Video Compression And The Future
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Mobile phones have screens, speakers and microphones. They can take pictures and record video. And they can connect to the Internet. So why you can't make a video-conference call from your mobile phone?
For the same reason on-demand video doesn't really work on mobile devices. And for the same reason you can only watch eight HDTV channels at home.
Most mobile devices connect to the Internet at about 10KB per second. Video requires a bandwidth of at least 50KB per second.
That's where video-compression technology currently stands, according to Deepak Turaga, video-compression researcher at IBM's T.J. Watson Research Center.
The distance between 10KB and 50KB is far, but it's a distance that Euclid Discoveries claims to have closed.
Euclid CEO Richard Wingard said that, after six years of research, his company can compress video-conferencing streams down to 1000 bits per second.
Object Versus Blocks
The advancement in Euclid's video-compression technology, Wingard said, is its integration of object-based compression. To achieve this, the company had to overcome block-based video compression.
Block-based compression works by segmenting the video into rows and columns that form blocks, which are the large pixels you sometimes see in streaming video over the Internet. Data is sent over the network only for the blocks that need updating in each frame.
Think about a television screen when the local news is on.
Because the camera is fixed on a talking head, most of the screen is still. If the screen were divided into blocks, the blocks in the areas that are stationary would not need to change very often, because sending that data would be redundant. By sending less data, video streams can be compressed using block-based compression.
But those few blocks in a newscast that do change with every frame can cause some trouble. This is because each block has to be re-transmitted in every frame.
Imagine, then, if there were some way for the compression software to recognize the talking head as a single object, rather than a collection of changing blocks.
This is where object-based compression enters the picture. Now it can transmit only what's changed about an object from frame to frame, rather than having to transmit new data for a host of blocks. Less data would be transmitted and higher compression would be achieved.
And it works well, Wingard said. "We've achieved in a validation environment a 460 percent compression, about a 600 percent improvement, " he told internetnews.com.
But Turaga said it isn't as simple as that.
"The basic concepts of object-based compression have been around for a while," Turaga told internetnews.com. "But the reason it wasn't successful was because it wasn't applicable to all different kinds of content."
The trouble with object-based compression is that it requires modeling all the objects that might appear in the video.
Without modeling a talking head, how can the compression software know that the talking head is an object that can only move in a certain way from frame to frame?
Thus, to use traditional object-based compression is to limit content to modeled objects the software can recognize.
The Secret Sauce
Chuck Pace, Euclid's chief software architect, said the company's compression technology isn't traditional object-based compression, adding that it doesn't require infinite object modeling to model objects.
Turaga and much of the video-compression field wonder how.
"That's our secret," Pace told internetnews.com. "What we've found is a set of [block-based] techniques and algorithms that give us the benefit of [object-based] techniques."
But the Euclid secret is for sale to the highest bidder.
Wingard is optimistic about finding a buyer. Advanced video-compression technology could be useful for a variety of industries, he noted.
Cable companies might want to offer more HDTV channels. Because this technology would compress a DVD quality full-length film from 700MB to an easily downloadable 50, online retailers might want to ante up.
Even security systems would benefit from cameras that need less bandwidth to transmit video feeds. Advertisers who suddenly so love rich-media might love low bandwidth video in their online ads even more.
And don't forget about video-conferencing from your mobile phone, Wingard added.
"We've been working on that one that since day one. If you look at cell phones now, they have cameras and screens but you can't video-conference."
No need to wonder if that's about to change, he said.