home page



Communication between PC and FLEXI-232

MELPe Sample Program for Developing VoIP Application

Compandent can provide its customers with a specially developed C++ sample program for full duplex exchange of MELPe compressed bitstream between PC and FLEXI-232 via USB or RS-232 ports, for record + loopback or playback. Such a program may be used as an example for developing applications such as MELPe VoIP between PCs and other MELPe VoIP terminals. The program is provided as MSVC++ project. The block diagram of a communication system including a PC and data terminal is illustrated in Figure 1.

Figure 1 Block Diagram of PC and data terminal system (USB or RS-232). (c) All rights reserved.

You may find the sample program helpful for developing your own application for VoIP communication such as illustrated below:

Figure 2 Block Diagram of Common PC and FLEXI-232 Based VoIP System. (c) All rights reserved.

Upon startup the program shows the following window. Set the correct COM port number, select the desired MELPe rate. You can browse and set the “Record File”, and the “Playback File”. These files contain MELPe compressed data (at the selected rate).

Figure 3 Dialog window of Compandent's sample program communicating MELPe bitstream between PC and FLEXI-232. (c) All rights reserved.

For details contact us, Download MELPe Package Fact Sheet MELPe Package Fact Sheet in PDF format , Compandent MELPe FAQ

Please note: Compandent owns intellectual property (IP) in the official (standard) MELPe implementation, and any of its derivatives (see for example USCO certificate of copyright registration numbers: TX0006703781 (postfilt.asm), TX0006845325 (lpc_lib.asm), TX0007161044 (lpc_lib.c), , and many more. Any party intending to develop products based on MELPe should contact Compandent as well as other IP holders regarding licensing.

To report bugs or suggestions to the MELPe algorithm implementation please mail to: MELPeSupport@compandent.com


Customer Reviews
Write an online review and share your thoughts with other customers.
5 out of 5 stars Highly Recommended!!!
Reviewer:   Project Engineer - Major Worldwide Defence Technology and Security Company (UK)

Integrating the Compandent MELPe package & FLEXI-232 DTE with our military modem device was seen as a possible risk area at the start of our project. Your first class technical support helped us immensely with our integration activities, including tailoring of the FLEXI-232 DTE firmware to meet our exacting requirements. We were up and running in less than a week of the package arriving in the UK and best of all no additional interfacing circuitry was required. Top marks!

Was this review helpful to you? Yes No


5 out of 5 stars Great package!!! Very professional!!!
Reviewer:   Product Manager - Defense industry (USA)

It was great pleasure doing business and working with you guys! I will be more than happy to support and recommend you. Compandent is a very professional and customer service oriented company. Your MELPe package was so easy to work with. It is a high quality software and has clear documentation. Thanks for everything, and we will support you as best we can.

Was this review helpful to you? Yes No


5 out of 5 stars Great product! Highly recommended!
Reviewer:   Project Manager - Secure Voice industry (Europe)

Compandent saved us many months of hard work, enabled us short time-to-market, and provided us with critical competitive advantage. Your package was very reliable, and achieved the best quality. The audio demo was very helpful for us in presenting our prototype successfully within a short period of time. It is pleasure working with Compandent. Highly recommended!

Was this review helpful to you?   Yes No


5 out of 5 starsHigh quality software & excellent service!
Reviewer: Engineering Manager - Wireless comm. industry (USA)

Way to go Compandent! We integrated your MELPe into our product almost instantly! The Test Vector and software verification was so easy, we had almost nothing to do, it was all automatically performed, so smooth and easy. Great package which includes everything one may need for using MELPe vocoder in a product. We started with the c54xx, and in the future we will probably use the c55xx as well!

Was this review helpful to you?   Yes No


5 out of 5 stars Excellent MELPe package, and very professional company!
Reviewer: Senior Engineer - NATO vendor (Europe)

Compandent knows the MELPe coder in-and-out! They responded promptly to any question or issue we had, and provided us with the correct answer and solution. Compandent's MELPe is very efficient computationally and memory-wise, which allowed us to run all our software on the c55xx! Definitely the best in the market. We will be more than happy to further recommend you.

Was this review helpful to you?  Yes No


4 out of 5 stars Recommended Good Product
Reviewer: Project Manager - Wireless Device Manufacturer (USA)

This package was easy to test/verify, implement, and use on our platform. Compandent has been extremely helpful and professional with all questions and concerns. One improvement which could be made is related to the memory map. Otherwise, the product has worked exactly as expected.

Was this review helpful to you?  Yes No


Compandent Inc. is a Third Party Partner for:


Copyright © Compandent Inc. 2001-2016, All Rights Reserved

eXTReMe Tracker