Transcript QuickTime

QuickTime
The Joy of Streaming!
QuickTime Streaming Server
Allows for real time delivery of media
over a network.
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intranet
internet
Content can be prerecorded or
broadcasted live.
QTSS
Open source code
Standards based
Runs on multiple UNIX platforms
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Mac OS X
Redhat
Solaris
FreeBSD
Compatible Streaming
Formats
Video
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QuickTime
AVI
Audio
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AIFF/AIFC
System 7 Sound
Sound Designer II
µLaw(AU)
Wav
Compatible Streaming
Formats
Midi
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Karaoke Midi
Standard Midi
Recommended Compression
Video
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Sorenson Video
H.263
H.261
Motion JPEG A
Recommended Compression
Audio
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MP3
Qdesign Music Codec
 instrumentals
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QualCOMM Pure Voice
 Voice only
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DVI 4:1
Alaw 2:1
µLaw 2:1
16-bit raw
Streaming Protocols
HTTP
FTP
RTP
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Realtime Transfer Protocol
RTCP
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Real Time Transport Control Protocol
RTSP
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Real Time Streaming Protocol
RTP
Realtime Transport Protocol
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1 minute of video is sent in 1 minute
Packets are time stamped
Live content and prerecorded can be streamed
Uses UDP
 Transport-independent
2 parts
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Thin protocol that supports real-time applications,
security, and content identification
Control part that uses RTCP
RTCP
Support for real-time conferencing
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Support for real-time conferencing
Source identification
Multicast-to-Unicast translators
Offers Quality-of-Service information
Synchronization of different media streams
Quality of Service
Routers provides a level of QoS
Helps with jitter and latency
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Required by some real-time and interactive
traffic.
All networks do not provide the same
level of QoS
RTSP
(Real Time Streaming Protocol)
Uses TCP/IP
Similar to HTTP
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Can be extended as HTTP is extended
Maintains state
Server and Client can make requests
Data is transmitted “Out-of-band”
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RTP
RDP
 Real Data Transport -- RealNetworks
Unicast
Unicast
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One to One
Client sends request using RTSP
Server Responds with streaming session
information.
 How many streams, what types, codecs they
use
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Streams are then sent to the client via RTP
Unicast
Multicast
One to Many
Client joins a multicast session
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SDP file
Multicast
SDP File
(Session Description Protocol)
Group Address
Port number
Commonly put on Webserver to
announce multicasts
Codecs
Tracks
Reflector
RTSP server
Accepts Media stream
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Multicast
Outputs unicast streams
Receiving Stream
Open file that contains streaming tracks
Open sdp file
Open url
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rtsp://nova.it.rit.edu/
Setting up the Movie
Pre-prerolling
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Establishing RTSP connection
Establishing RTP stream connections
Prerolling
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Allocate buffers
Open media handlers
Hint Track
Unicast has VCR like controls
Header reconstruction for media tracks
Precalculates data for server
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Off loads computation
Serving Hinted Movie