This is the first draft of the audio/vorbis media registration form to be
handled to the IANA. PLEASE comment extensively, even minor spelling
mistakes etc are to be stamped out of this I hope.
A media type for application/ogg (or should it be
application/oggsquish?) will be created separately.
I would be very happy if someone could supply the 4-letter filetype code
used by MacIntosh .ogg files.
Linus Walleij
--------
MIME media type name: audio
MIME subtype name: vorbis
Required parameters: none
Optional parameters: none
Encoding Considerations:
The vorbis audio data is usually wrapped inside an OggSQUISH
bitstream, see [OGG].
The vorbis audio data is binary data, and must be encoded for
non-binary transport; the Base64 encoding is suitable for Email,
Binary encoding could also be used. Further lossless compression
may be problematic as the vorbis data is already efficiently
compressed using psychoacoustic algorithms with highly optimized
bit-allocation.
Security Considerations:
Ideally, the vorbis file can not contain security-violating code
as the format is highly specified, see [VORBIS] and/or [COLEMAN].
However, fields can be abused if the recieving decoder
implementation has errors or extensions that make it possible
to embed interpretative or object code. The recieveing decoder
must therefore take these issues into account, and under no
circumstances allow untrusted code to be executed.
Vorbis files are not signed or encrypted using any applicable
encryption schemes. External security mechanisms must be added
if content confidentiality and autencity is to be achieved.
Interoperability considerations:
The vorbis format has proved to be widely implementable across
different computing platforms. An example implementation exists
that has been compiled on numerous platforms.
The technology involved in vorbis encoding and decoding is not
patented and may be used by third parties without patent
licenses or similar licensing issues.
Published specification:
See [VORBIS] and/or [COLEMAN].
Applications which use this media type:
Any application that implements the specification will be able
to encode or decode vorbis files.
Additional information:
Magic number(s): For vorbis files wrapped inside OggSQUISH
files, the first four bytes are 0x4f 0x67
0x67 0x53 corresponding to the string "OggS".
The vorbis header will then additionally
contain the lowercase string "vorbis"
(comprising the bytes 0x76 0x6f 0x72 0x62
0x69 0x73) at offset 0x1d, where offset 0x00
is the first byte of the file.
If vorbis files were to be delivered without
the OggSQUISH header the "vorbis" string
would
appear at offset 0x01. This should never occur.
File extension: .ogg
Macintosh File Type Code(s): none
Object Identifier(s) or OID(s): none
Person & email address to contact for further information:
Questions about this proposal should be directed to Linus
Walleij <triad@df.lth.se>. Technical questions about the
ogg and vorbis standards may be asked on the mailing lists
for respective developer community, see
<http://www.xiph.org/archives/>
Intended usage: COMMON
Author/Change controller:
This document was written by Linus Walleij <triad@df.lth.se>,
changes of this document will be handled by him or a
representative of the Xiphophorus company or the Vorbis
development community.
The Vorbis format, and its superformat OggSQUISH are controlled
by the Xiphophorus company and the respective development
communities.
References:
[OGG]
Xiphophorus company, "OggSquish logical and physical bitstream
overview".
<url:http://xiph.org/ogg/vorbis/doc/oggstream.html>
[VORBIS]
Xiphophorus company, "Ogg Vorbis Audio Bitstream".
<url:http://xiph.org/ogg/vorbis/doc/vorbis-stream.html>
[COLEMAN]
Coleman, Mike, "Vorbis Illuminated".
<url:http://www.mathdogs.com/vorbis-illuminated/>
--- >8 ----
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Always happy to point out spelling errors. Found 3. See below On Mon, May 14, 2001 at 11:03:40PM +0200, Linus Walleij wrote:> This is the first draft of the audio/vorbis media registration form to be > handled to the IANA. PLEASE comment extensively, even minor spelling > mistakes etc are to be stamped out of this I hope. > > A media type for application/ogg (or should it be > application/oggsquish?) will be created separately. > > I would be very happy if someone could supply the 4-letter filetype code > used by MacIntosh .ogg files. > > Linus Walleij > > > -------- > MIME media type name: audio > > MIME subtype name: vorbis > > Required parameters: none > > Optional parameters: none > > Encoding Considerations: > > The vorbis audio data is usually wrapped inside an OggSQUISH > bitstream, see [OGG]. > > The vorbis audio data is binary data, and must be encoded for > non-binary transport; the Base64 encoding is suitable for Email, > Binary encoding could also be used. Further lossless compression > may be problematic as the vorbis data is already efficiently > compressed using psychoacoustic algorithms with highly optimized > bit-allocation. > > Security Considerations: > > Ideally, the vorbis file can not contain security-violating code > as the format is highly specified, see [VORBIS] and/or [COLEMAN]. > However, fields can be abused if the recieving decoder^^^^^^^^^ receiving> implementation has errors or extensions that make it possible > to embed interpretative or object code. The recieveing decoder^^^^^^^^^^ receiving> must therefore take these issues into account, and under no > circumstances allow untrusted code to be executed. > > Vorbis files are not signed or encrypted using any applicable > encryption schemes. External security mechanisms must be added > if content confidentiality and autencity is to be achieved.^^^^^^^^^ authenticity> > Interoperability considerations: > > The vorbis format has proved to be widely implementable across > different computing platforms. An example implementation exists > that has been compiled on numerous platforms. > > The technology involved in vorbis encoding and decoding is not > patented and may be used by third parties without patent > licenses or similar licensing issues. > > Published specification: > > See [VORBIS] and/or [COLEMAN]. > > Applications which use this media type: > > Any application that implements the specification will be able > to encode or decode vorbis files. > > Additional information: > > Magic number(s): For vorbis files wrapped inside OggSQUISH > files, the first four bytes are 0x4f 0x67 > 0x67 0x53 corresponding to the string "OggS". > The vorbis header will then additionally > contain the lowercase string "vorbis" > (comprising the bytes 0x76 0x6f 0x72 0x62 > 0x69 0x73) at offset 0x1d, where offset 0x00 > is the first byte of the file. > > If vorbis files were to be delivered without > the OggSQUISH header the "vorbis" string would > appear at offset 0x01. This should never occur. > > File extension: .ogg > > Macintosh File Type Code(s): none > > Object Identifier(s) or OID(s): none > > Person & email address to contact for further information: > > Questions about this proposal should be directed to Linus > Walleij <triad@df.lth.se>. Technical questions about the > ogg and vorbis standards may be asked on the mailing lists > for respective developer community, see > <http://www.xiph.org/archives/> > > Intended usage: COMMON > > Author/Change controller: > > This document was written by Linus Walleij <triad@df.lth.se>, > changes of this document will be handled by him or a > representative of the Xiphophorus company or the Vorbis > development community. > > The Vorbis format, and its superformat OggSQUISH are controlled > by the Xiphophorus company and the respective development > communities. > > References: > > [OGG] > Xiphophorus company, "OggSquish logical and physical bitstream > overview". > <url:http://xiph.org/ogg/vorbis/doc/oggstream.html> > > [VORBIS] > Xiphophorus company, "Ogg Vorbis Audio Bitstream". > <url:http://xiph.org/ogg/vorbis/doc/vorbis-stream.html> > > [COLEMAN] > Coleman, Mike, "Vorbis Illuminated". > <url:http://www.mathdogs.com/vorbis-illuminated/> > > > --- >8 ---- > List archives: http://www.xiph.org/archives/ > Ogg project homepage: http://www.xiph.org/ogg/ > To unsubscribe from this list, send a message to 'vorbis-dev-request@xiph.org' > containing only the word 'unsubscribe' in the body. No subject is needed. > Unsubscribe messages sent to the list will be ignored/filtered.-- --- >8 ---- List archives: http://www.xiph.org/archives/ Ogg project homepage: http://www.xiph.org/ogg/ To unsubscribe from this list, send a message to 'vorbis-dev-request@xiph.org' containing only the word 'unsubscribe' in the body. No subject is needed. Unsubscribe messages sent to the list will be ignored/filtered.
> The technology involved in vorbis encoding and decoding is not > patented and may be used by third parties without patent > licenses or similar licensing issues.What about that (modified) BSD-license ? Shouldn't that be mentioned ? --- >8 ---- List archives: http://www.xiph.org/archives/ Ogg project homepage: http://www.xiph.org/ogg/ To unsubscribe from this list, send a message to 'vorbis-dev-request@xiph.org' containing only the word 'unsubscribe' in the body. No subject is needed. Unsubscribe messages sent to the list will be ignored/filtered.
Segher Boessenkool
2001-May-14 16:29 UTC
[vorbis-dev] audio/vorbis media type registration
Linus Walleij wrote:> > This is the first draft of the audio/vorbis media registration form to be > handled to the IANA. PLEASE comment extensively, even minor spelling > mistakes etc are to be stamped out of this I hope. > > A media type for application/ogg (or should it be > application/oggsquish?) will be created separately. > > I would be very happy if someone could supply the 4-letter filetype code > used by MacIntosh .ogg files.'OggS' Note that this is used for _any_ Ogg file, not just vorbis. And note that there doesn't exist a complete Quicktime Vorbis codec yet. As a media type I used 'Vrbs' for Vorbis content; this is only seen by Quicktime itself, and is not on the filesystem. Maybe Nicolai wants to comment as well? I hope he takes over the QT Vorbis effort, as I have neither time or enough QT experience right now :-)> > Linus Walleij > > -------- > MIME media type name: audio > > MIME subtype name: vorbis > > Required parameters: none > > Optional parameters: none > > Encoding Considerations: > > The vorbis audio data is usually wrapped inside an OggSQUISH > bitstream, see [OGG].Not usually, but always.> > The vorbis audio data is binary data, and must be encoded for > non-binary transport; the Base64 encoding is suitable for Email, > Binary encoding could also be used. Further lossless compression > may be problematic as the vorbis data is already efficiently > compressed using psychoacoustic algorithms with highly optimized > bit-allocation. > > Security Considerations: > > Ideally, the vorbis file can not contain security-violating code > as the format is highly specified, see [VORBIS] and/or [COLEMAN]. > However, fields can be abused if the recieving decoder > implementation has errors or extensions that make it possible > to embed interpretative or object code. The recieveing decoder > must therefore take these issues into account, and under no > circumstances allow untrusted code to be executed. > > Vorbis files are not signed or encrypted using any applicable > encryption schemes. External security mechanisms must be added > if content confidentiality and autencity is to be achieved.It is possible (and easy) to sign Ogg streams using the generic file comment headers; as far as I know, there's no standard way to do this yet, but GPG signing is one likely candidate.> > Interoperability considerations: > > The vorbis format has proved to be widely implementable across > different computing platforms. An example implementation exists > that has been compiled on numerous platforms. > > The technology involved in vorbis encoding and decoding is not > patented and may be used by third parties without patent > licenses or similar licensing issues. > > Published specification: > > See [VORBIS] and/or [COLEMAN]. > > Applications which use this media type: > > Any application that implements the specification will be able > to encode or decode vorbis files. > > Additional information: > > Magic number(s): For vorbis files wrapped inside OggSQUISH > files, the first four bytes are 0x4f 0x67 > 0x67 0x53 corresponding to the string "OggS". > The vorbis header will then additionally > contain the lowercase string "vorbis" > (comprising the bytes 0x76 0x6f 0x72 0x62 > 0x69 0x73) at offset 0x1d, where offset 0x00 > is the first byte of the file.I'm not sure if the "vorbis" header will always be at that location, although it seems right, yes. Monty?> > If vorbis files were to be delivered without > the OggSQUISH header the "vorbis" string would > appear at offset 0x01. This should never occur. > > File extension: .ogg > > Macintosh File Type Code(s): none'OggS'> > Object Identifier(s) or OID(s): none > > Person & email address to contact for further information: > > Questions about this proposal should be directed to Linus > Walleij <triad@df.lth.se>. Technical questions about the > ogg and vorbis standards may be asked on the mailing lists > for respective developer community, see > <http://www.xiph.org/archives/> > > Intended usage: COMMONTOTAL_WORLD_DOMINATION> > Author/Change controller: > > This document was written by Linus Walleij <triad@df.lth.se>, > changes of this document will be handled by him or a > representative of the Xiphophorus company or the Vorbis > development community.There's a non-profit Xiph.org now (or will be there shortly; Jack?)> > The Vorbis format, and its superformat OggSQUISH are controlled > by the Xiphophorus company and the respective development > communities. > > References: > > [OGG] > Xiphophorus company, "OggSquish logical and physical bitstream > overview". > <url:http://xiph.org/ogg/vorbis/doc/oggstream.html>Why do you spell it OggSQUISH (different capitalization) in the doc?> > [VORBIS] > Xiphophorus company, "Ogg Vorbis Audio Bitstream". > <url:http://xiph.org/ogg/vorbis/doc/vorbis-stream.html> > > [COLEMAN] > Coleman, Mike, "Vorbis Illuminated". > <url:http://www.mathdogs.com/vorbis-illuminated/> > > --- >8 ---- > List archives: http://www.xiph.org/archives/ > Ogg project homepage: http://www.xiph.org/ogg/ > To unsubscribe from this list, send a message to 'vorbis-dev-request@xiph.org' > containing only the word 'unsubscribe' in the body. No subject is needed. > Unsubscribe messages sent to the list will be ignored/filtered.Cheers, Segher --- >8 ---- List archives: http://www.xiph.org/archives/ Ogg project homepage: http://www.xiph.org/ogg/ To unsubscribe from this list, send a message to 'vorbis-dev-request@xiph.org' containing only the word 'unsubscribe' in the body. No subject is needed. Unsubscribe messages sent to the list will be ignored/filtered.
On Mon, May 14, 2001 at 11:03:40PM +0200, Linus Walleij wrote:> Encoding Considerations: > > The vorbis audio data is usually wrapped inside an OggSQUISH > bitstream, see [OGG].I would not say 'OggSquish'. I suspect the usage on the website is historical, and in any case there is another (lossless) audio codec called 'Squish' so it's confusing to use that for the container format. We've been calling it 'Ogg' or the 'Ogg bitream format'.> Security Considerations: > > Ideally, the vorbis file can not contain security-violating code > as the format is highly specified, see [VORBIS] and/or [COLEMAN]. > However, fields can be abused if the recieving decoder > implementation has errors or extensions that make it possible > to embed interpretative or object code. The recieveing decoder > must therefore take these issues into account, and under no > circumstances allow untrusted code to be executed.Note that Ogg, as a container format, can be used to encapsulate any sort of data you like, including executable content. That's a separate issue from what a given vorbis implementation might do with maliciously constructed audio packets, which does not itself have spec-level security issues.> Interoperability considerations: > > The vorbis format has proved to be widely implementable across > different computing platforms. An example implementation exists > that has been compiled on numerous platforms.'A broadly portable reference implemenation is available under a BSD license.' ?> If vorbis files were to be delivered without > the OggSQUISH header the "vorbis" string would > appear at offset 0x01. This should never occur.This point has been somewhat made by others. The description you give above applies solely to vorbis audio data in an ogg bitstream. One could easily have both ogg bitstreams that don't begin with the 'vorbis' header (not a concern here) and one can easily have vorbis audio data within another 'movie' or container format. In the latter case, I think it's appropriate to use the mimetype assigned to that other format, and reserve audio/vorbis for ogg-embedded vorbis data. The 'raw vorbis packets' case you describe is not something I think we'd ever want people to distribute. Could someone comment on how this would interact with the rtp/rtsp streaming delivery? --- >8 ---- List archives: http://www.xiph.org/archives/ Ogg project homepage: http://www.xiph.org/ogg/ To unsubscribe from this list, send a message to 'vorbis-dev-request@xiph.org' containing only the word 'unsubscribe' in the body. No subject is needed. Unsubscribe messages sent to the list will be ignored/filtered.