Com 597Streaming Media

Class 6July 26, 2007

Blog Log

• Belle: http://www.harvesteating.com/ & http://www.celebtv.com/

• Carie: Wine Spectator & Serious Eats• Chloe: KidzBop.com & NIKKI BEACH Nikki news• Kaichen: Music Box & Taste TV• Mr. Random (Mark) http://www.blaztv.com/

& http://www.canalmicro.com/

• Mini: Mediapost.com• Nancy: Lookandlearnit & TeachFirst• Randa: Crack the Case & blinkx• Stephanie : SuccessTV & tourvideos• Steve: Nomadsland & CubeNews1.com. • Tharaa: Fuzzydice • Tony: RealMeals & Marvel• Vaun: AussieMedia & RealVibez

• Amy: TheLookAndSoundOfPerfect.com

Randa

Netflicks and Silverlight

• Silverlight

Packetization

• To stream a file over the internet you need to break the file down• Kilobyte sized chunks• These are called packets• The audio and video needs to synch up and must be sent fast enough, but not too fast• Packets that are lost in transit need to be detected and resent

Packetization cont.

The process of breaking the streaming file into chunks is called packetization

Could I have a hint?• To speed up the process and reduce the work of servers

this is often done ahead of time

• This is called hinting

• Hinting adds additional information in the file (a hint track) to tell the media server how to packetize the stream.

 • The hint track not only has data defining what audio and

video exist in the file, but also how large a chunk to send over the internet and at what time intervals.

Common Internet File Formats

Category One

Video container file formats, hierarchical in structure and hold many different kinds of media (Audio, video and text.) This data is synchronized in time.

Common Internet File Formats

Category Two

Simple raw storage of stream formats

This holds the compressed video data without headers or footers They are essentially a live audio-video stream saved to disk

Common Internet File Formats

Category Three

Play list, index and scripting formats

These don’t hold the actual media files

These are pointers and commands that indicate where the files are located

These files are usually, comparatively small.

Microsoft and Windows Media

• The standardization of Windows Media technologies by international standards groups generally means the format will not suddenly change.

• Inertia = stability• MS has seen the benefits of non-discriminatory

licensing terms with companies• Low cost = wide distribution

Windows Media Technology

Like Real, there is a family of codecs • Video- Windows Media Video 8, Windows

Media Video 7, Microsoft MPEG-4 V3 & MPEG-4 V1

• Audio- Windows Media Audio V7 & ACELP.net voice codec

Windows Media also supports:

• Video- VP3, ClearVideo, VDOnet, Vivo video• Audio- Voxware MetaSound and MetaVoice,

Learnout and Hauspie, MP3, Vivo audio, and all pre-G2 Real Audio and Video codecs

 Why the Real support?• Windows Media started as NetShow, which

licensed RealNetworks technology

Microsoft Files

AVI (Audio Video Interleaved)• Developed in 1992• First real-time playback of video on a PC• These can hold most anything. It works on every

platform• It is not all that great at managing sync• It can be quite slow• This is because the file index is often located at

the end of the file• The format has been extended so much that

variations wont always play in every player

Microsoft Files

ASF (Advanced Streaming Format)• This is Microsoft’s proprietary format• MS Filed a patent for it in 1998• Released in 2002• One of the dominant formats• Fixed a lot of the problems inherent in AVI files• It can show up as WMV or WMA• Primarily designed to hold synchronized Audio

and video

Microsoft Files

ASX (Active Streaming Index)• Index files that work in the Windows Media

system• They are metadata pointers• The direct a player where to retrieve the

actual media files• Can be one URL or a long list (playlist)• They can be nested

Why choose Windows Media?• Consider your audience: • Whether you like the Company or not is irrelevant. If your target

audience is in the business world then you need to seriously consider Windows media

 • Because WM comes bundled with the Microsoft OS, and because

nearly every enterprise corporation runs on a Windows environment, a staggering percentage of the Fortune 1000 businesses will have Windows Media on their employee’s computers.

 • Microsoft is the clear leader in market share in the enterprise space • Plus, their server technology incorporates many aspects of DRM quite

seamlessly.

Profiles

• Windows Media Encoder uses Profiles

• What is a profile and how would I use one?

• A profile determines how files or source groups are encoded

• Each profile may include one or many target audiences, along with video and audio codec information

• You can save the profile and use it repeatedly

Target Audiences

• What is the concept of target audiences?

• This is the naming convention for their multiple bitrate technology

• With it you can select multiple target audiences (bit rates) and weave your different versions into one file

Moving Targets

• An anomaly with the WindowsMedia version of MBR is the video is encoded with multiple qualities of compression.

• But all the video files share only one Audio file• There are not multiple audio files only one so choose

wisely• The lowest audience profile will determine your audio

settings• All the video target audiences will share a video screen

size

Which encoding mode to choose?

• CBR? VBR?

• My recommendation:

• Start with VBR

• Then two pass CBR

• Then one pass CBR

Why VBR?• VBR when used on proper content

• Long and varied in complexity

• Will give you an appreciably better encoded clip given the same file size.

• CBR is often using the bits in the wrong places and not having enough available in the difficult spots

• The difference can be as high as 2-to-1

• Another way to look at it. If two files have the same quality, the VBR file will often be half the size of a CBR file

• If your source is a file and you want to encode with CBR, then two pass is better than one pass

Using the frame buffer with CBR

• Why use the default of 5 seconds?

• If you are streaming a longer file (over say 10 minutes) increasing the buffer to 30 seconds will often accomplish the same increase in quality that VBR does.

Windows .NET

• If you are streaming over a server with Windows Media Services in Windows .NET Standard or Enterprise editions you can enable Fast Start

• This allows the server to burst data to the players, filling the buffer in a shorter time than indicated, thus starting the file quicker

Microsoft Buzzword Translator

• Fast Start: Instant on playback

• Fast Cache: Download and cache the streaming content

• Fast reconnect: Automatically reconnect to a stream if interrupted

• Fast Recovery: Use forward error correction

Other Buzzwords

Real’s version of the same stuff

• TurboPlay It is their rapid playback and seeking technology

Instant On is QuickTime’s version

File Metrics• Measuring Streaming media quality is becoming widely

acknowledged as supremely important • Three companies currently are the market leaders in

measuring the quality of streaming media delivery • One of them is Keynote is the global leader in web

performance measurement • They acquired Streamcheck in 2003 • This is an automated service that measures both quality of

streams and reliability

How they do it:They measure audio and video streams from multiple locations throughout

North America, Japan and Europe • They use measurement computers, called “Agents”• And Agent will try and connect with your stream about 10 times an hour• Once connected they play your stream for about 60 seconds• The Agent computers will record:

Network Statistics like packet statisticsConnection statistics like connection success, bit rate, buffer and re-bufferServer statistics like server type streaming protocolPresentations statistics like frame rate, player errors, metafiles, URLs

Why do we have DRM?

• Content Concerns

• Digital audio and Video, if unmodified enables perfect duplication

• Low Cost or near-no-cost duplication

• The original does not degrade over time (video tape and film) probably

• The original does not degrade with duplication so copies are limited only by resources

This is why owners of digital content are paranoid

If the copy is as good as the original, why purchase the original?

The music industry points to slumping sales and cries “Pirates!”

Record companies usually blame the internet and file sharing as the root of their business failures. In 2003 27% or Americans and 13% of Europeans downloaded music through P2P networks.

The tangled web of the traditional music business

Peer-to-Peer NetworksWhere are they now?

More Information on file sharing and the music industry

“On the reproduction of the musical economy after the Internet”

Leyshon, Webb, French, Thrift & CreweMedia, Culture & Society, Vol. 27, 2005Sage Publications

Security

Most DRM have the following security features:

Secure downloads

Secure audio path – audio can’t be streamed from user’s computer

Persistence – each license is specific to a particular computer

Individualization – the license for a player is linked to a specific computer. You can’t just move the player and music to transfer the files

Revocability – if a license is stored on a server it can be revoked if a user breaches the licensing terms

Portable device support – files can be transferred, but most distributors will limit it to devices that support the Secure Digital Music Initiative (SDMI) copy-protection scheme

Payment Models Varities• Pay-as-you-go (iTunes)

• Monthly fee for unlimited use (subscription)

• One-time fee

• Pay Per View (PPV)

• Free – promote a product or service

• Timed fee

• Tiered access

• Trial offer

• Reward program

Streaming media server vendors also sell DRM tools

• Music producers, media creators and retailers in particular want to ensure their copyrights are protected

• Typical DRM features include– Strong encryption

– Producer defined business rules for accessing content

– Content licensing verification (“Are you authorized to view this?”)

– License auditing to track royalties

– Support for handheld devices and mobile phones

Types of rules that may be a part of a DRM system

• When, how, where and for how long rights are granted

• Limited number of CD copies

• File can only be played on one computer

• What devices are supported for transfer (iTunes/iPod model)

• For digital distribution to reach its potential copyrighted material needs to be protected

• System must be:– Truly secure

– Flexible

– Easy to use

– Integrated into existing e-comerce systems

• Many of the current systems are not very adequate because:

– Not secure enough – passwords can be shared, registration code can be hacked

– Not flexible enough – content providers want different models for subscription (monthly, pay per view, free trials)

– Inconvenient for users – to work it must block unauthorized use but be easy for authorized users. Passwords and registration keys are lame

– Difficult to integrate into a wide variety of devices and hardware – consumers want to transfer media they own to devices they own

• Some companies (and marketers) use DRM to mean any sort of control of media

– All forms of copy protection

– Digital watermarks

Real, Apple and Microsoft define it more narrowly

• Apple uses standard MPEG-4 audio technologies (AAC)

• This how they deliver music to iPods and iTunes

• They use proprietary DRM approach (FairPlay) that is unique

• Each manufacturer uses a proprietary DRM system

• Once again, it is unlikely there will be an industry “standard”

Implementing DRM• Here is a typical sequence of events:1) Media provider packages the media file – create file

and license2) Provider places file on a streaming server3) When user tries to play a file, media player requests a

license4) User’s computer downloads a license without any

action or directs a user to a register/payment page5) After the license is issued, the user can play the

content under the terms of the license

DRM Models

Encryption

• Encryption scrambles the content so that it cannot be viewed

• Need a decryption key

• This is most often an enabled viewer or player

• Many DRM solutions are asynchronous

• The key is not in your player but somewhere out on the internet

Encryption cont.

• A user needs to perform a separate action or transaction to secure the decryption key

• The problem for content distributors is you can hack the player to play the media without a key

The Encryption Dance

create encryption

scheme

scheme is hacked distribute scheme

Distributors they claim each successive scheme becomes more expensive to create and manage

Walled Garden• A walled garden is where content is secured behind a virtual

barrier

• A user must purchase access

• Authorization/authentication system– Wall Street Journal, ESPN & New York Times

• They have a public site with content available to the public

• They have a premium content site where a user pays an annual or monthly fee for access.

• This is a popular model among religious sites

“Cheap and Easy Access”iTunes

• To keep something from being stolen make the price less than/equal to the cost of theft

• This relies on the honesty of the majority of potential users

• Make it cheap and easy and most folks are more likely to buy than steal

Challenges

• Many consumers are conditioned that music is free (filesharing, radio, ripping)

• Value is difficult to establish when there is a ready supply, scarcity creates value

• Disney movie example

• For existing music the cat is out of the bag

PC Client Content/Download Managers

• Require consumers/users to download a management client on their computer

• This application connects to a dedicated service – a wholesale intermediary

• They can use ptp strategies to move the content to the consumer

• They can act as the DRM police

• Monitor and manage the user’s functions and actions on their computer

• They can enforce DRM irrespective of an internet connection

PC Client Content/Download Managers

• Bit Torrent

• Sony’s rootkit/CD copy protection debacle

• Privacy Issues / Data mining Digital Media permits intrusion & access on a

massively efficient scale International reach of technology subjects

networks to multiple cultures and laws (and multiple risks)

PC Client Content/Download Managers

• There is a push for Digital Licenses, separate from the media file and conforms to a standard format

• Separating a universal license from the media has many advantages

• It can accommodate many different licensing scenarios

• You don’t need to prevent file copying• Because file is on a server the provider has

complete control

Windows Media Rights Server• End-to-end DRM system for Windows Media• It supports a huge variety of security and business

model options• It delivers WMA and WMV files• WMRM (Windows Media Rights Manager) includes

server and client software development kits (SDK) so developers can write unique applications to encrypt files and issue licenses

• It does not play well with other platforms and older software

RealSystem Media Commerce Suite

• RealNetwork’s DRM solution

• The Packager – encrypts the media

• The License Server – issues content licenses

• Media Commerce Upgrade for Real Server – tracks the business side

• RealSystem Server plug-in – enables the service on a media server

• Like WMRM it enables a variety of business and distribution models

Flash

Flash Basics

• Macromedia’s Flash has been adopted as the de facto “rich media” solution in the industry

• It is used extensively in entertainment, games and advertising

• Graphics are essentially vector-based instructions

• Infinitely scalable in an interface

More Flash Basics

• Many companies now standardize embedded video on their sites as Flash Video

• Huge growth in handhelds and mobile delivery

• Flash files are called SWF (“swiff”)

• Files are closely tied to the authoring system

Even More Flash Basics

• Not really a codec• SWF files contain graphics and instructions how to

animate• Drawing is done with math (x/y/z axis and vectors

over time)• Files are often smaller• Not sending huge graphic files, just the parts and

instruction on how to recompose the animation on the user’s computer

Will these Flash Basics Ever End?

• With QuickTime support and Macromedia’s integration of the Sorenson Spark codec SWF can be used as a container for video

• The header information of a file has most of the same data types as the other codecs we have reviewed

– File version

– Length of file

– Frame size

– Frame count

The End of Flash Basics As We Have Known Them

• Two main types of tags – Definition tags – define content

– Control tags – control content

For example, definition tag defines and triangle and the control tag will move it across the screen

OK, I lied, this really is the final Flash Basics Slide. Perhaps

• SWF files are a progressive format• Blocks are sent in the order of use• This allows the file to be essentially streamed• Viewer can watch the parts as they arrive• This can occur without special server software – no

need for a media server• A web server, the flash content and a flash player

are the only requirements

Great Flash Video Example

http://www.lebronsbikeathon.com/ Video #11 & #14

Flash Example & Workshop

Workshop Demo

Let me walk you through before your begin

Customizing Your Settings• In the compression tab, check the bit rate selections

appropriate to your target audience

• Audio format: you can adjust the amount of bandwidth used by the audio track in your video. If you assign a lower audio rate then you are allocating more bits for the video.

• An example would be a sporting event file. High fidelity audio is not as important as smooth video. A music video may want more bits for audio because fidelity is more important in this scenario.