Intro to Live S treaming Andy Beach Techgeist, Inc @ andybeach - - PowerPoint PPT Presentation

Intro to Live S treaming

Andy Beach Techgeist, Inc @ andybeach

Types of Live S treams

• Webcast/ S

creencast

• S

ingle Camera (no switching)

• Multi-Camera

(switcher)

• Live Linear

Live S treaming Workflow

Live S treaming Basics - Video S

• urce

Good Quality Camera 3 Chip best option Don’ t forget about audio! Ideally mix room noise with handheld/ shotgun/ lav for better balanced audio

Live S treaming Basics - Acquisition

Video S witcher or Directly capturing?

• Multiple source or single?
• Mix audio and video if

possible Create single output or “ broadcast”

Live S treaming Basics - Encoding

Two Options

• Encoding final delivery
• Encoding a mezzanine

All Real-time Optimized to work with site bandwidth

Live S treaming Basics - Connectivity

For an S D S tream 1.5Mbps upload bandwidth is needed For HD S treams 4Mbps+ is needed Available bandwidth will fluctuate so as a general rule, target bitrate should be set no higher than half of your available upload bandwidth.

Live S treaming Basics - S treaming

S mall events may use dedicate server to publish streams (less than 100)

• May save some money, but

costs in time spent managing servers S everal stream services are also now available

• Priced per minute processed

usually (# minutes in plus # minutes out)

• May enable extra options like

advertising or subscriber tools

• S
• me services have free/ low

priced option tat carries ads

• r branding

Learning the Lingo

Encoding Terms

• CBR (Constant Bit Rate) encoding

The encoding soft ware at t empt t o keep t he t ot al bit s/ second const ant t hrough t he ent ire video. This makes t he size of t he file predict able and easier t o st ream. Most modern CODECs will allow you t o set an upper t hreshold on t he bit rat e and allow t he rat e t o drop when it is not required for qualit y t o help reduce t he amount of bandwidt h used.

• Variable bit rate encoding (VBR)

A met hod of encoding video t hat first analyses t he video and t hen compresses it . While it can t ake up t o t wice as long t o encode t he video, t hey are compressed at an opt imal rat e for t he smallest file size. The variabilit y in t he dat a rat e of t he dat a st ream does not make it appropriat e for RTS P st reamed cont ent , but good for progressive download or video on CDs or ot her physical media.

S treaming Terms

• Pull - A Pull is a connection initiated by a streaming server to

receive a broadcast from a designated encoder for re-distribution across a network.

• Push - A Push is a connection initiated by an encoder to a

streaming server to receive a broadcast for re-distribution across a

• network. This requires a username and password.
• Latency - Latency refers to the amount of time taken for data to

complete a return trip between two points.

• ABR –Adaptive BitRate Video S

treaming – the protocol developed by apple and used for iOS (and many products)

• RTMP – Real Time Media Protocol – developed by Adobe used by

Flash

Networking Terms

• Port - A Port is a channel used t o communicat e informat ion over a

net work int erface or prot ocol.

• Port Forwarding - Port Forwarding is t he process used t o negot iat e a

rout e t hrough a firewall.

• Bandwidth

The amount of informat ion t hat can be sent and processed per unit t ime. This is usually measured in kilobit s per second (kbs) so for example a modem has a t heoret ical bandwidt h of 56 kbs, while t he slowest form

• f et hernet has a maximum bandwidt h of 10,000 kbs (10 megabit s) -

remember t hat t here are 8 bit s in a byt e of informat ion, most files are measured in byt es (kilobyt es, megabyt es, et c.).

Connectivity Types

Wired Ethernet Connection

• Wired et hernet connect ions are preferred t o wifi. It 's import ant t hat your connect ion is not being shared

by any ot her comput ers or devices t hat might compet e for net work resources, especially when upload bandwidt h is limit ed. Y

• u’ re going t o be a bandwidt h hog!

Wireless Wi-Fi Connection

• Wi-Fi connect ions can be fine, but most Wi-Fi net works are shared wit h a lot of ot her people. If your

available bandwidt h get s t oo low, your st ream will suffer in qualit y or halt alt oget her. Make sure you are able t o have access t o a dedicat ed Wi-Fi net work t hat is not t oo congest ed. 3G or 4G Cellular Connection

• Y
• u can st ream on a single 4G or LTE but it s highly impract ical. Cellular connect ions vary depending on

your locat ion and how many ot her people are using t heir cellular devices in t hat same locat ion. S peeds and qualit y will be limit ed, so for high qualit y broadcast s, use Wi-Fi, wired connect ions or t he bonded cellular product . Bonded Cellular Connection

• The concept behind bonded cellular product s is t aking t he power of 4 or more cell connect ions and

combining t hem t o make st ronger dat a connect ion.

Three Types of Encoders

• Hardware
• High powered, often expensive purpose built solution
• Leverages specialized cards to accelerate encoding
• S
• ftware
• Flexible, highly configurable solution
• Leverages off the shelf CPU
• Appliance
• S
• ftware encoding in a purpose built chassis
• Highly tuned, combination of HW & S

W

Hardware

Fast, efficient Purpose built, Dedicate encoder Range from card/ chip to appliance form factor Harder to update Not as flexible Highly variable in price Not Practical for live streaming events $100-$1000’s

S

• ftware

Run on your HW – extremely flexible configurations/ throughput Low price point – good entry level options Performance varies based on your configurations $500-1000

Appliance & Turnkey

Blend of S W & commodity HD in server

• r portable formfactor

Purpose built, fairly rugged Lots of features/ options – very flexible Pretty well know performance specs Appliances->$30K Turnkey ->$3500-7000

S treaming Considerations

• Mezzanine stream to a streaming service provides best

performance & user experience for those starting out

• ABR is best for multi device playback, but harder to manage on

site

• RTMP mezzanine stream onsite to media server that packages/ encodes ABR

streams

• H.264 codec gets you the largest audience, but decide on

settings/ bit rates based on what your upload can support and your audience can consume

• Use locked down cameras if possible (versus handheld)

Ideal Bit Rates for ABR Resolutions (16x9)

Kbps Height Width

2500 1280 720 1800 960 540 1250 768 432 900 624 352 600 480 272 450 400 224 200 368 208

Mezzanine

Building your own live studio

Certified Turnkeys from Telestream

http://www.telestream.net/wirecast/matrox-vs4.htm

Other Considerations

• Know your st rengt hs
• Do what you can, outsource the rest
• Many hands make for light work
• Plan for bad t hings
• Not only plan, but actually run through fire drills
• “ The” event is not the first time you’ ve done everything
• Broadcast Bandwidt h – do not exceed about 50%
• f your connect ivit y
• Redundancy, Redundancy, Redundancy
• Back up encode solution, backhaul, publish points, etc
• Record locally
• S

pecs are measured in mont hs

• Bandwidth requirements, consumer devices, & available gear all change about

every 18 months