[xiph-commits] r14655 - trunk/standards
ivo at svn.xiph.org
ivo at svn.xiph.org
Thu Apr 3 21:52:25 PDT 2008
Author: ivo
Date: 2008-04-03 21:52:24 -0700 (Thu, 03 Apr 2008)
New Revision: 14655
Modified:
trunk/standards/draft-goncalves-rfc3534bis.txt
trunk/standards/draft-goncalves-rfc3534bis.xml
Log:
Update to address comments by Magnus Westerlund.
Modified: trunk/standards/draft-goncalves-rfc3534bis.txt
===================================================================
--- trunk/standards/draft-goncalves-rfc3534bis.txt 2008-04-03 19:00:12 UTC (rev 14654)
+++ trunk/standards/draft-goncalves-rfc3534bis.txt 2008-04-04 04:52:24 UTC (rev 14655)
@@ -5,11 +5,11 @@
Internet-Draft S. Pfeiffer
Obsoletes: 3534 (if approved) C. Montgomery
Intended status: Standards Track Xiph
-Expires: August 25, 2008 February 22, 2008
+Expires: October 6, 2008 April 4, 2008
Ogg Media Types
- draft-goncalves-rfc3534bis-01
+ draft-goncalves-rfc3534bis-02
Status of This Memo
@@ -34,7 +34,7 @@
The list of Internet-Draft Shadow Directories can be accessed at
http://www.ietf.org/shadow.html.
- This Internet-Draft will expire on August 25, 2008.
+ This Internet-Draft will expire on October 6, 2008.
Copyright Notice
@@ -52,9 +52,9 @@
-Goncalves, et al. Expires August 25, 2008 [Page 1]
+Goncalves, et al. Expires October 6, 2008 [Page 1]
-Internet-Draft Ogg Media Types February 2008
+Internet-Draft Ogg Media Types April 2008
Table of Contents
@@ -62,18 +62,19 @@
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Conformance and Document Conventions . . . . . . . . . . . . 3
3. Deployed Media Types and Compatibility . . . . . . . . . . . 4
- 4. Encoding Considerations . . . . . . . . . . . . . . . . . . 4
- 5. Security Considerations . . . . . . . . . . . . . . . . . . 5
- 6. Interoperability Considerations . . . . . . . . . . . . . . 6
- 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . 6
- 8. Ogg Media Types . . . . . . . . . . . . . . . . . . . . . . 6
- 8.1. application/ogg . . . . . . . . . . . . . . . . . . . . . . 6
- 8.2. video/ogg . . . . . . . . . . . . . . . . . . . . . . . . . 7
- 8.3. audio/ogg . . . . . . . . . . . . . . . . . . . . . . . . . 8
- 9. Copying Conditions . . . . . . . . . . . . . . . . . . . . . 9
- 10. References . . . . . . . . . . . . . . . . . . . . . . . . . 9
- 10.1. Normative References . . . . . . . . . . . . . . . . . . . . 9
- 10.2. Informative References . . . . . . . . . . . . . . . . . . . 10
+ 4. Relation Between the Media Types . . . . . . . . . . . . . . 4
+ 5. Encoding Considerations . . . . . . . . . . . . . . . . . . 5
+ 6. Security Considerations . . . . . . . . . . . . . . . . . . 5
+ 7. Interoperability Considerations . . . . . . . . . . . . . . 6
+ 8. IANA Considerations . . . . . . . . . . . . . . . . . . . . 7
+ 9. Ogg Media Types . . . . . . . . . . . . . . . . . . . . . . 7
+ 9.1. application/ogg . . . . . . . . . . . . . . . . . . . . . . 7
+ 9.2. video/ogg . . . . . . . . . . . . . . . . . . . . . . . . . 8
+ 9.3. audio/ogg . . . . . . . . . . . . . . . . . . . . . . . . . 9
+ 10. Copying Conditions . . . . . . . . . . . . . . . . . . . . . 10
+ 11. References . . . . . . . . . . . . . . . . . . . . . . . . . 10
+ 11.1. Normative References . . . . . . . . . . . . . . . . . . . . 10
+ 11.2. Informative References . . . . . . . . . . . . . . . . . . . 10
@@ -107,10 +108,9 @@
-
-Goncalves, et al. Expires August 25, 2008 [Page 2]
+Goncalves, et al. Expires October 6, 2008 [Page 2]
-Internet-Draft Ogg Media Types February 2008
+Internet-Draft Ogg Media Types April 2008
1. Introduction
@@ -164,9 +164,9 @@
-Goncalves, et al. Expires August 25, 2008 [Page 3]
+Goncalves, et al. Expires October 6, 2008 [Page 3]
-Internet-Draft Ogg Media Types February 2008
+Internet-Draft Ogg Media Types April 2008
implementations are "unconditionally compliant".
@@ -188,18 +188,22 @@
for complex data (e.g. multitrack visual, audio, textual and other
time-continuously sampled data), which is not clearly video or audio
data and thus not suited for either the video/ogg or audio/ogg types.
+ Refer to the following section for more details.
An Ogg bitstream generally consists of one or more logical bitstreams
that each consist of a series of header and data pages packetising
time-continuous binary data [RFC3533]. The content types of the
logical bitstreams may be identified without decoding the header
pages of the logical bitstreams through use of a [Skeleton]
- bitstream. Using Skeleton is REQUIRED for content served under the
- application/ogg type and RECOMMENDED for video/ogg and audio/ogg.
+ bitstream. Using Ogg Skeleton is REQUIRED for content served under
+ the application/ogg type and RECOMMENDED for video/ogg and audio/ogg,
+ as it is a type of identifier space used to describe the different
+ encapsulated data.
Furthermore, it is RECOMMENDED that implementations that identify a
logical bitstream which they cannot decode SHOULD ignore it, while
- continuing to decode the ones they can.
+ continuing to decode the ones they can. Such precaution ensures
+ backward and forward compatibility with existing and future data.
Ongoing work related to this registration may introduce optional
parameters in future revisions of this document. One example area of
@@ -208,8 +212,44 @@
examination of the bitstream. Implementations MUST consider the
impact of such an update.
-4. Encoding Considerations
+4. Relation Between the Media Types
+ As stated in the previous section, this document describes three
+ media types which are targeted at different data encapsulated in Ogg.
+ Since Ogg is capable of encapsulate any kind of data, the multiple
+
+
+
+Goncalves, et al. Expires October 6, 2008 [Page 4]
+
+Internet-Draft Ogg Media Types April 2008
+
+
+ usage scenarios have revealed interoperability issues between
+ implementations when dealing with content served solely under the
+ application/ogg type.
+
+ While this document does redefine the earlier definition of
+ application/ogg, this media type will continue to embrace the widest
+ net possible of content with the video/ogg and audio/ogg types being
+ smaller subsets of it. However, the video/ogg and audio/ogg types
+ take precedence in a subset of the usages, specifically when serving
+ multimedia content that is not complex enough to warrant the use of
+ application/ogg. Following this line of thought, the audio/ogg type
+ is an even smaller subset within video/ogg, as it is not intended to
+ refer to visual content.
+
+ As such, the application/ogg type is the recommended choice to serve
+ content aimed at scientific and other applications that require
+ various multiplexed signals or streams of continuous data. For
+ bitstreams containing visual, timed text, or any other type of
+ material that requires a visual interface, but which is not complex
+ enough to warrant serving under application/ogg, the video/ogg type
+ is recommended. In situations where the Ogg bitstream predominantly
+ contains audio data, it is recommended to use the audio/ogg type.
+
+5. Encoding Considerations
+
Binary: The content consists of an unrestricted sequence of octets.
Note:
@@ -217,22 +257,14 @@
in a suitable encoding without CR/LF conversion, 7-bit stripping,
etc.; base64 [RFC4648] is generally preferred for binary-to-text
encoding.
-
-
-
-Goncalves, et al. Expires August 25, 2008 [Page 4]
-
-Internet-Draft Ogg Media Types February 2008
-
-
o Media types described in this document are used for stream based
storage (such as files) and transport (such as TCP streams or
pipes); separate types are used for real-time transfer, such as
for the RTP payload formats of Theora [ThRTP] video, and Vorbis
[VoRTP] or Speex [SpRTP] audio, as well as for identification of
- the encapsulated content within Ogg.
+ the encapsulated data within Ogg.
-5. Security Considerations
+6. Security Considerations
Refer to [RFC3552] for a discussion of terminology used in this
section.
@@ -242,6 +274,13 @@
rigid definition. This format in itself is not more vulnerable than
any other content framing mechanism.
+
+
+Goncalves, et al. Expires October 6, 2008 [Page 5]
+
+Internet-Draft Ogg Media Types April 2008
+
+
Ogg does not provide for any generic encryption or signing of itself
or its contained bitstreams. However, it encapsulates any kind of
binary content and is thus able to contain encrypted and signed
@@ -254,8 +293,8 @@
content without prior validation of its origin by the end-user. This
may be an issue with applications that use Ogg for streaming or file
transfer in a networking scenario. An implementation decoding Ogg
- and its encapsulated content streams has to ensure correct handling
- of manipulated bitstreams, of buffer overflows, and similar issues.
+ and its encapsulated data streams has to ensure correct handling of
+ manipulated bitstreams, of buffer overflows, and similar issues.
It is also possible to author malicious Ogg bitstreams, which attempt
to call for an excessively large picture size, high sampling-rate
@@ -273,39 +312,39 @@
other means to prevent possibly dangerous operations. Such failure
might possibly be exploited to gain unauthorized access to a system
or sensitive information; such failure constitutes an unknown factor
-
-
-
-Goncalves, et al. Expires August 25, 2008 [Page 5]
-
-Internet-Draft Ogg Media Types February 2008
-
-
and is thus considered out of the scope of this document.
-6. Interoperability Considerations
+7. Interoperability Considerations
The Ogg container format is device-, platform- and vendor-neutral and
has proved to be widely implementable across different computing
platforms through a wide range of encoders and decoders. A broadly
- portable reference implementation [libogg] is available under the new
- (3-clause) BSD license, which is a free software license.
+ portable reference implementation [libogg] is available under the
+ revised (3-clause) BSD license, which is a Free Software license.
- The Ogg container format is not patented and may be implemented by
- third parties without intellectual property concerns.
-
The Xiph.Org Foundation has defined the specification,
interoperability, and conformance, and conducts regular
interoperability testing.
-7. IANA Considerations
+
+
+
+
+
+Goncalves, et al. Expires October 6, 2008 [Page 6]
+
+Internet-Draft Ogg Media Types April 2008
+
+
+8. IANA Considerations
+
This document registers two new media types and redefines the
existing application/ogg as defined in the following section.
-8. Ogg Media Types
+9. Ogg Media Types
-8.1. application/ogg
+9.1. application/ogg
Type name: application
@@ -315,11 +354,11 @@
Optional parameters: none
- Encoding considerations: See section 4.
+ Encoding considerations: See section 5.
- Security considerations: See section 5.
+ Security considerations: See section 6.
- Interoperability considerations: None, as noted in section 6.
+ Interoperability considerations: None, as noted in section 7.
Published specification: [RFC3533]
@@ -329,14 +368,6 @@
Additional information:
-
-
-
-Goncalves, et al. Expires August 25, 2008 [Page 6]
-
-Internet-Draft Ogg Media Types February 2008
-
-
Magic number(s): The first four bytes, 0x4f 0x67 0x67 0x53,
correspond to the string "OggS".
@@ -354,7 +385,15 @@
Intended usage: COMMON
Restrictions on usage: The type application/ogg SHOULD only be used
- in situations where it is not appropriate to serve content under the
+
+
+
+Goncalves, et al. Expires October 6, 2008 [Page 7]
+
+Internet-Draft Ogg Media Types April 2008
+
+
+ in situations where it is not appropriate to serve data under the
video/ogg or audio/ogg types. Data served under the application/ogg
type SHOULD use the .ogx file extension and MUST contain an Ogg
Skeleton logical bitstream to identify all other contained logical
@@ -364,7 +403,7 @@
Change controller: The Xiph.Org Foundation.
-8.2. video/ogg
+9.2. video/ogg
Type name: video
@@ -374,25 +413,17 @@
Optional parameters: none
- Encoding considerations: See section 4.
+ Encoding considerations: See section 5.
- Security considerations: See section 5.
+ Security considerations: See section 6.
- Interoperability considerations: None, as noted in section 6.
+ Interoperability considerations: None, as noted in section 7.
Published specification: [RFC3533]
Applications which use this media type: Multimedia applications,
including hardware-based, streaming, and conferencing tools.
-
-
-
-Goncalves, et al. Expires August 25, 2008 [Page 7]
-
-Internet-Draft Ogg Media Types February 2008
-
-
Additional information:
Magic number(s): The first four bytes, 0x4f 0x67 0x67 0x53,
@@ -407,21 +438,29 @@
Intended usage: COMMON
- Restrictions on usage: The type "video/ogg" MAY be used for Ogg
+ Restrictions on usage: The type "video/ogg" SHOULD be used for Ogg
bitstreams containing visual, audio, timed text, or any other type of
material that requires a visual interface. It is intended for
+
+
+
+Goncalves, et al. Expires October 6, 2008 [Page 8]
+
+Internet-Draft Ogg Media Types April 2008
+
+
content not complex enough to warrant serving under "application/
ogg"; for example, a combination of Theora video, Vorbis audio,
Skeleton metadata, and CMML captioning. Data served under the type
"video/ogg" SHOULD contain an Ogg Skeleton logical bitstream.
Implementations interacting with the type "video/ogg" SHOULD support
- multiplexed streams.
+ multiplexed bitstreams.
Author: See "Authors' Addresses" section.
Change controller: The Xiph.Org Foundation.
-8.3. audio/ogg
+9.3. audio/ogg
Type name: audio
@@ -431,24 +470,17 @@
Optional parameters: none
- Encoding considerations: See section 4.
+ Encoding considerations: See section 5.
- Security considerations: See section 5.
+ Security considerations: See section 6.
- Interoperability considerations: None, as noted in section 6.
+ Interoperability considerations: None, as noted in section 7.
Published specification: [RFC3533]
Applications which use this media type: Multimedia applications,
including hardware-based, streaming, and conferencing tools.
-
-
-Goncalves, et al. Expires August 25, 2008 [Page 8]
-
-Internet-Draft Ogg Media Types February 2008
-
-
Additional information:
Magic number(s): The first four bytes, 0x4f 0x67 0x67 0x53,
@@ -463,20 +495,28 @@
Intended usage: COMMON
- Restrictions on usage: The type "audio/ogg" MAY be used for files
- containing predominantly audio material. Files served under the
- "audio/ogg" type SHOULD have an Ogg Skeleton logical bitstream if
- they use the .oga extension. The .ogg and .spx file extensions are a
- specialization that require no Skeleton due to concerns of backwards-
- compatibility with existing implementations. Use of the .oga file
- extension is the preferred method of distributing audio material
- under the "audio/ogg" type.
+ Restrictions on usage: The type "audio/ogg" SHOULD be used when the
+ Ogg bitstream predominantly contains audio data. Content served
+
+
+Goncalves, et al. Expires October 6, 2008 [Page 9]
+
+Internet-Draft Ogg Media Types April 2008
+
+
+ under the "audio/ogg" type SHOULD have an Ogg Skeleton logical
+ bitstream if they use the .oga extension. The .ogg and .spx file
+ extensions are a specialization that require no Skeleton due to
+ concerns of backwards-compatibility with existing implementations.
+ Use of the .oga file extension is the preferred method of
+ distributing audio data under the "audio/ogg" type.
+
Author: See "Authors' Addresses" section.
Change controller: The Xiph.Org Foundation.
-9. Copying Conditions
+10. Copying Conditions
The authors agree to grant third parties the irrevocable right to
copy, use and distribute the work, with or without modification, in
@@ -484,9 +524,9 @@
permission is granted, redistributed modified works do not contain
misleading author, version, name of work, or endorsement information.
-10. References
+11. References
-10.1. Normative References
+11.1. Normative References
[RFC3533] Pfeiffer, S., "The Ogg Encapsulation Format Version 0",
RFC 3533, May 2003.
@@ -498,17 +538,10 @@
Extensions (MIME) Part One: Format of Internet Message
Bodies", RFC 2045, November 1996.
-
-
-Goncalves, et al. Expires August 25, 2008 [Page 9]
-
-Internet-Draft Ogg Media Types February 2008
-
-
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
-10.2. Informative References
+11.2. Informative References
[Ogg] Xiph.Org Foundation, "Ogg bitstream documentation: Ogg
logical and physical bitstream overview, Ogg logical
@@ -521,6 +554,13 @@
[Dirac] Dirac Group, "Dirac Specification",
<http://dirac.sourceforge.net/specification.html>.
+
+
+Goncalves, et al. Expires October 6, 2008 [Page 10]
+
+Internet-Draft Ogg Media Types April 2008
+
+
[Speex] Valin, J., "The Speex Codec Manual", February 2002,
<http://speex.org/docs/manual/speex-manual>.
@@ -554,13 +594,6 @@
"RTP Payload Format for the Speex Codec", July 2007,
<http://tools.ietf.org/html/draft-ietf-avt-rtp-speex>.
-
-
-Goncalves, et al. Expires August 25, 2008 [Page 10]
-
-Internet-Draft Ogg Media Types February 2008
-
-
[RFC3552] Rescorla, E. and B. Korver, "Guidelines for Writing RFC
Text on Security Considerations", BCP 72, RFC 3552,
July 2003.
@@ -568,6 +601,22 @@
[libogg] Xiph.Org Foundation, "The libogg API", June 2000,
<http://xiph.org/ogg/doc/libogg>.
+
+
+
+
+
+
+
+
+
+
+
+Goncalves, et al. Expires October 6, 2008 [Page 11]
+
+Internet-Draft Ogg Media Types April 2008
+
+
Authors' Addresses
Ivo Emanuel Goncalves
@@ -612,9 +661,16 @@
-Goncalves, et al. Expires August 25, 2008 [Page 11]
+
+
+
+
+
+
+
+Goncalves, et al. Expires October 6, 2008 [Page 12]
-Internet-Draft Ogg Media Types February 2008
+Internet-Draft Ogg Media Types April 2008
Full Copyright Statement
@@ -668,5 +724,5 @@
-Goncalves, et al. Expires August 25, 2008 [Page 12]
+Goncalves, et al. Expires October 6, 2008 [Page 13]
Modified: trunk/standards/draft-goncalves-rfc3534bis.xml
===================================================================
--- trunk/standards/draft-goncalves-rfc3534bis.xml 2008-04-03 19:00:12 UTC (rev 14654)
+++ trunk/standards/draft-goncalves-rfc3534bis.xml 2008-04-04 04:52:24 UTC (rev 14655)
@@ -6,11 +6,9 @@
<?rfc symrefs="yes" ?>
<?rfc rfcedstyle="yes" ?>
-<rfc ipr="full3978" docName="draft-goncalves-rfc3534bis-01" obsoletes="3534" category="std">
-
+<rfc ipr="full3978" docName="draft-goncalves-rfc3534bis-02" obsoletes="3534" category="std">
<front>
<title>Ogg Media Types</title>
-
<author initials="I.E." surname="Goncalves" fullname="Ivo Emanuel Goncalves">
<organization abbrev="Xiph">Xiph.Org Foundation</organization>
<address>
@@ -39,8 +37,7 @@
<uri>http://xiph.org</uri>
</address>
</author>
-
- <date day="22" month="February" year="2008"/>
+ <date day="4" month="April" year="2008"/>
<area>Internet</area>
<keyword>I-D</keyword>
<keyword>Internet-Draft</keyword>
@@ -48,23 +45,16 @@
<keyword>MIME</keyword>
<keyword>Video</keyword>
<keyword>Audio</keyword>
-
<abstract>
<t>This document describes the registration of media types for the <xref target="RFC3533">Ogg</xref> container format and conformance requirements for implementations of these types.</t>
</abstract>
</front>
-
<middle>
<section title="Introduction">
-
<t>This memo describes media types for Ogg, a data encapsulation format defined by the Xiph.Org Foundation. Refer to "Introduction" in <xref target="RFC3533"/> and "Overview" in <xref target="Ogg"/> for background information on this container format.</t>
-
<t>Binary data contained in Ogg, such as Vorbis and Theora, has historically been interchanged using the application/ogg media type as defined by <xref target="RFC3534"/>. This document obsoletes <xref target="RFC3534"/> and defines three media types for different types of content in Ogg to reflect this usage in the IANA media type registry, to foster interoperability by defining underspecified aspects, and to provide general security considerations.</t>
-
<t>The Ogg container format is known to contain <xref target="Theora"/> or <xref target="Dirac"/> video, <xref target="Speex"/> (narrow-band and wide-band speech), <xref target="Vorbis"/> or <xref target="FLAC"/> audio, and <xref target="CMML"/> timed text/metadata. As Ogg encapsulates binary data, it is possible to include any other type of video, audio, image, text or, generally speaking, any time-continuously sampled data.</t>
-
<t>While raw packets from these data sources may be used directly by transport mechanisms that provide their own framing and packet-separation mechanisms (such as UDP datagrams or RTP), Ogg is a solution for stream based storage (such as files) and transport (such as TCP streams or pipes). The media types defined in this document are needed to correctly identify such content when it is served over HTTP, included in multi-part documents, or used in other places where <xref target="RFC2045">media types</xref> are used.</t>
-
</section>
<section title="Conformance and Document Conventions">
<t>The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in BCP 14, <xref target="RFC2119"/> and indicate requirement levels for compliant implementations. Requirements apply to all implementations unless otherwise stated.</t>
@@ -78,31 +68,35 @@
<t>video/ogg</t>
<t>audio/ogg</t>
</list>
- <t>which are intended for common use and SHOULD be used when dealing with video or audio content respectively. This document also obsoletes the <xref target="RFC3534"/> definition of application/ogg and marks it for complex data (e.g. multitrack visual, audio, textual and other time-continuously sampled data), which is not clearly video or audio data and thus not suited for either the video/ogg or audio/ogg types.</t>
- <t>An Ogg bitstream generally consists of one or more logical bitstreams that each consist of a series of header and data pages packetising time-continuous binary data <xref target="RFC3533"/>. The content types of the logical bitstreams may be identified without decoding the header pages of the logical bitstreams through use of a <xref target="Skeleton"/> bitstream. Using Skeleton is REQUIRED for content served under the application/ogg type and RECOMMENDED for video/ogg and audio/ogg.</t>
- <t>Furthermore, it is RECOMMENDED that implementations that identify a logical bitstream which they cannot decode SHOULD ignore it, while continuing to decode the ones they can.</t>
+ <t>which are intended for common use and SHOULD be used when dealing with video or audio content respectively. This document also obsoletes the <xref target="RFC3534"/> definition of application/ogg and marks it for complex data (e.g. multitrack visual, audio, textual and other time-continuously sampled data), which is not clearly video or audio data and thus not suited for either the video/ogg or audio/ogg types. Refer to the following section for more details.</t>
+ <t>An Ogg bitstream generally consists of one or more logical bitstreams that each consist of a series of header and data pages packetising time-continuous binary data <xref target="RFC3533"/>. The content types of the logical bitstreams may be identified without decoding the header pages of the logical bitstreams through use of a <xref target="Skeleton"/> bitstream. Using Ogg Skeleton is REQUIRED for content served under the application/ogg type and RECOMMENDED for video/ogg and audio/ogg, as it is a type of identifier space used to describe the different encapsulated data.</t>
+ <t>Furthermore, it is RECOMMENDED that implementations that identify a logical bitstream which they cannot decode SHOULD ignore it, while continuing to decode the ones they can. Such precaution ensures backward and forward compatibility with existing and future data.</t>
<t>Ongoing work related to this registration may introduce optional parameters in future revisions of this document. One example area of effort may introduce a parameter that would allow for data in use within the media type to be asserted and determined without examination of the bitstream. Implementations MUST consider the impact of such an update.</t>
</section>
+ <section title="Relation Between the Media Types">
+ <t>As stated in the previous section, this document describes three media types which are targeted at different data encapsulated in Ogg. Since Ogg is capable of encapsulate any kind of data, the multiple usage scenarios have revealed interoperability issues between implementations when dealing with content served solely under the application/ogg type.</t>
+ <t>While this document does redefine the earlier definition of application/ogg, this media type will continue to embrace the widest net possible of content with the video/ogg and audio/ogg types being smaller subsets of it. However, the video/ogg and audio/ogg types take precedence in a subset of the usages, specifically when serving multimedia content that is not complex enough to warrant the use of application/ogg. Following this line of thought, the audio/ogg type is an even smaller subset within video/ogg, as it is not intended to refer to visual content.</t>
+ <t>As such, the application/ogg type is the recommended choice to serve content aimed at scientific and other applications that require various multiplexed signals or streams of continuous data. For bitstreams containing visual, timed text, or any other type of material that requires a visual interface, but which is not complex enough to warrant serving under application/ogg, the video/ogg type is recommended. In situations where the Ogg bitstream predominantly contains audio data, it is recommended to use the audio/ogg type.</t>
+ </section>
<section title="Encoding Considerations">
<t>Binary: The content consists of an unrestricted sequence of octets.</t>
<t>Note:</t>
<list style="symbols">
<t>Ogg encapsulated content is binary data and should be transmitted in a suitable encoding without CR/LF conversion, 7-bit stripping, etc.; <xref target="RFC4648">base64</xref> is generally preferred for binary-to-text encoding.</t>
- <t>Media types described in this document are used for stream based storage (such as files) and transport (such as TCP streams or pipes); separate types are used for real-time transfer, such as for the RTP payload formats of <xref target="ThRTP">Theora</xref> video, and <xref target="VoRTP">Vorbis</xref> or <xref target="SpRTP">Speex</xref> audio, as well as for identification of the encapsulated content within Ogg.</t>
+ <t>Media types described in this document are used for stream based storage (such as files) and transport (such as TCP streams or pipes); separate types are used for real-time transfer, such as for the RTP payload formats of <xref target="ThRTP">Theora</xref> video, and <xref target="VoRTP">Vorbis</xref> or <xref target="SpRTP">Speex</xref> audio, as well as for identification of the encapsulated data within Ogg.</t>
</list>
</section>
<section title="Security Considerations">
<t>Refer to <xref target="RFC3552"/> for a discussion of terminology used in this section.</t>
<t>The Ogg encapsulation format is a container and only a carrier of content (such as audio, video, and displayable text data) with a very rigid definition. This format in itself is not more vulnerable than any other content framing mechanism.</t>
<t>Ogg does not provide for any generic encryption or signing of itself or its contained bitstreams. However, it encapsulates any kind of binary content and is thus able to contain encrypted and signed content data. It is also possible to add an external security mechanism that encrypts or signs an Ogg bitstream and thus provides content confidentiality and authenticity.</t>
- <t>As Ogg encapsulates binary data, it is possible to include executable content in an Ogg bitstream. Implementations SHOULD NOT execute such content without prior validation of its origin by the end-user. This may be an issue with applications that use Ogg for streaming or file transfer in a networking scenario. An implementation decoding Ogg and its encapsulated content streams has to ensure correct handling of manipulated bitstreams, of buffer overflows, and similar issues.</t>
+ <t>As Ogg encapsulates binary data, it is possible to include executable content in an Ogg bitstream. Implementations SHOULD NOT execute such content without prior validation of its origin by the end-user. This may be an issue with applications that use Ogg for streaming or file transfer in a networking scenario. An implementation decoding Ogg and its encapsulated data streams has to ensure correct handling of manipulated bitstreams, of buffer overflows, and similar issues.</t>
<t>It is also possible to author malicious Ogg bitstreams, which attempt to call for an excessively large picture size, high sampling-rate audio, etc. Implementations SHOULD protect themselves against this kind of attack.</t>
<t>Ogg has an extensible structure, so that it is theoretically possible that metadata fields or media formats might be defined in the future which might be used to induce particular actions on the part of the recipient, thus presenting additional security risks. However, this type of capability is currently not supported in the referenced specification.</t>
<t>Implementations may fail to implement a specific security model or other means to prevent possibly dangerous operations. Such failure might possibly be exploited to gain unauthorized access to a system or sensitive information; such failure constitutes an unknown factor and is thus considered out of the scope of this document.</t>
</section>
<section title="Interoperability Considerations">
- <t>The Ogg container format is device-, platform- and vendor-neutral and has proved to be widely implementable across different computing platforms through a wide range of encoders and decoders. A broadly portable <xref target="libogg">reference implementation</xref> is available under the new (3-clause) BSD license, which is a free software license.</t>
- <t>The Ogg container format is not patented and may be implemented by third parties without intellectual property concerns.</t>
+ <t>The Ogg container format is device-, platform- and vendor-neutral and has proved to be widely implementable across different computing platforms through a wide range of encoders and decoders. A broadly portable <xref target="libogg">reference implementation</xref> is available under the revised (3-clause) BSD license, which is a Free Software license.</t>
<t>The Xiph.Org Foundation has defined the specification, interoperability, and conformance, and conducts regular interoperability testing.</t>
</section>
<section title="IANA Considerations">
@@ -114,9 +108,9 @@
<t>Subtype name: ogg</t>
<t>Required parameters: none</t>
<t>Optional parameters: none</t>
- <t>Encoding considerations: See section 4.</t>
- <t>Security considerations: See section 5.</t>
- <t>Interoperability considerations: None, as noted in section 6.</t>
+ <t>Encoding considerations: See section 5.</t>
+ <t>Security considerations: See section 6.</t>
+ <t>Interoperability considerations: None, as noted in section 7.</t>
<t>Published specification: <xref target="RFC3533"/></t>
<t>Applications which use this media type: Scientific and other applications which require various multiplexed signals or streams of data.</t>
<t>Additional information:</t>
@@ -128,7 +122,7 @@
<t>Macintosh File Type Code(s): OggX</t>
<t>Person & Email address to contact for further information: See "Authors' Addresses" section.</t>
<t>Intended usage: COMMON</t>
- <t>Restrictions on usage: The type application/ogg SHOULD only be used in situations where it is not appropriate to serve content under the video/ogg or audio/ogg types. Data served under the application/ogg type SHOULD use the .ogx file extension and MUST contain an Ogg Skeleton logical bitstream to identify all other contained logical bitstreams.</t>
+ <t>Restrictions on usage: The type application/ogg SHOULD only be used in situations where it is not appropriate to serve data under the video/ogg or audio/ogg types. Data served under the application/ogg type SHOULD use the .ogx file extension and MUST contain an Ogg Skeleton logical bitstream to identify all other contained logical bitstreams.</t>
<t>Author: See "Authors' Addresses" section.</t>
<t>Change controller: The Xiph.Org Foundation.</t>
</section>
@@ -137,9 +131,9 @@
<t>Subtype name: ogg</t>
<t>Required parameters: none</t>
<t>Optional parameters: none</t>
- <t>Encoding considerations: See section 4.</t>
- <t>Security considerations: See section 5.</t>
- <t>Interoperability considerations: None, as noted in section 6.</t>
+ <t>Encoding considerations: See section 5.</t>
+ <t>Security considerations: See section 6.</t>
+ <t>Interoperability considerations: None, as noted in section 7.</t>
<t>Published specification: <xref target="RFC3533"/></t>
<t>Applications which use this media type: Multimedia applications, including hardware-based, streaming, and conferencing tools.</t>
<t>Additional information:</t>
@@ -148,7 +142,7 @@
<t>Macintosh File Type Code(s): OggV</t>
<t>Person & Email address to contact for further information: See "Authors' Addresses" section.</t>
<t>Intended usage: COMMON</t>
- <t>Restrictions on usage: The type "video/ogg" MAY be used for Ogg bitstreams containing visual, audio, timed text, or any other type of material that requires a visual interface. It is intended for content not complex enough to warrant serving under "application/ogg"; for example, a combination of Theora video, Vorbis audio, Skeleton metadata, and CMML captioning. Data served under the type "video/ogg" SHOULD contain an Ogg Skeleton logical bitstream. Implementations interacting with the type "video/ogg" SHOULD support multiplexed streams.</t>
+ <t>Restrictions on usage: The type "video/ogg" SHOULD be used for Ogg bitstreams containing visual, audio, timed text, or any other type of material that requires a visual interface. It is intended for content not complex enough to warrant serving under "application/ogg"; for example, a combination of Theora video, Vorbis audio, Skeleton metadata, and CMML captioning. Data served under the type "video/ogg" SHOULD contain an Ogg Skeleton logical bitstream. Implementations interacting with the type "video/ogg" SHOULD support multiplexed bitstreams.</t>
<t>Author: See "Authors' Addresses" section.</t>
<t>Change controller: The Xiph.Org Foundation.</t>
</section>
@@ -157,9 +151,9 @@
<t>Subtype name: ogg</t>
<t>Required parameters: none</t>
<t>Optional parameters: none</t>
- <t>Encoding considerations: See section 4.</t>
- <t>Security considerations: See section 5.</t>
- <t>Interoperability considerations: None, as noted in section 6.</t>
+ <t>Encoding considerations: See section 5.</t>
+ <t>Security considerations: See section 6.</t>
+ <t>Interoperability considerations: None, as noted in section 7.</t>
<t>Published specification: <xref target="RFC3533"/></t>
<t>Applications which use this media type: Multimedia applications, including hardware-based, streaming, and conferencing tools.</t>
<t>Additional information:</t>
@@ -168,7 +162,7 @@
<t>Macintosh File Type Code(s): OggA</t>
<t>Person & Email address to contact for further information: See "Authors' Addresses" section.</t>
<t>Intended usage: COMMON</t>
- <t>Restrictions on usage: The type "audio/ogg" MAY be used for files containing predominantly audio material. Files served under the "audio/ogg" type SHOULD have an Ogg Skeleton logical bitstream if they use the .oga extension. The .ogg and .spx file extensions are a specialization that require no Skeleton due to concerns of backwards-compatibility with existing implementations. Use of the .oga file extension is the preferred method of distributing audio material under the "audio/ogg" type.</t>
+ <t>Restrictions on usage: The type "audio/ogg" SHOULD be used when the Ogg bitstream predominantly contains audio data. Content served under the "audio/ogg" type SHOULD have an Ogg Skeleton logical bitstream if they use the .oga extension. The .ogg and .spx file extensions are a specialization that require no Skeleton due to concerns of backwards-compatibility with existing implementations. Use of the .oga file extension is the preferred method of distributing audio data under the "audio/ogg" type.</t>
<t>Author: See "Authors' Addresses" section.</t>
<t>Change controller: The Xiph.Org Foundation.</t>
</section>
@@ -177,10 +171,8 @@
<t>The authors agree to grant third parties the irrevocable right to copy, use and distribute the work, with or without modification, in any medium, without royalty, provided that, unless separate permission is granted, redistributed modified works do not contain misleading author, version, name of work, or endorsement information.</t>
</section>
</middle>
-
<back>
<references title="Normative References">
-
<reference anchor="RFC3533">
<front>
<title>The Ogg Encapsulation Format Version 0</title>
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