Hollywood (CA) - High definition discs became the second most popular video medium in the first half of 2007, officially overtaking legacy format VHS.

According to a research piece from trade publication Video Business, sales of Blu-ray Discs and HD DVDs combined in the first half of 2007 beat VHS. During the last six months of 2006, the now-archaic format was still edging out the high definition newcomers.

By 2005, VHS’s market share in the home video market had fallen to around 15%, and has continued to fall ever since. Blu-ray and HD DVD overtaking the dying format was more or less expected, but through the end of 2006 the high-def competitors were still behind.

With the highly contentious battle between Blu-ray, fronted by Sony, and HD DVD, backed mainly by Toshiba and Universal, there was mounting concern that wary consumers would back off of both until a winner was decided.

However, both formats have already made significant marks in the home video market. Blu-ray’s Casino Royale reached 100,000 units shipped in March, beating the 11 months it took DVD to reach that milestone. Meanwhile, HD DVD took a hold with the first high definition disc box set to be on Amazon.com’s list of top five DVDs with the documentary series Planet Earth.

Warner’s short-titled "300" is the most recent newsmaker, selling 250,000 copies on Blu-ray and HD DVD in a single week.

It’s still a long way before the two formats really begin to chip into DVD, though. By comparison, over five million copies of the DVD version of Pirates of the Caribbean : Dead Man’s Chest were sold in its first 24 hours.