Audio problems as multimedia quality

1
Audio problems as multimedia quality

• Junichi Yoshio
• at AGS meeting
• in Helsinki
• on May 10, 2006

2
Importance of multimedia quality

• Audio, video and multimedia have come to be all
  digital. TC100 specifies IEC standards for
  these.
• High quality is expected. In each equipment, it
  may be guaranteed.
• However, in a system configuration of audio,
  video and multimedia, a problem of total quality
  may exist.

3
Problems in home use
AV Server
DVD
DTV
AV Amp
Lip-sync is funny?
??
Colour is not natural.
Voice is not clear.
Audio level is not good.
Unbalance surround sound!
Expensive system, but sometimes quality is not
good!
4
Problems of multimedia quality

• For Audio and video
• AV Synchronization or lip-sync? In progress,
  assigned as IEC 62312
• For Audio (with video)
• Loudness control
• Surround quality
• For Video
• (Problem may exist)

5
Loudness and surround

• Loudness problems
• Uncleanness of narration or announce in
  background sound
• Level unbalance of broadcast programs within one
  channel or between channels, also unbalance
  between sources
• Surround problems
• Critical balance of surround sound
• No effective methods for surround balance

6
Solutions

• Loudness
• Control method
• e.g. Separate loudness data and contents, these
  are stored and transmitted. User or equipment can
  adjust loudness with loudness data.
• Measurement method
• e.g. Loudness mater
• Surround
• Control method
• e.g. Expand above loudness data for all audio
  channels, then control
• Measurement method

7
Proposal and schedule

• Related organizations in Japan started to study
  loudness, this includes
• Loudness control procedure
• Metadata structure of loudness to LPCM data
• Transmission method of loudness data
• Multi-channel loudness control procedure
• ? These will be proposed to IEC

8

• At the next AGS, a specific proposal will be
  submitted
• Any comments and ideas regarding this issue are
  welcome