Digital Home Thoughts - News & Reviews for the Digital Home

"There are plenty of software options available for storing, compressing, and archiving data in different ways. These tools no longer simply reduce file size and merge your input files into a single, manageable archive. They also support automatic downsizing of images, virus-checking, content-checking to avoid unnecessary compression of files that already are compressed, splitting, encrypting, and more."

The importance of compression has flucuated over the years. Back in the days of dial-up access, compression was vital. Anything you downloaded usually came in the form of a zip, lzh or arc file. With ample storage and faster bandwidth, compression may not be quite as important, but it has become ubiquitous in the form of image and video codecs. Still, there are many uses for compression, such as encrypting files, collecting a group of files together and yes, even shrinking large files into more managable chunks. Tom's Hardware does a good comparison, and I think what should be of note is that there are viable free programs that can be used for your archiving needs. There has been more than a few times where I have helped people out who think that for any application, one has to buy it. For lots of applications, that is just not true. Personally, I favour 7-Zip. It is free, but I find it works quite well, and more importantly, it is really easy to use. What is your choice?

"AVCHD from the Lumix cameras has several drawbacks IMHO. It is difficult to edit in most NLE programs unless transcoding into AVI, the compression leaves large areas such as grass patches rendered without detail and has a general overall soft quality. This sequence, directly shot to compare the quality of unadjusted clips from AVCHD and MJPEG, looks at static and dynamic images, closeup and distant images to get a comprehensive view of the results. The two formats were assembled into a 1280 x 720 50fps timeline and exported as a mpeg4 file."

I generally set my Panasonic cameras to record in AVCHD, but after watching this video and thinking about how I use the video clips, I'm going to change my cameras to use MJPEG. I tend to edit all my video clips, so for me it makes sense to capture clips with as little compression as possible - and that means MJPEG. I have 16 GB cards in my cameras, and haven't come close to running out of space yet, so I'm not concerned with the added storage MJPEG takes up. If you're someone that tends not to edit your clips and just saves them as-is, AVCHD might make more sense. What video format do you use on your digital camera?

Over on EngadgetHD I've been having a discussion about bit rates with George Ou of ZDNet. George argues that unless the content you are watching is at least 28 mbps 1080p, it's "fake HD". Nevermind that the HD spec. includes resolutions from 1024x768 up to 3840x2160, and that it doesn't specify a bit rate (or rates). He goes on to say that Xbox Live Video Marketplace downloads in HD are "slightly better than DVD but nowhere near 1080i over-the-air HD broadcast quality."

Unfortunately George's argument is so narrow that he is ignoring several other factors that are for more significant. The real world considerations go far beyond bit rate and resolution. The per pixel bit rate for 720p XBLVM downloads is nearly identical to a 1080i OTA broadcast, and even identical to real world HD DVD bit rates. Granted, the resolution is lower, but the you won't see any added compression artifacts over 1080p HD discs. As it turns out, resolution is a non-issue for most people:

Almost every HDTV in homes today is 720p, not 1080p. The extra resolution available on HD DVD and Blu-Ray is wasted on most people. What's more, to take advantage of that extra resolution, you'd need:

• 1080p native source (many lower end HD players can only to 1080i or 720p)
• A 1080p HDTV that can display full resolution with 1:1 pixel mapping
• Screen size larger than 50"
• To be sitting closer than 10 feet

So who can tell the difference given these conditions? Maybe a tenth of a percent of all HDTV owners? A hundredth? Less? Yes, HD DVD and Blu-Ray are better than XBLVM downloads under theoretically ideal circumstances, but the vast majority of people will never notice the difference.

Then there's the issue of compression algorithms. DVD is encoded in MPEG-2, whereas most HD content is encoded in h.264 or VC-1. To hear George tell it, you'd think they were equals. Fact is the newer codecs result in smaller file sizes, fewer artifacts, and better picture quality. Next thing you know George will be arguing that JPEG should be abolished and all cameras should shoot in RAW.

It really irks me when people focus on minutiae, rather than taking the big picture into account. Full 1080p video downloads aren't yet practical. There isn't enough bandwidth to make it work. Most of the HDTV sets out there are 720p. In the real world, Xbox Live downloads are just as good as HD discs. Better yet, you don't have to make a trip to the store to pick one up.