📄 rfc2361.txt
字号:
Network Working Group E. FleischmanRequest for Comments: 2361 Microsoft CorporationCategory: Informational June 1998 WAVE and AVI Codec RegistriesStatus of this Memo This memo provides information for the Internet community. It does not specify an Internet standard of any kind. Distribution of this memo is unlimited.Copyright Notice Copyright (C) The Internet Society (1998). All Rights Reserved.Abstract Internet applications may reference specific codecs within the WAVE and AVI registries as follows: * video/vnd.avi; codec=XXX identifies a specific video codec (i.e., XXX) within the AVI Registry. * audio/vnd.wave; codec=YYY identifies a specific audio codec (i.e., YYY) within the WAVE Registry. Appendix A and Appendix B provides an authoritative reference for the interpretation of the required "codec" parameter. That is, the current set of audio codecs that are registered within the WAVE Registry are enumerated in Appendix A. Appendix B enumerates the current set of video codecs that have been registered to date within the AVI Registry.1 Introduction Internet-oriented multimedia applications reference multimedia content via predefined mechanisms (e.g., [2]). In the general case, this content was created primarily for the use of these Internet- oriented applications. Unfortunately, this Internet-oriented multimedia content represents a small minority of the total amount of multimedia content that has been created to date. For this reason, a growing interest is forming in establishing mechanisms by which the repertoire of multimedia content available to Internet-oriented applications(e.g., for RTSP [3]) may be greatly extended to include multimedia content that has been created outside of distinctly Internet contexts. For this to occur, a mechanism mustFleischman Informational [Page 1] RFC 2361 WAVE and AVI Codec Registries June 1998 be created for Internet protocols (e.g., [1], [3], [4]) to be able to identify the codecs by which this so-called "traditional" multimedia content has been encoded. Unfortunately, several distinct encoding systems exist for traditional multimedia content. Each system has its own registry to ensure unique and stable codec identifications within that system. Perhaps the best known of these registries are Microsoft (for WAVE and AVI content) and Apple (for QuickTime content). The purpose of this paper is to establish a mechanism by which codecs registered within Microsoft's WAVE and AVI Registries may be referenced within the IANA Namespace by Internet applications.2 References to Registries within the IANA Vendor Tree Reference [7] specifies that the IANA Namespace encompasses several trees. Discussions within the IETF-Types mailing list concluded that the most appropriate tree in which to reference codecs, which had already been registered by non-IANA Registries, is the Vendor Tree. As a result, the non-IANA registry is identified within the IANA Vendor tree by vnd.RegistryName. A specific codec, which has been registered within that registry, is identified by a required codec parameter as specified by Section 2.2.3 of [7].3 WAVE and AVI Registries Both the WAVE and AVI Registries are historic databases that have been maintained by Microsoft as a free service. The Registries sought to assist developers of WAVE and AVI content and to standardize WAVE and AVI content by 1) avoiding conflict and/or duplication with current definitions, and 2) providing the registered information in a standard document and format that is publicly available. The historic nature of these databases implies that unless the original registrants informed the registrar of a change of status (e.g., company acquired, new contact, new location, new phone), the contact information has generally not been updated from the originally registered values. Audio codecs within the WAVE Registry are identified by WAVE Format IDs. The (audio) WAVE Format ID is officially known as "WAVE form Registration Number". The WAVE Format ID is a hexadecimal integer value. These codecs may be referenced within the IANA namespace asFleischman Informational [Page 2] RFC 2361 WAVE and AVI Codec Registries June 1998 "audio/vnd.wave; codec=XXX", where XXX represents a valid WAVE Format ID (e.g., the WAVE Format ID of "123" is referenced within the IANA namespace by "audio/vnd.wave; codec=123"). Video codecs within the AVI Registry are identified by AVI Codec IDs. The AVI Codec ID value is a FourCC encoding. A FourCC is 32-bits long and represents a (case-sensitive) four-character (i.e., ASCII) code value. These codecs may be referenced within the IANA namespace as "video/vnd.avi; codec=XXX", where XXX represents a valid AVI Codec ID (e.g., the WAVE Format ID of "SCRN" is referenced within the IANA namespace by "video/vnd.avi; codec=SCRN"). Appendix A is an authoritative list of the complete set of audio codecs that have been registered (as of January 1998) within the WAVE Registry. Appendix B is an authoritative list of the complete set of video codecs that have been registered (as of January 1998) within the AVI registry.4 Mapping Codec IDs to GUID Values Direct mappings exist between WAVE Format IDs and GUIDs and between FourCC codec values and GUIDs [5]. [Note: GUIDs are Globally Unique Identifiers that are also known as Universally Unique Identifiers (UUIDs). UUIDs have been standardized within the Open Software Foundation's (OSF) Distributed Computing Environment (DCE).] These mappings enable GUID-oriented software to directly refer to these historic codec values. For example, the Advanced Streaming Format (ASF) [6] uses GUID values to refer to codecs, and the following mechanism is used to convert the historic WAVE and AVI codec values into the appropriate GUID value for use within ASF. WAVE Format IDs are converted to GUIDs by inserting the hexadecimal value of the WAVE Format ID into the XXXXXXXX part of the following template: {XXXXXXXX-0000-0010-8000-00AA00389B71}. For example, a WAVE Format ID of 123 has the GUID value of {00000123-0000-0010-8000- 00AA00389B71}. FourCC values are converted to GUIDs by inserting the FourCC value into the XXXXXXXX part of the same template: {XXXXXXXX-0000-0010- 8000-00AA00389B71}. For example, a conversion of the FourCC value of "H260" would result in the GUID value of {30363248-0000-0010-8000- 00AA00389B71}. [Note: the 32-bit FourCC value of "H260" is converted into hexadecimal 32-bit value (i.e., 30363248) because the initial XXXXXXXX of the GUID is defined as a DWORD and thus takes a 32-bit hexadecimal value. Endian considerations account for the apparent re-ordering of the original ASCII text.]Fleischman Informational [Page 3] RFC 2361 WAVE and AVI Codec Registries June 19985 Security Considerations This document merely registers a set of formats. It does nothing to address the security considerations of these formats. The format itself must be investigated for security issues with each format.Author's Address Eric Fleischman Microsoft Corporation One Microsoft Way Redmond, WA 98052-6399 USA EMail: ericfl@microsoft.com http://www.microsoft.com/asf/ Subsequent to this submittal the author has changed employers. He now can be reached at: The Boeing Company PO Box 3707, MS 7M-FM Seattle, WA 98124-2207 Phone: 425-865-2424 EMail: Eric.Fleischman@PSS.Boeing.comFleischman Informational [Page 4] RFC 2361 WAVE and AVI Codec Registries June 1998References [1] Schulzrinne, H., Casner, S., Frederick, R., and V. Jacobson,"RTP: A Transport Protocol for Real-Time Applications", RFC 1889, January 1996. [2] Schulzrinne, H., "RTP Profile for Audio and Video Conferences with Minimal Control", RFC 1890, January 1996. [3] Schulzrinne, H., Rao, A., and R. Lanphier, "Real Time Streaming Protocol (RTSP)", RFC 2326, April 1998. [4] Handley, M., and V. Jacobson, "SDP: Session Description Protocol", RFC 2327, April 1998. [5] "ASF Codec GUIDs", http://www.microsoft.com/asf/guids.htm [6] Microsoft Corporation, "Advanced Streaming Format (ASF) Specification", September 1997, http://www.microsoft.com/asf/specs.htm. [7] Freed, N., Klensin, J., and J. Postel, "Multipurpose Internet Mail Extensions (MIME) Part Four: Registration Procedures", RFC 2048, November 1996.Fleischman Informational [Page 5] RFC 2361 WAVE and AVI Codec Registries June 1998Appendix A Audio Codecs from the Microsoft WAVE Registry A.1 Microsoft Unknown Wave Format WAVE form Registration Number (hex): 0x0000 Codec ID in the IANA Namespace: audio/vnd.wave;codec=0 WAVE form wFormatTag ID: WAVE_FORMAT_UNKNOWN Contact: Terri Hendry, 425-936-2069 Microsoft Corporation One Microsoft Way Redmond, WA 98052-6399 USA A.2 Microsoft PCM Format WAVE form Registration Number (hex): 0x0001 Codec ID in the IANA Namespace: audio/vnd.wave;codec=1 WAVE form wFormatTag ID: WAVE_FORMAT_PCM Contact: Terri Hendry 425-936-2069 Microsoft Corporation One Microsoft Way Redmond, WA 98052-6399 USA A.3 Microsoft ADPCM Format WAVE form Registration Number (hex): 0x0002 Codec ID in the IANA Namespace: audio/vnd.wave;codec=2 WAVE form wFormatTag ID: WAVE_FORMAT_ADPCM Contact: Terri Hendry 425-936-2069 Microsoft Corporation One Microsoft Way Redmond, WA 98052-6399 USA A.4 IEEE Float WAVE form Registration Number (hex): 0x0003 Codec ID in the IANA Namespace: audio/vnd.wave;codec=3 WAVE form wFormatTag ID: WAVE_FORMAT_IEEE_FLOAT Contact: Terri Hendry 425-936-2069 Microsoft Corporation One Microsoft Way Redmond, WA 98052-6399 USAFleischman Informational [Page 6] RFC 2361 WAVE and AVI Codec Registries June 1998 A.5 Compaq Computer's VSELP WAVE form Registration Number (hex): 0x0004 Codec ID in the IANA Namespace: audio/vnd.wave;codec=4 WAVE form wFormatTag ID: WAVE_FORMAT_VSELP Additional information: VSELP codec for Windows CE 2.0 devices Contact: Doug Stewart 713-374-7925 Compaq Computer Corporation 20555 SH 249 Houston, TX 77269-2000 USA A.6 IBM CVSD WAVE form Registration Number (hex): 0x0005 Codec ID in the IANA Namespace: audio/vnd.wave;codec=5 WAVE form wFormatTag ID: WAVE_FORMAT_IBM_CVSD Contact: IBM Corporation A.7 Microsoft ALAW WAVE form Registration Number (hex): 0x0006 Codec ID in the IANA Namespace: audio/vnd.wave;codec=6 WAVE form wFormatTag ID: WAVE_FORMAT_ALAW Contact: Terri Hendry 425-936-2069 Microsoft Corporation One Microsoft Way Redmond, WA 98052-6399 USA A.8 Microsoft MULAW WAVE form Registration Number (hex): 0x0007 Codec ID in the IANA Namespace: audio/vnd.wave;codec=7 WAVE form wFormatTag ID: WAVE_FORMAT_MULAW Contact: Terri Hendry 425-936-2069 Microsoft Corporation One Microsoft Way Redmond, WA 98052-6399 USAFleischman Informational [Page 7] RFC 2361 WAVE and AVI Codec Registries June 1998 A.9 OKI ADPCM WAVE form Registration Number (hex): 0x0010 Codec ID in the IANA Namespace: audio/vnd.wave;codec=10 WAVE form wFormatTag ID: WAVE_FORMAT_OKI_ADPCM Contact: Oki A.10 Intel's DVI ADPCM WAVE form Registration Number (hex): 0x0011 Codec ID in the IANA Namespace: audio/vnd.wave;codec=11 WAVE form wFormatTag ID: WAVE_FORMAT_DVI_ADPCM Contact: Intel Corporation 5200 NE Elam Young Parkway Hillsboro, OR 97124 503-696-2448 A.11 Videologic's MediaSpace ADPCM WAVE form Registration Number (hex): 0x0012 Codec ID in the IANA Namespace: audio/vnd.wave;codec=12 WAVE form wFormatTag ID: WAVE_FORMAT_MEDIASPACE_ADPCM Contact: Videologic Home Park Estate Kings Langley England WD4 8LZ Telephone: 44-92-326-0511 A.12 Sierra ADPCM WAVE form Registration Number (hex): 0x0013 Codec ID in the IANA Namespace: audio/vnd.wave;codec=13 WAVE form wFormatTag ID: WAVE_FORMAT_SIERRA_ADPCM Contact: Stuart Goldstein 72170.301@compuserve.com Sierra Semiconductor Corp 2075 North Capitol Avenue San Jose, California 95132 USA 408-263-9300Fleischman Informational [Page 8] RFC 2361 WAVE and AVI Codec Registries June 1998 A.13 G.723 ADPCM WAVE form Registration Number (hex): 0x0014 Codec ID in the IANA Namespace: audio/vnd.wave;codec=14 WAVE form wFormatTag ID: WAVE_FORMAT_G723_ADPCM Contact: Bob Bauman 310-532-3092 Antex Electronics Coporation 3184-H Airway Ave. Costa Mesa, California 92627 USA A.14 DSP Solution's DIGISTD WAVE form Registration Number (hex): 0x0015 Codec ID in the IANA Namespace: audio/vnd.wave;codec=15 WAVE form wFormatTag ID: WAVE_FORMAT_DIGISTD Contact: DSP Solutions, Inc 2464 Embarcadero Way Palo Alto, California 94303 USA 415-494-8086 A.15 DSP Solution's DIGIFIX WAVE form Registration Number (hex): 0x0016 Codec ID in the IANA Namespace: audio/vnd.wave;codec=16 WAVE form wFormatTag ID: WAVE_FORMAT_DIGIFIX Contact: DSP Solutions, Inc 2464 Embarcadero Way Palo Alto, California 94303 USA 415-494-8086 A.16 Dialogic OKI ADPCM WAVE form Registration Number (hex): 0x0017 Codec ID in the IANA Namespace: audio/vnd.wave;codec=17 WAVE form wFormatTag ID: WAVE_FORMAT_DIALOGIC_OKI_ADPCM WAVEFORMAT use: for OKI ADPCM chips or firmware Contact: Dialogic Corporation 300 Littleton Road Parsippany, NJ 07054 USA 201-334-1268Fleischman Informational [Page 9] RFC 2361 WAVE and AVI Codec Registries June 1998 A.17 MediaVision ADPCM WAVE form Registration Number (hex): 0x0018 Codec ID in the IANA Namespace: audio/vnd.wave;codec=18 WAVE form wFormatTag ID: WAVE_FORMAT_MEDIAVISION_ADPCM WAVEFORMAT Name: ADPCM for Jazz 16 chip set Contact: Alex Cheng Media Vision, Inc California USA A.18 HP CU WAVE form Registration Number (hex): 0x0019 Codec ID in the IANA Namespace: audio/vnd.wave;codec=19 WAVE form wFormatTag ID: WAVE_FORMAT_CU_CODEC Contact: Cliff Chiang Telephone: 65-3747005 Hewlett-Packard Company⌨️ 快捷键说明
复制代码
Ctrl + C
搜索代码
Ctrl + F
全屏模式
F11
切换主题
Ctrl + Shift + D
显示快捷键
?
增大字号
Ctrl + =
减小字号
Ctrl + -