Nudged version 0.1.5

and added to main implementation

Cargo.lock

@@ -2,11 +2,12 @@
 # It is not intended for manual editing.
 [[package]]
 name = "bwavfile"
-version = "0.1.2"
+version = "0.1.5"
 dependencies = [
  "byteorder",
  "encoding",
  "serde_json",
+ "uuid",
 ]
 
 [[package]]
@@ -107,3 +108,9 @@ dependencies = [
  "ryu",
  "serde",
 ]
+
+[[package]]
+name = "uuid"
+version = "0.8.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9fde2f6a4bea1d6e007c4ad38c6839fa71cbb63b6dbf5b595aa38dc9b1093c11"

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "bwavfile"
-version = "0.1.2"
+version = "0.1.5"
 authors = ["Jamie Hardt <jamiehardt@me.com>"]
 edition = "2018"
 license = "MIT"
@@ -16,4 +16,5 @@ keywords = ["audio", "broadcast", "multimedia","smpte"]
 [dependencies]
 byteorder = "1.3.4"
 encoding = "0.2.33"
+uuid = "0.8.1"
 serde_json = "1.0.59"

src/audio_frame_reader.rs

@@ -4,9 +4,15 @@ use std::io::SeekFrom::{Start,};
 use byteorder::LittleEndian;
 use byteorder::ReadBytesExt;
 
-use super::chunks::WaveFmt;
+use super::fmt::{WaveFmt};
 use super::errors::Error;
+use super::CommonFormat;
 
+/// Read audio frames
+/// 
+/// The inner reader is interpreted as a raw audio data
+/// bitstream having a format specified by `format`.
+/// 
 #[derive(Debug)]
 pub struct AudioFrameReader<R: Read + Seek> {
     inner : R,
@@ -14,26 +20,64 @@ pub struct AudioFrameReader<R: Read + Seek> {
 }
 
 impl<R: Read + Seek> AudioFrameReader<R> {
-    /// Create a new AudioFrameReader, taking possession of a reader.
+
+    /// Create a new `AudioFrameReader`
+    /// 
+    /// ### Panics
+    /// 
+    /// This method does a few sanity checks on the provided format
+    /// parameter to confirm the `block_alignment` law is fulfilled
+    /// and the format tag is readable by this implementation (only
+    /// format 0x01 is supported at this time.) 
     pub fn new(inner: R, format: WaveFmt) -> Self {
         assert!(format.block_alignment * 8 == format.bits_per_sample * format.channel_count, 
             "Unable to read audio frames from packed formats: block alignment is {}, should be {}",
             format.block_alignment, (format.bits_per_sample / 8 ) * format.channel_count);
         
-        assert!(format.tag == 1, "Unsupported format tag {}", format.tag);
+
+        assert!(format.common_format() == CommonFormat::IntegerPCM , 
+                "Unsupported format tag {:?}", format.tag);
+                
         AudioFrameReader { inner , format }
     }
 
+    /// Locate the read position to a different frame
+    /// 
+    /// Seeks within the audio stream.
+    /// 
+    /// Returns the new location of the read position.
     pub fn locate(&mut self, to :u64) -> Result<u64,Error> {
         let position = to * self.format.block_alignment as u64;
         let seek_result = self.inner.seek(Start(position))?;
         Ok( seek_result / 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
+    /// 
+    /// A single frame is read from the audio stream and the read location
+    /// is advanced one frame.
+    /// 
+    /// Regardless of the number of bits in the audio sample, this method
+    /// always writes `i32` samples back to the buffer. These samples are 
+    /// written back "left-aligned" so samples that are shorter than i32
+    /// will leave the MSB bits empty. 
+    /// 
+    /// For example: A full-code sample in 16 bit (0xFFFF) will be written 
+    /// back to the buffer as 0x0000FFFF.
+    ///  
+    /// 
+    /// ### Panics
+    /// 
+    /// The `buffer` must have a number of elements equal to the number of 
+    /// channels and this method will panic if this is not the case.
     pub fn read_integer_frame(&mut self, buffer:&mut [i32]) -> Result<u64,Error> {
         assert!(buffer.len() as u16 == self.format.channel_count, 
             "read_integer_frame was called with a mis-sized buffer, expected {}, was {}", 
@@ -54,5 +98,4 @@ impl<R: Read + Seek> AudioFrameReader<R> {
 
         Ok( 1 )
     }
-}
-
+}

src/bext.rs

@@ -0,0 +1,82 @@
+
+pub type LU = f32;
+pub type LUFS = f32;
+pub type Decibels = f32;
+
+/**
+ * Broadcast-WAV metadata record.
+ * 
+ * The `bext` record contains information about the original recording of the 
+ * Wave file, including a longish (256 ASCII chars) description field, 
+ * originator identification fields, creation calendar date and time, a 
+ * sample-accurate recording time field, and a SMPTE UMID. 
+ * 
+ * For a Wave file to be a complaint "Broadcast-WAV" file, it must contain
+ * a `bext` metadata record.
+ * 
+ * For reference on the structure and use of the BEXT record
+ * check out [EBU Tech 3285](https://tech.ebu.ch/docs/tech/tech3285.pdf).
+ */
+#[derive(Debug)]
+pub struct Bext {
+
+    /// 256 ASCII character field with free text.
+    pub description: String,
+
+    /// Originating application.
+    pub originator: String,
+
+    /// Application-specific UID.
+    pub originator_reference: String,
+
+    /// Creation date in format `YYYY-MM-DD`.
+    pub origination_date: String,
+
+    /// Creation time in format `HH:MM:SS`.
+    pub origination_time: String,
+
+    /// Time of the start of this wave file, expressed as the number of samples
+    /// since local midnight.
+    pub time_reference: u64,
+
+    /// Bext chunk version.
+    /// 
+    /// Version 1 contains a UMID, version 2 contains a UMID and 
+    /// loudness metadata.
+    pub version: u16,
+
+    /// SMPTE 330M UMID
+    /// 
+    /// 
+    /// This field is `None` if the version is less than 1.
+    pub umid: Option<[u8; 64]>,
+
+    /// Integrated loudness in LUFS.
+    /// 
+    /// This field is `None` if the version is less than 2.
+    pub loudness_value: Option<LUFS>,
+
+    /// Loudness range in LU.
+    /// 
+    /// This field is `None` if the version is less than 2.
+    pub loudness_range: Option<LU>,
+
+    /// Maximum True Peak Level in decibels True Peak.
+    ///
+    /// This field is `None` if the version is less than 2.
+    pub max_true_peak_level: Option<Decibels>,
+
+    /// Maximum momentary loudness in LUFS.
+    ///
+    /// This field is `None` if the version is less than 2.
+    pub max_momentary_loudness: Option<LUFS>,
+
+    /// Maximum short-term loudness in LUFS.
+    /// 
+    /// This field is `None` if the version is less than 2.
+    pub max_short_term_loudness: Option<LUFS>,
+    // 180 bytes of nothing
+
+    /// Coding History.
+    pub coding_history: String
+}

src/chunks.rs

@@ -1,7 +1,5 @@
 use std::io::{Read, Write};
 
-use super::errors::Error as ParserError;
-
 use encoding::{DecoderTrap, EncoderTrap};
 use encoding::{Encoding};
 use encoding::all::ASCII;
@@ -9,180 +7,11 @@ use encoding::all::ASCII;
 use byteorder::LittleEndian;
 use byteorder::{ReadBytesExt, WriteBytesExt};
 
-/**
- * References:
- * - http://www-mmsp.ece.mcgill.ca/Documents/AudioFormats/WAVE/Docs/multichaudP.pdf
-*/
-#[derive(PartialEq)]
-enum FormatTags {
-    Integer = 0x0001,
-    Float = 0x0003,
-    Extensible = 0xFFFE
-}
+use uuid::Uuid;
 
-const PCM_SUBTYPE_UUID: [u8; 16] = [0x00, 0x00, 0x00, 0x01,
-                                    0x00, 0x00, 0x00, 0x10,
-                                    0x80, 0x00, 0x00, 0xaa,
-                                    0x00, 0x38, 0x9b, 0x71];
-
-const FLOAT_SUBTYPE_UUID: [u8; 16] = [0x00, 0x00, 0x00, 0x03,
-                                      0x00, 0x00, 0x00, 0x10,
-                                      0x80, 0x00, 0x00, 0xaa,
-                                      0x00, 0x38, 0x9b, 0x71];
-
-/*
-https://docs.microsoft.com/en-us/windows-hardware/drivers/audio/subformat-guids-for-compressed-audio-formats
-http://dream.cs.bath.ac.uk/researchdev/wave-ex/bformat.html
-
-These are from http://dream.cs.bath.ac.uk/researchdev/wave-ex/mulchaud.rtf
-*/
-
-#[derive(Debug)]
-pub enum WaveFmtExtendedChannelMask {
-    FrontLeft        = 0x1,
-    FrontRight       = 0x2,
-    FrontCenter      = 0x4,
-    LowFrequency     = 0x8,
-    BackLeft         = 0x10,
-    BackRight        = 0x20,
-    FrontCenterLeft  = 0x40,
-    FrontCenterRight = 0x80,
-    BackCenter       = 0x100,
-    SideLeft         = 0x200,
-    SideRight        = 0x400,
-    TopCenter        = 0x800,
-    TopFrontLeft     = 0x1000,
-    TopFrontCenter   = 0x2000,
-    TopFrontRight    = 0x4000,
-    TopBackLeft      = 0x8000,
-    TopBackCenter    = 0x10000,
-    TopBackRight     = 0x20000 
-}
-
-
-/**
- * Extended Wave Format
- * 
- * https://docs.microsoft.com/en-us/windows/win32/api/mmreg/ns-mmreg-waveformatextensible
- */
-#[derive(Debug)]
-pub struct WaveFmtExtended {
-
-    /// Valid bits per sample
-    pub valid_bits_per_sample : u16,
-
-    /// Channel mask
-    /// 
-    /// Identifies the speaker assignment for each channel in the file
-    pub channel_mask : WaveFmtExtendedChannelMask,
-
-    /// Codec GUID
-    /// 
-    /// Identifies the codec of the audio stream
-    pub type_guid : [u8; 16],
-}
-
-/**
- * WAV file data format record.
- * 
- * The `fmt` record contains essential information describing the binary
- * structure of the data segment of the WAVE file, such as sample 
- * rate, sample binary format, channel count, etc.
- *
- */
-#[derive(Debug)]
-pub struct WaveFmt {
-
-    /// A tag identifying the codec in use.
-    /// 
-    /// If this is 0xFFFE, the codec will be identified by a GUID
-    /// in `extended_format`
-    pub tag: u16,
-
-    /// Count of audio channels in each frame
-    pub channel_count: u16,
-
-    /// Sample rate of the audio data
-    pub sample_rate: u32,
-
-    /// Count of bytes per second
-    /// 
-    /// By rule, this is `block_alignment * sample_rate`
-    pub bytes_per_second: u32,
-
-    /// Count of bytes per audio frame
-    /// 
-    /// By rule, this is `channel_count * bits_per_sample / 8`
-    pub block_alignment: u16,
-
-    /// Count of bits stored in the file per sample
-    pub bits_per_sample: u16,
-
-    /// Extended format description
-    /// 
-    /// Additional format metadata if `channel_count` is greater than 2,
-    /// or if certain codecs are used.
-    pub extended_format: Option<WaveFmtExtended>
-}
-
-
-impl WaveFmt {
-
-    /// Create a new integer PCM format `WaveFmt` 
-    pub fn new_pcm(sample_rate: u32, bits_per_sample: u16, channel_count: u16) -> Self {
-        let container_bits_per_sample = bits_per_sample + (bits_per_sample % 8);
-        let container_bytes_per_sample= container_bits_per_sample / 8;
-
-        let tag :u16 = match channel_count {
-            0 => panic!("Error"),
-            1..=2 => FormatTags::Integer as u16,
-            _ => FormatTags::Extensible as u16,
-        };
-
-        WaveFmt {
-            tag, 
-            channel_count,
-            sample_rate,
-            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
-        }
-    }
-}
-
-/**
- * Broadcast-WAV metadata record.
- * 
- * The `bext` record contains information about the original recording of the 
- * Wave file, including a longish (256 ASCII chars) description field, 
- * originator identification fields, creation calendar date and time, a 
- * sample-accurate recording time field, and a SMPTE UMID. 
- * 
- * For a Wave file to be a complaint "Broadcast-WAV" file, it must contain
- * a `bext` metadata record.
- * 
- * For reference on the structure and use of the BEXT record
- * check out [EBU Tech 3285](https://tech.ebu.ch/docs/tech/tech3285.pdf).
- */
-#[derive(Debug)]
-pub struct Bext {
-    pub description: String,
-    pub originator: String,
-    pub originator_reference: String,
-    pub origination_date: String,
-    pub origination_time: String,
-    pub time_reference: u64,
-    pub version: u16,
-    pub umid: Option<[u8; 64]>,
-    pub loudness_value: Option<f32>,
-    pub loudness_range: Option<f32>,
-    pub max_true_peak_level: Option<f32>,
-    pub max_momentary_loudness: Option<f32>,
-    pub max_short_term_loudness: Option<f32>,
-    // 180 bytes of nothing
-    pub coding_history: String
-}
+use super::errors::Error as ParserError;
+use super::fmt::{WaveFmt, WaveFmtExtended};
+use super::bext::Bext;
 
 pub trait ReadBWaveChunks: Read {
     fn read_bext(&mut self) -> Result<Bext, ParserError>;
@@ -198,7 +27,7 @@ pub trait WriteBWaveChunks: Write {
 
 impl<T> WriteBWaveChunks for T where T: Write {
     fn write_wave_fmt(&mut self, format : &WaveFmt) -> Result<(), ParserError> {
-        self.write_u16::<LittleEndian>(format.tag)?;
+        self.write_u16::<LittleEndian>(format.tag as u16 )?;
         self.write_u16::<LittleEndian>(format.channel_count)?;
         self.write_u32::<LittleEndian>(format.sample_rate)?;
         self.write_u32::<LittleEndian>(format.bytes_per_second)?;
@@ -258,14 +87,34 @@ impl<T> WriteBWaveChunks for T where T: Write {
 impl<T> ReadBWaveChunks for T where T: Read {
 
     fn read_wave_fmt(&mut self) -> Result<WaveFmt, ParserError> {
+        let tag_value : u16;
         Ok(WaveFmt {
-            tag:                self.read_u16::<LittleEndian>()?,
+            tag: {
+                tag_value = self.read_u16::<LittleEndian>()?;
+                tag_value
+            },
             channel_count:      self.read_u16::<LittleEndian>()?,
             sample_rate:        self.read_u32::<LittleEndian>()?,
             bytes_per_second:   self.read_u32::<LittleEndian>()?,
             block_alignment:    self.read_u16::<LittleEndian>()?,
             bits_per_sample:    self.read_u16::<LittleEndian>()?, 
-            extended_format: None
+            extended_format: {
+                if tag_value == 0xFFFE {
+                    let cb_size = self.read_u16::<LittleEndian>()?;
+                    assert!(cb_size >= 22, "Format extension is not correct size");
+                    Some(WaveFmtExtended {
+                        valid_bits_per_sample: self.read_u16::<LittleEndian>()?,
+                        channel_mask: self.read_u32::<LittleEndian>()?,
+                        type_guid: {
+                            let mut buf : [u8; 16] = [0; 16];
+                            self.read_exact(&mut buf)?;
+                            Uuid::from_slice(&buf)?
+                        }
+                    })
+                } else {
+                    None
+                }
+            }
         })
     }
 
@@ -315,11 +164,36 @@ impl<T> ReadBWaveChunks for T where T: Read {
                     if version > 1 { Some(val) } else { None }
                 }, 
                 coding_history: {
-                    for _ in 0..=180 { self.read_u8()?; }
+                    for _ in 0..180 { self.read_u8()?; }
                     let mut buf = vec![];
                     self.read_to_end(&mut buf)?;
                     ASCII.decode(&buf, DecoderTrap::Ignore).expect("Error decoding text")
                 }
         })
      }
+}
+
+#[test]
+fn test_read_51_wav() {
+    use super::fmt::ChannelMask;
+    use super::common_format::CommonFormat;
+
+    let path = "tests/media/pt_24bit_51.wav";
+
+    let mut w = super::wavereader::WaveReader::open(path).unwrap();
+    let format = w.format().unwrap();
+    assert_eq!(format.tag, 0xFFFE);
+    assert_eq!(format.channel_count, 6);
+    assert_eq!(format.sample_rate, 48000);
+    let extended = format.extended_format.unwrap();
+
+    assert_eq!(extended.valid_bits_per_sample, 24);
+
+    let channels = ChannelMask::channels(extended.channel_mask, format.channel_count);
+
+    assert_eq!(channels, [ChannelMask::FrontLeft, ChannelMask::FrontRight, 
+        ChannelMask::FrontCenter, ChannelMask::LowFrequency,
+        ChannelMask::BackLeft, ChannelMask::BackRight]);
+
+    assert_eq!(format.common_format(), CommonFormat::IntegerPCM);
 }

src/common_format.rs

@@ -0,0 +1,99 @@
+use uuid::Uuid;
+
+/**
+ * References:
+ * - http://www-mmsp.ece.mcgill.ca/Documents/AudioFormats/WAVE/Docs/multichaudP.pdf
+*/
+
+// http://dream.cs.bath.ac.uk/researchdev/wave-ex/bformat.html
+
+const BASIC_PCM: u16        = 0x0001;
+const BASIC_FLOAT: u16      = 0x0003;
+const BASIC_MPEG: u16       = 0x0050;
+const BASIC_EXTENDED: u16   = 0xFFFE;
+
+/* RC 2361 §4:
+
+ WAVE Format IDs are converted to GUIDs by inserting the hexadecimal
+   value of the WAVE Format ID into the XXXXXXXX part of the following
+   template: {XXXXXXXX-0000-0010-8000-00AA00389B71}. For example, a WAVE
+   Format ID of 123 has the GUID value of {00000123-0000-0010-8000-
+   00AA00389B71}.
+
+*/
+
+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,
+    0x80, 0x00, 0x00, 0xaa, 0x00, 0x38, 0x9b, 0x71]);
+
+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, 
+    0x86, 0x44, 0xc8, 0xc1, 0xca, 0x00, 0x00, 0x00]);
+
+const UUID_BFORMAT_FLOAT: Uuid = Uuid::from_bytes([0x03, 0x00, 0x00, 0x00, 0x21, 0x07, 0xd3, 0x11,
+    0x86, 0x44, 0xc8, 0xc1, 0xca, 0x00, 0x00, 0x00]);
+
+
+fn uuid_from_basic_tag(tag: u16) -> Uuid {
+    let tail : [u8; 6] = [0x00,0xaa,0x00,0x38,0x9b,0x71];
+    Uuid::from_fields_le(tag as u32, 0x0000, 0x0010, &tail).unwrap()
+}
+
+/// Sample format of the Wave file.
+/// 
+///
+#[derive(Debug, Copy, Clone, PartialEq)]
+pub enum CommonFormat {
+    /// Integer linear PCM
+    IntegerPCM,
+ 
+    /// IEEE Floating-point Linear PCM
+    IeeeFloatPCM,
+ 
+    /// MPEG
+    Mpeg,
+ 
+    /// Ambisonic B-Format Linear PCM
+    AmbisonicBFormatIntegerPCM,
+ 
+    /// Ambisonic B-Format Float PCM
+    AmbisonicBFormatIeeeFloatPCM,
+ 
+    /// An unknown format identified by a basic format tag.
+    UnknownBasic(u16),
+ 
+    /// An unknown format identified by an extension UUID.
+    UnknownExtended(Uuid),
+}
+
+impl CommonFormat {
+    pub fn make(basic: u16, uuid: Option<Uuid>) -> Self {
+        match (basic, uuid) {
+            (BASIC_PCM, _) => Self::IntegerPCM,
+            (BASIC_FLOAT, _) => Self::IeeeFloatPCM,
+            (BASIC_MPEG, _) => Self::Mpeg,
+            (BASIC_EXTENDED, Some(UUID_PCM))  => Self::IntegerPCM,
+            (BASIC_EXTENDED, Some(UUID_FLOAT))=> Self::IeeeFloatPCM,
+            (BASIC_EXTENDED, Some(UUID_BFORMAT_PCM)) => Self::AmbisonicBFormatIntegerPCM,
+            (BASIC_EXTENDED, Some(UUID_BFORMAT_FLOAT)) => Self::AmbisonicBFormatIeeeFloatPCM,
+            (BASIC_EXTENDED, Some(x)) => CommonFormat::UnknownExtended(x),
+            (x, _) => CommonFormat::UnknownBasic(x)
+        }
+    }
+
+    pub fn take(self) -> (u16, Uuid) {
+        match self {
+            Self::IntegerPCM => (BASIC_PCM, UUID_PCM),
+            Self::IeeeFloatPCM => (BASIC_FLOAT, UUID_FLOAT),
+            Self::Mpeg => (BASIC_MPEG, UUID_MPEG),
+            Self::AmbisonicBFormatIntegerPCM => (BASIC_EXTENDED, UUID_BFORMAT_PCM),
+            Self::AmbisonicBFormatIeeeFloatPCM => (BASIC_EXTENDED, UUID_BFORMAT_FLOAT),
+            Self::UnknownBasic(x) => ( x, uuid_from_basic_tag(x) ),
+            Self::UnknownExtended(x) => ( BASIC_EXTENDED, x)
+        }
+    }
+}

src/errors.rs

@@ -1,6 +1,8 @@
 use std::io;
 use super::fourcc::FourCC;
 
+use uuid;
+
 /// Errors returned by methods in this crate.
 #[derive(Debug)]
 pub enum Error {
@@ -8,6 +10,9 @@ pub enum Error {
     /// An `io::Error` occurred
     IOError(io::Error),
 
+    /// An error occured reading a tag UUID
+    UuidError(uuid::Error),
+
     /// The file does not begin with a recognized WAVE header
     HeaderNotRecognized,
     
@@ -34,7 +39,8 @@ pub enum Error {
     InsufficientDS64Reservation {expected: u64, actual: u64},
 
     /// The file is not optimized for writing new data
-    DataChunkNotPreparedForAppend
+    DataChunkNotPreparedForAppend,
+
 }
 
 
@@ -42,4 +48,10 @@ impl From<io::Error> for Error {
     fn from(error: io::Error) -> Error {
         Error::IOError(error)
     }
+}
+
+impl From <uuid::Error> for Error {
+    fn from(error: uuid::Error) -> Error {
+        Error::UuidError(error)
+    }  
 }

src/fmt.rs

@@ -0,0 +1,247 @@
+use std::convert::TryFrom;
+use uuid::Uuid;
+use super::errors::Error;
+use super::common_format::CommonFormat;
+
+
+/// 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.
+/// 
+/// 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]
+}
+
+/// Describes a single channel in a WAV file.
+pub struct ChannelDescriptor {
+    /// Index, the offset of this channel's samples in one frame.
+    pub index: u16,
+
+    /// Channel assignment
+    /// 
+    /// This is either implied (in the case of mono or stereo wave files) or
+    /// explicitly given in `WaveFormatExtentended` for files with more tracks.
+    pub speaker: ChannelMask,
+
+    /// ADM audioTrackUIDs
+    pub adm_track_audio_ids: Vec<ADMAudioID>,
+}
+
+
+
+/*
+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
+*/
+
+#[derive(Debug, Clone, Copy, PartialEq)]
+pub enum ChannelMask {
+    DirectOut        = 0x0,
+    FrontLeft        = 0x1,
+    FrontRight       = 0x2,
+    FrontCenter      = 0x4,
+    LowFrequency     = 0x8,
+    BackLeft         = 0x10,
+    BackRight        = 0x20,
+    FrontCenterLeft  = 0x40,
+    FrontCenterRight = 0x80,
+    BackCenter       = 0x100,
+    SideLeft         = 0x200,
+    SideRight        = 0x400,
+    TopCenter        = 0x800,
+    TopFrontLeft     = 0x1000,
+    TopFrontCenter   = 0x2000,
+    TopFrontRight    = 0x4000,
+    TopBackLeft      = 0x8000,
+    TopBackCenter    = 0x10000,
+    TopBackRight     = 0x20000,
+}
+
+impl From<u32> for ChannelMask {
+    
+    fn from(value: u32) -> Self { 
+        match value {
+            0x1 => Self::FrontLeft,
+            0x2 => Self::FrontRight,
+            0x4 => Self::FrontCenter, 
+            0x8 => Self::LowFrequency,
+            0x10 => Self::BackLeft,
+            0x20 => Self::BackRight,
+            0x40 => Self::FrontCenterLeft,
+            0x80 => Self::FrontCenterRight,
+            0x100 => Self::BackCenter,
+            0x200 => Self::SideLeft,
+            0x400 => Self::SideRight,
+            0x800 => Self::TopCenter,
+            0x1000 => Self::TopFrontLeft, 
+            0x2000 => Self::TopFrontCenter,
+            0x4000 => Self::TopFrontRight,
+            0x8000 => Self::TopBackLeft,
+            0x10000 => Self::TopBackCenter,
+            0x20000 => Self::TopBackRight,
+            _ => Self::DirectOut 
+        }
+    }
+}
+
+impl ChannelMask {
+    pub fn channels(input_mask : u32, channel_count: u16) -> Vec<ChannelMask> {
+        let reserved_mask = 0xfff2_0000_u32;
+        if (input_mask & reserved_mask) > 0 {
+            vec![ ChannelMask::DirectOut ; channel_count as usize ]
+        } else {
+            (0..18).map(|i| 1 << i )
+                .filter(|mask| mask & input_mask > 0)
+                .map(|mask| Into::<ChannelMask>::into(mask))
+                .collect()
+        }
+    }
+}
+
+/**
+ * Extended Wave Format
+ * 
+ * https://docs.microsoft.com/en-us/windows/win32/api/mmreg/ns-mmreg-waveformatextensible
+ */
+#[derive(Debug, Copy, Clone)]
+pub struct WaveFmtExtended {
+
+    /// Valid bits per sample
+    pub valid_bits_per_sample : u16,
+
+    /// Channel mask
+    /// 
+    /// Identifies the speaker assignment for each channel in the file
+    pub channel_mask : u32,
+
+    /// Codec GUID
+    /// 
+    /// Identifies the codec of the audio stream
+    pub type_guid : Uuid,
+}
+
+/**
+ * WAV file data format record.
+ * 
+ * The `fmt` record contains essential information describing the binary
+ * structure of the data segment of the WAVE file, such as sample 
+ * rate, sample binary format, channel count, etc.
+ *
+ */
+#[derive(Debug, Copy, Clone)]
+pub struct WaveFmt {
+
+    /// A tag identifying the codec in use.
+    /// 
+    /// If this is 0xFFFE, the codec will be identified by a GUID
+    /// in `extended_format`
+    pub tag: u16,
+
+    /// Count of audio channels in each frame
+    pub channel_count: u16,
+
+    /// Sample rate of the audio data
+    pub sample_rate: u32,
+
+    /// Count of bytes per second
+    /// 
+    /// By rule, this is `block_alignment * sample_rate`
+    pub bytes_per_second: u32,
+
+    /// Count of bytes per audio frame
+    /// 
+    /// By rule, this is `channel_count * bits_per_sample / 8`
+    pub block_alignment: u16,
+
+    /// Count of bits stored in the file per sample
+    pub bits_per_sample: u16,
+
+    /// Extended format description
+    /// 
+    /// Additional format metadata if `channel_count` is greater than 2,
+    /// or if certain codecs are used.
+    pub extended_format: Option<WaveFmtExtended>
+}
+
+
+impl WaveFmt {
+
+    /// Create a new integer PCM format `WaveFmt` 
+    pub fn new_pcm(sample_rate: u32, bits_per_sample: u16, channel_count: u16) -> Self {
+        let container_bits_per_sample = bits_per_sample + (bits_per_sample % 8);
+        let container_bytes_per_sample= container_bits_per_sample / 8;
+
+        let tag : u16 = match channel_count {
+            1..=2 => 0x01,
+            x if x > 2 => 0xFFFE,
+            x => panic!("Invalid channel count {}", x)
+        };
+
+        WaveFmt {
+            tag, 
+            channel_count,
+            sample_rate,
+            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
+        }
+    }
+
+    /// Format or codec of the file's audio data.
+    /// 
+    /// The `CommonFormat` unifies the format tag and the format extension GUID. Use this
+    /// method to determine the codec.
+    pub fn common_format(&self) -> CommonFormat {
+        CommonFormat::make( self.tag, self.extended_format.map(|ext| ext.type_guid))
+    }
+
+    /// Channel descriptors for each channel.
+    pub fn channels(&self) -> Vec<ChannelDescriptor> {
+        match self.channel_count {
+            1 => vec![
+                ChannelDescriptor {
+                    index: 0,
+                    speaker: ChannelMask::FrontCenter,
+                    adm_track_audio_ids: vec![]
+                }
+            ],
+            2 => vec![
+                ChannelDescriptor {
+                    index: 0,
+                    speaker: ChannelMask::FrontLeft,
+                    adm_track_audio_ids: vec![]
+                },
+                ChannelDescriptor {
+                    index: 1,
+                    speaker: ChannelMask::FrontRight,
+                    adm_track_audio_ids: vec![]
+                }
+            ],
+            x if x > 2 => {
+                let channel_mask = self.extended_format.map(|x| x.channel_mask).unwrap_or(0);
+                let channels = ChannelMask::channels(channel_mask, self.channel_count);
+                let channels_expanded = channels.iter().chain(std::iter::repeat(&ChannelMask::DirectOut));
+
+                (0..self.channel_count)
+                    .zip(channels_expanded)
+                    .map(|(n,chan)| ChannelDescriptor {
+                        index: n,
+                        speaker: *chan, 
+                        adm_track_audio_ids: vec![]
+                    }).collect()
+            },
+            x => panic!("Channel count ({}) was illegal!", x),
+        }
+    }
+}
+

src/lib.rs

@@ -1,23 +1,63 @@
-//
 /*! 
 # bwavfile
  
 Rust Wave File Reader/Writer with Broadcast-WAV, MBWF and RF64 Support
  
-(Note: This crate is still in an alpha or pre-alpha stage of development. Reading of
+__(Note: This crate is still in an alpha or pre-alpha stage of development. Reading of
 files works however the interfaces may change significantly. Stay up-to-date on the
-status of this project at [Github][github].)
+status of this project at [Github][github].)__
+
+## Objectives and Roadmap
+
+This package aims to support read and writing any kind of WAV file you are likely 
+to encounter in a professional audio, motion picture production, broadcast, or music 
+production.
+
+Apps we test against:
+- Avid Pro Tools
+- FFMpeg
+- Audacity
+
+Wave features we want to support with maximum reliability and ease of use:
+
+- Large file size, RF64 support
+- Multichannel audio formats 
+- Embedded metadata
+
+In addition to reading the audio, we want to support all of the different 
+metadata planes you are liable to need to use.
+
+- Broadcast-WAV metadata (including the SMPTE UMID and EBU v2 extensions)
+- iXML Production recorder metadata
+- ADM XML (with associated `chna` mappings)
+- Dolby metadata block
+
+Things that are _not_ necessarily in the scope of this package:
+
+- Broad codec support. There are a little more than one-hundred 
+  [registered wave codecs][rfc3261], but because this library is targeting
+  professional formats being created today, we only plan on supporting
+  two of them: tag 0x0001 (Integer Linear PCM) and tag 0x0003 (IEEE Float 
+  Linear PCM).
+- Music library metadata. There are several packages that can read ID3
+  metadata and it's not particuarly common in wave files in any case. INFO
+  metadata is more common though in professional applications it tends not
+  to be used by many applications.
+
 
 ## Resources
 
 ### Implementation of Broadcast Wave Files
 - [EBU Tech 3285][ebu3285] (May 2011), "Specification of the Broadcast Wave Format (BWF)"
+  - [Supplement 1](https://tech.ebu.ch/docs/tech/tech3285s1.pdf) (July 1997): MPEG Audio
+- [EBU Rec 68](https://tech.ebu.ch/docs/r/r068.pdf): Signal modulation and format constraints
+
 
 ### Implementation of 64-bit Wave Files
 - [ITU-R 2088][itu2088] (October 2019), "Long-form file format for the international exchange of audio programme materials with metadata"
- - Presently in force, adopted by the EBU in [EBU Tech 3306v2][ebu3306v2] (June 2018).
+  - Presently in force, adopted by the EBU in [EBU Tech 3306v2][ebu3306v2] (June 2018).
 - [EBU Tech 3306v1][ebu3306v1] (July 2009), "MBWF / RF64: An extended File Format for Audio"
- - No longer in force, however long-established. 
+  - No longer in force, however long-established. 
 
 
 ### Implementation of Wave format `fmt` chunk
@@ -29,9 +69,21 @@ status of this project at [Github][github].)
 - [RFC 3261][rfc3261] (June 1998) "WAVE and AVI Codec Registries" 
 - [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) 
-    IBM Corporation and Microsoft Corporation, (August 1991)
+    (August 1991), IBM Corporation and Microsoft Corporation
 
 
+### Formatting of Specific Metadatums
+- [iXML Metadata Specification](http://www.gallery.co.uk/ixml/) (April 2019) 
+- EBU 3285 Supplements:
+  - [Supplement 2](https://tech.ebu.ch/docs/tech/tech3285s2.pdf) (July 2001): Quality chunk and cuesheet
+  - [Supplement 3](https://tech.ebu.ch/docs/tech/tech3285s3.pdf) (July 2001): Peak Metadata
+  - [Supplement 4](https://tech.ebu.ch/docs/tech/tech3285s4.pdf) (April 2003): Link Metadata
+  - [Supplement 5](https://tech.ebu.ch/docs/tech/tech3285s5.pdf) (May 2018): ADM Metadata
+  - [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"
+
 [ebu3285]: https://tech.ebu.ch/docs/tech/tech3285.pdf
 [ebu3306v1]: https://tech.ebu.ch/docs/tech/tech3306v1_1.pdf
 [ebu3306v2]: https://tech.ebu.ch/docs/tech/tech3306.pdf
@@ -48,20 +100,27 @@ status of this project at [Github][github].)
 
 extern crate encoding;
 extern crate byteorder;
+extern crate uuid;
 
-mod parser;
 mod fourcc;
 mod errors;
+mod common_format;
+
+mod parser;
 
-mod validation;
 
 mod raw_chunk_reader;
 mod audio_frame_reader;
 mod chunks;
+mod bext;
+mod fmt;
 
 mod wavereader;
 mod wavewriter;
 
+pub use errors::Error;
 pub use wavereader::{WaveReader};
-pub use chunks::{WaveFmt,Bext};
-pub use errors::Error;
+pub use bext::Bext;
+pub use fmt::{WaveFmt, WaveFmtExtended, ChannelDescriptor, ChannelMask};
+pub use common_format::CommonFormat;
+pub use audio_frame_reader::AudioFrameReader;

src/parser.rs

@@ -103,7 +103,6 @@ impl<R: Read + Seek> Iterator for Parser<R> {
 
     fn next(&mut self) -> Option<Event> {
         let (event, next_state) = self.advance();
-        //println!("{:?}", event);
         self.state = next_state;
         return event;
     }

src/validation.rs

@@ -1,144 +0,0 @@
-use super::parser::{Parser};
-use super::fourcc::{FourCC, FMT__SIG,DATA_SIG, BEXT_SIG, JUNK_SIG, FLLR_SIG};
-use super::errors::Error as ParserError;
-use super::wavereader::{WaveReader};
-
-use std::io::{Read,Seek};
-
-impl<R:Read + Seek> WaveReader<R> {
-    /**
-    *  Returns without `Err` if the source meets the minimum standard of 
-    *  readability by a permissive client:
-    *  1. `fmt` chunk and `data` chunk are present
-    *  1. `fmt` chunk appears before `data` chunk
-    */
-    pub fn validate_readable(&mut self) -> Result<(), ParserError> {
-        let (fmt_pos, _)  = self.get_chunk_extent_at_index(FMT__SIG, 0)?;
-        let (data_pos, _) = self.get_chunk_extent_at_index(DATA_SIG, 0)?;
-
-        if fmt_pos < data_pos {
-            Ok(())
-        } else {
-            Err( ParserError::FmtChunkAfterData)
-        }
-    }
-
-    /** 
-     * Validate minimal WAVE file
-     * 
-     * Returns without `Err` the source is `validate_readable` AND
-     * 
-     *   - Contains _only_ a `fmt` chunk and `data` chunk, with no other chunks present
-     *   - is not an RF64/BW64
-     * 
-     * Some clients require a WAVE file to only contain format and data without any other
-     * metadata and this function is provided to validate this condition.
-     * 
-     * ```
-     * # use bwavfile::WaveReader;
-     * 
-     * let mut w = WaveReader::open("tests/media/ff_minimal.wav").unwrap();
-     * w.validate_minimal().expect("Minimal wav did not validate not minimal!");
-     * ```
-     * 
-     * ```
-     * # use bwavfile::WaveReader;
-     * 
-     * let mut x = WaveReader::open("tests/media/pt_24bit_51.wav").unwrap();
-     * x.validate_minimal().expect_err("Complex WAV validated minimal!");
-     * ```
-    */
-    pub fn validate_minimal(&mut self) -> Result<(), ParserError>  {
-        self.validate_readable()?;
-
-        let chunk_fourccs : Vec<FourCC> = Parser::make(&mut self.inner)?
-            .into_chunk_list()?.iter().map(|c| c.signature ).collect();
-
-        if chunk_fourccs == vec![FMT__SIG, DATA_SIG] {
-            Ok(())
-        } else {
-            Err( ParserError::NotMinimalWaveFile )
-        }
-    }
-
-    /**
-     * Validate Broadcast-WAVE file format
-     * 
-     * Returns without `Err` if `validate_readable()` and file contains a 
-     * Broadcast-WAV metadata record (a `bext` chunk).
-     * 
-     * ```
-     * # use bwavfile::WaveReader;
-     * 
-     * let mut w = WaveReader::open("tests/media/ff_bwav_stereo.wav").unwrap();
-     * w.validate_broadcast_wave().expect("BWAVE file did not validate BWAVE");
-     * 
-     * let mut x = WaveReader::open("tests/media/pt_24bit.wav").unwrap();
-     * x.validate_broadcast_wave().expect("BWAVE file did not validate BWAVE");
-     * 
-     * let mut y = WaveReader::open("tests/media/audacity_16bit.wav").unwrap();
-     * y.validate_broadcast_wave().expect_err("Plain WAV file DID validate BWAVE");
-     * ```
-    */
-    pub fn validate_broadcast_wave(&mut self) -> Result<(), ParserError> {
-        self.validate_readable()?;
-        let (_, _) = self.get_chunk_extent_at_index(BEXT_SIG, 0)?;
-        Ok(())
-    } 
-
-    /**
-     * Verify data is aligned to a block boundary
-     * 
-     * Returns without `Err` if `validate_readable()` and the start of the 
-     * `data` chunk's content begins at 0x4000.
-    */
-    pub fn validate_data_chunk_alignment(&mut self) -> Result<() , ParserError> {
-        self.validate_readable()?;
-        let (start, _) = self.get_chunk_extent_at_index(DATA_SIG, 0)?;
-        if start == 0x4000 {
-            Ok(())
-        } else {
-            Err(ParserError::DataChunkNotAligned)
-        }
-    }
-
-    /**
-     * Returns without `Err` if:
-     *  - `validate_readable()`
-     *  - there is a `JUNK` or `FLLR` immediately at the beginning of the chunk 
-     *    list adequately large enough to be overwritten by a `ds64` (96 bytes)
-     *  - `data` is the final chunk
-    */
-    pub fn validate_prepared_for_append(&mut self) -> Result<(), ParserError> {
-        self.validate_readable()?;
-
-        let chunks = Parser::make(&mut self.inner)?.into_chunk_list()?;
-        let ds64_space_required = 92;
-
-        let eligible_filler_chunks = chunks.iter()
-            .take_while(|c| c.signature == JUNK_SIG || c.signature == FLLR_SIG);
-
-        let filler = eligible_filler_chunks
-            .enumerate()
-            .fold(0, |accum, (n, item)| if n == 0 { accum + item.length } else {accum + item.length + 8});
-
-        if filler < ds64_space_required {
-            Err(ParserError::InsufficientDS64Reservation {expected: ds64_space_required, actual: filler})
-        } else {
-            let data_pos = chunks.iter().position(|c| c.signature == DATA_SIG);
-        
-            match data_pos {
-                Some(p) if p == chunks.len() - 1 => Ok(()),
-                _ => Err(ParserError::DataChunkNotPreparedForAppend)
-            }
-        }
-    }
-}
-
-
-
-
-
-
-
-

src/wavereader.rs

@@ -2,14 +2,15 @@
 use std::fs::File;
 
 use super::parser::Parser;
-use super::fourcc::{FourCC, FMT__SIG, BEXT_SIG, DATA_SIG};
+use super::fourcc::{FourCC, FMT__SIG,DATA_SIG, BEXT_SIG, JUNK_SIG, FLLR_SIG};
 use super::errors::Error as ParserError;
 use super::raw_chunk_reader::RawChunkReader;
-use super::chunks::{WaveFmt, Bext};
+use super::fmt::{WaveFmt, ChannelDescriptor, ChannelMask};
+use super::bext::Bext;
 use super::audio_frame_reader::AudioFrameReader;
 use super::chunks::ReadBWaveChunks;
-//use super::validation;
-//use std::io::SeekFrom::{Start};
+
+
 use std::io::{Read, Seek};
 
 
@@ -130,6 +131,173 @@ impl<R: Read + Seek> WaveReader<R> {
     pub fn broadcast_extension(&mut self) -> Result<Bext, ParserError> {
         self.chunk_reader(BEXT_SIG, 0)?.read_bext()
     }
+
+    /// Describe the channels in this file
+    /// 
+    /// Returns a vector of channel descriptors, one for each channel
+    /// 
+    /// ```rust
+    /// # use bwavfile::WaveReader;
+    /// # use bwavfile::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);
+    /// ```
+    pub fn channels(&mut self) -> Result<Vec<ChannelDescriptor>, ParserError> {
+        
+        let format = self.format()?;
+        let channel_masks : Vec<ChannelMask> = match (format.channel_count, format.extended_format) {
+            (1,_) => vec![ChannelMask::FrontCenter],
+            (2,_) => vec![ChannelMask::FrontLeft, ChannelMask::FrontRight],
+            (n,Some(x)) => ChannelMask::channels(x.channel_mask, n),
+            (n,_) => vec![ChannelMask::DirectOut; n as usize]
+        };
+
+        Ok( (0..format.channel_count).zip(channel_masks)
+            .map(|(i,m)| ChannelDescriptor { index: i, speaker:m, adm_track_audio_ids: vec![] } )
+            .collect() )
+    }
+
+    /**
+    * Validate file is readable.
+    * 
+    *  `Ok(())` if the source meets the minimum standard of 
+    *  readability by a permissive client:
+    *  - `fmt` chunk and `data` chunk are present
+    *  - `fmt` chunk appears before `data` chunk
+    */
+    pub fn validate_readable(&mut self) -> Result<(), ParserError> {
+        let (fmt_pos, _)  = self.get_chunk_extent_at_index(FMT__SIG, 0)?;
+        let (data_pos, _) = self.get_chunk_extent_at_index(DATA_SIG, 0)?;
+
+        if fmt_pos < data_pos {
+            Ok(())
+        } else {
+            Err( ParserError::FmtChunkAfterData)
+        }
+    }
+
+    /** 
+     * Validate minimal WAVE file.
+     * 
+     * `Ok(())` if the source is `validate_readable()` AND
+     * 
+     *   - Contains _only_ a `fmt` chunk and `data` chunk, with no other chunks present
+     *   - is not an RF64/BW64
+     * 
+     * Some clients require a WAVE file to only contain format and data without any other
+     * metadata and this function is provided to validate this condition.
+     * 
+     * ### Examples
+     * 
+     * ```
+     * # use bwavfile::WaveReader;
+     * 
+     * let mut w = WaveReader::open("tests/media/ff_minimal.wav").unwrap();
+     * w.validate_minimal().expect("Minimal wav did not validate not minimal!");
+     * ```
+     * 
+     * ```
+     * # use bwavfile::WaveReader;
+     * 
+     * let mut x = WaveReader::open("tests/media/pt_24bit_51.wav").unwrap();
+     * x.validate_minimal().expect_err("Complex WAV validated minimal!");
+     * ```
+    */
+    pub fn validate_minimal(&mut self) -> Result<(), ParserError>  {
+        self.validate_readable()?;
+
+        let chunk_fourccs : Vec<FourCC> = Parser::make(&mut self.inner)?
+            .into_chunk_list()?.iter().map(|c| c.signature ).collect();
+
+        if chunk_fourccs == vec![FMT__SIG, DATA_SIG] {
+            Ok(())
+        } else {
+            Err( ParserError::NotMinimalWaveFile )
+        }
+    }
+
+    /**
+     * Validate Broadcast-WAVE file format
+     * 
+     * Returns `Ok(())` if `validate_readable()` and file contains a 
+     * Broadcast-WAV metadata record (a `bext` chunk).
+     * 
+     * ### Examples
+     * 
+     * ```
+     * # use bwavfile::WaveReader;
+     * 
+     * let mut w = WaveReader::open("tests/media/ff_bwav_stereo.wav").unwrap();
+     * w.validate_broadcast_wave().expect("BWAVE file did not validate BWAVE");
+     * 
+     * let mut x = WaveReader::open("tests/media/pt_24bit.wav").unwrap();
+     * x.validate_broadcast_wave().expect("BWAVE file did not validate BWAVE");
+     * 
+     * let mut y = WaveReader::open("tests/media/audacity_16bit.wav").unwrap();
+     * y.validate_broadcast_wave().expect_err("Plain WAV file DID validate BWAVE");
+     * ```
+    */
+    pub fn validate_broadcast_wave(&mut self) -> Result<(), ParserError> {
+        self.validate_readable()?;
+        let (_, _) = self.get_chunk_extent_at_index(BEXT_SIG, 0)?;
+        Ok(())
+    } 
+
+    /**
+     * Verify data is aligned to a block boundary.
+     * 
+     * Returns `Ok(())` if `validate_readable()` and the start of the 
+     * `data` chunk's content begins at 0x4000.
+    */
+    pub fn validate_data_chunk_alignment(&mut self) -> Result<() , ParserError> {
+        self.validate_readable()?;
+        let (start, _) = self.get_chunk_extent_at_index(DATA_SIG, 0)?;
+        if start == 0x4000 {
+            Ok(())
+        } else {
+            Err(ParserError::DataChunkNotAligned)
+        }
+    }
+
+    /**
+     * Verify audio data can be appended immediately to this file.
+     * 
+     * Returns `Ok(())` if:
+     *  - `validate_readable()`
+     *  - there is a `JUNK` or `FLLR` immediately at the beginning of the chunk 
+     *    list adequately large enough to be overwritten by a `ds64` (92 bytes)
+     *  - `data` is the final chunk
+    */
+    pub fn validate_prepared_for_append(&mut self) -> Result<(), ParserError> {
+        self.validate_readable()?;
+
+        let chunks = Parser::make(&mut self.inner)?.into_chunk_list()?;
+        let ds64_space_required = 92;
+
+        let eligible_filler_chunks = chunks.iter()
+            .take_while(|c| c.signature == JUNK_SIG || c.signature == FLLR_SIG);
+
+        let filler = eligible_filler_chunks
+            .enumerate()
+            .fold(0, |accum, (n, item)| if n == 0 { accum + item.length } else {accum + item.length + 8});
+
+        if filler < ds64_space_required {
+            Err(ParserError::InsufficientDS64Reservation {expected: ds64_space_required, actual: filler})
+        } else {
+            let data_pos = chunks.iter().position(|c| c.signature == DATA_SIG);
+        
+            match data_pos {
+                Some(p) if p == chunks.len() - 1 => Ok(()),
+                _ => Err(ParserError::DataChunkNotPreparedForAppend)
+            }
+        }
+    }
 }
 
 impl<R:Read+Seek> WaveReader<R> { /* Private Implementation */
@@ -139,7 +307,7 @@ impl<R:Read+Seek> WaveReader<R> { /* Private Implementation */
         Ok( RawChunkReader::new(&mut self.inner, start, length) )
     } 
 
-    pub fn get_chunk_extent_at_index(&mut self, fourcc: FourCC, index: u32) -> Result<(u64,u64), ParserError> {
+    fn get_chunk_extent_at_index(&mut self, fourcc: FourCC, index: u32) -> Result<(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) {

src/wavewriter.rs

@@ -3,7 +3,9 @@ use std::fs::File;
 use std::io::Cursor;
 
 use super::errors::Error;
-use super::chunks::{WaveFmt, Bext, WriteBWaveChunks};
+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 byteorder::LittleEndian;

tests/create_test_media.sh

@@ -1,15 +1,10 @@
 #!/bin/zsh
 
 mkdir -p media
-cd media
 
+touch media/error.wav
 
-touch error.wav
-
-unzip ../arch_pt_media.zip
-unzip ../arch_audacity_media.zip
-unzip ../arch_ff_media.zip
-rm -rf __MACOSX
+tar xzf test_media.tgz
 
 # create a silent bext wave file with fixture metadata and a time refernce starting at
 # one minute

tests/ffprobe_media_tests.json

@@ -1,4 +1,57 @@
 [
+  {
+    "streams": [
+      {
+        "index": 0,
+        "codec_name": "pcm_s24le",
+        "codec_long_name": "PCM signed 24-bit little-endian",
+        "codec_type": "audio",
+        "codec_time_base": "1/48000",
+        "codec_tag_string": "[1][0][0][0]",
+        "codec_tag": "0x0001",
+        "sample_fmt": "s32",
+        "sample_rate": "48000",
+        "channels": 2,
+        "channel_layout": "stereo",
+        "bits_per_sample": 24,
+        "r_frame_rate": "0/0",
+        "avg_frame_rate": "0/0",
+        "time_base": "1/48000",
+        "duration_ts": 4800,
+        "duration": "0.100000",
+        "bit_rate": "2304000",
+        "bits_per_raw_sample": "24",
+        "disposition": {
+          "default": 0,
+          "dub": 0,
+          "original": 0,
+          "comment": 0,
+          "lyrics": 0,
+          "karaoke": 0,
+          "forced": 0,
+          "hearing_impaired": 0,
+          "visual_impaired": 0,
+          "clean_effects": 0,
+          "attached_pic": 0,
+          "timed_thumbnails": 0
+        }
+      }
+    ],
+    "format": {
+      "filename": "tests/media/ff_pink.wav",
+      "nb_streams": 1,
+      "nb_programs": 0,
+      "format_name": "wav",
+      "format_long_name": "WAV / WAVE (Waveform Audio)",
+      "duration": "0.100000",
+      "size": "28902",
+      "bit_rate": "2312160",
+      "probe_score": 99,
+      "tags": {
+        "encoder": "Lavf58.45.100"
+      }
+    }
+  },
   {
     "streams": [
       {

tests/ffprobe_media_tests.rs

@@ -7,14 +7,19 @@ use std::io::Read;
 
 use bwavfile::WaveReader;
 
-// This seems rickety but we're going with it
+// Media Tests
+//
+// These tests compare metadata and format data read by ffprobe with the same values
+// as read by `WaveReader`.
+
+// This is rickety but we're going with it
 fn assert_match_stream<T>(stream_key: &str, 
                     other: impl Fn(&mut WaveReader<File>) -> T)
                     where T: PartialEq + Debug,
                           T: Into<Value>
                     {
 
-    let mut json_file = File::open("tests/media_ffprobe_result.json").unwrap();
+    let mut json_file = File::open("tests/ffprobe_media_tests.json").unwrap();
     let mut s = String::new();
     json_file.read_to_string(&mut s).unwrap();
     if let Value::Array(v) = from_str(&mut s).unwrap() { /* */
@@ -47,4 +52,4 @@ fn test_sample_rate() {
 #[test]
 fn test_channel_count() {
     assert_match_stream("channels", |w| w.format().unwrap().channel_count );
-}
+}

tests/integration_test.rs

@@ -2,6 +2,7 @@ extern crate bwavfile;
 
 use bwavfile::WaveReader;
 use bwavfile::Error;
+use bwavfile::{ ChannelMask}; 
 
 #[test]
 fn test_open() {
@@ -27,7 +28,7 @@ fn test_format_silence() -> Result<(),Error> {
 
     assert_eq!(format.sample_rate, 44100);
     assert_eq!(format.channel_count, 1);
-    assert_eq!(format.tag, 1);
+    assert_eq!(format.tag as u16, 1);
     Ok( () )
 }
 
@@ -74,4 +75,85 @@ fn test_minimal_wave()  {
     } else {
         assert!(true);
     }
-}
+}
+
+#[test]
+fn test_read() {
+    let path = "tests/media/audacity_16bit.wav";
+
+    let mut w = WaveReader::open(path).expect("Failure opening test file");
+
+    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);
+    assert_eq!(reader.read_integer_frame(&mut buffer).unwrap(), 1);
+    assert_eq!(buffer[0], 2012_i32);
+    assert_eq!(reader.read_integer_frame(&mut buffer).unwrap(), 1);
+    assert_eq!(buffer[0], 4524_i32); 
+}
+
+#[test]
+fn test_locate_multichannel_read() {
+    let path = "tests/media/ff_pink.wav";
+
+    let mut w = WaveReader::open(path).expect("Failure opening test file");
+
+    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);
+    assert_eq!(reader.read_integer_frame(&mut buffer).unwrap(), 1);
+    assert_eq!(buffer[0], -258742_i32); // 0x800000 = 8388608 // 8129866 - 8388608
+    assert_eq!(buffer[1], 0x0D7EF9_i32);
+
+    assert_eq!(reader.locate(100).unwrap(), 100);
+    assert_eq!(reader.read_integer_frame(&mut buffer).unwrap(), 1);
+    assert_eq!(buffer[0], 0x109422_i32);
+    assert_eq!(buffer[1], -698901_i32); // 7689707 - 8388608
+}
+
+#[test]
+fn test_channels_stereo() {
+    let path = "tests/media/ff_pink.wav";
+
+    let mut w = WaveReader::open(path).expect("Failure opening test file");
+    let channels = w.channels().unwrap();
+
+    assert_eq!(channels.len(), 2);
+    assert_eq!(channels[0].index,0);
+    assert_eq!(channels[1].index,1);
+    assert_eq!(channels[0].speaker,ChannelMask::FrontLeft);
+    assert_eq!(channels[1].speaker,ChannelMask::FrontRight);
+}
+
+#[test]
+fn test_channels_mono_no_extended() {
+    let path = "tests/media/audacity_16bit.wav";
+
+    let mut w = WaveReader::open(path).expect("Failure opening test file");
+    let channels = w.channels().unwrap();
+
+    assert_eq!(channels.len(), 1);
+    assert_eq!(channels[0].index,0);
+    assert_eq!(channels[0].speaker,ChannelMask::FrontCenter);
+}
+
+#[test]
+fn test_channels_stereo_no_fmt_extended() {
+    let path = "tests/media/pt_24bit_stereo.wav";
+
+    let mut w = WaveReader::open(path).expect("Failure opening test file");
+    let channels = w.channels().unwrap();
+
+    assert_eq!(channels.len(), 2);
+    assert_eq!(channels[0].index,0);
+    assert_eq!(channels[1].index,1);
+    assert_eq!(channels[0].speaker,ChannelMask::FrontLeft);
+    assert_eq!(channels[1].speaker,ChannelMask::FrontRight);
+}