Posts Tagged ‘Compression’

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Why VP8 matters

May 10, 2010

This post was made prior to the Google IO conference which is May 19 -> 20th, and as such things may change after this date.

VP8 is potentially a game-changer in the realm of both streaming, High-Definition, and mobile video devices. It also has the potential to help in the killing of Adobe Flash, and solve the HTML5 Video format war.

Currently there are two formats that are used in HTML5 Video by differing browsers: Ogg Theora and h.264

Both have support from different browsers, both have different camps fighting for their success, and both have their pros and cons.

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iLBC vs g729 — The quick guide to using compressed codecs in Elastix

November 21, 2009

We all know that g711 (alaw / ulaw) is meant to sound the best. It’s uncompressed and equivalent quality to ISDN, which most businesses are used to with their traditional PABX System.

However, it comes at a price, 64kbps + overheads means around 111kbps when you factor in everything else over an ADSL PPPoA / PPPoE connection.

Now that’s a LOT when you think about it, considering on a standard ADSL2+ line you’re going to max out at around 5-7 SIP lines, especially if it’s a shared connection. This is where a compressed codec such as (My personal favorite) iLBC, or g729, can be incredibly cost effective, as you can load up around 15-20 on the same sort of bandwidth. When you’re a small business, that means with the right kind of QoS, you can share your ADSL Broadband connection and still have 5-10 concurrent phone calls, all happily living together.

So do away with expensive BRI interfaces and monthly charges, and go SIP!

We’re going to look at a few things very briefly:

1) MOS – What is it and why do I care?

2) Which codec is right for me?

3) g729 – Installation

4) iLBC – Installation

5) Trunk and Extension setup

6) Testing the codecs

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