Update __init__.py

Version 1.0

.travis.yml

@@ -1,11 +1,13 @@
+dist: xenial
 language: python
 python:
     - "3.6"
     - "3.5"
-    - "3.4"
 script:
     - "python3 setup.py test"
 before_install:
-    - sudo apt-get install -y ffmpeg 
+    - "sudo apt-get update"
+    - "sudo add-apt-repository universe"
+    - "sudo apt-get install -y ffmpeg" 
 install:
     - "pip3 install setuptools"

README.md

@@ -1,3 +1,4 @@
+[![Build Status](https://travis-ci.com/iluvcapra/wavinfo.svg?branch=master)](https://travis-ci.com/iluvcapra/wavinfo)
 [![Documentation Status](https://readthedocs.org/projects/wavinfo/badge/?version=latest)](https://wavinfo.readthedocs.io/en/latest/?badge=latest) ![](https://img.shields.io/github/license/iluvcapra/wavinfo.svg) ![](https://img.shields.io/pypi/pyversions/wavinfo.svg) [![](https://img.shields.io/pypi/v/wavinfo.svg)](https://pypi.org/project/wavinfo/) ![](https://img.shields.io/pypi/wheel/wavinfo.svg)
 
 
@@ -9,18 +10,19 @@ production metadata.
 
 `wavinfo` reads:
 
-* __Broadcast-WAVE__ metadata, compliant with [EBU Tech 3285v2 (2011)][ebu], including embedded program loudness and coding history, if extant.
-* [__iXML__ production recorder metadata][ixml], including project, scene, and take tags, recorder notes and file family information.
-* The __wav format__ is also parsed, so you can access the basic sample rate and channel count information.
+* __Broadcast-WAVE__ metadata, compliant with [EBU Tech 3285v2 (2011)][ebu], including embedded program 
+  loudness and coding history, if extant. This also includes the [SMPTE 330M __UMID__][smpte_330m2011] 
+  Unique Materials Identifier.
+* [__iXML__ production recorder metadata][ixml], including project, scene, and take tags, recorder notes 
+  and file family information.
+* Most of the common __RIFF INFO__ metadata fields.
+* The __wav format__ is also parsed, so you can access the basic sample rate and channel count 
+  information.
 
 In progress:
-* [SMPTE 330M __UMID__][smpte_330m2011] Unique Materials Identifier.
 * iXML `STEINBERG` sound library attributes.
-* Most of the common __RIFF INFO__ metadata fields.
 * Pro Tools __embedded regions__.
 
-This module is presently under construction and not sutiable for production at this time.
-
 [ebu]:https://tech.ebu.ch/docs/tech/tech3285.pdf
 [smpte_330m2011]:http://standards.smpte.org/content/978-1-61482-678-1/st-330-2011/SEC1.abstract
 [ixml]:http://www.ixml.info
@@ -29,10 +31,8 @@ This module is presently under construction and not sutiable for production at t
 
 ## Demonstration
 
-
 The entry point for wavinfo is the WavInfoReader class.
 
-
 ```python
 from wavinfo import WavInfoReader
 
@@ -43,10 +43,8 @@ info = WavInfoReader(path)
 
 ### Basic WAV Data
 
-
 The length of the file in frames (interleaved samples) and bytes is available, as is the contents of the format chunk.
 
-
 ```python
 (info.data.frame_count, info.data.byte_count)
 >>> (240239, 1441434)
@@ -54,9 +52,27 @@ The length of the file in frames (interleaved samples) and bytes is available, a
 >>> (48000, 2, 6, 24)
 ```
 
-## Broadcast WAV Extension
+### Broadcast WAV Extension
 
+A WAV file produced to Broadcast-WAV specifications will have the broadcast metadata extension,
+which includes a 256-character free text descrption, creating entity identifier (usually the 
+recording application or equipment), the date and time of recording and a time reference for 
+timecode synchronization.
 
+The `coding_history` is designed to contain a record of every conversion performed on the audio
+file.
+
+In this example (from a Sound Devices 702T) the bext metadata contains scene/take slating
+information in the `description`. Here also the `originator_ref` is a serial number conforming
+to EBU Rec 99.
+
+If the bext metadata conforms to EBU 3285 v1, it will contain the WAV's 32 or 64 byte SMPTE 
+330M UMID. The 32-byte version of the UMID is usually just a random number, while the 64-byte 
+UMID will also have information on the recording date and time, recording equipment and entity, 
+and geolocation data.
+
+If the bext metadata conforms to EBU 3285 v2, it will hold precomputed program loudness values
+as described by EBU Rec 128.
 
 ```python
 print(info.bext.description)
@@ -91,8 +107,17 @@ print(info.bext.coding_history)
 
 
 
-## iXML Production Recorder Metadata
+### iXML Production Recorder Metadata
 
+iXML allows an XML document to be embedded in a WAV file.
+
+The iXML website recommends a schema for recorder information but 
+there is no official DTD and vendors mostly do their own thing, apart from 
+hitting a few key xpaths. iXML is used by most location/production recorders 
+to save slating information, timecode and sync points in a reliable way.
+
+iXML is also used to link "families" of WAV files together, so WAV files
+recorded simultaneously or contiguously can be related by a receiving client.
 
 ```python
 print("iXML Project:", info.ixml.project)
@@ -109,6 +134,22 @@ print("iXML File Family UID:", info.ixml.family_uid)
     iXML Tape: 18Y12M31
     iXML File Family Name: None
     iXML File Family UID: USSDVGR1112089007124001008206300
-    
+
+
+### INFO Metadata
+
+INFO Metadata is a standard method for saving tagged text data in a WAV or AVI
+file. INFO fields are often read by the file explorer and host OS, and used in 
+music library software.
+
+```python
+bullet_path = '../tests/test_files/BULLET Impact Plastic LCD TV Screen Shatter Debris 2x.wav'
+
+bullet = WavInfoReader(bullet_path)
+```
+
+    print("INFO Artist:",    bullet.info.artist)
+    print("INFO Copyright:", bullet.info.copyright)
+    print("INFO Comment:",   bullet.info.comment)
 
 

examples/demo.ipynb

@@ -11,13 +11,13 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 2,
+   "execution_count": 1,
    "metadata": {},
    "outputs": [],
    "source": [
     "from wavinfo import WavInfoReader\n",
     "\n",
-    "path = '../tests/test_files/A101_1.WAV'\n",
+    "path = '../tests/test_files/sounddevices/A101_1.WAV'\n",
     "\n",
     "info = WavInfoReader(path)"
    ]
@@ -33,7 +33,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 4,
+   "execution_count": 2,
    "metadata": {},
    "outputs": [
     {
@@ -42,7 +42,7 @@
        "(240239, 1441434)"
       ]
      },
-     "execution_count": 4,
+     "execution_count": 2,
      "metadata": {},
      "output_type": "execute_result"
     }
@@ -53,7 +53,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 7,
+   "execution_count": 3,
    "metadata": {},
    "outputs": [
     {
@@ -62,7 +62,7 @@
        "(48000, 2, 6, 24)"
       ]
      },
-     "execution_count": 7,
+     "execution_count": 3,
      "metadata": {},
      "output_type": "execute_result"
     }
@@ -80,7 +80,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 13,
+   "execution_count": 4,
    "metadata": {},
    "outputs": [
     {
@@ -130,7 +130,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 14,
+   "execution_count": 5,
    "metadata": {},
    "outputs": [
     {
@@ -142,9 +142,7 @@
       "iXML Take: 1\n",
       "iXML Tape: 18Y12M31\n",
       "iXML File Family Name: None\n",
-      "iXML File Family UID: USSDVGR1112089007124001008206300\n",
-      "A=PCM,F=48000,W=24,M=stereo,R=48000,T=2 Ch\r\n",
-      "\n"
+      "iXML File Family UID: USSDVGR1112089007124001008206300\n"
      ]
     }
    ],
@@ -157,6 +155,13 @@
     "print(\"iXML File Family UID:\", info.ixml.family_uid)"
    ]
   },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": []
+  },
   {
    "cell_type": "code",
    "execution_count": null,

examples/wavinfo.ipynb

@@ -96,7 +96,7 @@
      "name": "stdout",
      "output_type": "stream",
      "text": [
-      "WavBextFormat(description='dUBITS=12311804\\r\\ndSCENE=A101\\r\\ndTAKE=4\\r\\ndTAPE=18Y12M31\\r\\ndFRAMERATE=23.976ND\\r\\ndSPEED=023.976-NDF\\r\\ndTRK1=MKH516 A\\r\\ndTRK2=Boom\\r\\n', originator='Sound Dev: 702T S#GR1112089007', originator_ref='aa4CKtcd13Vk', originator_date='2018-12-31', originator_time='12:40:07', time_reference=2191709524, version=0, umid=None, loudness_value=0.0, loudness_range=0.0, max_true_peak=0.0, max_momentary_loudness=0.0, max_shortterm_loudness=0.0, coding_history='A=PCM,F=48000,W=24,M=stereo,R=48000,T=2 Ch\\r\\n')\n"
+      "<wavinfo.wave_bext_reader.WavBextReader object at 0x10d5f8ac8>\n"
      ]
     }
    ],
@@ -106,7 +106,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 8,
+   "execution_count": 7,
    "metadata": {},
    "outputs": [
     {
@@ -126,6 +126,63 @@
     "print(len(regn_bin))"
    ]
   },
+  {
+   "cell_type": "code",
+   "execution_count": 8,
+   "metadata": {},
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "{   'artist': 'Frank Bry',\n",
+      "    'comment': 'BULLET Impact Plastic LCD TV Screen Shatter Debris 2x',\n",
+      "    'copyright': '2018 Creative Sound Design, LLC (The Recordist Christmas '\n",
+      "                 '2018) www.therecordist.com',\n",
+      "    'created_date': '2018-11-15',\n",
+      "    'engineer': None,\n",
+      "    'genre': 'Bullets',\n",
+      "    'keywords': None,\n",
+      "    'product': 'The Recordist Christmas 2018',\n",
+      "    'software': 'Soundminer',\n",
+      "    'source': None,\n",
+      "    'tape': None,\n",
+      "    'title': None}\n",
+      "{   'coding_history': '',\n",
+      "    'description': 'BULLET Impact Plastic LCD TV Screen Shatter Debris 2x',\n",
+      "    'loudness_range': None,\n",
+      "    'loudness_value': None,\n",
+      "    'max_momentary_loudness': None,\n",
+      "    'max_shortterm_loudness': None,\n",
+      "    'max_true_peak': None,\n",
+      "    'originator': 'TheRecordist',\n",
+      "    'originator_date': '2018-12-20',\n",
+      "    'originator_ref': 'aaiAKt3fCGTk',\n",
+      "    'originator_time': '12:15:37',\n",
+      "    'time_reference': 57882,\n",
+      "    'version': 0}\n"
+     ]
+    }
+   ],
+   "source": [
+    "path = '../tests/test_files/BULLET Impact Plastic LCD TV Screen Shatter Debris 2x.wav'\n",
+    "\n",
+    "info = wavinfo.WavInfoReader(path)\n",
+    "\n",
+    "with open(path,'rb') as f:\n",
+    "    chunk_tree = wavinfo.wave_parser.parse_chunk(f)\n",
+    "    \n",
+    "pp.pprint(info.info.to_dict())\n",
+    "pp.pprint(info.bext.to_dict())"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": []
+  },
   {
    "cell_type": "code",
    "execution_count": null,

setup.py

@@ -4,18 +4,17 @@ with open("README.md", "r") as fh:
     long_description = fh.read()
 
 setup(name='wavinfo',
-      version='0.2',
+      version='1.0',
       author='Jamie Hardt',
       author_email='jamiehardt@me.com',
       description='WAVE sound file metadata parser.',
       long_description_content_type="text/markdown",
       long_description=long_description,
       url='https://github.com/iluvcapra/wavinfo',
-      classifiers=['Development Status :: 4 - Beta',
+      classifiers=['Development Status :: 5 - Production/Stable',
           'License :: OSI Approved :: MIT License',
           'Topic :: Multimedia',
 	  'Topic :: Multimedia :: Sound/Audio',
-          "Programming Language :: Python :: 3.4",
           "Programming Language :: Python :: 3.5",
           "Programming Language :: Python :: 3.6"],
       packages=['wavinfo'])

tests/test_wave_parsing.py

@@ -7,7 +7,7 @@ from unittest import TestCase
 
 import wavinfo
 
-FFPROBE='/usr/local/bin/ffprobe'
+FFPROBE='ffprobe'
 
 
 def ffprobe(path):
@@ -17,7 +17,8 @@ def ffprobe(path):
     process = subprocess.run(arguments, stdin=None, stdout=PIPE, stderr=PIPE)
 
     if process.returncode == 0:
-        return json.loads(process.stdout)
+        output_str = process.stdout.decode('utf-8')
+        return json.loads(output_str)
     else:
         return None
 
@@ -74,8 +75,8 @@ class TestWaveInfo(TestCase):
                 self.assertEqual( info.bext.originator_ref, '')
 
             # these don't always reflect the bext info
-            #self.assertEqual( info.bext.originator_date, ffprobe_info['format']['tags']['date']  )
-            #self.assertEqual( info.bext.originator_time, ffprobe_info['format']['tags']['creation_time']  )
+            # self.assertEqual( info.bext.originator_date, ffprobe_info['format']['tags']['date']  )
+            # self.assertEqual( info.bext.originator_time, ffprobe_info['format']['tags']['creation_time']  )
             self.assertEqual( info.bext.time_reference, int(ffprobe_info['format']['tags']['time_reference'])  )
 
             if 'coding_history' in ffprobe_info['format']['tags']:

wavinfo/__init__.py

@@ -1 +1,4 @@
 from .wave_reader import WavInfoReader
+
+__version__ = 1.0
+__author__ = 'Jamie Hardt'

wavinfo/riff_parser.py

@@ -3,30 +3,40 @@ import struct
 
 from collections import namedtuple
 
-ListChunkDescriptor = namedtuple('ListChunkDescriptor' , 'signature children')
+class ListChunkDescriptor(namedtuple('ListChunkDescriptor' , 'signature children')):
+
+    def find(chunk_path):
+        if len(chunk_path) > 1:
+            for chunk in self.children:
+                if type(chunk) is ListChunkDescriptor and \
+                        chunk.signature is chunk_path[0]:
+                            return chunk.find(chunk_path[1:])
+        else:
+            for chunk in self.children:
+                if type(chunk) is ChunkDescriptor and \
+                        chunk.ident is chunk_path[0]:
+                            return chunk
+
 
 class ChunkDescriptor(namedtuple('ChunkDescriptor', 'ident start length') ):
     def read_data(self, from_stream):
         from_stream.seek(self.start)
         return from_stream.read(self.length)
 
-
 def parse_list_chunk(stream, length):
-    children = []
-
     start = stream.tell()
 
     signature = stream.read(4)
 
+    children = []
     while (stream.tell() - start) < length:
         children.append(parse_chunk(stream))
 
     return ListChunkDescriptor(signature=signature, children=children)
 
-
 def parse_chunk(stream):
     ident = stream.read(4)
-    if len(ident) != 4: 
+    if len(ident) != 4:
         return
 
     sizeb = stream.read(4)
@@ -47,11 +57,3 @@ def parse_chunk(stream):
 
 
 
-
-
-
-        
-
-
-
-

wavinfo/wave_bext_reader.py

@@ -0,0 +1,86 @@
+import struct
+
+class WavBextReader:
+    def __init__(self,bext_data,encoding):
+        # description[256]
+
+        # originator[32]
+        # originatorref[32]
+        # originatordate[10]   "YYYY:MM:DD"
+        # originatortime[8]    "HH:MM:SS"
+        # lowtimeref U32
+        # hightimeref U32
+        # version U16
+        #
+        # V1 field
+        # umid[64]
+        #
+        # V2 fields
+        # loudnessvalue S16    (in LUFS*100)
+        # loudnessrange S16    (in LUFS*100)
+        # maxtruepeak   S16    (in dbTB*100)
+        # maxmomentaryloudness S16 (LUFS*100)
+        # maxshorttermloudness S16 (LUFS*100)
+        #
+        # reserved[180]
+        # codinghistory []
+        if bext_data is None:
+            return None
+
+        packstring = "<256s"+ "32s" + "32s" + "10s" + "8s" + "QH" + "64s" + "hhhhh" + "180s"
+
+        rest_starts = struct.calcsize(packstring)
+        unpacked = struct.unpack(packstring, bext_data[:rest_starts])
+
+        def sanatize_bytes(bytes):
+            first_null = next( (index for index, byte in enumerate(bytes) if byte == 0 ), None )
+            if first_null is not None:
+                trimmed = bytes[:first_null]
+            else:
+                trimmed = bytes
+
+            decoded = trimmed.decode(encoding)
+            return decoded
+
+        self.description     = sanatize_bytes(unpacked[0])
+        self.originator      = sanatize_bytes(unpacked[1])
+        self.originator_ref  = sanatize_bytes(unpacked[2])
+        self.originator_date = sanatize_bytes(unpacked[3])
+        self.originator_time = sanatize_bytes(unpacked[4])
+        self.time_reference  = unpacked[5]
+        self.version         = unpacked[6]
+        self.umid            = None
+        self.loudness_value          = None
+        self.loudness_range          = None
+        self.max_true_peak           = None
+        self.max_momentary_loudness  = None
+        self.max_shortterm_loudness  = None
+        self.coding_history  = sanatize_bytes(bext_data[rest_starts:])
+
+        if self.version > 0:
+            self.umid = unpacked[7]
+
+        if self.version > 1:
+            self.loudness_value          = unpacked[8] / 100.0
+            self.loudness_range          = unpacked[9] / 100.0
+            self.max_true_peak           = unpacked[10] / 100.0
+            self.max_momentary_loudness  = unpacked[11] / 100.0
+            self.max_shortterm_loudness  = unpacked[12] / 100.0
+
+
+    def to_dict(self):
+        return {'description':      self.description,
+                'originator':       self.originator,
+                'originator_ref':   self.originator_ref,
+                'originator_date':  self.originator_date,
+                'originator_time':  self.originator_time,
+                'time_reference':   self.time_reference,
+                'version':          self.version,
+                'coding_history':   self.coding_history,
+                'loudness_value':   self.loudness_value,
+                'loudness_range':   self.loudness_range,
+                'max_true_peak':    self.max_true_peak,
+                'max_momentary_loudness':   self.max_momentary_loudness,
+                'max_shortterm_loudness':   self.max_shortterm_loudness
+                }
+

wavinfo/wave_info_reader.py

@@ -0,0 +1,64 @@
+
+from .riff_parser import parse_chunk, ListChunkDescriptor
+
+class WavInfoChunkReader:
+
+    def __init__(self, f, encoding):
+        self.encoding = encoding
+
+        f.seek(0)
+        parsed_chunks = parse_chunk(f)
+
+        list_chunks = [chunk for chunk in parsed_chunks.children \
+                if type(chunk) is ListChunkDescriptor]
+
+        self.info_chunk  = next((chunk for chunk in list_chunks \
+                if chunk.signature == b'INFO'), None)
+
+        self.copyright      = self._get_field(f,b'ICOP')
+        self.product        = self._get_field(f,b'IPRD')
+        self.genre          = self._get_field(f,b'IGNR')
+        self.artist         = self._get_field(f,b'IART')
+        self.comment        = self._get_field(f,b'ICMT')
+        self.software       = self._get_field(f,b'ISFT')
+        self.created_date   = self._get_field(f,b'ICRD')
+        self.engineer       = self._get_field(f,b'IENG')
+        self.keywords       = self._get_field(f,b'IKEY')
+        self.title          = self._get_field(f,b'INAM')
+        self.source         = self._get_field(f,b'ISRC')
+        self.tape           = self._get_field(f,b'TAPE')
+
+
+    def _get_field(self, f, field_ident):
+
+        search = next( ( (chunk.start, chunk.length) for chunk in self.info_chunk.children \
+                if chunk.ident == field_ident ), None)
+
+        if search is not None:
+            f.seek(search[0])
+            data = f.read(search[1])
+            return data.decode(self.encoding).rstrip('\0')
+        else:
+            return None
+
+
+    def to_dict(self):
+        return {'copyright':    self.copyright,
+                'product':  self.product,
+                'genre':    self.genre,
+                'artist':   self.artist,
+                'comment':  self.comment,
+                'software': self.software,
+                'created_date': self.created_date,
+                'engineer': self.engineer,
+                'keywords': self.keywords,
+                'title':    self.title,
+                'source':   self.source,
+                'tape':     self.tape
+                }
+
+
+
+
+
+

wavinfo/wave_ixml_reader.py

@@ -1,4 +1,5 @@
 import xml.etree.ElementTree as ET
+import io
 
 class WavIXMLFormat:
     """
@@ -6,17 +7,18 @@ class WavIXMLFormat:
     """
     def __init__(self, xml):
         self.source = xml
-        self.parsed = ET.fromstring(xml)
+        xmlBytes = io.BytesIO(xml)
+        self.parsed = ET.parse(xmlBytes)
 
     def _get_text_value(self, xpath):
         e = self.parsed.find("./" + xpath)
         if e is not None:
             return e.text
-    
+
     @property
     def project(self):
         return self._get_text_value("PROJECT")
-        
+
     @property
     def scene(self):
         return self._get_text_value("SCENE")

wavinfo/wave_reader.py

@@ -2,8 +2,10 @@ import struct
 
 from collections import namedtuple
 
-from .wave_parser import parse_chunk, ChunkDescriptor, ListChunkDescriptor
+from .riff_parser import parse_chunk, ChunkDescriptor, ListChunkDescriptor
 from .wave_ixml_reader import WavIXMLFormat
+from .wave_bext_reader import WavBextReader
+from .wave_info_reader import WavInfoChunkReader
 
 WavDataDescriptor = namedtuple('WavDataDescriptor','byte_count frame_count')
 
@@ -22,7 +24,20 @@ class WavInfoReader():
 
     """
 
-    def __init__(self, path):
+    def __init__(self, path, info_encoding='latin_1', bext_encoding='ascii'):
+        """
+        Parse a WAV audio file for metadata.
+
+        * `path`: A filesystem path to the wav file you wish to probe.
+
+        * `info_encoding`: The text encoding of the INFO metadata fields.
+          `latin_1`/Win CP1252 has always been a pretty good guess for this.
+
+        * `bext_encoding`: The text encoding to use when decoding the string
+          fields of the Broadcast-WAV extension. Per EBU 3285 this is ASCII
+          but this parameter is available to you if you encounter a werido.
+
+        """
         with open(path, 'rb') as f:
             chunks = parse_chunk(f)
 
@@ -30,9 +45,9 @@ class WavInfoReader():
             f.seek(0)
 
             self.fmt    = self._get_format(f)
-            self.bext   = self._get_bext(f)
+            self.bext   = self._get_bext(f, encoding=bext_encoding)
             self.ixml   = self._get_ixml(f)
-
+            self.info   = self._get_info(f, encoding=info_encoding)
             self.data   = self._describe_data(f)
 
     def _find_chunk_data(self, ident, from_stream, default_none=False):
@@ -57,7 +72,6 @@ class WavInfoReader():
                 frame_count= int(data_chunk.length / self.fmt.block_align))
 
 
-
     def _get_format(self,f):
         fmt_data = self._find_chunk_data(b'fmt ',f)
 
@@ -78,97 +92,33 @@ class WavInfoReader():
         #0x0006	WAVE_FORMAT_ALAW	8-bit ITU-T G.711 A-law
         #0x0007	WAVE_FORMAT_MULAW	8-bit ITU-T G.711 µ-law
         #0xFFFE	WAVE_FORMAT_EXTENSIBLE	Determined by SubFormat
-        if unpacked[0] == 0x0001:
-            return WavInfoFormat(audio_format = unpacked[0],
-                    channel_count = unpacked[1],
-                    sample_rate   = unpacked[2],
-                    byte_rate     = unpacked[3],
-                    block_align   = unpacked[4],
+
+        #https://sno.phy.queensu.ca/~phil/exiftool/TagNames/RIFF.html
+        return WavInfoFormat(audio_format = unpacked[0],
+                    channel_count   = unpacked[1],
+                    sample_rate     = unpacked[2],
+                    byte_rate       = unpacked[3],
+                    block_align     = unpacked[4],
                     bits_per_sample = unpacked[5]
                     )
 
-    def _get_bext(self,f,encoding='ascii'):
+    def _get_info(self, f, encoding):
+        finder = (chunk.signature for chunk in self.main_list \
+                if type(chunk) is ListChunkDescriptor)
 
+        if b'INFO' in finder:
+            return WavInfoChunkReader(f, encoding)
+
+    def _get_bext(self, f, encoding):
         bext_data = self._find_chunk_data(b'bext',f,default_none=True)
-
-        # description[256]
-        # originator[32]
-        # originatorref[32]
-        # originatordate[10]   "YYYY:MM:DD"
-        # originatortime[8]    "HH:MM:SS"
-        # lowtimeref U32
-        # hightimeref U32
-        # version U16
-        # umid[64]
-        #
-        # EBU 3285 fields
-        # loudnessvalue S16    (in LUFS*100)
-        # loudnessrange S16    (in LUFS*100)
-        # maxtruepeak   S16    (in dbTB*100)
-        # maxmomentaryloudness S16 (LUFS*100)
-        # maxshorttermloudness S16 (LUFS*100)
-        # reserved[180]
-        # codinghistory []
-        if bext_data is None:
-            return None
-
-        packstring = "<256s"+ "32s" + "32s" + "10s" + "8s" + "QH" + "64s" + "hhhhh" + "180s"
-
-        rest_starts = struct.calcsize(packstring)
-        unpacked = struct.unpack(packstring, bext_data[:rest_starts])
-
-        def sanatize_bytes(bytes):
-            first_null = next( (index for index, byte in enumerate(bytes) if byte == 0 ), None )
-            if first_null is not None:
-                trimmed = bytes[:first_null]
-            else:
-                trimmed = bytes
-
-            decoded = trimmed.decode(encoding)
-            return decoded
-
-        bext_version = unpacked[6]
-        if bext_version > 0:
-            umid = unpacked[6]
-        else:
-            umid = None
-
-        if bext_version > 1:
-             loudness_value         = unpacked[8] / 100.0,
-             loudness_range         = unpacked[9] / 100.0
-             max_true_peak          = unpacked[10] / 100.0
-             max_momentary_loudness = unpacked[11] / 100.0
-             max_shortterm_loudness = unpacked[12] / 100.0
-        else:
-            loudness_value          = None
-            loudness_range          = None
-            max_true_peak           = None
-            max_momentary_loudness  = None
-            max_shortterm_loudness  = None
-
-        return WavBextFormat(description=sanatize_bytes(unpacked[0]),
-                originator      = sanatize_bytes(unpacked[1]),
-                originator_ref  = sanatize_bytes(unpacked[2]),
-                originator_date = sanatize_bytes(unpacked[3]),
-                originator_time = sanatize_bytes(unpacked[4]),
-                time_reference  = unpacked[5],
-                version         = unpacked[6],
-                umid            = umid,
-                loudness_value  = loudness_value,
-                loudness_range  = loudness_range,
-                max_true_peak   = max_true_peak,
-                max_momentary_loudness = max_momentary_loudness,
-                max_shortterm_loudness = max_shortterm_loudness,
-                coding_history = sanatize_bytes(bext_data[rest_starts:])
-                )
+        return WavBextReader(bext_data, encoding)
 
     def _get_ixml(self,f):
-
         ixml_data = self._find_chunk_data(b'iXML',f,default_none=True)
         if ixml_data is None:
             return None
 
-        ixml_string = ixml_data.decode('utf-8')
+        ixml_string = ixml_data
         return WavIXMLFormat(ixml_string)