Droege Computing Services
20 West Colony Place, Suite 120
Durham, NC 27705
Audio Webcast Guidelines
The audio you will be broadcasting depends on several components, both hardware and
software, that need to be set correctly in order for the audio stream to function properly. These
guidelines will be an explanation of these components in the order that they affect the signal.
You will need to first set up your computer’s hardware to broadcast, then make sure your
software is up and running. For a quick reference to potential problems, see the section on
Troubleshooting.
Contents:
1. Hardware / Setup
2. Software
a. Installation
b. Running Your Webcast
3. Troubleshooting
a. Broadcasting
b. Listening
Droege Computing Services
20 West Colony Place, Suite 120
Durham, NC 27705
1. Hardware
The first component is your microphone/soundcard interface.
Depending on your setup, there are multiple ways to get recorded audio of
your voice or other sound into your computer. In all cases it starts with
your microphone that plugs into either your sound card or other preamp
1/8" jack and plug
device. Most of the time, this will involve plugging your microphone into
the ‘mic in’ jack on your computers sound console, usually a pink 1/8’’ jack like the one shown to
the right. The gain can be controlled via the windows audio control. It can be accessed usually
by double-clicking the icon in your system tray, or through Windows Control Panel. In
Windows XP, the screen looks like the one shown below, and will let you adjust the input gain of
your microphone, as well as mute it when desired. In Windows Vista, the screen and menus
may looks slightly different, but you should be able to find sliders and controls for each audio
source.
When troubleshooting a ‘no sound’ issue, this is the best place to start. Even audio
professionals forget to un-mute the mic at times. By talking into the mic and adjusting the gain
via the control panel, you should be able to tell if your mic is working by hearing it come out of
your speakers. If not, double check your
sound card properties to make sure your
audio device is installed properly and that
the drivers are up-to-date. Also, be
careful to avoid feedback that may occur
if the sound from your speakers is picked
up by the microphone and sent back
through the speakers.
It is also a good idea to
experiment with microphone placement
and levels. Many lower-end computer
microphones can be very sensitive to distortion and overload when the sound source is too close.
If you find that your voice is too ‘woofy’ or muffled, try backing away physically from the mic to
get a cleaner signal. Usually about 6-12 inches is good for spoken word, perhaps more if you
speak loudly. This will require you to turn up your microphone gain to compensate, but be
careful not to turn it up too much or you will experience clipping and compromised quality.
Clipping occurs when the audio signal, which is composed of many peaks and valleys, is
squashed and the tops of the peaks are ‘clipped’ off resulting in unwanted distortion and loss of
intelligibility (see next page). Think about someone yelling into a cheap walkie-talkie versus
someone speaking in a room with you. Experimenting with microphone distance and adjusting
the settings in the control panel should allow you to get a clean and intelligible signal. If the
overall signal is still too quiet, that can be adjusted later in the encoding program.
Droege Computing Services
20 West Colony Place, Suite 120
Durham, NC 27705
Clean Signal
Clipped Signal
If you are planning to have multiple people speaking during a given broadcast, it is a
good idea to be watchful of the settings of your microphone. Be prepared to adjust the input gain
up or down depending on the volume of the person speaking and their distance to the
microphone. When preparing for a broadcast, remember to test the level of the microphone
before going live to ensure that everything is functioning properly. The middle of a webcast is
the worst time to discover that your microphone is broken or that your software is configured
incorrectly. In the next section, you will setup the Adobe Flash Media Encoder to take the audio
from your microphone to the server that will be broadcasting your webcast.
Droege Computing Services
20 West Colony Place, Suite 120
Durham, NC 27705
2. Software
-Installation and Configuration
Configuration of your software will require a few steps. First, navigate to
http://www.droegecomputing.com/DCSDownloads.asp. You will need to download two
components, those labeled ‘Adobe Flash Player Encoder Software’ and ‘Flash Player
Configuration for Broadcasting’. The links should look like this.
The first link is the installer for the program
that will handle the process of taking the audio from
your microphone and turning it into data that can
be transmitted over the internet. This process is
called ‘encoding’ and is handled by the Adobe Encoder software, assuming that it is configured
correctly. In order to make that easy, we have provided a configuration utility that will pre-load
the correct settings. You will need to first install the encoding software, then the configuration
utility. Follow the instructions on the screen to install both, and when that is
complete, you should see an icon on your desktop that looks like the one to your
right. This is a shortcut that will load the encoder and the correct settings in one
step. If everything has been successful, you should see the screen pictured below.
You are now almost ready to begin broadcasting.
As mentioned before, this is the program you will be using to encode the audio from your
microphone into a digital format that can be broadcast over the internet in ‘compressed’ form.
Compressed simply means that instead of broadcasting each individual bit of audio in a row, the
encoder discards certain bits such as
those that are similar to those adjacent,
or too quiet to hear. This has the effect
of greatly reducing the amount of date
needing to be transmitted, and thus
allowing more simultaneous listeners.
This also has an effect on audio quality,
but we’ll discuss that later.
When you first run the program,
it will show you the basic screen you will
use to set up your stream. At the top
middle of the screen you will see LED’s
that will read out your audio signal level.
By keeping an eye on this you can verify
that your level is within the nominal range. A good rule of thumb is to keep your level around
2/3 of the way up to 1) keep your signal hot enough to be encoded clearly, and 2) low enough to
Droege Computing Services
20 West Colony Place, Suite 120
Durham, NC 27705
avoid the occasional clipped word or phrase. The LED’s will be light green in color when
you’re in the optimal range. The program will automatically select your default audio
device for you, so you should be able to talk into your microphone and see the LED’s
bouncing. If not, check the field for ‘device’ and select your active sound card from the list.
Also, make sure that the check box for ‘audio’ is checked in order to enable the stream. If
you want to stream only audio for the time being, remember to de-select the ‘video’ box.
Here, you can adjust your encoding volume to make up for a weak signal. If you hear your
voice coming through as clearly as possible without overloading your mic via the gain control in
Windows, but your LED’s are too low, then you can adjust the overall volume of your encoded
stream to compensate. This allows you to get a clean, loud signal without sacrificing quality. If
your signal level is too low, the encoding discussed below will not work as efficiently.
If you used the configuration utility provided by
us, the correct settings should be already loaded, but just
in case they didn’t, we’ll discuss them anyway. In the
Audio column you will see several encoding options.
These are important because they will determine where
on the ‘audio quality vs. data size’ scale you will be. As a
general rule, the better the quality, the more size and
bandwidth you will need. If you were to stream music,
you would want to select at least 44100 KHz 128 Kbps
Stereo to approximate your average FM radio. Since we
are encoding spoken word and trying to maximize our
number of simultaneous listeners, we will go for a much
smaller encoding size. In our case, we will aim for a
sample rate of 11 KHz, a bit rate of 20 Kbps, and a single
Mono channel. Your audio encoding settings should look like this if it is set correctly, with the
exception that you should substitute the name of your audio device. These settings will give you
audio quality roughly equivalent to an AM radio station or telephone line. Again, the objective is
to maintain spoken intelligibility while simultaneously maximizing the number of people
listening. Under normal operation, you should not need to adjust these settings. Again, the
settings provided by us should be adequate to get started.
-Running Your Webcast
Further to the right you will see a column devoted to
the specifics of your audio stream. This has less to do with
the actual audio and more to do with the specifics of the
server. First, make sure that the ‘stream to Flash Media
Server’ box is checked. Then, verify the correct FMS (Flash
Media Server) URL to which you will be posting the audio.
In our case, you will be posting it to the local server at DCS
that will handle the web-posting and listener juggling. The
address will be one of two IP’s depending on the channel on
Droege Computing Services
20 West Colony Place, Suite 120
Durham, NC 27705
which you will be operating. Your assigned channel will be provided to you by us at DCS and
will determine your destination IP. For Channels A-E, the FMS URL will be 216.166.231.26
and for Channels F-J the FMS URL will be 70.62.103.242. Also make sure that the box for
‘stream’ represents the correct channel – IE ChannelA, ChannelB, etc. Below that is the ‘autoadjust’ setting which is only used for video streams, and shouldn’t be something to worry about
until you decide to add video at some point in the future. Below that there is an option for ‘save
to file’ which can be a useful feature if desired. It allows you to record your audio broadcast to
your computer in multiple files determined by length or size, whichever you prefer. Should you
need to reference anything said or discussed or recorded in your audio broadcast, this can and
will be a valuable tool. You can set the desired filename and path for these audio files to be
saved. In addition, should a video stream be added at a later date, these .flv files will contain
that video information as well.
Now you are ready to hit the big green start button and begin your stream. You will be
prompted for a username and password, which you will be provided with by us at DCS. If
everything is correct you should be broadcasting your audio. You or someone else on a different
computer can now navigate to ______________ to listen to your broadcast. If you are having
trouble making everything work correctly, see the next section under ‘broadcasting’ for a list of
things to check. If your broadcast is functional, but you or someone is having issues listening,
see the section entitled ‘listening’ to verify that your system is set up to receive the webcast.
After you have established a working connection, if you have changed any settings since
loading the program, you will need to save these settings so that they will load automatically
when you click the desktop icon. Under the file menu, select ‘save profile’ and navigate to
C:\Program Files\Droege Computing Services\Audio Broadcast\
and save your current working settings over the default droegebroadcast.xml file. This is
the file that will be loaded automatically, ensuring that each time you will be able to load the
program and broadcast without any problems.
Droege Computing Services
20 West Colony Place, Suite 120
Durham, NC 27705
3. Troubleshooting/Maintenance
-Broadcasting
If problems arise (as they inevitably do) and you’re not broadcasting correctly, the first
step is to go back and check through the setup process to see if you missed anything. It’s easy to
accidentally skip a step and not realize it. If you’re done this and the webcast is still not
functioning, try to systematically ascertain where the issue is.
1. First verify that you are getting a signal from your microphone into the Adobe Encoder.
If you are seeing the green LED’s bounce as you talk, then you know that the issue is not
your microphone or sound card, and there must be an issue with the encoding or
broadcasting side – skip to step 4. If you aren’t seeing the green LED’s, first check your
microphone. Is it plugged in all the way to the right jack on your computer? Are you
sure it’s not old or broken? Have you used it before with other programs? If you’re in
doubt, try to plug in a different mic if available and see if that works. Also try adjusting
or jiggling the cable slightly to see if perhaps the connection was merely loose or dusty.
2. Make sure that your microphone is selected in the Windows Control Panel, that the gain
is turned up sufficiently, and that it is un-muted.
3. If you can get sound from your microphone in Windows, but cannot see the green LED’s,
check to make sure that the proper audio input device is selected in the middle ‘audio’
section of the encoder screen. The device auto-detect may not work correctly if you have
multiple audio devices or microphones installed in your system.
4. If you are successfully getting audio into the Adobe Encoder, but are still having
problems, verify that your broadcast settings to the right of the screen are correct. The
encoder should load with the correct address settings already, but if not, double check
the settings outlined in Section 2. If your computer tells you that the broadcast is
operational, but you are unable to listen on a different computer, the issue may be with
that machine, and not with the broadcast – see the section on ‘listening’.
-Listening
If you are having issues listening to or hearing the audio stream, make sure that your
computer’s sound device is working properly, and that you have the latest version of Adobe
Flash Player installed. The best way to check this is to navigate to a popular site such as
www.youtube.com, www.hulu.com, or www.cnn.com and see if you can get audio functionality
from there. If you know your sound device and speakers are working, you can update your
Adobe Flash Player by heading to www.Adobe.com. The latest version is 10.0.22.87. If your
Flash Player is updated and you still are not hearing anything, try a different internet browser
than the one you are using. Internet Explorer, Firefox, and Opera are all browsers known to be
compatible with our audio stream.
If all of these are still unsuccessful, and you are unable to listen, even on multiple
computers, please contact our webcast administrator at [email protected] or 919-403-9459
with a description of the problem.