From c0db3e77d939e19a315a64d11ae5322341daa770 Mon Sep 17 00:00:00 2001 From: lu_zero Date: Thu, 21 Jun 2007 14:57:34 +0000 Subject: [PATCH] Draft update svn path=/trunk/vorbis/; revision=13163 --- doc/draft-ietf-avt-rtp-vorbis-05.txt | 134 +++++++++++++++++------------------ doc/draft-ietf-avt-rtp-vorbis-05.xml | 28 ++++++-- 2 files changed, 89 insertions(+), 73 deletions(-) diff --git a/doc/draft-ietf-avt-rtp-vorbis-05.txt b/doc/draft-ietf-avt-rtp-vorbis-05.txt index 25fa4ef..2923e8d 100644 --- a/doc/draft-ietf-avt-rtp-vorbis-05.txt +++ b/doc/draft-ietf-avt-rtp-vorbis-05.txt @@ -88,7 +88,7 @@ Table of Contents 7.1. Mapping Media Type Parameters into SDP . . . . . . . . . . 20 7.1.1. SDP Example . . . . . . . . . . . . . . . . . . . . . 21 7.2. Usage with the SDP Offer/Answer Model . . . . . . . . . . 21 - 8. Congestion Control . . . . . . . . . . . . . . . . . . . . . . 21 + 8. Congestion Control . . . . . . . . . . . . . . . . . . . . . . 22 9. Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 9.1. Stream Radio . . . . . . . . . . . . . . . . . . . . . . . 22 10. Security Considerations . . . . . . . . . . . . . . . . . . . 23 @@ -125,7 +125,7 @@ Internet-Draft draft-ietf-avt-rtp-vorbis-05 May 2007 quadraphonic, 5.1, ambisonic, or up to 255 discrete channels). Vorbis encoded audio is generally encapsulated within an Ogg format - bitstream [10], which provides framing and synchronization. For the + bitstream [11], which provides framing and synchronization. For the purposes of RTP transport, this layer is unnecessary, and so raw Vorbis packets are used in the payload. @@ -209,7 +209,7 @@ Internet-Draft draft-ietf-avt-rtp-vorbis-05 May 2007 Marker (M): 1 bit Set to zero. Audio silence suppression not used. This conforms to - section 4.1 of [12]. + section 4.1 of [13]. Payload Type (PT): 7 bits @@ -304,7 +304,7 @@ Internet-Draft draft-ietf-avt-rtp-vorbis-05 May 2007 Raw Vorbis packets are currently unbounded in length, application profiles will likely define a practical limit. Typical Vorbis packet sizes range from very small (2-3 bytes) to quite large (8-12 - kilobytes). The reference implementation [11] typically produces + kilobytes). The reference implementation [12] typically produces packets less than ~800 bytes, except for the setup header packets which are ~4-12 kilobytes. Within an RTP context, to avoid fragmentation, the Vorbis data packet size SHOULD be kept @@ -322,7 +322,7 @@ Internet-Draft draft-ietf-avt-rtp-vorbis-05 May 2007 Each Vorbis payload packet starts with a two octet length header, which is used to represent the size in bytes of the following data payload, followed by the raw Vorbis data padded to the nearest byte - boundary, as explained by the vorbis specification [12]. The length + boundary, as explained by the vorbis specification [13]. The length value is stored as network byte order integer. For payloads which consist of multiple Vorbis packets the payload @@ -346,7 +346,7 @@ Internet-Draft draft-ietf-avt-rtp-vorbis-05 May 2007 in temporal order. Channel mapping of the audio is in accordance with the Vorbis I - Specification [12]. + Specification [13]. 2.4. Example RTP Packet @@ -410,7 +410,7 @@ Internet-Draft draft-ietf-avt-rtp-vorbis-05 May 2007 blocks of information are often referred to collectively as the "codebooks" for a Vorbis stream, and are nominally included as special "header" packets at the start of the compressed data. In - addition, the Vorbis I specification [12] requires the presence of a + addition, the Vorbis I specification [13] requires the presence of a comment header packet which gives simple metadata about the stream, but this information is not required for decoding the frame sequence. @@ -463,7 +463,7 @@ Internet-Draft draft-ietf-avt-rtp-vorbis-05 May 2007 A Vorbis Packed Configuration is indicated with the Vorbis Data Type field set to 1. Of the three headers defined in the Vorbis I - specification [12], the identification and the setup MUST be packed + specification [13], the identification and the setup MUST be packed 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 the @@ -664,7 +664,7 @@ Internet-Draft draft-ietf-avt-rtp-vorbis-05 May 2007 and so on. These metadata messages are not intended to be fully descriptive but to offer basic track/song information. Clients MAY ignore it completely. The details on the format of the comments can - be found in the Vorbis documentation [12]. + be found in the Vorbis documentation [13]. @@ -711,7 +711,7 @@ Internet-Draft draft-ietf-avt-rtp-vorbis-05 May 2007 in the RTP packet with as many Vorbis packets as will fit, up to a maximum of 15, except when such bundling would exceed an application's desired transmission latency. Path MTU is detailed in - [5] and [6]. + [6] and [7]. A fragmented packet has a zero in the last four bits of the payload header. The first fragment will set the Fragment type to 1. Each @@ -917,31 +917,31 @@ Internet-Draft draft-ietf-avt-rtp-vorbis-05 May 2007 possible values are: inline, in_band, out_band, MAY be included multiple times - configuration: the base64 [8] representation of the Packed + configuration: the base64 [9] representation of the Packed Headers (Section 3.2.1). It MUST follow the associated delivery-method parameter ("inline"). Optional parameters: - configuration-uri: the URI of the configuration headers in case - of out of band transmission. In the form of - "protocol://path/to/resource/". Depending on the specific + configuration-uri: the URI [4] of the configuration headers in + case of out of band transmission. In the form of + "protocol://path/to/resource/", depending on the specific method, a single configuration packet could be retrived by its - number, or multiple packets could be aggregated in a single - stream. Such aggregates MAY be compressed using either bzip2 - [15] or gzip [13]. A sha1 [9] checksum MAY be provided for - aggregates. In this latter case the URI will end with the + Ident number, or multiple packets could be aggregated in a + single stream. Such aggregates MAY be compressed using either + bzip2 [16] or gzip [14]. A sha1 [10] checksum MAY be provided + for aggregates. In this latter case the URI will end with the aggregate name, followed by its compressed extension if - applies, a "!" and the base64 [8] representation of the + applies, a "!" and the base64 [9] representation of the sha1hash of the above mentioned compressed aggregated as in: "protocol://path/to/resource/aggregated.bz2!sha1hash". The - trailing '/' discriminates which of two methods are in use. It - MUST follow the associated delivery method parameter (either - "in_band" or "out_band"). + trailing '/' discriminates which of two methods are in use. + The configuration-uri MUST follow the associated delivery + method parameter ("out_band"). Non hierarchical protocols and + protocols using for special purposes the '!' separator MAY + point just to a resource aggregate using their specific syntax. - Encoding considerations: - This media type is framed and contains binary data. @@ -953,6 +953,10 @@ Barbato Expires December 1, 2007 [Page 17] Internet-Draft draft-ietf-avt-rtp-vorbis-05 May 2007 + Encoding considerations: + + This media type is framed and contains binary data. + Security considerations: See Section 10 of RFC XXXX. @@ -995,10 +999,6 @@ Internet-Draft draft-ietf-avt-rtp-vorbis-05 May 2007 Luca Barbato - Change controller: - - IETF AVT Working Group delegated from the IESG - @@ -1009,6 +1009,11 @@ Barbato Expires December 1, 2007 [Page 18] Internet-Draft draft-ietf-avt-rtp-vorbis-05 May 2007 + Change controller: + + IETF AVT Working Group delegated from the IESG + + 6.1. Packed Headers IANA Considerations The following IANA considerations MUST only be applied to the packed @@ -1051,11 +1056,6 @@ Internet-Draft draft-ietf-avt-rtp-vorbis-05 May 2007 None - Person & email address to contact for further information: - - Luca Barbato: - IETF Audio/Video Transport Working Group - @@ -1065,6 +1065,11 @@ Barbato Expires December 1, 2007 [Page 19] Internet-Draft draft-ietf-avt-rtp-vorbis-05 May 2007 + Person & email address to contact for further information: + + Luca Barbato: + IETF Audio/Video Transport Working Group + Intended usage: COMMON Restriction on usage: @@ -1084,13 +1089,13 @@ Internet-Draft draft-ietf-avt-rtp-vorbis-05 May 2007 The following paragraphs defines the mapping of the parameters described in the IANA considerations section and their usage in the - Offer/Answer Model [7]. + Offer/Answer Model [8]. 7.1. Mapping Media Type Parameters into SDP The information carried in the Media Type media type specification has a specific mapping to fields in the Session Description Protocol - (SDP) [4], which is commonly used to describe RTP sessions. When SDP + (SDP) [5], which is commonly used to describe RTP sessions. When SDP is used to specify sessions the mapping are as follows: o The type name ("audio") goes in SDP "m=" as the media name. @@ -1109,11 +1114,6 @@ Internet-Draft draft-ietf-avt-rtp-vorbis-05 May 2007 included in the SDP "a=fmtp" attribute and MUST follow the delivery-method that applies. - If the stream comprises chained Vorbis files and all of them are - known in advance, the Configuration Packet for each file SHOULD be - passed to the client using the configuration attribute. - - Barbato Expires December 1, 2007 [Page 20] @@ -1121,6 +1121,10 @@ Barbato Expires December 1, 2007 [Page 20] Internet-Draft draft-ietf-avt-rtp-vorbis-05 May 2007 + If the stream comprises chained Vorbis files and all of them are + known in advance, the Configuration Packet for each file SHOULD be + passed to the client using the configuration attribute. + The URI specified in the configuration-uri attribute MUST point to a location where all of the Configuration Packets needed for the life of the session reside. @@ -1136,12 +1140,12 @@ Internet-Draft draft-ietf-avt-rtp-vorbis-05 May 2007 configuration packet is inlined in the sdp, other configurations could be fetched at any time from the first provided uri using or all the known configuration could be downloaded using the second uri. - The inline base64 [8] configuration string is omitted because of the + The inline base64 [9] configuration string is omitted because of the length. c=IN IP4 192.0.2.1 m=audio RTP/AVP 98 a=rtpmap:98 vorbis/44100/2 - a=fmtp:98 delivery-method=in_band; configuration=base64string; + a=fmtp:98 delivery-method=inline; configuration=base64string; delivery-method=out_band; configuration-uri=rtsp://path/to/the/resource; delivery- method=out_band; configuration-uri=http://another/path/to/ @@ -1160,16 +1164,12 @@ Internet-Draft draft-ietf-avt-rtp-vorbis-05 May 2007 The only paramenter negotiable is the delivery method. All the others are declarative: the offer, as described in An Offer/Answer - Model Session Description Protocol [7], may contain a large number of + Model Session Description Protocol [8], may contain a large number of delivery methods per single fmtp attribute, the answerer MUST remove every delivery-method and configuration-uri not supported. All the parameters MUST not be altered on answer otherwise. -8. Congestion Control - - Vorbis clients SHOULD send regular receiver reports detailing - Barbato Expires December 1, 2007 [Page 21] @@ -1177,6 +1177,9 @@ Barbato Expires December 1, 2007 [Page 21] Internet-Draft draft-ietf-avt-rtp-vorbis-05 May 2007 +8. Congestion Control + + Vorbis clients SHOULD send regular receiver reports detailing congestion. A mechanism for dynamically downgrading the stream, known as bitrate peeling, will allow for a graceful backing off of the stream bitrate. This feature is not available at present so an @@ -1212,7 +1215,7 @@ Internet-Draft draft-ietf-avt-rtp-vorbis-05 May 2007 The client could choose to fetch the Configuration from the alternate source as soon as it discovers a Configuration packet got lost in- - band or use selective retransmission [14], if the server supports the + band or use selective retransmission [15], if the server supports the feature. A serverside optimization would be to keep an hash list of the @@ -1225,9 +1228,6 @@ Internet-Draft draft-ietf-avt-rtp-vorbis-05 May 2007 - - - Barbato Expires December 1, 2007 [Page 22] Internet-Draft draft-ietf-avt-rtp-vorbis-05 May 2007 @@ -1277,10 +1277,10 @@ Internet-Draft draft-ietf-avt-rtp-vorbis-05 May 2007 [3] Schulzrinne, H. and S. Casner, "RTP Profile for Audio and Video Conferences with Minimal Control.", RFC 3551. - [4] Handley, M., Jacobson, V., and C. Perkins, "SDP: Session - Description Protocol", RFC 4566, July 2006. + [4] Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform + Resource Identifier (URI): Generic Syntax", RFC 3986. - [5] Mogul, J. and S. Deering, "Path MTU discovery", RFC 1191, + [5] Handley, M., Jacobson, V., and C. Perkins, "SDP: Session @@ -1289,38 +1289,41 @@ Barbato Expires December 1, 2007 [Page 23] Internet-Draft draft-ietf-avt-rtp-vorbis-05 May 2007 + Description Protocol", RFC 4566, July 2006. + + [6] Mogul, J. and S. Deering, "Path MTU discovery", RFC 1191, November 1990. - [6] McCann et al., J., "Path MTU Discovery for IP version 6", + [7] McCann et al., J., "Path MTU Discovery for IP version 6", RFC 1981. - [7] Rosenberg, J. and H. Schulzrinne, "An Offer/Answer Model with + [8] Rosenberg, J. and H. Schulzrinne, "An Offer/Answer Model with Session Description Protocol (SDP)", RFC 3264. - [8] Josefsson, S., "The Base16, Base32, and Base64 Data Encodings", + [9] Josefsson, S., "The Base16, Base32, and Base64 Data Encodings", RFC 3548. - [9] National Institute of Standards and Technology, "Secure Hash + [10] National Institute of Standards and Technology, "Secure Hash Standard", May 1993. 12.2. Informative References - [10] Pfeiffer, S., "The Ogg Encapsulation Format Version 0", + [11] Pfeiffer, S., "The Ogg Encapsulation Format Version 0", RFC 3533. - [11] "libvorbis: Available from the Xiph website, + [12] "libvorbis: Available from the Xiph website, http://www.xiph.org". - [12] "Ogg Vorbis I specification: Codec setup and packet decode. + [13] "Ogg Vorbis I specification: Codec setup and packet decode. Available from the Xiph website, http://www.xiph.org". - [13] Deutsch, P., "GZIP file format specification version 4.3", + [14] Deutsch, P., "GZIP file format specification version 4.3", RFC 1952. - [14] Friedman, T., Caceres, R., and A. Clark, "RTP Control Protocol + [15] Friedman, T., Caceres, R., and A. Clark, "RTP Control Protocol Extended Reports (RTCP XR)", RFC 3611, November 2003. - [15] Seward, J., "libbz2 and bzip2". + [16] Seward, J., "libbz2 and bzip2". Author's Address @@ -1337,9 +1340,6 @@ Author's Address - - - Barbato Expires December 1, 2007 [Page 24] Internet-Draft draft-ietf-avt-rtp-vorbis-05 May 2007 diff --git a/doc/draft-ietf-avt-rtp-vorbis-05.xml b/doc/draft-ietf-avt-rtp-vorbis-05.xml index fa5d1f4..7a77f70 100644 --- a/doc/draft-ietf-avt-rtp-vorbis-05.xml +++ b/doc/draft-ietf-avt-rtp-vorbis-05.xml @@ -821,18 +821,20 @@ Configuration packet with the result detailed in the - the URI of the configuration headers in case -of out of band transmission. In the form of "protocol://path/to/resource/". -Depending on the specific method, a single configuration packet could be -retrived by its number, or multiple packets could be aggregated in a single -stream. Such aggregates MAY be compressed using either + the URI of +the configuration headers in case of out of band transmission. +In the form of "protocol://path/to/resource/", depending on the specific +method, a single configuration packet could be retrived by its Ident number, or +multiple packets could be aggregated in a single stream. +Such aggregates MAY be compressed using either bzip2 or gzip. A sha1 checksum MAY be provided for aggregates. In this latter case the URI will end with the aggregate name, followed by its compressed extension if applies, a "!" and the base64 representation of the sha1hash of the above mentioned compressed aggregated as in: "protocol://path/to/resource/aggregated.bz2!sha1hash". The trailing '/' discriminates which of two methods are in use. -It MUST follow the associated delivery method parameter (either "in_band" or "out_band"). +The configuration-uri MUST follow the associated delivery method parameter ("out_band"). +Non hierarchical protocols and protocols using for special purposes the '!' separator MAY point just to a resource aggregate using their specific syntax. @@ -1249,6 +1251,20 @@ Ridolfo, Francesco Varano, Giampaolo Mancini, Dario Gallucci, Juan Carlos De Mar + + +Uniform Resource Identifier (URI): Generic Syntax + + + + + + + + + + + -- 2.7.4