RFC 4695, "RTP Payload Format for MIDI", November 2006

Note: This RFC has been obsoleted by RFC 6295

Errata ID: 17
Status: Verified
Type: Technical
Publication Format(s) : TEXT
Reported By: John Lazzaro
Date Reported: 2007-01-18

In this errata, we briefly summarize several errata to RFC 4695,
reported by Alfred Hoenes. The listed errata either fix normative
problem in RFC 4695, or describe editorial errata that may be
particularly confusing to the implementor.

The presentation below is brief. See the main text of
<draft-ietf-avt-rfc4695-bis-00.txt> for a bis version of RFC 4695 that
integrates the fixes listed below in a more-complete way, and also
includes many other editorial fixes.

John Lazzaro, lazzaro@eecs.berkeley.edu

---

[1] In Appendix C.1 and Appendix C.2.3 of RFC 4695, an ABNF rule
related to System Chapter X is incorrectly defined as:

       <parameter> = "__" <h-list> ["_" <h-list>] "__"

The correct version of this rule is:

       <parameter> = "__" <h-list> *( "_" <h-list> ) "__"

[2] In Appendix C.6.3 of RFC 4695, the URIs permitted to be assigned
to the "url" parameter are not stated clearly.  URIs assigned to "url"
MUST specify either HTTP or HTTP over TLS transport protocols.

In Appendix C.7.1 and C.7.2 of RFC 4695, the transport
interoperability requirements for the "url" parameter are not stated
clearly.  For both C.7.1 and C.7.2, HTTP is REQUIRED and HTTP over TLS
is OPTIONAL.

[3] Both fmtp lines in both session description examples in Appendix
C.7.2 of RFC 4695 contain instances of the same syntax error (a
missing ";" at a line wrap after "cm_used=2M0.1.2").

[4] In Appendix D of RFC 4695, all uses of "*ietf-extension" in rules
are in error, and should be replaced with "ietf-extension".  Likewise,
all uses of "*extension" are in error, and should be replaced with
"extension".  This bug incorrectly lets the null token be assigned to
the j_sec, j_update, render, smf_info, and subrender parameters.

[5] In Appendix D of RFC 4695, the definitions of the <command-type>
and <chapter-rules> incorrectly allow lowercase letters to appear in
these strings. The correct definitions of these rules appear below:
    command-type =   [A] [B] [C] [F] [G] [H] [J] [K] [M]
                    [N] [P] [Q] [T] [V] [W] [X] [Y] [Z]

   chapter-list =   [A] [B] [C] [D] [E] [F] [G] [H] [J] [K]
                    [M] [N] [P] [Q] [T] [V] [W] [X] [Y] [Z]

   A        = %x41
   B        = %x42
   C        = %x43
   D        = %x44
   E        = %x45
   F        = %x46
   G        = %x47
   H        = %x48
   J        = %x4A
   K        = %x4B
   M        = %x4D
   N        = %x4E
   P        = %x51
   Q        = %x52
   T        = %x54
   V        = %x56
   W        = %x57
   X        = %x58
   Y        = %x59
   Z        = %x5A

[6] In Appendix D of RFC 4695, the definitions of the <four-octet>,
<nonzero-four-octet>, and <midi-chan> are incorrect.  The correct
definitions of these rules appear below:
    nonzero-four-octet =  (NZ-DIGIT 0*8(DIGIT))
                       / (%x30-33 9(DIGIT))
                       / ("4" %x30-31 8(DIGIT))
                       / ("42" %x30-38 7(DIGIT))
                       / ("429" %x30-33 6(DIGIT))
                       / ("4294" %x30-38 5(DIGIT))
                       / ("42949" %x30-35 4(DIGIT))
                       / ("429496" %x30-36 3(DIGIT))
                       / ("4294967" %x30-31 2(DIGIT))
                       / ("42949672" %x30-38 (DIGIT))
                       / ("429496729" %x30-34)

   four-octet        = "0" / nonzero-four-octet
   midi-chan         = DIGIT / ("1" %x30-35)
   DIGIT             = %x30-39
   NZ-DIGIT          = %x31-39

[7] In Appendix D of RFC4695, the rule <hex-octet> is
incorrect.  The correct definition of this rule appears below.
    hex-octet   = %x30-37 U-HEXDIG
   U-HEXDIG    = DIGIT / A / B / C / D / E / F

   ; DIGIT as defined in [5] above
   ; A, B, C, D, E, F as defined in [4] above

[8] In Appendix D of RFC4695, the rules <base64-unit> and
<base64-pad> are defined unclearly.  The rewritten rules
appear below:
    base64-unit = 4(base64-char)
   base64-pad  = (2(base64-char) "==") / (3(base64-char) "=")

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