Streaming Video over the Internet: Approaches and Directions

1
Streaming Video over the Internet Approaches and
Directions

• Dapeng Wu, Yiwei Thomas Hou et al.

Presented by Abhishek Gupta agupta_at_cs.ubc.ca
2
Introduction

• Issues in Video Streaming.
• Transmission of Real Time Video typically has
  bandwidth and delay requirements.
• Current Internet does not offer any QoS
  guarantees to streaming video.
• For multicast it is difficult to achieve both
  efficiency and flexibility.

3
Overview

• Key areas in streaming video.
• Video Compression Scalable and Nonscalable
  coding.
• Application-layer QoS control.
• Continuous media distribution services.
• Streaming servers.
• Media synchronization mechanisms.
• Protocols for streaming media.

4
Architecture For Streaming Video
5
Video Compression

• Nonscalable Video Coding.

Nonscalable video Encoder
Nonscalable video Encoder
6
Video Compression(contd.)

• Scalable Video Encoding.

Scalable video encoder
Scalable video decoder
7
Application Requirements from Encoder and Decoder

• Bandwidth Rate control.
• Delay - Buffering.
• Loss Multiple description coding.
• Video Cassette recorder like functions.
• Decoding Complexity.

8
Application Layer QoS Control

• Congestion Control
• Rate Control
• Source Based Probe based, Model based (TCP
  friendly)
• Receiver Based Channel based, Model based.
• Hybrid Rate Control Destination set grouping
  and layered multicast scheme.
• Rate Shaping Match the rate of a pre-compressed
  bitstream to a target rate by use of filters.

9
Application Layer QoS Control (contd.)

• Error Control
• Forward Error Correction (FEC) Channel coding,
  Source coding, Joint channel/source coding.
• Delay-Constrained Retransmission.
• Error-resilient coding Multiple description
  coding.
• Error concealment Spatial and Temporal
  Interpolation.

10
Continuous Media Distribution Services

• Network filtering.
• Improved video quality.
• Bandwidth efficiency.
• Application level multicast.
• Media bridges-Interconnection of media multicast
  networks enabled through application level
  peering relationships.
• Content replication.
• Caching
• Mirroring

11
Streaming Servers

• Components.
• Communicator Application layer and transport
  protocols.
• Operating System Real time support for
  streaming applications.
• Storage System Support for continuous media
  storage and retrieval.

12
Streaming Servers (contd.)

• Real Time Operating Systems
• Process management EDF and rate- monotonic
  scheduling.
• Resource Management - Admission Control, Resource
  Allocation.
• File Management

13
Streaming Servers (contd.)

• Storage System
• Increase throughput with data stripping.
• Increase capacity with tertiary and hierarchical
  storage.
• Use SAN, NAS.
• Fault tolerance.

14
Media Synchronization

• Intra-stream synchronization Within a time
  dependent data stream.
• Inter-stream synchronization Between different
  time dependent data streams.
• Inter-object synchronization Between time
  dependent and time independent data.

15
Protocols for Streaming Video

• Network layer protocols IP.
• Transport protocols TCP, UDP, RTP, RTCP.
• Session control protocols RTSP, SIP.

16
Protocols for Streaming Video (contd.)
Protocol Stacks for Media Streaming
17
Protocols for Streaming Video (contd.)

• Transport Protocols RTP and RTCP.
• RTP
• Time Stamping
• Sequence numbering
• Payload type identification
• Source identification
• RTCP
• QoS Feedback
• Participant information
• Control packets scaling
• Inter-media synchronization
• Minimal session control information.

18
Protocols for Streaming Video (contd.)

• Session control protocols RTSP and SIP
• RTSP
• Support VCR like options
• Provide means for choosing delivery channels and
  delivery mechanisms based upon RTP.
• Media retrieval
• Adding media to existing session.
• SIP Similar to RTSP but supports user mobility.

19
Future Directions

• Video Compression How about using a combination
  of encoding schemes?
• Application Level QoS The effectiveness of TCP
  like rate control.
• Continuous media distribution services A
  scalable, cost-effective, efficient and
  incremental deployable infrastructure for
  continuous media distribution.
• Streaming servers VCR like control, Storage
  mechanisms, scalability, fault tolerance.
• Media synchronization Synchronization in
  multicast video while supporting VCR-like
  interactive functions.
• Protocols Caching, support for pause/resume
  operation in caches, security in protocols.