Daniel Pocock: Recording live events like a pro (part 1: audio)
Whether it is a technical talk at a conference, a political rally or a budget-conscious wedding, many people now have most of the technology they need to record it and post-process the recording themselves.
For most events, audio is an essential part of the recording. There are exceptions: if you take many short clips from a wedding and mix them together you could leave out the audio and just dub the couple's favourite song over it all. For a video of a conference presentation, though, the the speaker's voice is essential.
These days, it is relatively easy to get extremely high quality audio using a lapel microphone attached to a smartphone. Lets have a closer look at the details.
Using a lavalier / lapel microphone
Full wireless microphone kits with microphone, transmitter and receiver are usually $US500 or more.
The lavalier / lapel microphone by itself, however, is relatively cheap, under $US100.
The lapel microphone is usually an omnidirectional microphone that will pick up the voices of everybody within a couple of meters of the person wearing it. It is useful for a speaker at an event, some types of interviews where the participants are at a table together and it may be suitable for a wedding, although you may want to remember to remove it from clothing during the photos.
There are two key features you need when using such a microphone with a smartphone:
Full wireless microphone kits with microphone, transmitter and receiver are usually $US500 or more.
The lavalier / lapel microphone by itself, however, is relatively cheap, under $US100.
The lapel microphone is usually an omnidirectional microphone that will pick up the voices of everybody within a couple of meters of the person wearing it. It is useful for a speaker at an event, some types of interviews where the participants are at a table together and it may be suitable for a wedding, although you may want to remember to remove it from clothing during the photos.
There are two key features you need when using such a microphone with a smartphone:
- TRRS connector (this is the type of socket most phones and many laptops have today)
- Microphone impedance should be at least 1k (that is one kilo Ohm) or the phone may not recognize when it is connected
- 16 bit or greater sample size
- 48kHz sample rate
- Disable AGC
- WAV file format
The full changelog can be found in
I recently got access to several ProLiant m400 ARM64 servers at work.
Since Debian is currently working on the migration to GCC 5, I thought it
would be nice to rebuild the Debian archive on ARM64 to see if GCC 5 is
ready. Fortunately, I found no obvious compiler errors.
During the process, I noticed several areas where ARM64 support can be
improved. First, a lot of packages failed to build due to missing
dependencies. Some missing dependencies are libraries or tools that have
not been ported to ARM64 yet, but the majority was due to the lack of
popular programming languages on ARM64. This requires upstream porting
work, which I'm sure is going on already in many cases. Second, over 160
packages failed to build due to out-of-date autoconf and libtool scripts.
Most of these bugs have been reported over a year ago by the
ARM64 porters (Matthias Klose from Canonical/Ubuntu and Wookey from
ARM/Linaro) and the PowerPC porters, but unfortunately they haven't been
fixed yet.
Finally, I went through all packages that list specific architectures in
debian/control and filed wishlist bugs on those that looked
relevant to ARM64. This actually prompted some Debian and upstream
developers to implement ARM64 support, which is great!
Back in 2010 when I needed an ADSL2 router in the US I bought a
Update: A Canonical employee responded

If you wonder why it was so silent here over the last weeks, there is a simple explanation: I am on scientific freak weeks
As you might know, in my main profession I am 







In
The Independent reports that David Cameron
A couple of months ago, I was invited to give the starting course for the