FS-1015

FS-1015 is a secure telephony speech encoding standard developed by the United States Department of Defense and later by NATO. It is also known as LPC-10 and STANAG 4198.

The standard was finished 1984. The algorithm used is a linear predictive coding vocoder. The vocoder enables understandable speech, but the quality is very unnatural and synthetic. The compression rate is 20 times better than that of the MP3 algorithm.

The codec uses a bit rate of 2.4 kbit/s, requiring 20 MIPS of processing power, 2 kilobytes of RAM and features a frame size of 22.5 ms. Additionally, the codec requires a large lookahead of 90 ms.

Recently an improved version of the standard was introduced. With a longer super frame structure and better quantizer, the bit rate is reduced to 800 bit/s.[1]

External links

References

  1. ↑ Xianglin, Wang; C.-C. Jay Kuo (May 1998). "An 800 bit/s VQ-based LPC voice coder". The Journal of the Acoustical Society of America. 103 (5): 2778. doi:10.1121/1.422247. Retrieved 2007-03-24.


This article is issued from Wikipedia - version of the 10/25/2015. The text is available under the Creative Commons Attribution/Share Alike but additional terms may apply for the media files.