Media streaming

Joni AlhonenVBP07S

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• Multimedia, which is broadcasted simultaneously as it is played by the receiver

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Contents

• History• Technology– Codecs– On-demand and live streaming– Unicast and multicast

• IPTV• WirelessHD• Summary

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History

• 1950s - First attempts to playback media on a computer

• TV and radio as mass medias• In the 1980s computers powerful enough to

play multimedia – Streaming not technically possible yet– No demand

• 80s -90s technology developing

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Hardware development

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History

• Early 90s - Mbone– Required special hardware and software– Rolling Stones concert– First online streamed broadcasts

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History

• RealNetworks RealMedia– Media streaming pioneers– 1995 RealAudio

• 1996 Microsoft NetShow• 1997 RealVideo• 1998 Apple QuickTime• 1999 NetShow => WindowsMedia• 2000: 85% of online streaming material in real

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History

• Problems at the change of the millenium– Real player not uesr friendly

->users deleting real player->computer manufacturers did not pre-install

– Windows and Apple– IT-bubble– > Other businesses took over

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History

• 2000s– Web speed and coverage– More processing power– Internet standardized: TCP/IP, HTTP, ja HTML– Internet commercialized– >more demand for streamable media

• Still developing:– Wireless devices– HD-quality– The above combined– >new challenges

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Technology

• Codecs– Audio compression. Mp3, Vorbis, AAC– Video compression. H.263, V8

• Encoded audio and video packed eg. FLV, WMV, QuickTimeMovie, MPEG-x

• Bit-flow sent from streaming server to receiver using transfer protocol such as RTSP

• Receiver can interact with the streaming server via control protocol such as RTCP

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On-demand vs live-streaming

• Media can be broadcasted either live or previously recorded

• Live streaming– Broadcasted live or with a few second delay

• On-demand– Production has been saved previously and is

broadcasted to the receiver on demand

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On-demand vs live-streaming

• On-demand– Played right away– Or progressively• Saved on disk while simultaneously played back

– On the service providers server

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On-demand vs live streaming

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Technology

• Unicast vs Multicast• Unicast– Sending media at a single, targeted receiver

• Multicast– Sending same media to multiple receivers. – Used in IPTV-broadcasts

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IPTV

• Streaming media + TV • In Finland: Elisa, Welho, Sonera• 2,5 Mbps speed required for SD-quality

videostreaming • Min. 10Mbps speed required for HD-quality• Material on the service providers server – Does not require the user to have HDD-space for

temporary storage

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WirelessHD (WiHD)

• Standard for streaming HD-video for wireless devices-Sony, LG, Panasonic, Samsung, Toshiba behind the standard

• Competitors: Wireless High-definition Interface and Wireless HDMI

• No need to install extra cabling beneficial!

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Summary

• Media streaming used since the 90s – More demand with better technology

• Media streamed online for many purposes– Live streaming– On-demand

• Streamed media packed for broadcast and opened at the receiving end

• With new devices comes the demand for new technologies – HD-video wireless transfer

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