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Project Presentation
Reminder
• 13th November 1 – 5pm
• Read your emails/Visit web sites for more information (later)
Reminder
• Please check your project title• Please check your grades
Reviews Categories
• 4 categories• No submission• Did not demonstrate understanding• Understand and summarize• Understand, think and summarize
What I Hope You Have Learned
• How to read papers?• How to evaluate papers?• Think critically about what you
read
Recent Papers
from conferences
Sessions
•Session 1: Movies and Music•Session 2: Peer-to-Peer
Streaming•Session 3: Power-Friendly
Movies and Music
Session 1
Characterizing DVD
Wu-Chi Feng et. al.Packet Video 2003
Motivations
• Lots of DVD videos available• How are they encoded?• What is the implications to our
research?
DVD data
•107 video streams•140 hours•80 DVDs
Bit-rates
• Maximum DVD bit rates 10 Mbps• Found on DVD 3.3 – 7.8 Mbps
• VBR• Quantization values change over time
(only Spy Kids is CBR)
GOPs and Sequences
• Each GOP was encoded into a different sequence
• GOP sizes: around 12 frames
NUS.SOC.CS5248OOI Wei Tsang
Sequence
sequence header:• width• height• frame rate• bit rate• :
NUS.SOC.CS5248OOI Wei Tsang
GOP: Group of Picture
gop header:• time• :
NUS.SOC.CS5248OOI Wei Tsang
Picture
pic header:• number• type (I,P,B)• :
Frame Patterns
• Most videos have varying• Number of frames within a GOP • Frame patterns
(ID4 has 134 unique GOP
patterns)
Frame Pattern
• Scene Change Detection used extensively
• IPPPPPPP quite common!
Implication to Research
• Cannot assume fixed frame pattern
• Cannot always drop B frames
Network Musical Performances
UC BerkeleyNOSSDAV 2001
Goal
• Show that networked musical performances (NMP) can be done