Free online QCP to AU converter

Source format: QCP

QCP is a compressed audio format associated with Qualcomm PureVoice, commonly used for voice recordings and older mobile-phone audio content. It was designed to store speech efficiently at low bitrates, so it is often found in voicemail systems, legacy mobile devices, and archived audio messages. QCP files are usually intended for speech playback rather than high-fidelity music.

Target format: AU

AU is a simple audio container format originally developed for Unix systems. It is widely recognized by older software and some audio tools, and it can store audio in several encodings, including PCM and some compressed variants. AU is useful when you need a basic, broadly compatible audio file for legacy systems, development work, or simple playback.

How to perform the conversion

The most reliable way to convert QCP to AU is to use desktop audio software that can open QCP and export to AU, or to use a command-line tool if your system supports the codec.

Option 1: Use Audacity with an import plugin or supported decoder

1. Install Audacity and make sure your system has a way to decode QCP files. In some cases, QCP support may depend on additional libraries or an external decoder.
2. Open the QCP file in Audacity using File → Open.
3. If the file imports correctly, verify the audio plays back normally.
4. Export the audio with File → Export → Export Audio.
5. Choose AU as the output format if it is available, then save the file.

Option 2: Use FFmpeg from the command line

If your FFmpeg build can read the QCP file, conversion is straightforward:

ffmpeg -i input.qcp output.au

If FFmpeg does not recognize the QCP file, you may need to first convert it to a more common intermediate format such as WAV using a decoder that supports Qualcomm PureVoice, then create the AU file from that intermediate audio.

Option 3: Convert on 101convert.com

You can also convert the file on 101convert.com for free, without installing any software. Upload the .qcp file, choose AU as the output format, and download the converted file when it is ready.

Notes on quality, compatibility, or limitations

QCP is speech-oriented, so converting it to AU does not improve audio quality; it only changes the container and encoding. If the AU file is saved as uncompressed PCM, the output may be much larger than the original QCP file.

Compatibility depends heavily on whether your software can decode QCP. This is the main limitation of the conversion. Some modern audio tools do not support QCP at all, especially if the file comes from older mobile devices or voicemail systems.

AU itself is a legacy-friendly format, but support varies by player. If you need maximum compatibility with modern devices, a different target such as WAV or MP3 may be more practical, depending on your use case.