Web voice mail allows to send voice messages from web sites to any existing e-mail client software, even to free web based e-mail like Hotmail and Yahoo. The recipient receives the usual e-mail message with link to Mp3 audio file. He/she can download Mp3 file and listen it by any existing Mp3 playback program.
To voice message recording on the web voice mail page the audio recording applet is used. It records in Mp3 format.
Audio recording applet is developed in Java 1.1 and does not require the Java 1.3-1.5 plug-in installation.
To Mp3 encoding/decoding the LAME Mp3 audio codec is used.
1. Audio recording applet (RPAppletMp3.cab, RPAppletMp3.jar)
2. Sound capture/playback, LAME Mp3 encoding/decoding DLL (jaudioMp3.tar)
4. Server scripts (retrive.php, sendmail.php)
5. Web page example ( mail.php)
6. Documentation.
Target OS Platform: Windows 98/2000/ME/XP/2003.
Target browsers: Microsoft Internet Explorer 4.0 and up, Netscape 7.
Web Servers: Any (PHP support required).
The idea of voice mail is very simple. Web voice mail application creates the text and voice messages and send them to web server via HTTP by POST method. On the server side the server scripts create usual e-mail message body with text message and with link to Mp3 file (voice message). Mp3 file is stored on the server. Server script passes the e-mail message body to Mail Transfer Agent, which send it to recepient. Recepient receives the e-mail message with text and link to Mp3 file and downloads Mp3 file.
To voice message recording the Mp3 audio recording applet is used. The functionality of recording applet is following:
1. Audio capture from sound card. The sampling frequencies are 8000Hz, 11025Hz, 16000Hz, 22050Hz, 32000Hz, 44100Hz, 48000Hz.
2. LAME Mp3 audio encoding/decoding.
3. Playback of the recorded Mp3 file for sound quality and content evaluation.
4. Uploading of Mp3 file to web server via HTTP.
Demo version allows to record 20 sec only.
The Mp3 audio recording applet is developed in Java 1.1. So, the applet works with Microsoft Java 1.1 ( i.e. Recording applet works on the target browsers with default browser JVM installation) and with Java plug-in 1.3-1.5. The recording applet uses native methods for sound capture and LAME Mp3 encoding/decoding. They are developed in C++ and implemented as DLL ( jaudioMp3.tar ). The DLL will be installed on the client computer if the applet is being used for the first time. The recording applet is digitally signed. For digitally signing the Thawte certificate is used.