Audio Capture

The audio capture feature is capable of recording up to two mono audio feeds automatically. On a dedicated capture machine this can be the one and only audio card in the machine. On a stand-alone Burli workstation, two sound cards can be used in the computer; typically one sound card to capture up to two audio feeds and the other for local recording, editing and playback.

Background audio capture

These settings control automatic background recording. This is usually analogue audio feeds from wire services or similar sources, however you can use it to automatically record any audio that can be delivered to the line-in of the computer sound card.

Mode

Set this to ‘Background Audio Capture’ to turn the feature on.

Recording Device

Select a sound card from the list. Note that you cannot share background and foreground recording on one sound card. If you only have one consumer-grade sound card in the computer, there will probably only be one option to choose here.

Format

Select an audio format (PCM Linear or MP2). If you select an MP2 format, select a bitrate that suits your operation. You may wish to check your automation system’s sample/bitrate if you intend to share files between it and Burli; keeping the same audio settings across your systems can keep things a lot simpler. Also note that linear (PCM) audio is faster to edit, save and open and always sounds better than compressed (MP2) audio.

There is a setting available to set all workstations to the same Foreground audio format to assure that all audio which is being recorded will be in the same format. Contact Burli Support for the details.

Samples

Select a sample rate for audio recording. The higher the rate, the better the sound quality, but the larger the audio files. Most radio newsrooms choose 44100 Hz, though 32000 and 22050 are still used in some AM operations. Broadcasters with digital output often use 48000 Hz. Whichever you choose, it is important to use the same sample rate throughout your newsroom on all Burli workstations. While Burli can and does convert common sample rates when they are combined, audio quality suffers from conversion and some editing functions (such as the Wave Wizard) do not accept multiple sample rates in one mix.

You may, however, want to use a very low sample rate (e.g. 8000) for recording material that will never be used on-air, such as monitoring another radio station.

Channels

Each of the left and right channels will record a separate mono audio source. Each channel is set-up separately. To configure a channel, click on the check box beside Left or Right and select from the options below.

Five Automated Methods

Burli offers five methods of automated audio capture. Choose the capture method for each channel from the dropdown box:

  • Use the Switch method if the audio source offers momentary or continuous on/off contacts. Click the ‘More’ button to choose the switches that will be responsible for intercepting these signals. If the source sends two separate signals for starting and stopping, specify the two switch pins (1 to 4). If the source closes the switch for recording, then re-opens the same switch to stop recording, provide the one switch pin (1 to 4). Most newsrooms opt to use I/O PCI cards for contact closures, but Burli can also detect signals on a consumer gameport .Consult the Gameport interfacepage for more information.
  • Use the Clock method to record the audio source at specific times during the day. For example, Burli can record from the top of each hour to five minutes past each hour, weekdays from 9am to 5pm. Click the ‘More’ button to add as many time intervals as required.
  • Use the User method to provide two additional recording channels to the user at a Burli editing workstation. The user can start and stop recording on these channels either using keyboard commands or by remote start. When recording is stopped in this mode, the wave file is placed in the bottom window. If a local folder is not visible in the bottom window, Burli switches to the ‘Work’ local folder.
  • Use the Threshold method to record the audio source only when a significant audio level is present. Click the ‘More’ button to set the threshold level (the point at which the audio level is significant), the number of seconds of below-threshold audio to wait before posting the file, and the number of seconds below which Burli rejects the audio. The settings will depend on your particular audio source, and may need refinement over time. Use this capture method only if it is not possible to use the Switch method.
  • Use the Telephone method to record the audio originating from the Burli Telephone Recording System. This feature lets reports dial in to the newsroom, then record, audition, and post audio to the Burli in-queue.

A system tray icon resembling a reel-to-reel machine is displayed on the Windows task bar when background recording is active; red lights indicate when the left and/or right audio channel is recording.

Directory

Provide a unique directory name for each audio channel. The directory settings determine the subdirectories in which Burli stores the audio on the file server; it also determines how the audio appears in the In-queue. For example, if ‘bn-reg’ is the directory, an audio feed moving on that channel at 9:45pm will appear as ‘bn-reg 09:45pm’ in the In-queue’s slug list. The audio itself will be saved in a directory called bn-reg on the file server. Some characters such as slashes (\ or /) cannot be used in the directory name.

Hold factor

For each capture channel, specify the minimum number of hours (typically 24 to 48 hours) before which Burli will delete the audio file. Specify zero (0) hours only if you are providing a value for the decay factor, described below.

Decay factor

The decay factor determines a given audio file’s shelf life based on whether it’s being actively used. The decay factor is the period of time for which the file has to sit unused beyond the hold time before it is deleted. So a file that has already exceeded its hold time (above) will not be deleted until it has also sat unused for the decay time as well. This prevents the system from deleting important audio that, while old, is still in active use. Specify zero (0) hours only if you are providing a value for the hold factor, described above.

Here are some examples…

Sample ‘hold and ‘decay’ factors

If you are running a small- to mid-sized newsroom that makes average use of audio, try setting the ‘hold’ factor to 12 hours, and the ‘decay’ factor to 0 hours. This means that Burli will delete these audio files 12 hours after they were created, regardless of their association to scripts. Unless you are actively using script audio clips created 10 or 11 hours ago, the decay factor has little or no relevance.

If you are running a busy newsroom that makes active use of audio, you are probably (or should be) more concerned about file space on your main server. Why retain audio files that aren’t being used? Yet you don’t want Burli to delete audio files that are associated with the next major newscast, even if that newscast references an audio clip originally received many hours ago. Using a combination of ‘hold’ and ‘decay’ values, you can fine tune file usage on your server. One sample approach is to set ‘hold’ hours to 6, and ‘decay’ hours to 3. These values mean that Burli will retain audio files for at least 6 hours. In addition, Burli will retain the file if any script has referenced that file within the last 3 hours.

Another sample approach is to set ‘hold’ hours to 0 and ‘decay’ hours to 12. These values mean that Burli will delete any In-queue audio files that haven’t been used in a script for at least twelve hours, if ever. The downside of this setting is in situations where your newsroom is unattended for a period longer than the decay time; if nobody is there to associate the audio with a script, Burli will dump it — unless you provide a longer hold factor, which determines the minimum number of hours, under any circumstance, to keep an audio file.

Confused? If in doubt, try using a combination of hold=12, decay=2. If you find that files disappear prematurely, or that your server fills up, that’s the time to reread this section.

More…

Each recording method has additional set-up options. Click the More… button to configure these options.

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