wavinfo 1.0

WAVE sound file metadata parser.

wavinfo

The wavinfo package allows you to probe WAVE files and extract extended metadata, with an emphasis on production metadata.

wavinfo reads:

• Broadcast-WAVE metadata, compliant with EBU Tech 3285v2 (2011), including embedded program loudness and coding history, if extant. This also includes the SMPTE 330M UMID Unique Materials Identifier.
• iXML production recorder metadata, 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:

• iXML STEINBERG sound library attributes.
• Pro Tools embedded regions.

Demonstration

The entry point for wavinfo is the WavInfoReader class.

from wavinfo import WavInfoReader

path = '../tests/test_files/A101_1.WAV'

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.

(info.data.frame_count, info.data.byte_count)
>>> (240239, 1441434)
(info.fmt.sample_rate, info.fmt.channel_count, info.fmt.block_align, info.fmt.bits_per_sample)
>>> (48000, 2, 6, 24)

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.

print(info.bext.description)
print("----------")
print("Originator:", info.bext.originator)
print("Originator Ref:", info.bext.originator_ref)
print("Originator Date:", info.bext.originator_date)
print("Originator Time:", info.bext.originator_time)
print("Time Reference:", info.bext.time_reference)
print(info.bext.coding_history)

sSPEED=023.976-ND
sTAKE=1
sUBITS=$12311801
sSWVER=2.67
sPROJECT=BMH
sSCENE=A101
sFILENAME=A101_1.WAV
sTAPE=18Y12M31
sTRK1=MKH516 A
sTRK2=Boom
sNOTE=

----------
Originator: Sound Dev: 702T S#GR1112089007
Originator Ref: USSDVGR1112089007124001008206301
Originator Date: 2018-12-31
Originator Time: 12:40:00
Time Reference: 2190940753
A=PCM,F=48000,W=24,M=stereo,R=48000,T=2 Ch

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.

print("iXML Project:", info.ixml.project)
print("iXML Scene:", info.ixml.scene)
print("iXML Take:", info.ixml.take)
print("iXML Tape:", info.ixml.tape)
print("iXML File Family Name:", info.ixml.family_name)
print("iXML File Family UID:", info.ixml.family_uid)

iXML Project: BMH
iXML Scene: A101
iXML Take: 1
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.

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)