The QCP File Format and Media Types for Speech Data
RFC 3625

Document Type RFC - Informational (October 2003; Errata)
Updates RFC 3555
Last updated 2015-10-14
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IESG IESG state RFC 3625 (Informational)
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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.
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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
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