ITU-T G.722-1988/AMD.1-2010 64 kbit/s 之内的7 kHz 音频编码 7 kHz audio-coding within 64 kbit/s

pdf标准 ITU-T G.722-1988/AMD.1-2010 64 kbit/s 之内的7 kHz 音频编码 7 kHz audio-coding within 64 kbit/s

96 页 0 下载 0 浏览 0 评论 0 收藏 3.0分
温馨提示:当前标准最多只能预览 10 页,若标准超出了 10 页,请下载原标准以浏览全部内容。
ITU-T G.722-1988/AMD.1-2010 64 kbit/s 之内的7 kHz 音频编码 7 kHz audio-coding within 64 kbit/s 第 1 页 ITU-T G.722-1988/AMD.1-2010 64 kbit/s 之内的7 kHz 音频编码 7 kHz audio-coding within 64 kbit/s 第 2 页 ITU-T G.722-1988/AMD.1-2010 64 kbit/s 之内的7 kHz 音频编码 7 kHz audio-coding within 64 kbit/s 第 3 页 ITU-T G.722-1988/AMD.1-2010 64 kbit/s 之内的7 kHz 音频编码 7 kHz audio-coding within 64 kbit/s 第 4 页 ITU-T G.722-1988/AMD.1-2010 64 kbit/s 之内的7 kHz 音频编码 7 kHz audio-coding within 64 kbit/s 第 5 页
下载标准到电脑,方便使用
还有 5 页未阅读,继续阅读
本标准由 5zbz2018-09-16 14:36:58上传分享

国外分类,ITU,ITU-T(电信标准分局),itu,amd,kbit,之内,khz,音频,编码,khz,audio,coding,within,kbit

INTERNATIONAL TELECOMMUNICATION UNION ITU-T TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU G.722 Amendment 1 (11/2010) SERIES G: TRANSMISSION SYSTEMS AND MEDIA, DIGITAL SYSTEMS AND NETWORKS Digital terminal equipments – Coding of voice and audio signals 7 kHz audio-coding within 64 kbit/s: New Annex B with superwideband embedded extension Amendment 1 CAUTION ! PREPUBLISHED RECOMMENDATION This prepublication is an unedited version of a recently approved Recommendation. It will be replaced by the published version after editing. Therefore, there will be differences between this prepublication and the published version. FOREWORD The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. NOTE In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure e.g. interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. INTELLECTUAL PROPERTY RIGHTS ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. As of the date of approval of this Recommendation, ITU [had/had not] received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database at http://www.itu.int/ITU-T/ipr/.  ITU 2011 All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. ITU-T Recommendation G.722 Amendment 1 (ex G.722-SWB) 7 kHz audio-coding within 64 kbit/s: New Annex B with superwideband embedded extension Summary Annex B describes a scalable superwideband (SWB, 50-14000 Hz) speech and audio coding algorithm operating at 64, 80 and 96 kbit/s. The G.722 superwideband extension codec is interoperable with G.722. The output of the G.722 SWB coder has a bandwidth of 50-14000 Hz. The coder operates with 5 ms frames, has an algorithmic delay of 12.3125 ms and a worst case complexity of 22.76 WMOPS. By default, the encoder input and decoder output are sampled at 32 kHz. The superwideband encoder for improved G.722 64 kbit/s core produces an embedded bitstream structured in two layers corresponding to two available bit rates from 80 to 96 kbit/s. The superwideband encoder for improved G.722 56 kbit/s core produces an embedded bitstream structured in one layer corresponding to one available bit rate 64 kbit/s. This 64 kbit/s mode is also scalable with the 80 kbit/s and 96 kbit/s modes. The bitstream can be truncated at the decoder side or by any component of the communication system to instantaneously adjust the bit rate to the desired value (96 kbit/  80 kbit/  64 kbit/s) with no need for out-of-band signalling. The underlying algorithm includes three main parts: higher band enhancements, bandwidth extension (BWE) and transform coding in modified discrete cosine transform (MDCT) domain based on algebraic vector quantization (AVQ). Annex B contains an electronic attachment with the ANSI C source code, which is an integral part of this Annex. Rec. ITU-T G.722 (1988)/Amd.1 (11/2010) – Prepublis

给标准打分
您好可以输入 255 个字符
本站的中文名字叫什么( 答案:找标准 )
评论列表
  • 暂时还没有评论,期待您的金玉良言