Speex manual-Introduction to speex

Preface:I didn't find any Chinese documents related to speex, so I want to translate some of the documents used in speex's English manual. Speex Official Website: http://speex.org/can be found under Documentation PDF or HTML ol version of the English manual. I will pay the original English section for each section. translation errors may occur due to lack of English skills or familiarity in the speech decoding field. I hope you will not be able to give me any further advice and make common progress.

PS: If you need to repost it and indicate the source, I am very grateful.

 

Introduction

1.1 get help

1.2 about this document

Postscript

 

Introduction:

The speex codec (http://www.speex.org/) exists because there is a need for a speech codec that is open-source and free from software patent royalties. these are essential conditions for being usable in any open-source software. in essence, speex is to speech what Vorbis is to audio/music. unlike accessing other speech codecs, speex is not designed for mobile phones but rather for Packet Networks and Voice over IP (VoIP) applications. file-based compression is of course also supported.

voice conversation codec requires a free open-source software, so it was born speex library, which can be used in any open-source software. Actually, speex for voice dialogs, it is equivalent to Vorbis [ A coding software that compresses sound sources, open source and copyright-free ] for audio / music. Unlike most speech codec libraries, speex not designed for mobile phones, VoIP (Voice over IP) apply Programs and support file-based compression.

 

The speex codec is designed to be very flexible and support a wide range of Speech Quality and bit-rate. support for very good quality speech also means that speex can encode Wideband Speech (16 KHz sampling rate) in addition to Narrowband Speech (telephone quality, 8 KHz sampling rate ).

SpeexThe codec library is designed flexibly and supports a wide range of Speech Quality and bit rates. Good speech quality support means that in addition to Narrowband Speech(Telephone quality,8 kHzSampling Rate)Broadband speech(Telephone quality,16 kHzSampling Rate)Encoding/decoding.

 

designing for VoIP instead of mobile phones means that speex is robust to lost packets, but not to upted ones. this is based on the assumption that in VoIP, packets either arrive unaltered or don't arrive at all. because speex is targeted at a wide range of devices, it has modest (adjustable) Complexity and a small memory footprint.

SpeexDesigned for useVoIPInstead of mobile phones, it meansSpeexProper Handling of Packet Loss,No data corruption. InVoIPIs based on the assumption that data packets will either not be changed or arrive.SpeexFor most devices, it has moderate (adjustable) Complexity and small memory usage.

 

all the design goals led to the choice of CELP as the encoding technique. one of the main reasons is that CELP has long proved that it cocould work reliably and scale well to both low bit-rates (e.g. dod celp @ 4.8 kbps) and high bit-rates (e.g. g.728 @ 16 kbps ).

All these designs aim to introduce code-driven Linear Prediction(CELP)Encoding technology, because long-term practice shows that it has low bit rate (suchDod celp @ 4.8 kbps) And high bit rate (suchG.728 @ 16 kbps).,High reliability.

1.1Get help

As for each open source projects, there are always ways to get help with speex. These include:
• This Manual
• Other documentation on the speex website (http://www.speex.org /)
• Mailing List: Discuss any speex-related topic on speex-dev@xiph.org (not just for developers)
• IRC: the main channel is # speex on irc.freenode.net. Note that due to time differences, it may take a while to get someone, so please be patient.
• Email the author privately at jean-marc.valin@usherbrooke.ca only for private/delicate topics you do not wish to discuss publically.

Similar to most open-source projects,SpeexYou can also get help in a variety of ways, including:

LThis manual

LSpeexOfficial site (Http://www.speex.org/ ).

L email list: Discussion speex sent to speex-dev@xiph.org ( not limited to developers )

L IRC : irc.freenode.net speex channel acquisition, which may take a while

LIf you do not want to discuss some topics publiclyEmailAuthorJean-marc.valin@usherbrooke.ca

 

before asking for help (mailing list or IRC), it is important to first read this manual (OK, so if you made it here it's already a good sign ). it is generally considered rude to ask on a mailing list about topics that are clearly detailed in the documentation. on the other hand, it's perfectly OK (and encouraged) to ask for clarifications about something covered in the manual. this Manual does not (yet) cover everything about speex, so everyone is encouraged to ask questions, send comments, feature requests, or just let us know how speex is being used.

Before asking for help (email list orIRC), It is best to read this manual carefully (haha, you have a good start here ).EmailPoor. Of course, this manual cannot includeSpeexAll the knowledge points, so I hope you will give more questions and insights, as well as the functions that need to be improved or added, or just let us know that you are usingSpeex.

 

here are some additional guidelines related to the mailing list. before reporting bugs in speex to the list, it is stronugly recommended (if possible) to first test whether these bugs can be reproduced using the speexenc and speexdec (see section 4)
command-line utilities. bugs reported based on 3rd party code are both harder to find and far too often caused by errors that have nothing to do with speex.

send the report bugs speexenc and speexdec (see section 4 section) test whether the bugs reproduction, many reports bug All are caused by Code of a third party, which is hard to find, errors often do not concern speex .

1.2About this document

This document is divided in the following way. section 2 describes the different speex features and defines limit basic terms that are used throughout this manual. section 4 documents the standard command-line tools provided in the speex distribution. section 5 describes des detailed instructions about programming using the libspeex API. section 7 has some information related to speex and standards.

The document consists of the following parts:2SectionSpeexFeatures and basic terms used in some documents. The4Section is aboutSpeexProvides standard command line tools. The5Section is usedLibspeex APIProgramming details. The7Section is aboutSpeexStandard information.

 

The three last sections describe the algorithms used in speex. these sections require signal processing knowledge, but are not required for merely using speex. they are intended for people who want to understand how speex really works and/or want to do research based on speex. section 8 explains the general idea behind CELP, while sections 9 and 10 are specific to speex.

The last three sections introduce Speex UsedAlgorithm. This part requires signal processing knowledge, but this is for those who want to know Speex Or is based on Speex If only Speex Library is not required. The 8 This section introduces CELP (Code-driven Linear Prediction) encoding, 9 And 10 Section is about Speex .

 

Postscript:

if you already have a Chinese version of this manual, you can leave it with me. Otherwise, you may need to continue to improve your English version, it is not a bad thing.