About: Compression, Codecs, and the Windows Media Encoder
This week's topic was requested by a newsletter reader. It's always a good one
to discuss, and I appreciate getting requests to cover specific topics.
All video files are compressed. They need to be in order to be more easily stored
and transmitted. The codecs are the underlying hardware or software devices that do the compression
or decompression. And software such as Movie Maker, PhotoStory and the Encoder help you pick appropriate
compression settings and produce your movies.
Codecs achieve compression by removing redundant info in the file.... and even
more compression by eliminating some of the video/audio info that it thinks you won't miss, or will
miss the least...
And of course, everyone feels their codec is better than the others. There are
thousands of codecs. You might be familiar with Divx AVI files, Apple's MOV files, MPEG1 and 2, and
Windows Media Video and Audio (WMV and WMA files). You might not be familiar with Panasonic's Digital
Video, Cinepak, Huffy or even Microsoft Video 1.
Windows Media version 9 codecs are newer and better than the others!!!! That's
one of the reasons we use Movie Maker and PhotoStory.
In this newsletter,
I'll explore video file compression, the topic of compression versus quality, spend some time on
bit rate (a measure of compression and quality), the Windows Media 9 codecs, and a mini-tutorial
on using the Windows Media Encoder to convert a file.
How about a poll
this week? I'm curious about your knowledge and skill levels.
I don't want to overwhelm newbies, nor do I want to hold back info for advanced users. So I'll
warn you up front that I might not change my subject matter or style, but I'll share the statistics
with you in the next newsletter.... and use the results as guidance.
Pick from the following the one that most closely aligns with you. Just send
an email to
email@example.com and tell me what letter you pick:
A - I'm a newbie to video editing and computers, learning about digital
movie editing but not yet into doing it. For now, I'd just like to read and think.
B - I'm a newbie to video editing and computers, and dabbling in the early
phases of doing digital movie editing. Any topic is great, but most of what I read goes over
C - I'm skilled in digital video editing but not with computers.
D - I have high computer skills but digital video editing is new to me.
E - I have moderate skills with both computers and video editing. I'd like
to read more about advanced topics.
F - I am very skilled with computers, and would like to bring my video
editing knowledge up to that level.
G - I know more about computers and digital video editing than you do. I
just read your newsletters for fun.
If it's hard to choose between
a couple, give me both.
Some Basics About Video File Compression
99.99% of the video files that we use on our computers are compressed. The rare
person who is working with uncompressed video files probably isn't using Movie Maker or reading these
newsletters, so I'll make the statement a bit stronger and say that all video files we use
are compressed. Some are more compressed than others.
Compression is a process for removing redundant data from a digital media file
or stream to reduce its size or the bandwidth used.
The closest we get to uncompressed is the Digital Video file that is recorded
on the tape of our mini-digital or digital8 camcorder. There's about a 5:1 compression ratio from the
info captured by the camcorder versus what it can lay down on the tape as the tape moves through the
camcorder in standard play mode. In a recent post, I called DV-AVI uncompressed and was promptly corrected....
it's compressed.... but it's still pretty big.
It's actually easier to start with the basis that all video files we work with
are compressed because that leads directly into the next part of the topic.... the compression format
and the amount.
Digital video files are compressed to make them more easily stored or transmitted.
They need compression when heading for storage, and decompression when being viewed.
Some compression can be done by hardware... a camcorder or some sort of hardware
capture device are a couple examples. Other compression is done by software using codecs.
We've all heard of codecs by now. Many of us got part of our orientation with
Movie Maker by learning that some codecs clashed with Movie Maker, and Movie Maker lost and crashed.
There are thousands of audio and video codecs, and many of the codecs have adjustable
settings.... so the possibilities are almost endless. Look at the GSpot utility (see the Setup > Software
page of the website for a link to GSpot) and the info it has about video compression codecs. Here's the
list of known video compression formats sorted alphabetically by codec. I'm just showing you the 28 in
the list that start with the letter 'A'... I'm not even wanting to count how many there are in the full
The full GSpot list of audio codecs isn't near as long. Here's the GSpot listing
of the audio codecs currently installed on my laptop.
It would be complex enough if there was only one video or audio codec associated
with a video file, but there are usually two, one used for the video and the other for audio. And they
might be mixed or matched.
'Flash forward' - you preview a clip in your collection
and it plays great.... Movie Maker only needs to deal only with a couple codecs for the single source
file..... then you have 50 video and music/audio clips on the timeline and preview your movie. With the
many codecs involved, previewing the timeline is that much more complex, so Movie Maker has to shift
gears to preview things differently. Sometimes a clip plays fine in the collection but not on the timeline....
that's how things work or don't with codecs.
An interesting thing about codecs is that a number of them on your computer might
be used to play a particular file. Movie Maker will start at the top of the list to pick one that will
probably work. If the first one doesn't, it'll go to the second, and then the next, etc.
File Compression Versus Video Quality
I'll generalize again. The bigger the file size, the less it is compressed. The
smaller the file size, the more it is compressed.
Bigger, less compressed files, have higher quality. Smaller, more compressed files
have lower quality.
I have a whole website page devoted to showing dozens of different versions of
the same file... it's the Saving Movies > Sample Video Clips page. The original DV-AVI file runs 21 seconds
and is 70 MB in size. Scroll the page and see that the compressed files made from it run from 84K to
You want both smaller files and higher quality. That's the quest for compression
processes. What's a good tradeoff of file size versus quality? From the perspective of a Movie Maker
2 user, you get two file format choices - DV-AVI and WMV.
If you are heading toward showing your movie on a TV, then DV-AVI is your preferred
path.... it might look or play poorer on your computer, but a little faith says it's the best choice
when it gets to a TV. Your choice of compression is taken care of... whatever the Digital Video codec
gives you. Of course the next step to convert the DV-AVI file to an MPEG2 one will be a significant compression
process that will determine the viewing quality, more so than the starting DV-AVI file.... but that's
beyond Movie Maker.
If you'll be viewing your movie on your computer, or via discs or the internet
on other computers, then WMV is the preferred format. But it won't be as easy as picking DV-AVI; you'll
have lots of options for settings to deal with.
If some of your audience will watch it on a TV, others on a disc on their computers,
and still others via downloads or streaming video from an internet server, you might want to render the
movie a few times and give each the best choice for their viewing.
About Bit Rates
A good practical indicator of quality is bit rate. Consider two aspects of your
viewers' assessment of quality.... (1) the visual/audio quality, and (2) the smoothness of playback.
When discussing bit rate, we're usually talking about the total bit rate... that's
the bits for the video and the audio, and a few more bits for 'overhead'. The figure we'll see in MM2
is the total.
Playing a High Definition movie on a low end computer isn't a good experience,
as the bits of data overwhelm the system and the movie pauses, hesitates, misses frames, etc. The computer
tries its best, but there is too much data flowing into it to give a good quality presentation. You might
think the file is bad, but it's the ability of the computer to play it smoothly.
And using a high end computer to view a highly pixilated video made from poor
quality video and audio inputs isn't pleasant either, no matter how smoothly it plays.
Movie Maker 2 provides an easy way to gauge how many bits of data the saved movie
will need to flow each second to be able to see the rendered movie play smoothly... regardless of visual/audio
This screen of the Save Movie Wizard shows the highest bit rate I've dealt for
WMV files so far in MM2, the 8.4 Mbps rate for my emulated 1080p high definition movies. It's easy to
see what the bit rate will be, even before committing to rendering the movie. Movie Maker tells you (unless
you picked a Variable Bit Rate option). Change the option in the pick list and see the change in the
bit rate figure.
A computer with a 3.0 GHz CPU is needed to play a 1080p file smoothly.
Most people don't have one.
And, with the same project on the timeline as for the above figure, here's the
situation if I select a good setting for those viewing on a dial up modem. See the 38 Kbps figure, which
is over 2000 times less bits per second than the high quality choice above. Two extreme choices for saving
the same movie.
For the same playing time, the measure of file size versus quality between these
two choices is: 274+ MB for 1080p and 1.3 MB for a dial up modem.
Custom profiles for use with MM2 must have video target bit rates between 4 Kbps
and 20 Mbps.... note that Digital Video (DV-AVI) is 25 Mbps for both NTSC and PAL.
What's a Good Bit Rate?
Look for your personal sweet spot in bit rate for each movie you render... a rate
that depends on your usual methods of distribution and your viewers ability to play your movies smoothly.
For my web-based movies, I use a bit rate of about 350 Mbps as a rule of thumb.
I'll usually pick my option by using the choice 'Best fit to file size ___', toggling the file size figure
and watching the bit rate at the lower left of the wizard. When the display size is right for web-based
movies (320x240 is good for my standard aspect ratio ones), and the bit rate is about 350 Mbps, that's
what I'll go with.
The standard profiles in MM2 go as high as 2.1 Mbps.... you can drive the rate
up higher with custom profiles, as I've done in my simulated High Resolution ones.
Windows Media 9 Codecs
There are seven Windows Media Audio and Video 9 Series codecs.
|Windows Media Audio 9
||Audio codec for general use in encoding complex
audio, such as music. (the normal one used by Movie Maker 2)
|Windows Media Audio 9 Professional
||Audio codec for encoding complex audio, such
as music. Supports multichannel and 24-bit encoding. (used by the Encoder)
|Windows Media Audio 9 Lossless
||Audio codec for lossless encoding.
|Windows Media Audio 9 Voice
||Audio codec optimized for encoding the human
voice at high compression ratios. This is the preferred codec for streams consisting mostly of
spoken words. For content that is mixed music and speech, this codec can dynamically change the
encoding algorithm used to get optimal quality.
|Windows Media Video 9
||Video codec for general use in encoding complex
video, such as movies. (used by Movie Maker 2 - with a few exceptions for the Pocket PC choices)
|Windows Media Video 9 Screen
||Video codec optimized for encoding sequential
screenshots. This codec is often used for software training or support by recording monitor images
as computer applications are used. (used by Encoder when doing screen capture)
|Windows Media Video 9 Image
Video codec for converting bitmap images (still photographs) with deformation
information into compressed video. (used by PhotoStory)
Seven Media Series 9 codecs. But we know from MM2 experience that there are lots
of choices when using these seven.... the choices are in the settings.
The profiles we select from in MM2, or the custom ones we create by tweaking
the settings in the Profile Editor, are all dealing with the settings within these codecs.
Think of the hundreds or thousands of codecs that we saw in GSpot.... many
of those have as many possible settings as those presented by the Windows Media series codecs.
Some Windows Media Products
Movie Maker is good for capturing
video from camcorders or recorded analog tapes, making a movie with a single bit rate, and mono or stereo
audio. It was intended for home or casual users.
For businesses, Microsoft
Producer enters the scene, allowing you to render a movie to a number of different
bit rates at the same time, and to integrate info from Power Point presentations with other material
such as a video of the person doing the presentation.
For professionals (and anyone
else who wants to use it), the Windows Media Encoder also supports features such
as screen capture, live video capture, multiple-data streams in one file, and surround sound audio.
Windows Media Encoder - Mini-Tutorial
Let's quickly step through the Encoder, using it to convert a file. I'll take
a high definition trailer file of the Magic of Flight and convert it to a DVD quality file.
Here's the opening window of the Encoder.
Once you pick Convert File, you get this screen to specify the source file and
the output. I'm picking the Magic of Flight trailer and making a copy of it in the same folder.
Next is your choice of distribution method. Let's pick the one that includes a
Then use the Video and Audio pick lists to select something appropriate for a
See the Tip at the bottom of the window about being able to adjust the settings
after completing the wizard. The wizard sets you up with a good balance of settings, but the Encoder
lets you tweak them further.
I'm not going into tweaking the settings.... let's just render the new file from
the source file. See that the Encoder shows both the source file being used and the new file being rendered
(for the second pass of a two pass VBR process).
After the rendering is done, the Encoder shows you the tally of the results. I
aborted this rendering before it was finished, as I was doing it just to get some screen shots for this
newsletter, so don't look too closely at the figures.
Note that the above info includes such things as dropped video frames and audio
There are different approaches that users of Movie Maker can use. The person who
requested this topic saves his movies as DV-AVI and then uses the Encoder to tweak the settings of his
WMV files. My approach is to learn about profile settings, make custom profiles and use them with Movie
Maker 2... skipping the step of saving the movie to a DV-AVI file. Both approaches work.
My personal interest is in the 82 profiles in the c:\Program Files\Windows Media
Components\encoder\Settings subfolder. They have been setup by Microsoft to achieve a good balance in
the various profile settings, a great starting point to make custom profiles for MM2. Use any of them
with the Profile Editor to make additional choices for Movie Maker 2.
That's more than enough for this newsletter. See you on the newsgroup and forums.
Don't forget to respond to the poll.
I look forward to any comments or discussion about this newsletter on the forums at
Movie Maker 2 -
Photo Story 2 -
Products and Services
I'm involved in many things that support the users of Movie Maker and PhotoStory, and adding more
daily. Here's a list of those that are available to the public. Some are free and others are reasonably
Movie Maker 2 - Do Amazing Things
its online companion on
Movie Maker 2 - Zero to Hero (with support on the Friends of Ed forum)
Wrote 14 hacks that will be included in a new O'Reilly book about Windows Media Hacks
When ordering these books, I'd appreciate you using the links to Amazon on the main page of
Movie Maker 2 -
www.papajohn.org - with two goals: to help you solve
problems, and to be the online companion to the Do Amazing Things book
PhotoStory 2 -
Online Support - Forums and Newsgroups:
I'm a regular at many online
forums and newsgroups, the main ones being:
Movie Maker 2 and PhotoStory 2 forums at
Movie Maker 2 forum at SimplyDV.com -
Movie Maker 2 newsgroup at microsoft.public.windowsxp.moviemaker
PhotoStory 2 newsgroup at microsoft.public.plus
Weekly Movie Maker 2/PhotoStory 2 newsletter. Subscribing is free via the link
on the main page of
Tentative topics for upcoming newsletters (subject to change):
#11 - (open to your suggestions)
Transition Maker 2 - a utility that you can use to make the ultimate in personal and custom transitions
for Movie Maker 2 -
I routinely do beta testing for Pixelan and think very highly of their people and products: Their
SpiceFX packages of additional transitions and effects for Movie Maker 2 are available at:
If you can't save a movie from your project, I'll divide an overly complex one into manageable sub-projects
and provide detailed instructions to render the parts and assemble them into your final movie. $49.95
- for details, see the sidebar on the Problem Solving > Can't Save Movie page of
Movie Maker 2/Photo Story 2 training and support services start at $50 per hour - email
with an outline of your needs. I'll work with you to define and implement the project.
About John 'PapaJohn' Buechler from Microsoft.com
||John "PapaJohn" Buechler, of Kalamazoo, Mich., goes by PapaJohn
online. An avid user of Movie Maker since its first release, and a
regular supporter of the community of Movie Maker users, John
received a 2003 MVP award from Microsoft for that support. In March
2003, he started a comprehensive website about Movie Maker 2 at
He maintains the website, writes books and articles, teaches, and
provides support services - all for the community of Movie Maker 2
users. An engineer by formal education, John is a computer database
and multimedia expert by business and personal experience. He
co-authored the first book about Movie Maker 2 and is actively
working on a second one. You can find his advice in the
Windows XP Movie Maker newsgroup and in the
Windows Movie Makers Forums.
newsletter is republished with permission of John "PapaJohn" Buechler.
Please note that this is an archive of
newsletters and some information may become outdated. PapaJohn, and the webmaster of this
site, provides this information
"AS IS" with no warranties.