thoughton:digitallife A glance at SheerVideo

A glance at SheerVideo

I recently read a reference to lossless video codec named SheerVideo. I've never used a lossless codec before and I know nothing about them. SheerVideo has a 20 day free trial available, so I thought I'd have a look. The first thing I noticed was that the installer didn't work! This must be a common problem, since there is an included document titled "Manually Installing SheerVideo". The instructions consist of where to put the codec files.

Update 8/12/04: Andreas Wittenstein of BitJazz contacted me about the installer problem and directed me to an updated v2.0.2.1 version on BitJazz's website. The new version installs without a hitch! How's that for great service?!

What's the big deal?
There seems to be very little information about SheerVideo available online, but after reading what I could find, including this seemingly-incomplete review, it seems that uncompressed video is usually used in professional video post-production where video might be edited any number of times so a lossy codec cannot be used when saving the file between edits. Apparently uncompressed video suffers from huge file sizes which require extremely fast SCSI hard drives. We're talking hundreds of gigabytes for 2 hours of video here. By comparison, all codecs used in home video editing are compressed, including DV files which are probably the largest files (of any sort) most home users will ever experience. 2 hours of DV video is around 25 gigabytes. Apparently one of the things that makes SheerVideo stand out is that the files are small enough to be able to use (relatively) slower but inexpensive firewire hard disks instead of faster but expensive SCSI ones. A couple of months ago I wrote about DIY RAIDs for uncompressed (HD) video.

How large are we talking about?
I wanted to see how large SheerVideo files were in comparison to some high quality video I had lying around on my hard disk. I also wanted to see a lossless codec in action. This is what I found:

Source: 70.7MB - Photo-JPEG, 45 seconds, 720x486
Output: 173.2MB - SheerVideo
Output: 432.3MB - Uncompressed AVI
Export time: 45 seconds

Source: 49.8MB - MPEG2, 21 seconds, 720x480
Output: 233.4MB - SheerVideo
Output: 511.8MB - Uncompressed AVI
Export time: 45 seconds

Source: 13.9MB - DV, 4 seconds, 720x576
Output: 50.8MB - SheerVideo
Output: 118.8MB - Uncompressed AVI
Export time: 8 seconds

Just out of interest I also tried it with a low quality clip:

Source: 20.4MB - Sorenson 3, 47 seconds, 640x480
Output: 483.9MB - SheerVideo
Output: 1081.2MB - Uncompressed AVI
Export time: 60 seconds

In all cases the SheerVideo exported in the same amount of time as the Uncompressed AVI. Also the quality of both exported files were indistinguishable from the original (except for one thing, read on). What I did notice was that the SheerVideo files were slightly brighter than the original, but apparently this might be a QuickTime playback bug to do with gamma correction.

Will I ever use it?
Very rarely. On some occasions I've had problems converting partially corrupted mpeg1 files downloaded from the internet. A direct conversion from mpeg1 to (for example) divx will fail when it hits the corrupt data, but I've found that exporting the mpeg1 to Uncompressed AVI and from there to my desired format usually bypasses the problem. In the future I suppose I will use SheerVideo instead of Uncompressed AVI, but as the file is merely an intermediate file and gets deleted soon afterward the smaller size of the SheerVideo will be less significant.

Posted on 4 December 2004, to Mac Video