Commit b168c23d authored by lu_zero's avatar lu_zero

Yet another change in the headers packing, in practice nothing changes if you...

Yet another change in the headers packing, in practice nothing changes if you use a dummy comment header ( 2| 30| 28| ident| comment| setup| ) but should be flexible enough to be used for other codecs or evolutions of vorbis

svn path=/trunk/vorbis/; revision=12929
parent 30845145
......@@ -466,15 +466,15 @@ Internet-Draft draft-ietf-avt-rtp-vorbis-04 May 2007
specification [12], the identification and the setup MUST be packed
together as they are, while the comment header MAY be replaced with a
dummy one. The packed configuration follows a generic way to store
xiph codec configurations: the first byte stores the number of
following packets minus one, the next bytes represent the size of the
packets, every byte set to 0xff means that the next byte has to be
add to the current sum in order to have the complete size; the
headers immediately follows the list of sizes. The headers are
packed in the same order they are present in ogg: identification,
comment, setup.
xiph codec configurations: The first field stores the number of
following packets minus one (count field), the next ones represent
the size of the headers (length fields), the headers immediately
follow the list of length fields. The size of the last header is
implicit. The count and the length fields are encoded using the
following logic: the most significant bit in the octect is used as
mark, if set to 1 the value continues in the next byte; the other 7
bits are used to store the value. The headers are packed in the same
order they are present in ogg: identification, comment, setup.
......@@ -643,7 +643,7 @@ Internet-Draft draft-ietf-avt-rtp-vorbis-04 May 2007
The key difference between the in-band format and this one, is there
is no need for the payload header octet. In this figure the comment
has a size bigger than 255 bytes.
has a size bigger than 127 bytes.
3.3. Loss of Configuration Headers
......@@ -1259,7 +1259,8 @@ Internet-Draft draft-ietf-avt-rtp-vorbis-04 May 2007
Mike Smith, Phil Kerr, Michael Sparks, Magnus Westerlund, David
Barrett, Silvia Pfeiffer, Stefan Ehmann, Alessandro Salvatori.
Politecnico di Torino (LS)^3/IMG Group in particular Federico
Ridolfo, Francesco Varano, Giampaolo Mancini, Juan Carlos De Martin.
Ridolfo, Francesco Varano, Giampaolo Mancini, Dario Gallucci, Juan
Carlos De Martin.
12. References
......@@ -1280,7 +1281,6 @@ Internet-Draft draft-ietf-avt-rtp-vorbis-04 May 2007
Description Protocol", RFC 4566, July 2006.
[5] Mogul, J. and S. Deering, "Path MTU discovery", RFC 1191,
November 1990.
......@@ -1289,6 +1289,8 @@ Barbato Expires November 5, 2007 [Page 23]
Internet-Draft draft-ietf-avt-rtp-vorbis-04 May 2007
November 1990.
[6] McCann et al., J., "Path MTU Discovery for IP version 6",
RFC 1981.
......@@ -1338,8 +1340,6 @@ Author's Address
Barbato Expires November 5, 2007 [Page 24]
Internet-Draft draft-ietf-avt-rtp-vorbis-04 May 2007
......
......@@ -438,9 +438,9 @@ re-transmission of the configuration headers.
A Vorbis Packed Configuration is indicated with the Vorbis Data Type field set
to 1. Of the three headers, defined in the
<xref target="vorbis-spec-ref">Vorbis I specification</xref>, the
identification and the setup MUST be packed together as they are, while the comment header MAY be replaced with a dummy one.
The packed configuration follows a generic way to store xiph codec configurations: the first byte stores the number of following packets minus one, the next bytes represent the size of the packets, every byte set to 0xff means that the next byte has to be add to the current sum in order to have the complete size; the headers immediately follows the list of sizes. The headers are packed in the same order they are present in ogg: identification, comment, setup.
</t>
identification and the setup MUST be packed together as they are, while the comment header MAY be replaced with a dummy one. The packed configuration follows a generic way to store xiph codec configurations: The first field stores the number of following packets minus one (count field), the next ones represent the size of the headers (length fields), the headers immediately follow the list of length fields. The size of the last header is implicit.
The count and the length fields are encoded using the following logic: the most significant bit in the octect is used as mark, if set to 1 the value continues in the next byte; the other 7 bits are used to store the value.
The headers are packed in the same order they are present in ogg: identification, comment, setup.</t>
<figure anchor="Packed Configuration Figure" title="Packed Configuration Figure">
<artwork><![CDATA[
......@@ -559,7 +559,7 @@ there is only a 2 byte length tag to define the length of the packed headers.
</figure>
<t>
The key difference between the in-band format and this one, is there is no need
for the payload header octet. In this figure the comment has a size bigger than 255 bytes.
for the payload header octet. In this figure the comment has a size bigger than 127 bytes.
</t>
</section>
......@@ -1205,7 +1205,7 @@ Giles, Tor-Einar Jarnbjo, Colin Law, John Lazzaro, Jack Moffitt, Christopher
Montgomery, Colin Perkins, Barry Short, Mike Smith, Phil Kerr, Michael Sparks,
Magnus Westerlund, David Barrett, Silvia Pfeiffer, Stefan Ehmann, Alessandro
Salvatori. Politecnico di Torino (LS)³/IMG Group in particular Federico
Ridolfo, Francesco Varano, Giampaolo Mancini, Juan Carlos De Martin.
Ridolfo, Francesco Varano, Giampaolo Mancini, Dario Gallucci, Juan Carlos De Martin.
</t>
</section>
......
Markdown is supported
0% or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment