End-user perspective on small office tools & technology

Freeswitch En Route To Support For G.719 Codec

VVX_1500_D_Freeswitch.jpgThink back to the handful of new audio codecs that have been released over the past few years; CELT, SILK and Opus to name a few. Then there are the handful of proprietary codecs that have become available under more attractive licenses. Polycom’s Siren family come to mind on that front. In all of these cases I have observed that the Freeswitch development team are typically amongst the very first to implement any new codec.

In recent weeks they have added support for G.719, an ITU standard codec created by Polycom and Ericsson. With a  sample rate of 48 KHz, G.719 is a full-bandwidth codec, supporting a useful audio channel of 20 Hz- 20 KHz. It does so with end-to-end delay of only 40 ms and at bit rates from 32 kbps to 128 kbps. It also supports stereo audio.

Upon completion of the ITU standards process Polycom published a white paper on the codec; G.719: The First ITU-T Standard for Full-Band Audio (pdf).

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Confirming The Quality Of One’s Tools

Zoom-H2-Nexus7-AudioTool.jpgWhen experimenting with a new audio path I like to take measurements. Long ago, in an age of techno-pre-history known as the late 1980’s,  I craved what were then an emerging class of computerized test instruments, like the Audio Precision System One. Happily, today such costs are unwarranted given the current class of programmable smart devices. I’ve been very happy with Audio Tool For Android running on my Nexus 7 tablet.

If I am to trust the measurements that Audio Tool allows me to make I need to start by confirming the validity of it’s measure using a known reference signal. I was also making use of the Zoom H2 Handy Portable Stereo Recorder, so I decided to record the output of the sweep generator in Audio Tool to the H2. Then I tool the resulting WAV file into Adobe Audition to see what resulted.

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Waiting For Doorbot: Appification Can Be Disappointing

Like many people, I’ve come to enjoy using a tablet to do things that were once entirely in the domain of the computer. Over the past year the Nexus 7 has become part of my routine. I use it routinely for checking email, reading news feed & e-books and watching the occasional video, amongst other things. It’s a wonderful device.

There are some things that I do with the tablet that leverage specialty apps, like the remote control for our Nest thermostat. This makes perfect sense to me as the function of both the thermostat and the app are clearly and completely defined. Also, their operation is largely isolated from the rest of the elements of our lives. For example, we simply don’t require that the Nest integrate with the home phones.

With such clearly defined requirements, or more exactly, limits to the scope of requirements, a smart phone/tablet app is good solution. It certainly makes more sense than a traditional hardware remote control as one might get with a TV.

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BlackMagic, Nexus Devices, MHL and SlimPort

As I tinker with various things around here I’m finding that I need some tools to be able to capture experimental results in a manner that provides assets for this blog. Recently I’ve added a couple of new tools which I though you might find interesting.

This process of “tooling-up” started last year when I purchased a BlackMagic Design Intensity Pro capture card. That card has been mentioned a few times previously. It allows me to capture video from an HDMI connected source.

The Intensity Pro card has been very handy for a variety of things. Since computers these days are capable of screen resolutions that are also common to HDTVs I have used it to record the output of PC desktops. That has included screencast tutorials as well as the output of specific programs, like Adobe Audition.

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Belkin Ships Dyle Mobile HDTV Tuner For iOS

Belkin-Dyle-HDTV-Receiver-372I’m not the biggest fan of watching TV on a tablet or cell phone. I know that people do it, but I still prefer the more traditional experience of a large television or even a decent computer screen. So normally the announcement of the new Belkin Wireless Dyle Mobile TV Receiver would not be all that interesting. However, I live in Houston, at the receiving end of Hurricane Alley. Such a device could be a handy item to have on-hand in a powerless, post-hurricane situation.

This little device mates to the 30-pin connector on suitable Apple devices. That includes the iPhone 4, iPhone 4S, iPad, iPad 2, or iPad (3rd generation) allowing you to receive local TV signals without any 3G, 4G or Wifi connection. It retails for $129.

Of course, to be useful the Dyle signals must be available over-the-air in your area. That’s true for most major cities in the US. There is a web site that lets you check your location by zip code.

Looking back a few years to the time after Hurricane Ike, local TV news was a important source of information. When we were without power for tend days we lived on an 8 KW generator shared with our neighbor.

That situation highlighted the need to conserve power, using only the essential things around the house. We initially ran the refrigerator, lights as required, our core network components and a laptop.

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