Confusion and video editing

There are three situations that most amateur video users just can’t put their head around. On online forums these are the most common exporting issues.

1. Pixel aspect ratios
I bet that trigonometry might feel simpler to some people. No matter how many tutorials are on the web about pixel aspect ratios, users just don’t understand them. I really hope that camera manufacturers stop using non-square pixels because it confuses the hell out of people, and most of the time they f*ck up their web exports resulting in youtube videos where people in them have heads looking like eggs, or in videos with vertical letterboxing.

2. Interlacing
Ah, this one is funny. Users who have never seen interlacing before are in panic. They come over to the forums and scream that their camera is dying! There are “weird horizontal lines everywhere” and they wonder if warranty is still good to send the camera back! Again, it’s a matter of the camera manufacturers to stop using freaking interlacing. We are not in the 1950s anymore.

3. AVI and MOV
There’s the misconception that all AVI files are DivX/XViD, and all MOV files are “the same”. People don’t understand that avi/mov are simply containers that can hold any kind of media format inside them, and instead they associate them with specific codecs. I got an email the other day: “why my 2 minute footage is 6 GB, I exported as AVI, it should have been smaller than that”. Ah, well, because you saved using the uncompressed codec. Duh.


Richard wrote on January 22nd, 2008 at 5:50 AM PST:

And the really tricky part is designing a User Interface for setting Pixel-Aspect Ratios and such stuff. Especially if you are totally sure that the majority of the users won’t have the slightest clue what the Application is asking.

I’ve recently posted a proposal for a “User Interface” solution to this problem to the cinelerra Mailinglist:

So, Framesize, Interlacing and Pixel-Aspect are hard problems. In my humble Opinion the only serious attempt to solve that problem in a fashion that is at least somehow universial, is the following.

You need several tools, One Tool would be like the unix “file” utility. A tool that scans a video source and makes a good guess about what kind of Interlacing and Pixel-Aspect is being used.

The Second Tool is some kind of machine readable Knowledge-Database, that is filled with rules and heuristics about common frame-sizes, their assorted pixel-aspects, and how and when and when certain formats are used, and how they should be converted to other formats when necessary. This information will likely be useful to the “Source-Analysis-Tool” as well, as mentioned in the paragraph above.

Additionally the Knowledge Base should also be sprinkled with human readable information, Such as: “You are exporting a 24p file to 29.97i, a 3:2 Pulldown will be performed for conversion, for more information about that, click here…”.

Ideally the knowledge base should have information available for most of the common cases. In case there are conflicting rules, or two equally likely options, the database should have enough information available to ask the user the question whether he prefers A or B.


Dominique wrote on January 22nd, 2008 at 8:06 AM PST:


As a starting hobbyist, I appreciate your of outlining some of the minor pitfalls.

Cesar wrote on January 22nd, 2008 at 9:32 AM PST:

Deinterlacing is the most difficult thing to get it done right when your footage is a high motion 60 fields per second scene.

This is the admin speaking...
Eugenia wrote on January 22nd, 2008 at 3:40 PM PST:

For pixel aspect ratios all it needs for people to get it, is a visual representation as to how things change when they choose a different ratio. Vegas’ project properties is very good for what it is, but a visual representation would make it even better.

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