PapaJohn's MVP LogoMovie Maker 2 and Photo Story
Newsletter #60 - July 2, 2005

A Source File - from Cradle to Grave

Movie Maker makes a great a file utility in addition to being a video editor. I'll often use it to capture video footage from my camcorder, split the footage into clips, and render the keepers to new files. Then I'll delete the originally captured file and clean out the collections. When doing these I don't consider any of the clips to be 'source files'... they are 'potential source files' that are kept in my library folders.
When there's a new project starting up, I'll import files from the library into the collections, work on them there a bit, and move selected clips into the project. At this point, I'm using Movie Maker as the editor, and I consider the imported files to be 'source files'... I'll expect them to stay in the collections and project until I've rendered the movie and archived the project. 
Source files are always a great topic... you should know as much as you can about the types of files that work in Movie Maker, how Movie Maker handles them, and how to ensure they remain available until no longer needed. In this issue, I'll take a source file and follow it from importing file to archiving.

In addition to the normal collection and project views, I'll look inside things we don't usually see, the contents of a collection database and the info in the project file... to see what's there and learn from it.
Because DV-AVI files are the largest and most difficult source files to manage, I'll pick one of those.
... before that, here are a few notes...

  • After issuing last week's newsletter about converting DVR-MS files... someone posted a couple tips about how to use the DVR 2 WMV utility, one of those that didn't make the cut last week because all I got were error messages. With his tips, I did some test conversions. When I found it can use custom profiles, I developed one to get high quality 8+ Mbps bitrate WMV files. The conversions were quick and easy when it works... it doesn't always.
I added the new method to the Importing Source Files > Video > Recorded TV page of the site. So it has gone from having one method to three in a week. The DVR 2 WMV utility is the first and easiest... even if a bit buggy...
  • Another tool I tried this week is WMRecorder, a utility to capture streaming WMV video to WMV files on your hard drive. I tried the test one that came with the app, and a couple others... it worked and the captured videos worked in MM2. The trial version which I used is limited to a 2 minute capture... the full unlimited version is $29.95.
  • I'll be recording the second of the bi-weekly radio sessions on Saturday, this time reducing the number of Q&A items a bit to make time for a new feature, a 'tip of the session'... the first tip will be about getting audio into Movie Maker.
.... on to the main topic

Importing a DV-AVI Source File
When you 'import' a source file, MM2 doesn't make a copy of it. It simply checks the file over, gets its vital stats... file name, folder location, duration, starting and ending points, file type, pixel dimensions, and frame rate.
It also makes a thumbnail image from the first frame and stores the image with the vital stats in the collection database, a file that contains the info for all the source files and clips currently in your collections.
A single video source file can be represented by a single clip in a collection, or it can be split into many clips, automatically by Movie Maker or manually by you. If split, then each of the multiple clips get treated as individual items in the database. A one hour camcorder tape could be one 13 GB source file in a folder on your computer, but with hundreds of clips in your collection(s) being linked to it.
As you import the source file and split it into clips in the collection, Movie Maker will open the file as needed to get the info needed for each clip. It'll add the info to the database and then move on to do other things. It won't keep the source file open. Other apps are free to use the same file.
Each time you open Movie Maker, one of the things it does is check the source files for the collection database... are they all there? If not, a big red-X replaces the thumbnail to indicate there's something that needs resolution.
But the source file needs to be there if and when it's needed again. In some sense (getting summary info and a thumbnail image), the process is an 'importing' one. In another sense, it's more of a dynamic 'linking' one, opening the file only when it needs additional information... when previewing or splitting it.

The Usual View...


When I first captured my camcorder footage of an air show in Chicago, I did a lot of work using Movie Maker as a file utility, splitting the footage into the more interesting clips, and rendering individual DV-AVI files... using MM1 to make type II clips universally accepted by other editing apps and utilities. I put the pack of long-term keeper clips on a set of data CDs and cataloged them. You can fit a 3+ minute DV-AVI clip on a CD.

To prepare for this newsletter, I cleaned out my collections, copied one of the source files from the CD to my laptop's library, and imported it. The only thing in the collections at the right is that clip, a 31 second one.

I then moved the clip to the timeline, split it in two, and added a transition...

The picture at the right is our traditional user-oriented view of the collections and the project timeline. Let's look inside the collection database and the project file to see what source file info is stored there.

The collection database and project files are encrypted, not easy to understand... but let's take a peek anyway.

Inside the Collection Database (MEDIATAB1.DAT)...Collection

Here's the section of the collection database, a MEDIATAB1.DAT file, that has the info we're interested in... you don't have to be a programmer to understand some of the underlined items to see what info relates to the source file.

  • - File size - 113,864 bytes
        • - File type - Video Clip
        • - Duration - 30.597+ seconds
        • - DV = "yes"... typically a 0 means no and a 1 yes.
        • - Frame rate - 29.97+
        • - Height - 480 pixels
        • - Width - 720 pixels
        • - Path - c:\Library\Video\Source Files\Chicago Airshow\Helicopter-11.AVI

There are no pointers in the collection database to the project file. The might not be a project that uses the clip.

It's a one way process. The source file info goes into the collection database, and then clip info from the collection cascades into the project file when the clip is copied to it... it never flows back from the project to the collection. Projects are complete in themselves, not needing the collection database... but still needing the source file.

Inside the Project File (MSWMM)...

The project file looks similar... computer encryption code, some programming info, and enough words to understand which source file is being used.Inside Project File

Splitting the clip and adding a transition makes the info in the project file a bit more complex.

Don't dwell on the details... the important thing is that the project file contains all the info about the clips for the project, including thumbnail images, but it doesn't contain copies of the source files themselves.

It has some into about the source file.. most of the info just before the upper red line:

- File size - 113,864 bytes

- File type - Video Clip

- Duration - 30.597+ seconds

- DV = "yes"... typically a 0 means no and a 1 yes.

- Frame rate - 29.97+

- Height - 480 pixels

- Width - 720 pixels

- Path - c:\Library\Video\Source Files\Chicago Airshow\Helicopter-11.AVI

The sequence the source file info appears is the same in both the collection database and the project file. When you drag a clip from a collection into a project, it's quicker and easier to just copy the info about it from the collection database than it is to re-open the source file and collect the same data.

All the added info between the red lines is due to splitting the clip and adding a transition... and any added trim points, fades, and other things you do to clips on the timeline.

Photo Story handles project files very differently. It copies the entire set of source files into the project file... a Photo Story project files grows large while a Movie Maker project file stays relatively small. You wouldn't want a one hour DV-AVI file of 13 GB to be copied into each project file that used a segment of it.

Just as a collection database doesn't have any pointers to project files, the project file doesn't have any pointers to a collection database. Take a project file and its source files to another computer and you can do your next editing session there. 

Source File Portability...

At this point I wanted to check the info in the project file when I moved it and its source files to a thumb drive... the project will be ultra-portable for editing sessions on any computer running XP and your version of Movie Maker. Be careful not to step up to a higher version or the project file won't open again when brought back to the lower version. if you're using MM2.0, don't go to your friend's computer running MM2.1 and expect to take the project back home.  

I used a MuVo portable music player that also works as a thumb drive, one with 128 MB of flash memory. After moving the files, I used MM2 to re-establish the link to resolve the big red Xs in both the collection and the project.

But I was pressing the limits of the space on the thumb drive, so right after the move, I swapped the helicopter clip out with a smaller airplane clip. Residual Clip InfoThat resulted in an oddity that I don't understand. The first clip was 'Helicopter-11.AVI' deep in a sub-folder in my library on the c drive. The clip I replaced it with was '6 planes-3.AVI' in the folder on the thumb drive. 

I had deleted the original helicopter clip from the project and the collection... when I looked inside the revised collection database, the original helicopter clip was no longer referenced... but when I checked the revised project file, both the original and the new source files were referenced... for some reason the original pointer wasn't deleted. Other than taking up a little extra space in the file, I didn't run into any issues when I previewed and rendered the movie.

... it left me wondering, so I've submitted the item to Microsoft for comment. And I tried it again, replacing the second clip used with a third one. The project file is acting like a log, now with 3 source files referenced when the first two are no longer being used.

The residual pointers in the project file can never help, but might bite you someday... I don't know when or how. If you're just doodling a bit at the beginning of a new project, testing different clips for the opener, I recommend starting over with a new project file when you're ready to expand the project.

Source File Changes...

Once a DV-AVI source file is in a project and the key data neatly stored, Movie Maker only checks that the file is still in place. It doesn't check any deeper than that, so it's very tolerant of changes to the source file... so tolerant that you can replace them with slightly or totally different DV-AVI files, or even a WMV file. Why would you ever want to do that? I can think of many reasons.

Look at the amazing possibilities this feature supports... say you've put hundreds of hours into making your project perfect in every way... but then you notice things you can't easily change in Movie Maker:

  • A scene is overly dark and the brightness effect of Movie Maker isn't sufficient to enhance it. >>> Open the clip in VirtualDub, use the levels adjustment and resave the clip in the same place with the same name. Movie Maker will continue to use the clip with the new enhancement.
  • You wish you had added your logo to part of the movie. >>> Do it to the source file(s)... over on the side with Movie Maker, VirtualDub, or another utility.
  • You have a 13.679 second clip in the middle of your project and it's packed with effects, transitions, titling and other things around it... you have a 35 second clip that you would like to use instead, but just for the first 13.679 seconds of it. But you're afraid to touch the project now. >>> Put the new clip in there in place of the original and it'll be done automatically... it's always a good idea to make a backup of the original one... do it easily by leaving the videofile.avi file in place, changing it's name to videofile.old and slipping in the new 35 second clip as videofile.avi. The project is already set to use just the first 13.679 seconds of the source file, and will automatically stop after that duration.
The new source file can be any length, regardless of the duration of the first one. If the new duration is longer, the project will clip the info from it. If the new duration is shorter, it'll show blackness from the end of the new clip until the project duration is reached.
  • You have a 5 minute DV-AVI clip but you find that the audio has glitches that you hadn't noticed before... you also have a high quality WMV version of the same file and the audio is fine. >>> Slip the WMV file in there and it'll act fine as the replacement... be sure the name and extension fully aligns with the source file being replaced.
  • The project consists of hundreds of subclips from some DV-AVI source files, and the rendering to a DV-AVI file results in lots of audio glitches. >>>> Swap the DV-AVI source files out with high quality WMV files and try again.
  • You have a great Photo Story 3 story that you would rather use in the spot that one of the DV-AVI clips is, and the transitions and effects already in the project will fit in nicely. >>> a PS3 story will work as a substitute for the DV-AVI clip. No need to touch the project editing. When you look at the timeline, you'll see the original clip thumbnail in the collection and on the timeline, but the previewing and rendering will use the frames from the story instead. 
These are a few things I can think of, all good reasons to swap a DV-AVI source file out with either another DV-AVI clip or a WMV.

Backing Up and Archiving 

Digital camcorder tape storage is easy and economical... my per tape cost at Sam's Club is now $2-1/2 for an hour of DV-AVI files... and the price keeps creeping down.

... you can recapture it from the tape when you need it.

One key to doing this is to have good records... so you know where the source file starts on the tape... the project file itself tells you the original source file name and folder location.... right click on the clip (even if it has a big red X) and check its properties. The other key is trying it to gain confidence that it'll work when you need it.

If you're careful to note the starting point of a DV-AVI source file... the exact frame that marks the T=0 point... perhaps take a snapshot of the wave patterns of the audio track to serve as a fingerprint, or save a 5 second starting snippet for later reference...


Conclusions and Closing
Part of me is a hacker, enjoying the experiential studying of how things work, things like how a collection database and project file stores info about a source file, and what I can do and can't.
Another part of me wants to share what I learn with others... and the weekly newsletters have been a great way to do it... the website and newsletters are now the core of what I'm doing on a regular basis, reaching far more people than the various postings on forums and newsgroups.
For those celebrating the Independence Day holiday weekend, have a wonderful one... take lots of pictures and video... and make movies and stories next week.

Have a great weekend...