BWF format

1
BWF format

• By Junichi Yoshio
• At TC100/AGSTC100S
• On May 16, 2007

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What is BWF?
3
BWF

• BWF stands Broadcast Wave Format
• It is specified by EBU, an audio file format
  based on WAVE format of Microsoft
• Base Specification
• Tech 3285 Ver.0, 1997The specification of the
  Broadcast Wave Format for PCM audio data (now
  referred to as Version 0) was published in 1997.
• Tech 3285 Ver.1, 2001Version 1 differs from
  Version 0 only in that 64 of the 254 reserved
  bytes in Version 0 are used to contain an SMPTE
  UMID and the field is changed.

4
BWF starts in professional application

• Japan
• Contents in radio broadcasting studio and CM
  materials are dealt in BWF with MO media.
• BWF recorder is used for live recording.
• DVD Forum specified DVD-BWF format.
• Europe
• In particular, German broadcasting studio uses
  BWF for audio recordings.
• USA
• Hollywood movie studio uses BWF recorder for
  audio recording of movie shooting.
• Recorder makers
• In Japan, FOSTEX, Otari, Kowa and many
  manufactures makes BWF recorder.
• All DAW support BWF format.

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WAVE fromat

• WAVE stands,
• Waveform Audio Format
• It is a audio part of RIFF format.
• Resource Interchange File Format (RIFF) was made
  by IBM Corporation and Microsoft Corporation for
  multimedia in 1991.
• In 1995, attachment was added.
• Until about 2000(?) the maintenance of audio
  codec code was involved in SKD(?) but the current
  situation is not clear.

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WAVE structure
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(No Transcript)
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BWF format

• It added extra chunks to WAVE for broadcasting
  use.
• Originally EBU made this for broadcastin
• EBU European Broadcasting Union
• In Japan, JPPA extend BWF as BWF-J for Japanese
  use
• JPPA Japan Post-Production Assosiation
• AES has a plan to propose their BWF format to IEC
• AES Audio Engineering Society

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Definition of Tech 3285
Source EBU Tech 3285
10
WAVE definition
Source EBU Tech 3285
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bext chunk definition
Source EBU Tech 3285
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BWF-J structure
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Standardizing organizations of BWF
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Organizations and works

• EBU
• Extension of 64 bit address, multi-channel
  extension, Tech 3306 specifies these.
• JPPA
• BWF-J Level1 Edition 2 was published.
• AES
• AES31-2 was published, BWF file transfer and
  exchange.
• AES31-3 will be published, BWF simple project
  interchange.
• ITU-R
• ITU-R BR.1352-2
• JEITA
• Making JEITA guideline with AES31-2?BWF-J.

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Problems
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BWF-J and BWF

• BWF-J uses 2 byte character (Japanese) in bext
  chunk, but the original BWF specification uses
  only ASCII.
• 2 byte character will cause malfunction in ASCII
  machine, it is not allowed in the original BWF
  machine.
• It is agreed in AES that if Japan or other 2 byte
  language country use 2 byte in BWF, the new chunk
  should be used.
• Currently, ABE proposed the new ubxtchunk usage
  to ITU-R.

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Maintenance of RIFF format

• Microsoft seems to abandon the maintenance of
  RIFF format.
• Windows shifts to the new format such as
  MediaPlayer10, RIFF is no more necessary.
• Many concerned people asked Microsoft about the
  maintenance of RIFF, but they could not get any
  sufficient answer, because it is ambiguous who is
  the person in charge.
• There is a need for the new audio format to BWF
  such as MPEG-4 ALS and other, the maintenance of
  RIFF is indispensable.
• Request to AGS IEC/TC100 ask Microsoft about
  RIFF maintenance.

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BWF is not an international standard

• BWF is coming to use by many audio applications,
  however it is still the specification in EBU. The
  problem of compatibility and the relation between
  derived specification is not clarified.
• AES has a plan to propose AES31-2 to IEC.
• JEITA follows AES activity.