The trend toward wideband telephony continues unabated. Earlier this week I learned that Aastra's recent v2.5 firmware release for their SIP phones has added support for a variety of wideband codecs. Aastra phones have long been a favorite, their 480i…
Michael Stanford of Wirevolution has an article called Better Sounding Calls in the March issue of Internet Telephony that was today published on TMCs HDVoice Community site. While very general it's nevertheless a nice article. He cites Speex developer Jean-Marc…
There has been for many years a subtle conflict ongoing in telecom space. Various vendors have created digital encoding techniques (codecs) that target common network issues. Since various network realities exist so too do various approaches to the problems faced. So a range of codecs exist in the marketplace. Typically a high-quality solution comes with an associated cost, reflecting the very fact that the solution has merit.
The poster-child for this is the G.729a codec. Over time this patented codec has become the industry standard low-bitrate codec for voice applications. Who can argue. It works well. It squeezes reasonable voice quality down to under 30 kbps and it’s compute overhead is acceptable on available hardware.
The release a couple of months back of the Skype v4.o client for Windows was noteworthy as the introduction of their in-house developed SILK codec. Earlier today during an eComm 2009 presentation Jonathan Christensen, Skype GM Audio & Video, announced that SILK was being released under a royalty free license.
SILK was notable as being capable of narrowband (8KHz), wide band (16KHz) and super-wideband (24KHz) sample rates. Skype claims the codec dynamically adapts both sample rate and bitrate in response to variable network quality. They have published a PDF with a very general overiew of codec performance expressed in terms of bitrates, CPU requirements and MOS scores.
Michael Standford at WiRevolution has a nice interview with Skype's Jonathan Christensen. In it they talk about Skype's new "SILK" super-wideband codec. They compare it in very general terms against the companies existing SVOPC codec. Apparently SILK offers not only…
Global IP Solutions, the people behind the codec package that helped bring Skype to prominence, has recently launched a blog. Amongst their first entries they decided to weigh in with a response to my recent rant about soft phones. I…