From ed463b078809d942a2f0119ec9392c4a43fde0b1 Mon Sep 17 00:00:00 2001
From: drowe67 <david@rowetel.com>
Date: Thu, 23 Nov 2023 19:21:17 +1030
Subject: moved some introductory info from DD to Intro

---
 doc/codec2.tex | 21 +++++++++++++--------
 1 file changed, 13 insertions(+), 8 deletions(-)

(limited to 'doc/codec2.tex')

diff --git a/doc/codec2.tex b/doc/codec2.tex
index 22fa749..882f0b3 100644
--- a/doc/codec2.tex
+++ b/doc/codec2.tex
@@ -62,7 +62,16 @@ pinstyle/.style = {pin edge={to-,thin,black}}
 
 \section{Introduction}
 
-Codec 2 is an open source speech codec designed for communications quality speech between 700 and 3200 bit/s. The main application is low bandwidth HF/VHF digital radio. It fills a gap in open source voice codecs beneath 5000 bit/s and is released under the GNU Lesser General Public License (LGPL).  It is written in C99 standard C.
+Codec 2 is an open source speech codec designed for communications quality speech between 700 and 3200 bit/s. The main application is low bandwidth HF/VHF digital radio. It fills a gap in open source voice codecs beneath 5000 bit/s and is released under the GNU Lesser General Public License (LGPL).
+
+Key feature includes:
+\begin{enumerate}
+\item A range of modes supporting different bit rates, currently (Nov 2023): 3200, 2400, 1600, 1400, 1300, 1200, 700C.  The number is the bit rate, and the supplementary letter the version (700C replaced the earlier 700, 700A, 700B versions). These are referred to as ``Codec 2 3200", ``Codec 700C"" etc.
+\item Modest CPU (a few 10s of MIPs) and memory (a few 10s of kbytes of RAM) requirements such that it can run on stm32 class microcontrollers with hardware FPU.
+\item Codec 2 has been designed for digital voice over radio applications, and retains intelligible speech at a few percent bit error rate.
+\item An open source reference implementation in the C language for C99/gcc compilers, and a \emph{cmake} build and test framework that runs on Linux/MinGW.  Also included is a cross compiled stm32 reference implementation.
+\item Ports to non-C99 compilers (e.g. MSVC, some microcontrollers, native builds on Windows) are left to third party developers - we recommend the tests also be ported and pass before considering the port successful.
+\end{enumerate}
 
 The Codec 2 project was started in 2009 in response to the problem of closed source, patented, proprietary voice codecs in the sub-5 kbit/s range, in particular for use in the Amateur Radio service.
 
@@ -70,6 +79,8 @@ This document describes Codec 2 at two levels.  Section \ref{sect:overview} is a
 
 This production of this document was kindly supported by an ARDC grant \cite{ardc2023}.  As an open source project, many people have contributed to Codec 2 over the years - we deeply appreciate all of your support.
 
+
+
 \section{Codec 2 for the Radio Amateur}
 \label{sect:overview}
 
@@ -256,14 +267,8 @@ Bit rate & 3200 & 700 \\
 
 Codec 2 is based on sinusoidal \cite{mcaulay1986speech} and Multi-Band Excitation (MBE) \cite{griffin1988multiband} vocoders that were first developed in the late 1980s.  Descendants of the MBE vocoders (IMBE, AMBE etc) have enjoyed widespread use in many applications such as VHF/UHF hand held radios and satellite communications. In the 1990s the author studied sinusoidal speech coding \cite{rowe1997techniques}, which provided the skill set and a practical, patent free baseline for starting the Codec 2 project:
 
-Some features of Codec 2:
+Some features of the Codec 2 Design:
 \begin{enumerate}
-\item A range of modes supporting different bit rates, currently (Nov 2023): 3200, 2400, 1600, 1400, 1300, 1200, 700 bits/s.  These are referred to as ``Codec 2 3200", ``Codec 700C"" etc.
-\item Modest CPU (a few 10s of MIPs) and memory (a few 10s of kbytes of RAM) requirements such that it can run on stm32 class microcontrollers with hardware FPU.
-\item An open source reference implementation in the C language for C99/gcc compilers, and a \emph{cmake} build and test framework that runs on Linux.  Also included is a cross compiled stm32 reference implementation.
-\item Ports to non-C99 compilers (e.g. MSVC, some microcontrollers, native builds on Windows) are left to third party developers - we recommend the tests also be ported and pass before considering the port successful.
-\item Codec 2 has been designed for digital voice over radio applications, and retains intelligible speech at a few percent bit error rate.
-\item A suite of automated tests used to verify the implementation.
 \item A pitch estimator based on a 2nd order non-linearity developed by the author.
 \item A single voiced/unvoiced binary voicing model.
 \item A frequency domain IFFT/overlap-add synthesis model for voiced and unvoiced speech speech.
-- 
cgit v1.2.3

