The QCP File Format and Media Types for Speech Data
RFC 3625
| Document | Type |
RFC - Informational
(October 2003; Errata)
Updates RFC 3555
|
|
|---|---|---|---|
| Last updated | 2020-01-21 | ||
| Stream | ISE | ||
| Formats | plain text html pdf htmlized with errata bibtex | ||
| Stream | ISE state | (None) | |
| Consensus Boilerplate | Unknown | ||
| Document shepherd | No shepherd assigned | ||
| IESG | IESG state | RFC 3625 (Informational) | |
| Telechat date | |||
| Responsible AD | Allison Mankin | ||
| IESG note | This documents a storage format for QCELP audio - it is time-sensitive to 3GPP2, which needs it for the streaming applications of the EVRC and SMV vocoders. It was discussed by the AVT Working Group, which published its own storage format for data from those vocoders, but agreed this one, with a distinct name, was equally publishable. | ||
| Send notices to | (None) | ||
Network Working Group R. Gellens
Request for Comments: 3625 H. Garudadri
Updates: 3555 Qualcomm
Category: Informational September 2003
The QCP File Format and Media Types for Speech Data
Status of this Memo
This memo provides information for the Internet community. It does
not specify an Internet standard of any kind. Distribution of this
memo is unlimited.
Copyright Notice
Copyright (C) The Internet Society (2003). All Rights Reserved.
Abstract
RFC 2658 specifies the streaming format for 3GPP2 13K vocoder (High
Rate Speech Service Option 17 for Wideband Spread Spectrum
Communications Systems, also known as QCELP 13K vocoder) data, but
does not specify a storage format. Many implementations have been
using the "QCP" file format (named for its file extension) for
exchanging QCELP 13K data as well as Enhanced Variable Rate Coder
(EVRC) and Selectable Mode Vocoders (SMV) data. (For example,
Eudora(r), QuickTime(r), and cmda2000(r) handsets).
This document specifies the QCP file format and updates the
audio/qcelp media registration to specify this format for storage,
and registers the audio/evrc-qcp and audio/smv-qcp media types for
EVRC and SMV (respectively) data stored in this format.
Gellens & Garudadri Informational [Page 1]
RFC 3625 QCP File Format and Media Types September 2003
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Conventions Used in this Document. . . . . . . . . . . . . . . 2
3. QCP File Format. . . . . . . . . . . . . . . . . . . . . . . . 2
4. IANA Considerations. . . . . . . . . . . . . . . . . . . . . . 10
4.1. Update of Media Type Audio/qcelp . . . . . . . . . . . . 10
4.2. Update of Media Type Audio/vnd.qcelp . . . . . . . . . . 10
4.3. Registration of Audio/EVRC-QCP . . . . . . . . . . . . . 11
4.4. Registration of Audio/SMV-QCP. . . . . . . . . . . . . . 12
5. Security Considerations. . . . . . . . . . . . . . . . . . . . 13
6. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 13
7. References . . . . . . . . . . . . . . . . . . . . . . . . . . 13
7.1. Normative References . . . . . . . . . . . . . . . . . . 13
7.2. Informative References . . . . . . . . . . . . . . . . . 13
8. Intellectual Property Statement. . . . . . . . . . . . . . . . 14
9. Editors' Addresses . . . . . . . . . . . . . . . . . . . . . . 14
10. Full Copyright Statement . . . . . . . . . . . . . . . . . . . 15
1. Introduction
This document specifies the QCP format for storage of [QCELP] 13K,
[EVRC], and [SMV] vocoder frames in files which may reside on network
elements (e.g., media servers, Multimedia Messaging System (MMS)
centers, etc.) and third-generation cellular (3G) handsets, or be
transmitted via email or other mechanisms.
Vocoder frames read from a QCP file may be streamed using protocols
and formats outside the scope of this document, delivered to an
[EVRC], [SMV], or [QCELP] 13K decoder, or otherwise processed.
The QCP format supports [QCELP] 13K as well as [EVRC] and [SMV] data.
Note that this format is different from the EVRC and SMV storage
format specified in [EVRC-SMV].
2. Conventions Used in this Document
The key words "REQUIRED", "MUST", "MUST NOT", "SHOULD", "SHOULD NOT",
and "MAY" in this document are to be interpreted as described in BCP
14, RFC 2119 [KEYWORDS].
3. QCP File Format
The following describes the QCP file format using [ABNF].
A qcp file contains data frames generated by the [QCELP], [EVRC], or
[SMV] vocoders.
Gellens & Garudadri Informational [Page 2]
RFC 3625 QCP File Format and Media Types September 2003
qcp-file = riff-qlcm fmt vrat [labl] [offs] data [cnfg]
[text]
riff-qlcm = RIFF riff-size QLCM
fmt = FMT chunk-size major minor codec-info
; major and minor are set to the version of
; the QCP file format used to generate the
; file - currently, the following versions
; are defined:
;
; major = 2, minor = 0
; used for SMV.
; major = 1, minor = 0
; used for QCELP-13K and EVRC
vrat = VRAT chunk-size var-rate-flag size-in-packets
labl = LABL chunk-size label
offs = OFFS chunk-size step-size num-offsets *offset
; number of repetitions of offset must equal
; num-offsets
data = DATA chunk-size *packet [pad]
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