Study DV-AVI File Rendering
This issue was planned to be about converting MPEG-2 files to AVI, but the AC/DC converter on
the power chord of my Toshiba laptop stopped working last Thursday, and it's back to the CompUSA
repair center in Texas. Until it returns, I'm back to using my older minimalist Dell Inspiron 3200...
266 Mhz CPU, 144 MB of RAM, and an almost full 4 GB hard drive. I needed a topic a bit less challenging
on the laptop so I thought I'd revisit a couple issues about rendering movies to DV-AVI files.
It'll be two years ago next month that a couple of us did some testing of the generational losses
we saw in both DV-AVI and WMV files... re-rendering a previously saved video would lose a frame
or so. What frame and why?
During that testing I had pointed to the visual loss of the 27th frame of each DV-AVI clip on
the timeline... one lost frame per clip when rendering to a new DV-AVI movie file.
The routine stream of posts from users noticing audio and visual issues with saved DV-AVI files
continues... so I thought it would be a good time to revisit the subject, and this time look as
closely at the audio track as the visual.
This will be one of those newsletters that some readers don't like, can't follow, or get confused
about... rather than not read it at all, skip to the conclusions and closing section at any time
to see what the bottom line is.
I'll start with a 15 second Photo Story... one that diagonally pans a still image at a constant
speed that shows the change in position from one frame to the next. After studying the visual frames,
I'll add a music track and study the audio in as much detail as the visual. Even this minimalist
laptop can handle a 15 second DV-AVI file.
The lost 27th frame of the first clip is still there. SP2 and MM2.1 haven't resolved it. With
the help of Photo Story 3, TMPGEnc, Excel, and Audacity, we can look closer at missing frame locations
and dropped audio segments. When I looked with a magnifying glass a couple years ago, it's more
like being able to check it today with a microscope.
... but before getting into it, here are some notes about current items...
Current Interesting Items
Ellen, a newsletter subscriber, sent an email pointing me to a great website... 2,650 downloadable
midi-files of piano tunes free to use as background music in non-commercial stories and movies.
I checked one pack and this piece in it:
That was enough to wet my appetite for the rest. It's midi-music but sounding 10 times better
than the midi-music that I'm used to hearing. The website is
Remember those old 'player pianos' that automatically play a tune from a paper roll... Terry
Shaw has been rounding up rolls from around the world, scanning them to get the paper cutout info
converted to digital files, and then creating midi-files from them.
The midi file format isn't supported by Movie Maker, but plays fine in the Windows Media Player.
My sample WMA file is a Movie Maker 2 narration file recorded as I played the midi file in WMP10.
It's that easy to use one in a project.
The site also has a downloadable master index to all 2,650 tunes in an Excel spreadsheet. I've
downloaded all the tunes and the index.
I was reading a book about Adobe Premiere Elements and surprised to see that it can only work
with Digital Video source files... no analog sources with conversion devices... even analog to DV-AVI
conversion devices won't work with it, such as using a digital camcorder as a pass-through device.
Page 47 of the Visual Quick Start Guide for Premiere Elements says "... you'll have to use another
program... such as Windows Movie Maker... to capture footage using this method (pass-thru)...".
On the other hand, the software is probably great. Similar to Premiere itself, you can use as
many as 99 audio tracks and 99 video. You can do clip speed reversals, freeze a frame, link audio
and video clips to retain sync, do sophisticated motion and transparency effects, apply 'rubber-band'
volume controls to a clip, When saving a movie, you can opt to burn a DVD (it includes DVD menuing),
save as a DV-AVI, export to a camcorder, export to MPEG format... or Quick Time (MOV), or WMV. Having
used Photoshop/Photoshop Elements and Premiere for a number of years, I'm sure the package offers
a lot for the cost.
I tried using the Windows Media File Editor to embed a website address in a video. It worked
in a sample on my website... go to
this page, scroll down to the embedded media player, enter HelloWorld.wmv above it (be careful
as it's case-sensitive), tab a couple times to move the focus to the start button... and play the
22 second video.
At the end of the video the NASA World Wind website will automatically open. The website page
includes info about how to embed the URL.
.... on to the main topic
To prepare for the assessment...
...I did a diagonal pan of a single large picture, using Photo Story 3 to make a high quality
video clip... no audio, no starting transition, and accepting PS3's duration for the smooth pan
- 15 seconds. I wanted something fairly plain, but with moving pictures and text, and a linearly
smooth pan so I could see any breakdown in the smoothness from one frame to the next.
MM2 said the story file (WMV) was 14.93 seconds long. I wanted a DV-AVI file as a starting point,
not a Photo Story, so I used MM2 to save it a DV-AVI file.
I imported the saved DV-AVI file right back into MM2... where in the collection bin MM2 said
it was 14.88 seconds long... I'd been used to the
dropping of the 27th frame when making the DV-AVI file, so the shorter duration by 0.05 seconds
I dragged the DV-AVI clip from the collection to the timeline. The duration of the timeline per
the monitor was 14.87 seconds, but the position of the end of the clip showed as 14.80 seconds.
With Movie Maker's preview mode being a rough draft 15 frames per second, this difference is
probably not significant... just noted.
I was only getting ready for the serious studying... let's move on to our quality checking and
see what we can learn.
First Quality Check - the Dropped 27th Frame
In this first generation rendering, using only one clip on the timeline, there should only be
the dropped 27th frame... something to start the detailed studying with.
I used TMPGEnc to extract the first 50 frames to individual JPG files. When it reached the 50th
frame in the saving process, I pressed the Stop button and ended up with 52 extracted frames.
Frame numbers start with 0 (zero), not 1... so the missing 27th would be the picture file #26...
I flipped through the images in IrfanView, like you would a deck of cards. I didn't see any break
in the visual flow when I flipped past the 27th frame.
Sub-Splitting the Single Clip
Let's go ahead and split the clip on the timeline into five 3 second sub-clips, do nothing more
to it, and render it to a DV-AVI file... the timeline stayed the same during the clip splitting
in the project... 14.87 seconds of duration showing under the monitor.
The newly rendered DV-AVI file shows as 14.67 seconds... down 1/5 of second in duration (5 frames
at 30 frames per second is about 1/5 of a second). At this point I'm thinking the generational loss...
the 27th frame of each clip... is doing it.
Splitting each of the sub-clips again... each into 3 parts... gets the project to 15 clips on
the timeline. The saved DV-AVI file is now 14.53 seconds... going down.
One more round of splitting each clip into 3 parts... the project is now 45 clips on the timeline.
Still 14.87 seconds on the timeline before saving, but now all the way down to 13.57 seconds after
saving. We've dropped almost 1-1/2 seconds by splitting the clip into 45 sub-clips.... 1 frame per
clip... with this approach the 27th frame generational loss issue seems to be a constant at 1 frame
But how does it effect the smoothness of playing? Is it still smooth, with the same beginning
and ending frames, just playing quicker to get through it? What frames are missing?
I used TMPGEnc to make sets of images from each frame of the saved DV-AVI files. There were 446
frames from the full starting clip.... and 411 from the file rendered from 45 sub-clips... 35 fewer
frames... but that wasn't 45 fewer, a chink in my long-standing point that it was dropping one frame
per clip... it's not, or not unless TMPGEnc somehow sees frames differently than Movie Maker.
It's time to study the sets of frames closer. Believe it or not, time to open Excel.
Study Missing Frames/Images
I did a number of passes with the renderings and frame extractions, and put the lists of files
into an Excel spreadsheet to help evaluate them.
The baseline file with no audio was a single 15 second clip, 446 extracted frames. When split
into 15 clips on the timeline, there were 10 fewer extracted frames. I checked the data in Excel
and noticed that the extracted frames each had a different file size, reasonable as I had opted
for JPG images... comparing the files sizes of the two sets of frame images showed each to be exactly
comparable... until... YES!!! the 27th frame wasn't there. The 28th frame and beyond were aligned
to continue the pattern.
But I also saw that maybe I lucked out by seeing the first missing frame as the 27th... by continuing
the comparison, and making a close but not exact comparison of where the missing frames were relative
to the clips on the timeline, the 10 dropped frames were located as follows:
27th frame of the first clip (this was exact... the ones that follow are approximate locations)
last frame of the 2nd clip (because it's approximate, it could be the first frame of the 3rd
last frame of the 3rd clip
last frame of the 6th clip
last frame of the 9th clip
20th frame of the 10th clip
27th frame of the 12th clip
last frame of the 13th clip
last frame of the 14th clip
last frame of the 15th clip
The missing ones were mostly not the 27th frame of each clip... and some clips had no missing
Split into 45 clips on the timeline... 35 dropped frames... checked again in the spreadsheet,
but I won't put the details here. The locations of the dropped frames didn't always align. In fact,
the first dropped frame wasn't the 27th... it was the 29th.
Some users had reported that adding an effect, any effect, was enough to resolve audio issues,
so I tried adding an effect to see what it did to the dropping frames.
A single clip with the mirror-horizontal effect applied had 1 dropped frame, the 27th. And the
15 clips with the mirror-horizontal effect applied to each of them also had 1 dropped frames, the
27th. Adding the effect to each clip on the timeline had effectively stopped further frame drops.
This newsletter can only be so long, and I want to get into the audio track also, so I'm stopping
here with the visual issues...
I'd be glad to email
you a copy of the spreadsheet if you ask.
Study the Audio Track
This is my first comparable study of missing info on the audio track. I started with a new 15
second clip, this one with music, rendered to what I call the audio baseline clip of 15 seconds.
I split the baseline clip into 15 clips... at each of the full 1 second points of the timeline.
Here's a picture showing part of the baseline clip with music, split into 15 one-second clips.
On the audio track below it is a copy of the baseline audio DV-AVI file. At this point the two audio
tracks are in sync.
Pre-rendered 15 Clip Splitting... and Baseline Audio Track
And now another view. The same baseline clip is on the Audio/Music track, but I replaced split
15 sub-clips with the new DV-AVI file rendered from them, a single clip.
The rendering had resulted in the 10 dropped visual frames; looking at the audio shows that,
what starts off being in sync drifts apart over the duration of the project... and the drifting
apart starts at about the 27th frame.
Newly Rendered DV-AVI Clip versus the Baseline Audio
Let's zoom into the first second. I've marked the figure below to show where the 25th and 30th
frames are. The sync is there exactly thru at least the first 25 frames. I've circled the spot where
they begin to diverge... and, with my bias toward it going off as the 27th frame is dropped, it
appears that's what's happening.
Close-up of the First Second
In this technical analysis, I'm trying to determine if it's a sudden shift of audio or a gradual
loss of sync... it appears to be sudden, which correlates with the kinds of clicking or metallic
sounds reported as you hit such points during playback.
The visual showed the loss of only one frame by the time the 32nd frame is reached. The audio
shift looks more like 2 frames...
this assessment is close, but not exact. Each frame of a Movie Maker project is really a double-frame,
so taking a magnifying glass to it can't get you to the single frame level.
The visual frame assessments showed a loss of 10 frames over the 15 second clip. The image at
the right shows how much the audio is off by the end of the project... MM2 reports the new clip
as 14:38 and the baseline clip as 14:85, a shortening of 0.47 seconds... 14 frames. Not exactly
10, but in the same ballpark.
Do the two files end on the same note or beat? Yes, they do.... so the shrinkage or loss is between
the opening and closing notes. The audio isn't being trimmed at the end.
Is it a progressive movement out of sync? No, it's a sudden shift at certain points. We looked
closely at the first one, at about the 27th frame of the first clip. The next shift occurs right
after the end of the 2nd clip, aligned with the visual loss of the next frame. The visual then lost
another frame right after the start of the 3rd frame... the next audio shift was in the same place.
It's looking like segments of the audio are suddenly dropped at the points the visual frames are
The audio waves in the Movie Maker timeline are like using a magnifying glass. Let's get out
a microscope and look even closer.
An Even Closer Look at the Dropped Audio...
This is probably the most important part of this analysis... is there a segment of audio being
dropped, and if so, by how much? Let's use the Audacity utility to check the end of the first second...
where the first visual frame is dropped and some audio with it.
The upper two tracks of the next figure are the two channels of the stereo track from the baseline
clip, before splitting into 15 smaller clips. The bottom two are the same tracks from the DV-AVI
file rendered from the project which was split into 15 clips.
I used TMPGEnc to rip WAV files from the two DV-AVI files, and then put the imported WAV files
into Audacity for this analysis.
This picture shows both files in full sync past the mid-point of the first second. I've zoomed
into the Audacity timeline to view it in increments of 10,000ths of a second.
The next picture shows the beginning of the departure in wave patterns... with the wave patterns
being minimal in some parts, I had to do a lot of close looking to detect this point.
The two sets of tracks were identical in patterns up to this point, at about the 27th frame.
With a sudden departure in patterns, how much is dropped? This next picture shows it.. a 0.065
second segment... 2 frames of a 29.97 frames per second video. The segments of the audio track shown
in the upper two tracks are missing from the lower two.
Just one more picture and we're finished... showing the shift in the audio tracks due
to the dropped 0.65 second segment. We've now measured the dropped audio pretty precisely... 0.065
seconds = 2 frames.
At this point in the timeline, the extracted visual frames show us dropping one visible frame, but
the audio timeline shows the loss of 2 audio frames... the audio losses may actually be a more precise
way of assessing it than comparing extracted visual frames.
That's enough for this newsletter... for those who have gotten this far, I hope it's been interesting,
even if not particularly positive or helpful.
Conclusions and Closing
Some users report visual problems with saved DV-AVI files... others report audio issues. This
analysis shows why there can be both. When the visual and audio tracks of a movie play in real time,
the content can be such that missed information can be noticed or not noticed. It's a problem only
if you can notice the loss of info... or the shifting out of sync ends up causing alignment issues.
What we can say is that, at the lower level, the rendered DV-AVI movie is different than the
source files... slight or not, it is different.
We're building a pattern of lost visual frames aligning with lost audio frames. We can see the
visuals in the extracted frame pictures. Can we hear the audio glitches? After this analysis, I
rendered the shortened audio track to a CD quality WMA file and listened many times. I think I hear
issues but it's hard to tell conclusively... maybe because I don't particularly care for the music
the Bottom Line when heading toward a DVD:
For today it's: save your movies a couple or a few times: to DV-AVI for the best visual, to a
WMV file for the best audio, and then marry the visual and audio tracks together into a final DV-AVI
file rendered from one long clip. You'll have only one small hiccup at the 27th frame... within
the first second of your opening. If there's blackness and quiet for the first second, the split-second
hiccup won't be a problem.
What about audio/video sync issues? I ran across those in many places doing the wedding videos...
you just have to manage them during editing. Sync the video and audio where it's most important...
and resync as needed.
This is a small study... which shows the world isn't perfect yet. But it keeps trending in the
right direction. Nothing I've learned this week detracts from being able to use Movie Maker to achieve
amazing results, and I hope the information helps you learn a bit more about what's happening. It's
certainly helping me.
I look forward to comments and discussion about this and other newsletters on the forums at:
Windows Movie Makers.net
Have a great week...
Movie Maker 2 and Photo Story 3 - www.papajohn.org
Photo Story 2 - www.photostory.papajohn.org
Products and Services
I’m involved in many things that support the users of Movie Maker and Photo Story, and adding
more daily. Here’s a list of what is available to the public. Some are free and others reasonably
Books and Magazines
Movie Maker 2 - Do Amazing Things
its online companion on www.papajohn.org)
Maker 2 - Zero to Hero - with support on the
Friends of Ed forum
MaximumPC’s winter 2005 quarterly special... had a 7 page tutorial ‘Make a Killer Home Movie
with Maker 2’. The special edition of the video that was made for it is now
on my website as a
Publishing of Birmingham, U.K. is rolling out the first book about VirtualDub, expected in April.
My contribution was the introductory chapter... I’m glad to be part of any effort that helps
join the worlds of Movie Maker and open source software.
Movie Maker 2 and Photo Story 3 - www.papajohn.org - the
site’s 3 goals are: an online companion to the Do Amazing Things book, a detailed tutorial on Photo
Story 3, and helping you solve Movie Maker 2 problems.
PhotoStory 2 - www.photostory.papajohn.org -
a detailed tutorial about using it. It’s not a problem-solving site.
Online Support - Forums and Newsgroups
I’m a regular on many online forums and newsgroups, the key ones being:
Forums are open to all for viewing, but require registration of those who want to post. Moderators
actively participate to ensure the forum discussions move forward and stay on track.
Movie Maker 2 forum at SimplyDV.com
Newsgroups are wide open for all to view and post... moderation is collective by the participants.
Windows XP Movie Maker newsgroup -
Photo Story 2 newsgroup -
Photo Story 3 newsgroup -
Movie Maker 2/Photo Story newsletter. The annual subscription is $20 and the link to subscribe
is on the main page of my Movie Maker website at:
Topics for upcoming newsletters (always subject to change):
#50 - April 23 - Converting MPEG-2 files... there are new utilities and revisions to older ones...
the issue will look at the current state of converting files to make ones that work in Movie Maker.
#51 - April 30 - Civil War Project - part III - finishing the parts and moving toward the integrated
movie project. I probably won’t use the snippet of this week’s newsletter... as I’ll keep the focus
on Gettysburg. You can expect to hear more of the old time player piano music.
#52 - May 7 - Custom text clips
#53 - May 14 - Capturing video clips from DVDs... another topic where new utilities, and changes
to existing ones, are becoming available or evolving.
#54 - May 21 - open
Older newsletters (more than 6 issues ago) are posted by Rob Morris to an
Archive Site at his Windows
Movie Makers website.
Drop an email at any time to suggest a topic of interest to you....
Software Add-On Transitions and Effects
Maker 2 (TM2) is a utility for the ultimate in making your own personal and custom transitions
for Movie Maker 2. It’s a joint product from Patrick Leabo, the programmer, and myself. Version
2 was released a week ago and I’m still working on updating the online tutorial.
routinely beta test the Pixelan packages and
think very highly of their people and products.
ProDAD’s Adorage package for Movie Maker 2 provides an additional source of professionally developed
transitions and effects.
Managing your personal information is more of a challenge as hard drives get bigger and the internet
My personal database has been an ongoing project over many years, and is now available to others.
Info is on the Managing > Personal Database page of my site, and in the database package itself.
It’s available free to regular newsletter subscribers... send an email request.
To others it’s $10. To order, use the button on the top of the Managing > Personal Database page.
An online gallery that fully aligns with the main priority of the website is the
‘PapaJohn Expert Zone’ at neptune.
Check it at Neptune and the Distributing > Neptune
page of the website, where there’s a developing tutorial about how to use the service.
The Portage, Michigan library added two new training sessions: Introduction to Movie Maker, and
an Advanced Movie Maker Workshop. The initial sessions will be:
Monday - June 13 - 6-7:30 Introduction to Movie Maker 2
Monday - July 18 - 6-7:30 Movie Maker 2 Workshop
Monday - August 15 - 6-7:30 Movie Maker 2 Workshop
Other fee-based services
you can’t save a movie because your project has become too complex, e-mail a copy and I’ll divide
it into manageable sub-projects, and provide detailed instructions about how 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 a Movie page of www.papajohn.org
Movie Maker 2/Photo Story training and support services start at $50 per hour - send an email
- PapaJohn@CharterMi.net and I’ll help you determine
your needs, and work with you to plan and implement them.
Wedding combo website/video packages - starting at $2,500 + travel expenses. See
Jill-MarkWedding or the bottom branch of the Movie
Maker 2 website for a sample of what you can expect for the online portion of the package.
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.
Visit - PapaJohn's Movie Maker 2 and
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