MPEG Implementation Guidelines

1
MPEG Implementation Guidelines

• Ken McCann

2
DVB Family of Standards

• The DVB family of standards use a common baseband
  specification for all transmission channels
• terrestrial
• cable
• satellite
• microwave

3
DVB Data Containers

• MPEG Transport Stream is used to provide DVB
  data containers which may contain a flexible
  mixture of
• video
• audio
• data services

4
Examples of DVB Data Containers
Channel bandwidth can be used in different ways
5
MPEG Implementation Guidelines

• First version of DVBs MPEG Implementation
  Guidelines, ETR 154, was published in 1995
• Initial emphasis was on SDTV
• Revised in 1997 to include HDTV
• SDTV and HDTV versions of a program may be
  simulcast
• 1999 revision is due to be published shortly and
  includes options for
• Active Format Description
• MPEG Audio Metadata
• Dolby AC-3 audio

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Main Features of Video

• Flexibility of the generic MPEG-2 video standard
  is maintained to the maximum extent practical
• Bitstreams and IRDs are classified as SDTV or
  HDTV
• Applications are classified as contribution or
  distribution

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Primary Classification of DVB IRDs and Bitstreams
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MPEG Profiles and Levels
422P_at_HL
MAX. BIT-RATE
300 Mbit/s
HP_at_HL
100 Mbit/s
HP_at_H14L
MP_at_HL
80 Mbit/s
60 Mbit/s
SSP_at_H14L
40 Mbit/s
MP_at_H14L
422P_at_ML
20 Mbit/s
HP_at_ML
HIGH
SNRP_at_ML
MP_at_ML
HIGH-1440
SP_at_ML
422
SNRP_at_LL
LEVELS
MAIN
HIGH
MP_at_LL
SPATIALLY SCALABLE
SNR SCALABLE
LOW
PROFILES
MAIN
SIMPLE
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DVB Guidelines for HDTV Distribution

• Utilises full flexibility of MPEG MP_at_HL
• Mandatory upper limits of
• 1152 lines per frame
• 1920 luminance samples per line
• 62,668,800 luminance samples per sec.
• Recommends use of
• 1080 active lines per frame
• 1920 luminance samples per line

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DVB Guidelines for HDTV Contribution

• HDTV contribution encoders produce bitstreams
  that comply with 422P_at_HL or MP_at_HL
• HDTV contribution IRDs are capable of decoding
  both 422P_at_HL or MP_at_HL bitstreams.
• Recommends use of
• 1080 active lines per frame
• 1920 luminance samples per line

11
Chromaticity

• SDTV needs compatibility with legacy displays, so
  default SDTV chromaticity in DVB is
• same as PAL for 25Hz
• same as NTSC for 30Hz
• HDTV has unified world-wide chromaticity and no
  legacy displays
• default is BT.709 for both 25Hz and 30Hz
• simulcast allows mixture of legacy chromaticity
  for SDTV and BT.709 for HDTV

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Main Audio Features of DVB IRDs

• 32 kHz, 44.1 kHz and 48 kHz sampling
• All IRDs support MPEG stereo Layer I and Layer II
  decoding
• IRDs may also optionally support
• MPEG-2 backwards compatible multi-channel
  decoding
• Dolby AC-3 decoding

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Main Audio Features of DVB Bitstreams

• In general, audio content is encoded using MPEG
  stereo Layer II, even if it is also encoded using
  Dolby AC-3
• In specific situations where all IRDs are
  required to support Dolby AC-3 then simulcast of
  MPEG stereo is not required

14
Conclusions

• DVB standards fully support HDTV by terrestrial,
  cable, satellite or microwave delivery
• Australia will lead the way to HDTV in the DVB
  World