Speex手册----Speex 简介

前言：没搜到Speex相关的中文资料，所以想将Speex的英文手册中会用到的部分翻译出来。Speex官网：http://speex.org/ 可以再Documentation下找到PDF版或HTML OL版的英文手册。每段我都会付上英文原段落，可能会由于英文技能的匮乏或语音解码领域的不熟悉会有翻译错误，也望各位发现后能够不吝赐教，大家共同进步。

PS:如需转载，注明出处，不胜感激

 

简介

1.1 获得帮助

1.2 关于此文档

后记

 

简介：

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 many 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.

由于语音对话编解码需要一个免费的开源软件，所以诞生了Speex库，可以在任何开源软件中使用。实际上，Speex对于语音对话来讲，相当于Vorbis[一种可将声音来源加以压缩的编码软件，开放源码且免版权]对于音频/音乐。和大多数语音编解码库不一样的是，Speex不是为移动电话而设计的，而是为分组网络的VOIP(Voice over IP)应用程序，同时支持基于文件的压缩。

 

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).

       Speex编解码库的设计非常灵活，支持广泛的语音质量和比特率。良好的语音质量支持意味着除了窄带语音( 电话质量，8kHz采样率)外还可以对宽带语音( 电话质量，16kHz采样率)进行编解码。

 

    Designing for VoIP instead of mobile phones means that Speex is robust to lost packets, but not to corrupted 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.

       Speex被设计用于VoIP而不是移动电话，意味着Speex对于丢包能够妥善处理,不会有损坏数据。这在VOIP里是基于这样的假设，数据包要么不被改变的到达，要么不会到达。Speex针对于大多数的设备，因此它拥有适中（可调整）的复杂性和较小内存占用。

 

   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 could 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).

       所有这些设计的目的是为了引入码激励线性预测(CELP)编码技术，因为长期实践表明它对于低比特率（如DoD CELP@ 4.8kbps）和高比特率（如G.728 @ 16kbps）的工作性能良好,可靠性高。

1.1      获得帮助

As for many open source projects, there are many 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 [email protected] (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 [email protected] only for private/delicate topics you do not wish to discuss publically.

类似于大多数开源项目，Speex也可以能过多种获得帮助的路径，包括：

l         本手册

l         Speex官方站点（http://www.speex.org/ ）的其他文档

l         邮件列表：讨论Speex相关发送至 [email protected] (不是仅限于开发者)

l         IRC：通过irc.freenode.net Speex频道获取，可能需要耐心等待一段时间

l         如果不想公开讨论一些主题，可Email作者[email protected]

 

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.

在寻求帮助前（邮件列表或IRC），最好先仔细阅读本手册（呵呵，看到这里说明你已经有一个不错的开始），如果文档中介绍的很详细的问题你仍然去Email多不好。当然，本手册也不可能囊括关于Speex所有的知识点，所以也希望大家多提问题和见解、以及需要改进或增加的功能，或者是仅仅让我们知道您在使用Speex。

 

Here are some additional guidelines related to the mailing list. Before reporting bugs in Speex to the list, it is strongly 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.

在发送报告Bugs的邮件时，也对大家有些额外的要求，建议（如果可能）先使用Speexenc和Speexdec（见第4节）命令行工具测试能否使Bugs再现，很多报告的Bug都由第三方的代码引起而难以发现，造成的错误往往不关Speex的事。

1.2      关于此文档

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

文档分为几部分，第2节介绍Speex的特性以及一些文档中用到的基本术语。第4节是关于Speex提供的标准命令行工具。第5节是使用libspeex API进行编程的详细说明。第7节是一些关于Speex相关标准的信息。

 

    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.

    最后三节介绍了Speex使用的算法。这部分需要信号处理相关知识，但这是对于那些想了解Speex的真正工作原理或基于Speex进行研究的人，如果仅仅是使用Speex库则不是必需的。第8节大概介绍了CELP（码激励线性预测）编码，9和10节是关于Speex的一些具体介绍。

 

后记：

如果哪位同学已拥有此手册的中文版本，可留我一份，不然偶得继续增强英文了，也不算一件坏事。