let data_padding = vec![0u8; data_pad_length as usize];
+        Ok(1)
+    }
 
-        written += self.primitive_append_chunk(JUNK_SIG, &data_padding)?;
+    pub fn end(self) -> Result<WaveWriter<W>, Error> {
+        self.inner.end()
+    }
+}
 
-        self.inner.write_fourcc(DATA_SIG)?;
-        self.inner.write_u32::<LittleEndian>(0)?;
 
-        written += 8;
-        self.inner.seek(SeekFrom::Start(4))?;
-        self.inner.write_u32::<LittleEndian>(written as u32)?;
+pub struct WaveChunkWriter<W> where W: Write + Seek {
+    inner : WaveWriter<W>,
+    content_start_pos : u64,
+    length : u64
+}
+
+impl<W> WaveChunkWriter<W> where W: Write + Seek {
+
+    fn begin(mut inner : WaveWriter<W>, ident : FourCC) -> Result<Self,Error> {
+        let length : u64 = 0;
+        inner.inner.write_fourcc(ident)?;
+        inner.inner.write_u32::<LittleEndian>(length as u32)?;
+        inner.increment_form_length(8)?;
+        let content_start_pos = inner.inner.seek(SeekFrom::End(0))?;
+        Ok( WaveChunkWriter { inner , content_start_pos, length } )
+    }
+
+    fn end(mut self) -> Result<WaveWriter<W>, Error> {
+        if self.length % 2 == 1 {
+            self.inner.inner.seek(SeekFrom::End(0))?;
+            self.inner.inner.write(&[0u8])?;
+            self.inner.increment_form_length(1)?;
+        }
+        Ok( self.inner )
+    }
+
+    fn increment_chunk_length(&mut self, amount: u64) -> Result<(), std::io::Error> {
+        self.length = self.length + amount;
+        if self.length < u32::MAX as u64 {
+            self.inner.inner.seek(SeekFrom::Start(self.content_start_pos - 4))?;
+            self.inner.inner.write_u32::<LittleEndian>(self.length as u32)?;
+        } else {
+            todo!()
+        }
 
         Ok(())
     }
+}
 
-    fn primitive_append_chunk(&mut self, signature: FourCC, data: &[u8]) -> Result<u64,Error> {
-        assert!((data.len() as u32) < u32::MAX, 
-            "primitive_append_chunk called with a long data buffer");
+impl<W> Write for WaveChunkWriter<W> where W: Write + Seek {
 
-        self.inner.write_fourcc(signature)?;
-        self.inner.write_u32::<LittleEndian>(data.len() as u32)?;
-        self.inner.write_all(&data)?;
-        let padding : u64 = data.len() as u64 % 2;
-        if padding == 1 {
-            self.inner.write_u8(0)?;
-        }
+    fn write(&mut self, buffer: &[u8]) -> Result<usize, std::io::Error> { 
+        self.inner.inner.seek(SeekFrom::End(0))?;
+        let written = self.inner.inner.write(buffer)?;
+        self.increment_chunk_length(written as u64)?;
+        self.inner.increment_form_length(written as u64)?;
 
-        Ok(8 + data.len() as u64 + padding)
+        Ok( written )
+    }
+
+    fn flush(&mut self) -> Result<(), std::io::Error> { 
+        self.inner.inner.flush()
     }
 }
 
+/// Wave, Broadcast-WAV and RF64/BW64 writer.
+/// 
+/// ```
+/// use bwavfile::{WaveWriter,WaveFmt};
+/// # use std::io::Cursor;
+/// 
+/// // Write a three-sample wave file to a cursor
+/// let mut cursor = Cursor::new(vec![0u8;0]);
+/// let format = WaveFmt::new_pcm(48000, 24, 1);
+/// let w = WaveWriter::new(&mut cursor, format).unwrap();
+///
+/// let mut frame_writer = w.audio_frame_writer().unwrap();
+///
+/// frame_writer.write_integer_frame(&[0i32]).unwrap();
+/// frame_writer.write_integer_frame(&[0i32]).unwrap();
+/// frame_writer.write_integer_frame(&[0i32]).unwrap();
+/// frame_writer.end().unwrap();
+/// ``` 
+pub struct WaveWriter<W> where W: Write + Seek {
+    inner : W,
+    form_length: u64,
+
+    /// Format of the wave file.
+    pub format: WaveFmt
+}
+
+impl WaveWriter<File> {
+
+    /// Create a new Wave file at `path`.
+    pub fn create(path : &str, format : WaveFmt) -> Result<Self, Error> {
+        let f = File::create(path)?;
+        Ok( Self::new(f, format)? )
+    }
+}
+
+impl<W> WaveWriter<W> where W: Write + Seek {
+
+    /// Wrap a writer in a Wave writer.
+    /// 
+    /// The inner writer will immediately have a RIFF WAVE file header 
+    /// written to it along with the format descriptor (and possibly a `fact`
+    /// chunk if appropriate).
+    pub fn new(mut inner : W, format: WaveFmt) -> Result<Self, Error> {
+        inner.write_fourcc(RIFF_SIG)?;
+        inner.write_u32::<LittleEndian>(0)?;
+        inner.write_fourcc(WAVE_SIG)?;
+
+        let mut retval = WaveWriter { inner, form_length: 0, format};
+        retval.increment_form_length(4)?;
+
+        let mut chunk = retval.begin_chunk(FMT__SIG)?;
+        chunk.write_wave_fmt(&format)?;
+        let retval = chunk.end()?;
+
+        Ok( retval )
+    }
+
+    /// Create a new chunk writer, which takes posession of the `WaveWriter`.
+    /// 
+    /// Begin writing a chunk segment. To close the chunk (and perhaps write 
+    /// another), call `end()` on the chunk writer.
+    pub fn begin_chunk(mut self, ident: FourCC) -> Result<WaveChunkWriter<W>,Error> {
+        self.inner.seek(SeekFrom::End(0))?;
+        WaveChunkWriter::begin(self, ident)
+    }
+
+    pub fn audio_frame_writer(mut self) -> Result<AudioFrameWriter<W>, Error> {
+        // append elm1 chunk
+
+        let framing = 0x4000;
+
+        let lip = self.inner.seek(SeekFrom::End(0))?;
+        let to_add = framing - (lip % framing) - 16;
+        let mut chunk = self.begin_chunk(ELM1_SIG)?;
+        let buf = vec![0u8; to_add as usize];
+        chunk.write(&buf)?;
+        let closed = chunk.end()?;
+
+        let inner = closed.begin_chunk(DATA_SIG)?;
+        Ok( AudioFrameWriter { inner } )
+    }
+
+    fn increment_form_length(&mut self, amount: u64) -> Result<(), std::io::Error> {
+        self.form_length = self.form_length + amount;
+        self.inner.seek(SeekFrom::Start(4))?;
+        self.inner.write_u32::<LittleEndian>(self.form_length as u32)?;
+        Ok(())
+    }
+
+}
+
+#[test]
+fn test_new() {
+    use std::io::Cursor;
+    use super::fourcc::ReadFourCC;
+    use byteorder::ReadBytesExt;
+
+    let mut cursor = Cursor::new(vec![0u8;0]);
+    let format = WaveFmt::new_pcm(4800, 24, 1);
+    WaveWriter::new(&mut cursor, format).unwrap();
+
+    cursor.seek(SeekFrom::Start(0)).unwrap();
+    assert_eq!(cursor.read_fourcc().unwrap(), RIFF_SIG);
+    let form_size = cursor.read_u32::<LittleEndian>().unwrap();
+    assert_eq!(cursor.read_fourcc().unwrap(), WAVE_SIG);
+    assert_eq!(cursor.read_fourcc().unwrap(), FMT__SIG);
+    let fmt_size = cursor.read_u32::<LittleEndian>().unwrap();
+    assert_eq!(form_size, fmt_size + 8 + 4);
+}
+
+#[test]
+fn test_write_audio() {
+    use std::io::Cursor;
+    use super::fourcc::ReadFourCC;
+    use byteorder::ReadBytesExt;
+
+    let mut cursor = Cursor::new(vec![0u8;0]);
+    let format = WaveFmt::new_pcm(48000, 24, 1);
+    let w = WaveWriter::new(&mut cursor, format).unwrap();
+    
+    let mut frame_writer = w.audio_frame_writer().unwrap();
+
+    frame_writer.write_integer_frame(&[0i32]).unwrap();
+    frame_writer.write_integer_frame(&[0i32]).unwrap();
+    frame_writer.write_integer_frame(&[0i32]).unwrap();
+
+    frame_writer.end().unwrap();
+
+    cursor.seek(SeekFrom::Start(0)).unwrap();
+
+    cursor.seek(SeekFrom::Start(0)).unwrap();
+    assert_eq!(cursor.read_fourcc().unwrap(), RIFF_SIG);
+    let _ = cursor.read_u32::<LittleEndian>().unwrap();
+    assert_eq!(cursor.read_fourcc().unwrap(), WAVE_SIG);
+    assert_eq!(cursor.read_fourcc().unwrap(), FMT__SIG);
+    let seek = cursor.read_u32::<LittleEndian>().unwrap();
+    cursor.seek(SeekFrom::Current(seek as i64)).unwrap();
+
+    assert_eq!(cursor.read_fourcc().unwrap(), ELM1_SIG);
+    let seek = cursor.read_u32::<LittleEndian>().unwrap();
+    cursor.seek(SeekFrom::Current(seek as i64)).unwrap();
+
+    assert_eq!(cursor.read_fourcc().unwrap(), DATA_SIG);
+    let data_size = cursor.read_u32::<LittleEndian>().unwrap();
+    assert_eq!(data_size, 9);
+
+    let tell = cursor.seek(SeekFrom::Current(0)).unwrap();
+    assert!(tell % 0x4000 == 0);
+    
+
+}

tests/integration_test.rs

@@ -81,11 +81,12 @@ fn test_minimal_wave()  {
 fn test_read() {
     let path = "tests/media/audacity_16bit.wav";
 
-    let w = WaveReader::open(path).expect("Failure opening test file");
+    let mut w = WaveReader::open(path).expect("Failure opening test file");
+    let mut buffer = w.format().unwrap().create_frame_buffer();
 
     let mut reader = w.audio_frame_reader().unwrap();
 
-    let mut buffer = reader.create_frame_buffer();
+    
 
     assert_eq!(reader.read_integer_frame(&mut buffer).unwrap(), 1);
     assert_eq!(buffer[0], -2823_i32);
@@ -99,12 +100,11 @@ fn test_read() {
 fn test_locate_multichannel_read() {
     let path = "tests/media/ff_pink.wav";
 
-    let w = WaveReader::open(path).expect("Failure opening test file");
+    let mut w = WaveReader::open(path).expect("Failure opening test file");
+    let mut buffer = w.format().unwrap().create_frame_buffer();
 
     let mut reader = w.audio_frame_reader().unwrap();
 
-    let mut buffer = reader.create_frame_buffer();
-
     assert_eq!(reader.read_integer_frame(&mut buffer).unwrap(), 1);
     assert_eq!(buffer[0], 332702_i32);
     assert_eq!(buffer[1], 3258791_i32);