MPEG21 bitstream syntax description for scalable video codecs

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MPEG-21 bitstream syntax description for scalable
video codecs

• Chris Poppe
• Sam Lerouge
• Wesley De Neve
• Rik Van de Walle
• Davy De Schrijver

Sravanthi Kolloju 2444637
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Introduction

• Cell phones and PDA s are capable of running
  video files
• But both of them have dissimilar characteristics
  in terms of memory processing power and
  bandwidth.
• So for every device there is need of using
  different bitstream for video broadcast.

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Main Idea

• Multichannel Publication Environment.
• MPEG-21 Bitstream Syntax Description language
  (BSDL).
• Creates high-level XML description of the
  structure of the bitstream.

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Bitstream Syntax description language(BSDL)

• MPEG-21 is build around one central concept
  called
• Digital Item (DI)
• BSDL belongs Digital Item Adaptation (DIA)
• DIA consists of several tools like

• Bitstream Syntax Description (BSD)
• Bitstream Schema

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Related Work

• Another language used for multimedia
  representation is FLAVOR (Formal Language for
  Audio-Visual Object Representation.
• FLAVOR code describes structure of a bit
  stream and this code can in turn be translated
  into C or Java.
• FLAVOR which supports XML features is known as
  XFLAVOR.
• MPEG video mark up language is a description
  language that has the same functionality of
  XFLAVOR .

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Scalable video coding

• There are different types of video coding
  used for different applications
• Fully scalable video coding MC-EZBC This coding
  consists of all the information of original video
  stream.
• Temporal scalability Is used to achieve a video
• with lower frame rate.
• Spatial scalability Is used to achieve a video
  with lower resolution.
• SNR scalability Is used to achieve lower
  bitrate

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Fully Scalable Video Coding

• In this picture decomposition is done by
  dividing in to
• low frequency frames and high frequency frames.

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Structure of a MC-EZBC bitstream

• The header consists of general information about
  the bitstream.
• The general bitstream consists of header and
  payload.
• Payload contains sizes of GOPs following the
  actual GOPs structure.

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Bitstream to XML

• Based on the bitstream BS Schema is generated.
• The corresponding XML code is created by making
  use of
• BintoBsd and BSSchema.

• lt?xml version1.0gt
• ltBitstream namespacegt
• ltheadergt
• ltNUMBER_GOPsgt
• ltGOPSIZEgt
• ltGOPgt
• ltGOPgt
• .
• .
• lt/Bitstreamgt

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Adaptation of Temporal Scalability

• By using temporal scalability a video with a
  lower frame
• rate is obtained.
• The lower frame rate is obtained by eliminating
  eight
• high frequency frames in fully scalable video
  coding.
• H frames can be eliminated by removing the
  highest
• content tag in each GOP tag.

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Spatial Scalability

• A lower resolution video frame is obtained by
  using Spatial Scalability.
• This is obtained by eliminating highest subbands
  of each substream.

SNR Scalability

• A bitstream with a lower bit rate is generated
  with SNR
• Scalability.
• The encoding process in SNR scalability
  delivers a
• compressed bit stream and also a file
  containing
• information about the bit planes of different
  subbands.

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Conclusion

• Coding format-independent adaptation frame work
  for binary media resources is discussed.
• To evaluate the performance of the BSDL
  framework, bitstreams encoded by two different
  coding schemata were discussed.
• Various scalability methods are achieved by
  adaptive XML.

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References

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  Format-Agnostic
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  Proceedings
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• Thank You