Digital Video Revolution: Streaming Video for the Masses

by Reno Marioni 19 Jan 2001

Reno Marioni is the Founder and CEO of a digital travel Adventure Zone

Network entertainment site for world travelers, explorers and adventurers.

The site showcases streaming video, audio and interactive content from

around the globe.

Page 1

Just a couple of years ago, producing your own short movie

meant going to film school, raising a lot of money, buying

expensive equipment and looking for distribution via film

festivals.

Basically, it was out of reach for most people. Today, with the

right talent and desire, we all have a shot at being filmmakers

for 1/10th or 1/20th of the cost. A whole new creative world

has opened up, thanks to the advent of several new consumer

technologies: high-quality and low-priced digital video, powerful

desktop PCs, inexpensive and easy-to-use video editing

software and a new distribution channel on the Web.

And as broadband DSL and cable modem access increase, so will

the audience for digital video on the Web. In addition to the

Internet, numerous new devices and appliances will be available

to distribute your work. We are already beginning to see short

videos on airplanes, in hotel lobbies, on handhelds and through

interactive TV.

To produce and showcase your own digital video involves

several key steps:

a. Shoot your video footage (use an analog or digital video

camera)

b. Capture (input video onto your Mac or PC hard drive using a

Firewire connection or video capture card)

c. Edit (use consumer-level software video editing tool)

d. Compress/Encode (use bundled video editing tool or

dedicated video compression tool)

e. Distribute (to Web, CD, DVD, etc.)

In this article, we're going to focus primarily on the encoding

and compression process with special emphasis on encoding for

the Web, which as you'll find out is a fine art.

Page 2 — Video Encoding

What is video encoding and why is it important?

First of all, digital video files are HUGE. Roughly five minutes of

uncompressed video will consume nearly one gigabyte of space

on your hard drive, and no one - not even your adoring mother

-- is going to download or stream a video that large. So

compression helps you optimize the video while retaining the

highest quality possible for distribution on the Web.

Before compressing/encoding video for the Web, you need to

consider the following settings and criteria:

1. What Video Format/Architecture (QuickTime, Real, Windows

Media)?

2. What Data Rate?

3. What Frame Rate?

4. What Window Size?

5. Streaming Method: Progressive or Real-time?

The file compression process begins when you take your edited

video clip and encode to a particular video format -- e.g.,

QuickTime, Windows Media, or Real Media -- and compress the

file size to output to either CD, DVD, or the Web. Encoding for

the Web is the trickiest part as there are far more variables to

deal with, such as constrained bandwidth, which results in

jerky, annoying videos on the Web.

In order to encode a steady sample, it's important to have a

well-shot video source. This is why you don't see many

MTV-style videos on the web -- the transitions are too fast,

rapid camera movement doesn't compress well, and you're likely

to have jerky, delayed images, even when compressed at a low

frame rate.

Before encoding your edited video files you have to ask yourself

the following questions:

a. Which streaming method is best for my setup, progressive

(HTTP) or Real-time (RTSP) streaming?

b. What format do I want to use (Real, QuickTime, Windows

Media, or other)?

c. What is my delivery mechanism (Web, CD, DVD, etc.)?

d. If output is for the Web, what Web connections am I

targeting (56k modem, ISDN, DSL/Cable, T1)?

Page 3 — What is streaming video? And which method do I

choose?

There are two main types of streaming: progressive streaming

(on demand) and real-time streaming (live or in real-time).

Progressive streaming takes a compressed video file and

downloads it to your hard drive via HTTP over the Internet.

Real-time streaming is usually broadcast to your browser

directly from a server. Real-time streaming uses RTSP (real time

streaming protocol) so you'll need access to a special video

streaming server.

Progressive Streaming

Progressive streaming is the easiest route for beginners as it

requires no special server, such as a streaming server. You can

use a standard Web server to upload your compressed video

file. Quality is generally better using progressive streaming than

with real-time. And once you decide to play the video online,

the whole file begins to download to your hard drive.

Progressive users also can't jump ahead to other sections of the

video.

Depending on the format of the video (such as Real), some

progressive files may require you to download the entire video

before playing it. This creates one of those annoying "hurry up

and wait" scenarios. Thankfully, QuickTime supports a 'fast

start' feature which automatically kick-starts your video player

as it downloads. In an age of instant gratification, this is a

great feature and QuickTime is the only major video architecture

that supports it for now. For that feature alone, QuickTime is

much better suited for progressive streaming than RealVideo 8

or Windows Media 7.

In general, progressive streaming works best for videos under

three minutes, such as movie trailers, and the shorts you see on

sites such as Apple Quicktime TV, iFilm, Atom Films, and on

home video sites such as Share Your World.

Page 4 — Real-time Streaming

Unlike progressive streaming, real-time streaming requires a

special streaming server. This can be a QuickTime Streaming

Server (RTSP), a Real Networks Server or a Windows Media

Server.

Video streamed for real-time plays automatically. You don't

need to download the entire video before playing. You can jump

to any location in the video clip. And the clip always resides on

the server. Video encoded for real-time streaming generally tries

to keep pace with the user's connection speed in order to

minimize interruptions and stalling. There's nothing you can do

about general Net congestion, but the streaming server at least

tries to compensate by maintaining a constant connection.

You'll find real-time streaming is best suited for longer videos --

such as live event broadcasts, presentations, training videos

and lectures -- where users can skip ahead to other parts of

the clip and don't have to download a huge video file. It also

offers good protection for your content as users can't download

it to their hard drives and redistribute your work. Unfortunately,

the video quality isn't as good with real-time as with

progressive. But getting quality video on the Web is all about

trade-offs.

If you're just starting out, you might want to create a simple

Web page, encode your video using a progressive streaming

method, and embed the clip into your site. Or, if you're

determined to stream the video, you might consider using a

third party and their servers. Companies such as Media 100 and

Sorenson Broadcast Services offer a range of encoding, hosting

and streaming services.

Page 5 — Video Architectures and Codecs

The three main video formats on the Web are RealVideo,

Quicktime and Windows Media. When choosing a video

architecture and format, you need to evaluate current market

trends and also decide which is the best fit for you and your

audience.

Currently, RealVideo is the most popular and widespread video

format used on the Web. Real recently released version 8, but

you must buy the server software to use it; the cost after

software purchase is based on connection usage. Windows

Media from Microsoft is also widespread and is currently in

version 7. Although Windows runs its own proprietary server

protocol (not the standard RTSP), it's free and it runs on the

widely available Windows Server Platforms.

QuickTime Streaming Server from Apple, the third major format,

is based on RTSP. It's an open standard and available on

multi-platform servers from UNIX to NT. As Apache is to Web

servers, QuickTime Streaming is to video servers. And the best

part is it's free. Many professionals believe QuickTime offers the

best quality, as well as the elegant interface that Apple

products are famous for.

Video Codecs:

In order to understand video compression, you first need to

become familiar with "codecs" and how they work. Codec stands

for compression/decompression, and it's the piece of software

you use to compress very large files, such as video or audio,

into much smaller files that can be sent out to multiple media.

Normally, you will choose a codec according to the video format

you are using.

For example, Sorenson Video 3 codec from Sorenson Media is

compatible with the QuickTime format and is the de facto codec

for QuickTime Video compression. Real Video 8 codec runs in

conjunction with Real Server. The same compatibility issues

apply to audio codecs such as Qdesign Music Pro for QuickTime.

Codecs generally come bundled with your video editing software

or with compression suites such as Media Cleaner. Every year,

new and improved codecs are released to make files even

smaller, while encoding faster and producing better quality

video.

You'll probably use one of the following codecs for video

compression:

a. Sorenson Video

b. RealVideo

c. Windows Media Video

d. MPEG-1, MPEG-2, MPEG-4

e. H261/H263

f. On2

Page 6 — MPEG-4

Although Windows Media, Quicktime and Real Media are the

major players, an open format called MPEG-4 holds great

promise and could become the de facto video codec standard in

the same way that MP3 has become the dominant format for

music on the Web. MPEG-4 has momentum behind for several

reasons:

1. Ubiquity: Streaming video today is mostly viewed on the

Web, but the future in streaming video will be far more prolific

across multiple devices, appliances, platforms and computers.

Streaming Video will be seen in hotel lobbies, supermarkets,

airplanes, videophones, TVs and more. MPEG-4 appears to be

the codec and standard for future devices to come.

2. Unified Standard: Today, there are many codecs. The

problems that people face is sorting out which codecs to use

with which video architectures in the encoding process. The job

would be far easier for digital media professionals if people could

encode just once for all platforms and devices.

3. Quality: MPEG-4 appears to be the most efficient encoding

standard and will encode at incredibly high-quality over the

most constrained bandwidth requirements. From what we have

seen, people will be able to have full screen VHS quality video.

Sorenson media is developing an ISO-compliant MPEG-4 codec,

as is Microsoft for use in Windows Media.

The bottom line is that MPEG-4 will be awesome in quality and

will be embedded into many new and exciting devices.

Video Encoding:

The vast majority of video content creators use Media Cleaner

Pro from Terran Interactive as their full-service

compression/encoding suite. It's an essential software package

and is widely used in the digital entertainment industry. The

Media Cleaner Pro EZ version is priced around $250 per copy,

and more often than not it comes bundled with popular video

editing tools.

Here's how a sample encoding process might go:

Once you've finished editing your video using software such as

Apple's iMovie or Final Cut Pro, Adobe's Premier, Media100

CineStream and Cleaner EditDV or Microsoft's Moviemaker, you

save and export the edited clip to a folder on your desktop.

In some editing suites such as EditDV or Premiere, you can

export directly from the editing tool into Media Cleaner Pro,

removing an extra step in the encoding process. Once your clips

are in a compression suite such as Media Cleaner Pro, you're

ready to prepare the clip for a particular distribution medium.

You then go through a series of check box options, which

determine the size of the clip, the data rate, the frame rate,

etc. Media Cleaner, for example, allows you to select your video

format (e.g. QuickTime), your delivery method (e.g. Web), your

data rate (e.g. for 56k-modem), your frame rate (e.g. 10 frames

per second), and the size of your video viewing area (e.g. 240 x

180 pixels).

Page 7 — Real World

At Adventure Zone Network, we use Final Cut Pro as our editing

tool, Adobe After Effects for composing and effects, and Media

Cleaner Pro v5 for compressing and preparing each video file for

output. We also use Real Video 8, Sorenson Developer 2.1, and

Windows Media 7 as our primary video codecs and Qdesign

Music Design for preparing audio files for QuickTime. We also use

Real Audio.

We use Apple G4s for editing and encoding our videos. There's

not an Avid system in the house. Everything is done digitally, on

the desktop, and all the software is available at consumer level

prices. To see some streaming video samples that use these

codecs and tools, go to the Channel Zero section and see

videos from around the globe.

We shoot video using mini DV tapes (NTSC) as our source and

capture digital video using a Firewire (IEEE1394) connected to

the Firewire port of our Apple Macs. We don't generally use an

analog source, as it creates an extra step to convert to digital

using a Sony DMA-200 digital converter. As well as the standard

Firewire connection, you can use a video capture card such as

those produced by Osprey to capture video at the source into

your computer for editing. Without a doubt, you get the best

results using a digital video camera hooked up to your computer

via Firewire. All the latest Mac systems include a Firewire port.

Page 8 — The Trade-offs

The optimal goal is to produce the highest quality video that

streams with minimal or no interruptions and a quick download.

For Web delivery, this means trade-offs.

On one hand, if you produce a high quality video with a high

frame rate (regular movies play at 24 frames per second), a

large viewing window, and a high data rate, you will get a video

that looks great but will only be viewable for people with fast

connections. If you encode with speed and delivery in mind, the

quality suffers. In an era of instant gratification, there is no

quick fix for making quality video accessible to a wide audience.

Finding a balance between video quality and connection speed

that best serves your target audience is the key.

Sample Settings

A sample encoding settings for 56kbit modem delivery using

NTSC DV source might look like this:

Streaming Method: Real-time Streaming

Data Rate: 40 Kb

Although we may have a 56 Kb modem, our true connection

speed is nearly always lower than 56 Kb. Therefore, setting to

40 Kb or around that rate minimizes the interruptions that occur

due to general Net congestion.

Window Size: 160 x 120 pixels

For 56 Kb, if you increase the display size of your video, quality

will immediately suffer due to the larger file size. You need to

keep the display size to 160 x 120 pixels or only slightly larger.

This is what many people disparagingly call a "postage stamp"

display.

Frame Rate: Use 5 for 6 frames per second (fps).

Uncompressed video typically plays at around 30 fps (NTSC) or

25 fps (PAL). Choose a frame rate that evenly divides into the

above figures. Since many of us use NTSC in the US, you'll need

to select a frame rate such as 5, 6, 7.5, 10, or 15 fps

depending on connection speed. As modem delivery is very

slow, we suggest 5 or 6 fps, then scaling up based on data rate

and Web connection.

Page 9 — Encoding Methods and DVD

If you're encoding for progressive streaming delivery, use the

2-pass Variable Bit Rate (VBR) setting, which is supported both

in Real Video 8 and QuickTime 4 & 5 versions. You won't find

this feature in Windows Media 7. VBR encoding is a great

feature to enhance the overall quality of your video. It works

like a 2-pass encoding approach, analyzing your video first for

choke points, then compressing it. It's a longer process but the

results are better.

Some techniques used in video streaming actually mix encoding

techniques. It's more common now to see companies encode for

modem (e.g. 56kb) delivery using progressive download and for

higher data rates (e.g. ISDN and DSL) using real-time streaming

methods. The mix and match approach works well because it's

hard to do real-time streaming for 56Kb delivery unless you're

streaming a talking head video, which compresses better due to

minimal camera movement.

When you start the encoding process, use a very short clip

because it will take a long time (even with a fast computer).

You can enter different settings into Media Cleaner Pro 5 until

you get the best results for the type of video you are

compressing. Then be sure to save these settings for future

use.

Media Cleaner Pro offers new users a wizard interface, which

takes you through the encoding process to create your own

settings. However, the results are often poor and you have to

go through a lot of trial and error before you really start to see

optimized results. Start with the wizard interface then try the

advanced settings until you find the results you like best. There

is no magic bullet here. The experimental phase can be very

frustrating and time consuming to say the least, but once you

have the settings you like, you can reuse them for future

encoding jobs.

DVD Distribution

If you go to a Blockbuster store today, you might notice that

DVD is well on its way to replacing analog VHS tapes. Up until

this point, the main focus in digital video has been on Web

distribution, but producing your own videos and 'burning' them

on DVD is also possible for 'pro-sumers'.

Until recently, encoding and 'burning' DVDs required very

expensive equipment. Apple Computer has introduced new but

powerful consumer level DVD software called iDVD and iDVD

Studio that can deliver professional results.

Media100's Terran Division also has a product called Cleaner

MPEG Charger that helps you create and encode for DVD.

Generally, DVDs use MPEG-2 codecs and you can encode at far

greater data rates than you might for the Web, with a full

screen window size to boot.

Page 10 — Community Sites

There are several useful video community sites that can help

you find further information about video encoding.

See 2-pop, which supports a vast bulletin board for everything

from video encoding, editing and capture to special effects.

Another Site called Streaming Media is a great portal which

offers media talk radio shows, highlights everything from

content and technology to industry trends and news, discussed

by the latest luminaries.

Digital video creation, distribution and communication represents

the next killer app. And it's a very exciting and fun process once

you get the hang of it. Like everything, it requires learning a

few key tools, some perseverance to get them working in

tandem, and some trial and error until you're happy with the

results. And beware -- once you get into it, you might get

hooked.