qcp.txt

详细说明了高通QCP音频的文件格式

Internet Draft  The Audio/QCP Media Type and File Format  February 2003


    }
    
    <offsets in increments chunk - 'offs'> {
        BYTE[4]   id                     = {'o', 'f', 'f', 's'}
        UINT32    size                   = size of 'offs' subchunk
                                           excluding id and size
        UINT32    stepSize;
            // in 100ms increments, i.e., stepSize of 10 means 1 second
        UINT32    numOfOffsets;          // number of offsets
        UINT32    Offsets[numOfOffsets]; // actual array of offsets 
    }
    Note:  Step size MUST be in increments of 100 ms.
    
    <configuration chunk - 'cnfg'> {
        BYTE[4] id      = {'c', 'n', 'f', 'g'}
        UINT32  size    = size of 'cnfg' subchunk excluding id and
                          size
        UINT16  config  = bitmapped configuration word
    }
    
    <text chunk - 'text'> {
        BYTE[4] id      = {'t', 'e', 'x', 't'}
        UINT32  size    = size of 'text' subchunk excluding id and size
        BYTE[ ]         = Any length of a zero-terminated text string
    }
    
4.  READING A QCP FILE
    
    The following parameters in format chunk (fmt ) MUST be checked to
    successfully read QCP files:
    
    Version numbers MUST match.  Currently, mjv = 1 and mnv = 0 are
    defined.  If the version numbers do not match, the file MUST be
    rejected.
    
    The codec identifier that is found in the Id member of the
    type_qpl_info
    
    struct MUST be one of the following three IDs for playback on the
    QCELP 13K and EVRC vocoders.
    
    QCELP 13K Vocoder ID = {5E7F6D41-B115-11D0-BA91-00805FB4B97E}
    
    QCELP 13K Vocoder ID = {5E7F6D42-B115-11D0-BA91-00805FB4B97E}
    






Garudadri                  [Page 7]                  Expires August 2003

Internet Draft  The Audio/QCP Media Type and File Format  February 2003


    EVRC Vocoder ID = {E689D48D-9076-46b5-91EF-736A5100CEB4}
    
    For a codec with one of the above two IDs for the QCELP 13K vocoder,
    the version member (Id) of the type_qpl_info struct MUST be 1.  If
    it is not, the file MUST be rejected.
    
    For a codec with the EVRC Vocoder ID, the version member (Id) of
    type_qpl_info struct MUST be 1.  If it is not, the file MUST be
    rejected.
    
    
5.  WRITING A QCP FILE
    
    The following requirements MUST be met for the successful creation
    of QCP files:
    
    In the fmt chunk, the version MUST be mjv = 1 or mnv = 0.
    
    The codec identifier that is found in the Id member of the
    type_qpl_info struct MUST be one of the following three IDs for
    playback on the QCELP 13K or EVRC vocoders:
    
    QCELP 13K Vocoder ID = {5E7F6D41-B115-11D0-BA91-00805FB4B97E} --
    this is the recommended identifier for the QCELP 13K vocoder
    
    QCELP 13K Vocoder ID = {5E7F6D42-B115-11D0-BA91-00805FB4B97E}
    
    EVRC Vocoder ID = {E689D48D-9076-46b5-91EF-736A5100CEB4}
    
    For a codec with the IDs listed above for the QCELP 13K vocoder, the
    version member (Id) of type_qpl_info struct MUST be either 1.
    
    For a codec with the EVRC Vocoder ID, the version member (Id) of
    type_qpl_info struct MUST be 1.
    
    The header byte MUST be included for each of the packets in the data
    chunk, whether the packets are variable-rate or fixed-rate.
    
    
6.  Registration of Media Type Audio/qcp
    
    Media Type Name:           audio

    Media Subtype Name:        qcp

    Required Parameter:        vocoder=QCELP-13k
                               vocoder=EVRC

    Optional parameters:       none


Garudadri                  [Page 8]                  Expires August 2003

Internet Draft  The Audio/QCP Media Type and File Format  February 2003


    The 'vocoder' parameter is required.  It MUST be present and set to
    one of two possible values:  QCELP-13K or EVRC.  Case is not
    significant.
    
    Encoding considerations:
            The storage format specified in this document may be used
    with any transport mechanism.
    
        Security considerations:
            See Section 7 "Security Considerations" of this document.
    
    Public specification:       this document

   Additional information:      no
    
        Magic number: none
        File extensions: qcp, QCP
        Macintosh file type code: none
        Object identifier or OID: none
    
        Intended usage:
            COMMON.  This file format is already in wide use in Internet
    email user agents, multimedia authoring and playing software, and
    CDMA2000 handsets.
    
        Person & email address to contact for further information:
            Harinath Garudadri [e-mail]
    
        Author/Change controller:
            Harinath Garudadri [e-mail] to be determined
    
    
7.  Security Considerations
    
        This document specifies a file format only, not a streaming
    protocol payload format nor a transfer method.  As such, it
    introduces no security risks aside from those associated with any
    audio codec or media file format (for example, denial of service by
    transmitting a file larger than the receiver can handle).  Note that
    those security concerns must be understood before using the file
    format specified here.
    
    
8.  Acknowledgements
    






Garudadri                  [Page 9]                  Expires August 2003

Internet Draft  The Audio/QCP Media Type and File Format  February 2003


        The authors would like to acknowledge that the qcp fileformat
    was originally developed by others within Qualcomm.  The authors
    would like to thank Chuck Han and Livingstone Song for their
    contributions leading to this specification.
    
    
9.  Normative References
    
        [KEYWORDS] Bradner, "Key words for use in RFCs to Indicate
    Requirement Levels", RFC 2119, Harvard University, March 1997.
    
        [QCELP] TIA/EIA/IS-733.  TR45:  High Rate Speech Service Option
    for Wideband Spread Spectrum Communications Systems.  Available from
    Global Engineering [phone] or [phone].  May also be
    ordered online at http://www.eia.org/eng/.
    
        [EVRC] TIA/EIA/IS-127, "Enhanced Variable Rate Codec, Speech
    Service Option 3 for Wideband Spread Spectrum Digital Systems",
    January 1997.
    
        [PureVoice] McKay, "RTP Payload Format for PureVoice(tm) Audio",
    RFC2658, Qualcomm, August 1999.
    
        [SMV-EVRC] "RTP Payload Format for Enhanced Variable Rate Codecs
    (EVRC) and Selectable Mode Vocoders (SMV)", Li,
    draft-ietf-avt-evrc-smv-03.txt
    
    
10.  Authors Address
    
    Harinath Garudadri
    [e-mail]
    QUALCOMM Incorporated
    5775 Morehouse Drive
    San Diego, CA  92121
    USA

    Randall Gellens
    [e-mail]
    QUALCOMM Incorporated
    5775 Morehouse Drive
    San Diego, CA  92121
    USA
    
    






Garudadri                 [Page 10]                 Expires August 2003

Internet Draft  The Audio/QCP Media Type and File Format  February 2003


Intellectual Property Statement
    
        The IETF takes no position regarding the validity or scope of
    any intellectual property or other rights that might be claimed to
    pertain to the implementation or use of the technology described in
    this document or the extent to which any license under such rights
    might or might not be available; neither does it represent that it
    has made any effort to identify any such rights.  Information on the
    IETF's procedures with respect to rights in standards-track and
    standards-related documentation can be found in BCP-11.  Copies of
    claims of rights made available for publication and any assurances
    of licenses to be made available, or the result of an attempt made
    to obtain a general license or permission for the use of such
    proprietary rights by implementors or users of this specification
    can be obtained from the IETF Secretariat.
    
        The IETF invites any interested party to bring to its attention
    any copyrights, patents or patent applications, or other proprietary
    rights which may cover technology that may be required to practice
    this standard.  Please address the information to the IETF Executive
    Director.
    
    
Full Copyright Statement
    
        Copyright (C) The Internet Society 2003.  All Rights Reserved.
    
        This document and translations of it may be copied and furnished
    to others, and derivative works that comment on or otherwise explain
    it or assist in its implementation may be prepared, copied,
    published and distributed, in whole or in part, without restriction
    of any kind, provided that the above copyright notice and this
    paragraph are included on all such copies and derivative works.
    However, this document itself may not be modified in any way, such
    as by removing the copyright notice or references to the Internet
    Society or other Internet organizations, except as needed for the
    purpose of developing Internet standards in which case the
    procedures for copyrights defined in the Internet Standards process
    must be followed, or as required to translate it into languages
    other than English.
    
        The limited permissions granted above are perpetual and will not
    be revoked by the Internet Society or its successors or assigns.
    







Garudadri                 [Page 11]                 Expires August 2003

Internet Draft  The Audio/QCP Media Type and File Format  February 2003


        This document and the information contained herein is provided
    on an "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET
    ENGINEERING TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED,
    INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE
    INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED
    WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
    
    











































Garudadri                 [Page 12]                 Expires August 2003