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QCP File Format
Filename extension.qcp
Internet media typeaudio/qcelp[1]
Magic numberRIFF ... QLCM
Developed byQualcomm
Initial releaseAugust 1999 (1999-08)[2]
Type of formataudio file format
Container forQCELP 13K, Enhanced Variable Rate Coder (EVRC), and Selectable Mode Vocoder (SMV)
Extended fromRIFF
StandardMIME Type Registration of RTP Payload Formats
Open format??

The QCP file format is used by many cellular telephone manufacturers to provide ring tones and record voice. It is based on RIFF, a generic format for storing chunks of data identified by tags. The QCP format does not specify how voice data in the file is encoded. Rather, it is a container format. QCP files are typically encoded QCELP or EVRC.

Qualcomm, which originated the format, has removed an internal web page link from the page that formerly discussed QCP. "Out of an abundance of caution, due to the December 31st, 2007 injunction ordered against certain Qualcomm products, Qualcomm has temporarily removed certain web content until it can be reviewed and modified if necessary to ensure compliance with the injunction. It may be several more days or weeks before these pages are accessible again. Thank you for your patience."[3]

QCP files have the same signature as RIFF files: A SOF (start of file) header of 52494646 ("RIFF"), and an EOF (end of file) of 0000.

Playing QCP files[edit]

Qualcomm offers downloads of the software and SDK for its PureVoice voice and audio enhancement products that can play and convert QCP files.[4]


  1. ^ Gellens, R.; Garudadri, H. (September 2003). "The QCP File Format and Media Types for Speech Data". Internet Engineering Task Force. Retrieved 2011-03-01.
  2. ^ K. McKay (August 1999). "MIME Type Registration of RTP Payload Formats". Internet Engineering Task Force. Retrieved 2011-03-01.
  3. ^ "About Qualcomm". Qualcomm. 2008. Archived from the original on 2008-02-27. Retrieved 2008-05-14.
  4. ^ "Qualcomm Products and Services - PureVoice Downloads". Qualcomm. Retrieved 2010-12-28.