PapaJohn Productions
Newsletter #111 - July 8, 2006

Audio Wave Patterns


Movie Maker doesn't include sophisticated audio editing features. You can mute a clip, fade into or out of it, adjust the volume of a selected clip or the relative volume between the project's video and music/audio tracks... and look at the wave patterns displayed in the timeline.
In Photo Story 3 you can't do that much, so we'll limit the discussion to Movie Maker.
I use the wave patterns a lot when editing a project, often as a quick confirmation that things are going well, as the guide to exactly where to make the  and later to make final alignment adjustments of the clips on the timeline.
Let's start with the audio of a DV-AVI file captured from a mini-DV camcorder, a common starting point, and one that has integrated visual and audio tracks where synching is often critical.

Movie Maker can rip audio from video files into compressed WMA files, which are great for use as audio source files in movie projects. But to get an uncompressed WAV file to edit in Audacity, you need something else.
I use TMPGEnc 2.5 to rip the audio from a DV-AVI or WMV file (including PS3 stories) to uncompressed WAV files (File > Output to file > WAVE file).
TMPGEnc says the audio stream of the DV-AVI file is PCM, 48.000 kHz, 16 Bit, Stereo, which aligns with what Movie Maker reports.... note that I changed my Sony TRV-80 camcorder setting from the default 12-bit audio to the higher quality 16-bit.
Focus On
When I finished getting the WAV sample, I realized I'd done one or two extra rendering steps... but I had all my pictures for the newsletter by then, and going from one DV-AVI file to another shouldn't change the uncompressed audio... so I left the files and screen shots as is.
Here's the pattern of the WAV file imported into Movie Maker 2. We have visual wave pattern alignment between the captured video file and the ripped WAV file. This next image is a link to the ripped WAV file. Being uncompressed, it's a 6 MB file for 30 seconds of audio.
Click to Listen
This WAV file will be our benchmark for this newsletter.
... before getting into it further, a few notes...


Vista Corner... the test Renaissance Wedding DVDs I made with Vista were cute and played well, but had a menu issue that made them unusable. The 2nd and 3rd of the 4 menu screens were totally black when played... even though the menu buttons on the pages worked fine if you groped around in the dark to find them. 

I completed the DVD project for the Renaissance Wedding with Roxio's MyDVD Premier 8. It was kind of slow going, like when a timeline is getting pretty full in Movie Maker and things hit a big slow-down point. There were also some minor error messages or other issues along the way, but it ended up fine.
I rendered the DVD project to an iso image file on the hard drive, and then used MyDVD to burn the discs from the iso file. The iso file is 4.4 GB in size, and the DVD plays for 67+ minutes.
It took a few hours to render the MPEG-2 files and build the iso image, but it's now only about 10 minutes per disc to burn them from the image. The most important thing is the discs burn cleanly and play well.
There's just one remaining step, printing the labels directly on the discs with an Epson R200 printer. I have some printable white discs but need to get some printable silver ones (personal preference).

My first for-sale video on Google Video... submitted on May 3... still has the status of "Video is verified; stay tuned - it will be live shortly"... that's now over 2 months in the queue to be online.
I'm taking bets as to whether or not it ever gets to the next step of 'being live'.

The MaximumPC issue with the Photo Story 3 tutorial is in distribution to go on the bookstore shelves July 18th.
.... back to the main topic...

30 Second Audio Sample
Here's the first view of the WAV file in Audacity... which shows the left and right channels individually, compared to the wave pattern of the same WAV file in Movie Maker which shows the combined channels of the stereo track. The pattern is smoothed a bit for the thumbnail depiction by Movie Maker.
You can see how the visual pictures compare, and how easily it is to pick alignment points.
Audacity View 
MM2 Tightest ViewLet's zoom into a 2 second segment around the 15 second point. The picture at the right shows the tallest most zoomed in view I could get in Movie Maker. I won't show the closest view in Audacity as it really doesn't have a limit for such zooming... it can be both a magnifying glass and a high powered microscope when it comes to looking at wave patterns. 
Movie Maker's view is sufficient for syncing clips... Audacity can help you do microscopic audio editing.
The important thing here is simply to note how consistent the views of the wave patterns in a captured DV-AVI file and a ripped uncompressed WAV file are. The ripped file can be edited in audio apps and a 'fixed' segment returned to Movie Maker and used in a project with easy-to-align wave patterns. 
We've been looking at uncompressed audio files. Let's explore the patterns of the same 30 second sample in compressed WMA and MP3 formats.

MM2 Audio Profiles
WMA Files....
When you have audio-only in a project timeline, and save the movie... Movie Maker knows you want to render it to an audio WMA file.
Here are the choices of audio profiles. The first 8 come with Movie Maker. The other two are custom profiles I use to save the audio as a CD quality mono file, and to rip higher than the high quality stereo audio from DV-AVI files.
2 Second Collage
I rendered the 30 second sample to each of the profiles... to see how the wave patterns compare, and to make files you can listen to.
I annotated the pictures with the file sizes. All 10 of them combined are about 2/3 the size of the single uncompressed WAV file. Compression makes a big difference.
Click on the pictures to hear them play...
Audacity-MP3Audacity can save the WAV file as an MP3.... the figure at the right shows the wave patterns of the MP3 file in MM2... and they look similar. 
2 Second Collage
2 Second Collage
I played the WAV file in Audacity and captured it as a narration in Movie Maker 2 as it played, using the stereo mix option for the source. It worked fine. I'm not showing the wave patterns of the captured file, as they looked just like all the others on this page.
The bit rate property of the captured WMA file was 142 kbps, which places it up there with the high quality choices in MM2. It's become my standard way to get audio into WMA format if it doesn't import into Movie Maker.
2 Second Collage
Captured as Narration
2 Second Collage
2 Second Collage
2 Second Collage
2 Second Collage
2 Second Collage
2 Second Collage
I'm quickly running out of ways to process the audio clip to show how the wave patterns for the same clip can look different... so I'll conclude by saying they don't differ significantly... they look the same.

Conclusions and Closing
The wave patterns for a selected clip look similar... it could be the audio track of a DV-AVI file, a ripped WAV file, a WMA file ripped from a video or captured as a narration, or an MP3...
The full range of quality choices in Movie Maker have little to no effect on the patterns. Differences in what you hear are more significant.
No matter how you process the audio, it's pretty easy to sync an audio clip with its original DV-AVI or WMV file.  What I mean by that is, if you have a clip that needs some sort of audio 'fixing' in Audacity, ripping the audio to a WAV file with TMPGEnc, adjusting it in Audacity, and then capturing it back into Movie Maker as a narration file... it's easy to re-sync.
I make lots of editing decisions about where to split or trim a clip based on the audio track. When I do it, I zoom all the way into the timeline and make the split based on what I hear and the wave patterns. The visual part is usually more forgiving in moving the split point a few frames or more.  

Have a great week...