Exploring the Future Potential of AI-Enabled Smartphone Processors
Internet TV
1. Internet TV – Yet another TV ??
Broadcast Multimedia course – TUT - 2008
Adrian Hornsby
2. Short on Internet
Internet
− world's largest computer network
− collection of smaller networks, computers, and
people who use them.
− around 28 million people
Until recently, multimedia and internet were not
really going together
− Not enough bandwidth, load, errors, traffic ...
3. Yet another one ...
Digital Media Revolution …
• Huge increase in media content
• Faster communications
• New user experience
• New consumer demand
New digital devices + new digital transmission
systems =
New digital transmission system
10/29/08
4. Yet another TV system !!!
Internet Television (TV), iTV
− Television like content distributed through the
internet.
Running on existing IP infrastructure (DSL, Wifi, 3G data ...)
Distribution model
− Live Streaming
− VOD
− But also P2P (P2PTV)
5. Tell me more ...
Differ from IPTV
− Not a dedicated network but over the internet
No real QoS
− Does not require set-top box
− Provider not always clear
Legal and none legal content
− Quick to market with Low investment cost
− Usually uses advertisement as main revenue
6. And how does that one works ??
Browser + media player (plugins)
− No special equipment, just a computer and a
connection to internet
Several options ...
− HTTP streaming (basic and advanced flavor)
− RTP based multicast streaming
− RTSP based streaming
7. HTTP streaming ? hmm ...
(basic flavor)
Simplest and cheapest way to stream video
from a website
No special type of website or host
− recognizes common video file types
Good option for websites with modest traffic
No live video
− HTTP method needs complete files stored on the
server.
− No automatic detection of end user's connection
speed
different file for different speeds
8. HTTP streaming
(basic flavor)
HTTP-like live streaming
1- Clients request with HTTP-Get message
2- Server replies with a HTTP-OK response
3- ... continuous stream of data (usually port 8000)
4- Also referred as HTTP-push
long-lived HTTP connection.
keep the connection open by running a long loop
9. HTTP streaming basic flavor
Web Browser
HTTP meta file
Web
HTTP content
Server
Media Player
10. HTTP streaming (advanced flavor)
Similar to basic flavor except media sent by
specialized streaming media server
− Data delivery process differs
No passive http push technique
Data send actively and intelligently,
− eg. data rate associated with compressed media streams
Server and client in touch, responses to feedbacks
Stream usually controlled by ZeroWindow / KeepAlive
mechanism
− Receiving host use the window field in each acknowledgment to inform the sending host how
much more data it can receive [rfc793],0 if receiver is pausing the stream. When playing
resumes, the receiver sends another ACK with a nonzero window size.
11. HTTP streaming (advanced flavor)
Web Browser
HTTP meta file
Web
Server
Media Player
HTTP media content
Streaming
Server
12. ... hmm I prefer advanced flavor !
More efficient network throughput
Better audio and video quality
Support for advanced features
Larger number of users
Content copyright handling
Multiple delivery options
13. HTTP streaming servers example
Basic flavor
− Apache
Special flavor
− Shoutcast
− Icecast
− VLC
− Window media server
14. RTP-based streaming
So called multicast streaming
− requires global multicast address (€€)
−
No subscription
subscription
Combining RTP over UDP
More for Live events, no “real” control on
stream
19. RTSP streaming
Web Browser
HTTP meta file
Web
Server rtsp://example.org/example/current.rm
RTSP commands
Media Player
Streaming RTP media content
Server
HTTP media content
(rare)
RTSP may also be combained with HTTP streaming !!
20. RTP/RTSP
streaming servers example
VLC
Darwin
Windows Media Server
Helix
Live555
Feng
21. Business Model
Free
Pay per clip, per time
Ads
On demand / Live
Open / Proprietary (downloadable player)
Central / Distributed / P2P
22. Internet TV and some limitations ...
− Internet network
− No QoS
− Bandwidth issue
− Poor Audio Video Quality
− Interrupted Delivery
− Content protection
− Long Channel Zapping
− Poor content
− Advertising !!
24. Short on Internet (remake)
Internet
− world's largest computer network
− collection of smaller networks, computers, and
people who use them.
− around 28 million people
Until recently, multimedia and internet were not
really going together
− Not enough bandwidth, load, errors, traffic ...
25. Internet and multimedia
First with emails @, files ...
Then FTP and Gopher ...
Tradition of sending in one-to-one model
(unicast)
Recently .. explosion of digital information
Pictures, Videos, Presentations ...
Need for real-time multimedia communications
One-to-many
− Bye bye unicast
− Welcome multicast over the internet !!
26. Internet and multicast ...
Early 90's:
The Multicast Internet (quot;the MBonequot;)
− region of public Internet connected by IP Multicast
Critical piece of the technology needed to make
multiple-person data, voice, and video
conferencing on the Internet -- in fact, sharing
any digital information -- cheap and convenient.
[http://www.savetz.com/mbone/ch3.html]
27. Mbone ....
Virtual network on top of the Internet
Invented by Van Jacobson, Steve Deering and Stephen
Casner in 1992.
Minimize the traffic for shared AV conferencing
MBONE is free
− Unix based network of mrouters that support IP
Multicast
− enables access to real-time multimedia on the
Internet
tunneling protocol
− encapsulated multicast packets in unicast packets
224.0.0.0 - 239.255.255.255
29. But it no longer exist ...
Multiprotocol Extensions for BGP (MBGP)
− IETF RFC 2858
− allows different address families to be distributed in
parallel
− exchange of inter-domain multicast routing
information
− Uses PIM to build trees and forward multicast
traffic.
30. M6bone
What is it ??
− An IPv6 Multicast test network
− M6Bone started in July 2001
− 24 networks & 45 sites
Goals
− Offer IPv6 Multicast connectivity
− Test and develop Ipv6 Multicast
− Standardization and recommendation
− Deploy advanced service on Ipv6
http://www.m6bone.net
32. Applications
Mbone tools: sdr, vic, rat, nte, wb
Freeamp patches (mp3/rtp)
MIM (mpeg-1/mp3 over rtp)
ttcp and iperf
Multicast beacon (written in java), just worked for ipv6
Available content
Misc vic/rat sessions
TUR (Trondheim Underground Radio)
NRK (Norwegian national broadcasting) radio channels
All global IPv4 multicast sessions (through gateway)
Maybe this time will be a success !!