Frequently Asked Questions about ListenUp
For questions about evaluation, sales and licensing see our Sales FAQ.
- What machines and browsers does ListenUp run on?
- Can I change the appearance of the ListenUp Applet?
- How long a message can I record?
- Do I need to know Java programming in order to integrate ListenUp?
- How much server programming is required?
- Can I upload files in MP3 format?
- Can we sign the Applet using our own digital certificate?
- What tasks are handled by ListenUp and what tasks am I responsible for?
Yes. You can change the background color and replace the buttons with your own images using a "skin". You can also select a tall or wide layout. Documentation here.
In FreeMode you can record messages up to 60 seconds in length. For sites with paid licenses there is no inherent limit. You can specify "maxRecordTime" as an Applet parameter so that users cannot record too long a message.
Recorded messages are normally stored in memory so the heap size of Java may limit the size. If you need to record a very long message then you can enable "useFileCache". The recording will be written to disk as it is recorded. The file will be deleted after the message is uploaded. We have recorded messages up to one hour in length using this technique.
No. We wrote ListenUp in Java but you only need to know HTML and one server scripting language like PHP, JSP or ASP.
To put ListenUp on your webite you will need to do some server programming. We have found that, while most customers have similar requirements for the recorder, they have very different requirements for the server software. Customers are building voice email systems, language training systems, dating service messaging, real estate sales systems, etc. So we leave the server programming up to the customer. We provide simple PH, ASP and JSP scripts that will receive the uploaded file and place it in a folder. After that you will need to integrate that uploaded recording into your own web application. If you do need help developing your custom programming then we can provide engineering services on an hourly basis.
Our ListenUp Applet uses Speex and ADPCM compression algorithms instead of MP3. One reason is because Speex is based on a vocal model and does a better job of compressing voice than MP3 does. MP3 is designed to handle arbitrary sound and music and is not as good at compressing voice as Speex is. Also MP3 would require us to pay an expensive license fee if we wanted to distribute it legally.
You can, however, upload a voice message using Speex, ADPCM or WAV sample. Then you can convert it to MP3 on your server using your own MP3 encoder like "lame".
Yes. We provide an "Unsigned" version of the ListenUp JAR file and Speex JAR file. It is technically possible to sign that with your own certificate. We use the Thawte Code Signing Certificate. You could also use the Verisign Certificate. There are many different kinds of certificates so make sure you get the kind that can sign Java Applets.
Tasks done by ListenUp:
- ListenUp runs on the client computer.
- ListenUp records audio and uploads it to the server.
- ListenUp downloads audio from the server and plays it.
Tasks done by You or Your Software:
- Your Software runs on the server.
- You write the script to receive the uploaded audio(same technique used to handle HTML FORM data).
- Your Software can add other funtions such as voice email, voice forums, voice messaging, etc.(we can provide examples).
- You write the server-side application.