From: lu_zero Date: Thu, 16 Aug 2007 08:54:30 +0000 (+0000) Subject: Simplify configuration-uri handling X-Git-Tag: v1.3.3~307 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=c750c6af56056f627d9c17e1726a889af33f2e5f;p=platform%2Fupstream%2Flibvorbis.git Simplify configuration-uri handling svn path=/trunk/vorbis/; revision=13558 --- diff --git a/doc/draft-ietf-avt-rtp-vorbis-06.txt b/doc/draft-ietf-avt-rtp-vorbis-06.txt index 50886b2..311cce7 100644 --- a/doc/draft-ietf-avt-rtp-vorbis-06.txt +++ b/doc/draft-ietf-avt-rtp-vorbis-06.txt @@ -83,12 +83,12 @@ Table of Contents 5.1. Example Fragmented Vorbis Packet . . . . . . . . . . . . . 14 5.2. Packet Loss . . . . . . . . . . . . . . . . . . . . . . . 16 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 17 - 6.1. Packed Headers IANA Considerations . . . . . . . . . . . . 19 + 6.1. Packed Headers IANA Considerations . . . . . . . . . . . . 18 7. SDP related considerations . . . . . . . . . . . . . . . . . . 20 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 . . . . . . . . . . . . . . . . . . . . . . 22 + 8. Congestion Control . . . . . . . . . . . . . . . . . . . . . . 21 9. Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 9.1. Stream Radio . . . . . . . . . . . . . . . . . . . . . . . 22 10. Security Considerations . . . . . . . . . . . . . . . . . . . 23 @@ -125,7 +125,7 @@ Internet-Draft draft-ietf-avt-rtp-vorbis-06 Jun 2007 quadraphonic, 5.1, ambisonic, or up to 255 discrete channels). Vorbis encoded audio is generally encapsulated within an Ogg format - bitstream [14], 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-06 Jun 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 [10]. Payload Type (PT): 7 bits @@ -304,7 +304,7 @@ Internet-Draft draft-ietf-avt-rtp-vorbis-06 Jun 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 [15] 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-06 Jun 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 [10]. 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-06 Jun 2007 in temporal order. Channel mapping of the audio is in accordance with the Vorbis I - Specification [12]. + Specification [10]. 2.4. Example RTP Packet @@ -410,7 +410,7 @@ Internet-Draft draft-ietf-avt-rtp-vorbis-06 Jun 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 [10] 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. @@ -457,13 +457,13 @@ Internet-Draft draft-ietf-avt-rtp-vorbis-06 Jun 2007 The Packed Configuration (Section 3.1.1) Payload is sent in-band with the packet type bits set to match the Vorbis Data Type. Clients MUST be capable of dealing with fragmentation and periodic re-transmission - of [17] the configuration headers. + of [14] the configuration headers. 3.1.1. Packed Configuration 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 [10], 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-06 Jun 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 [10]. @@ -928,42 +928,30 @@ Internet-Draft draft-ietf-avt-rtp-vorbis-06 Jun 2007 "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 [11] or gzip [13]. 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 [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. - 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. - - + single stream. Non hierarchical protocols MAY point to a + resource using their specific syntax. + Encoding considerations: + This media type is framed and contains binary data. + Security considerations: + See Section 10 of RFC XXXX. + Interoperability considerations: -Barbato Expires December 27, 2007 [Page 17] - -Internet-Draft draft-ietf-avt-rtp-vorbis-06 Jun 2007 + None - Encoding considerations: - This media type is framed and contains binary data. - Security considerations: - See Section 10 of RFC XXXX. - Interoperability considerations: +Barbato Expires December 27, 2007 [Page 17] + +Internet-Draft draft-ietf-avt-rtp-vorbis-06 Jun 2007 - None Published specification: @@ -999,25 +987,27 @@ Internet-Draft draft-ietf-avt-rtp-vorbis-06 Jun 2007 Luca Barbato + 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 + headers. -Barbato Expires December 27, 2007 [Page 18] - -Internet-Draft draft-ietf-avt-rtp-vorbis-06 Jun 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 - headers. + +Barbato Expires December 27, 2007 [Page 18] + +Internet-Draft draft-ietf-avt-rtp-vorbis-06 Jun 2007 + Type name: audio @@ -1056,21 +1046,24 @@ Internet-Draft draft-ietf-avt-rtp-vorbis-06 Jun 2007 None + Person & email address to contact for further information: + Luca Barbato: + IETF Audio/Video Transport Working Group + Intended usage: COMMON -Barbato Expires December 27, 2007 [Page 19] - -Internet-Draft draft-ietf-avt-rtp-vorbis-06 Jun 2007 - Person & email address to contact for further information: - Luca Barbato: - IETF Audio/Video Transport Working Group - Intended usage: COMMON + + +Barbato Expires December 27, 2007 [Page 19] + +Internet-Draft draft-ietf-avt-rtp-vorbis-06 Jun 2007 + Restriction on usage: @@ -1114,6 +1107,13 @@ Internet-Draft draft-ietf-avt-rtp-vorbis-06 Jun 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. + + The URI specified in the configuration-uri attribute MUST point to a + location where all of the Configuration Packets needed for the life + Barbato Expires December 27, 2007 [Page 20] @@ -1121,12 +1121,6 @@ Barbato Expires December 27, 2007 [Page 20] Internet-Draft draft-ietf-avt-rtp-vorbis-06 Jun 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. The port value is specified by the server application bound to the @@ -1171,16 +1165,18 @@ Internet-Draft draft-ietf-avt-rtp-vorbis-06 Jun 2007 parameters MUST not be altered on answer otherwise. +8. Congestion Control + + Vorbis clients SHOULD send regular receiver reports detailing + congestion. A mechanism for dynamically downgrading the stream, + + Barbato Expires December 27, 2007 [Page 21] Internet-Draft draft-ietf-avt-rtp-vorbis-06 Jun 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 alternative would be to redirect the client to a lower bitrate stream @@ -1215,7 +1211,7 @@ Internet-Draft draft-ietf-avt-rtp-vorbis-06 Jun 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 [16], if the server supports the + band or use selective retransmission [13], if the server supports the feature. A serverside optimization would be to keep an hash list of the @@ -1228,6 +1224,10 @@ Internet-Draft draft-ietf-avt-rtp-vorbis-06 Jun 2007 + + + + Barbato Expires December 27, 2007 [Page 22] Internet-Draft draft-ietf-avt-rtp-vorbis-06 Jun 2007 @@ -1303,29 +1303,21 @@ Internet-Draft draft-ietf-avt-rtp-vorbis-06 Jun 2007 [9] Josefsson, S., "The Base16, Base32, and Base64 Data Encodings", RFC 3548. - [10] National Institute of Standards and Technology, "Secure Hash - Standard", May 1993. - - [11] Seward, J., "libbz2 and bzip2". - - [12] "Ogg Vorbis I specification: Codec setup and packet decode. + [10] "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", - RFC 1952. - 12.2. Informative References - [14] Pfeiffer, S., "The Ogg Encapsulation Format Version 0", + [11] Pfeiffer, S., "The Ogg Encapsulation Format Version 0", RFC 3533. - [15] "libvorbis: Available from the Xiph website, + [12] "libvorbis: Available from the Xiph website, http://www.xiph.org". - [16] Friedman, T., Caceres, R., and A. Clark, "RTP Control Protocol + [13] Friedman, T., Caceres, R., and A. Clark, "RTP Control Protocol Extended Reports (RTCP XR)", RFC 3611, November 2003. - [17] Rey, J., Leon, D., Miyazaki, A., Varsa, V., and R. Hakenberg, + [14] Rey, J., Leon, D., Miyazaki, A., Varsa, V., and R. Hakenberg, "RTP Retransmission Payload Format", RFC 4588, July 2006. @@ -1340,6 +1332,14 @@ Author's Address + + + + + + + + Barbato Expires December 27, 2007 [Page 24] Internet-Draft draft-ietf-avt-rtp-vorbis-06 Jun 2007 diff --git a/doc/draft-ietf-avt-rtp-vorbis-06.xml b/doc/draft-ietf-avt-rtp-vorbis-06.xml index 9aecf6a..3230557 100644 --- a/doc/draft-ietf-avt-rtp-vorbis-06.xml +++ b/doc/draft-ietf-avt-rtp-vorbis-06.xml @@ -826,15 +826,8 @@ 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. -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. +Non hierarchical protocols MAY point to a resource using their specific +syntax. @@ -1266,7 +1259,6 @@ Ridolfo, Francesco Varano, Giampaolo Mancini, Dario Gallucci, Juan Carlos De Mar - SDP: Session Description Protocol @@ -1277,13 +1269,11 @@ Ridolfo, Francesco Varano, Giampaolo Mancini, Dario Gallucci, Juan Carlos De Mar - - Path MTU discovery @@ -1296,7 +1286,6 @@ Ridolfo, Francesco Varano, Giampaolo Mancini, Dario Gallucci, Juan Carlos De Mar deering@xerox.com - @@ -1325,34 +1314,13 @@ Ridolfo, Francesco Varano, Giampaolo Mancini, Dario Gallucci, Juan Carlos De Mar - - -Secure Hash Standard - -National Institute of Standards and Technology - - - - - - -libbz2 and bzip2 - - - + Ogg Vorbis I specification: Codec setup and packet decode. Available from the Xiph website, http://www.xiph.org - - - - -GZIP file format specification version 4.3 - - - +