Free online TREC to OPUS converter

What the TREC format is

.trec is the TechSmith Recording File format created by Camtasia Recorder and older Camtasia versions. It can contain screen video, microphone audio, system audio, cursor data, and recording metadata, so it is used for screen captures, software demonstrations, and narrated training recordings. TREC is a proprietary recording container and is normally opened or edited in Camtasia.

What the OPUS format is

.opus usually stores audio encoded with the Opus codec. It is designed for speech, music, voice calls, streaming, and low-bitrate transmission, with good quality at relatively small file sizes. OPUS is appropriate when you need the soundtrack from a TREC recording rather than its screen video; it is supported by applications such as VLC, Firefox, Chrome, and FFmpeg-based media tools.

How to convert TREC to OPUS

Using Camtasia and FFmpeg

1. Open the .trec file in Camtasia.
2. Export only the audio through File → Export → Audio, if that option is available in your Camtasia version. Choose WAV for an uncompressed intermediate file, or M4A if Camtasia offers it.
3. Convert the exported audio with FFmpeg. For a general-purpose stereo file, run ffmpeg -i recording.wav -c:a libopus -b:a 128k recording.opus.
4. For speech or narration, use a lower bitrate such as 64k: ffmpeg -i recording.wav -c:a libopus -b:a 64k narration.opus.
5. Open the resulting .opus file in VLC or another Opus-compatible player and check that the required audio channels and duration are present.

If Camtasia exports M4A instead of WAV, replace recording.wav with the M4A filename in the same FFmpeg command. You can also convert the file free on the 101convert.com website without installing software, provided its TREC-to-OPUS converter accepts the particular TREC recording.

Quality and compatibility limits

This conversion extracts the audio and permanently removes screen video, cursor movement, and Camtasia editing data. Exporting to WAV before encoding avoids an additional lossy compression step; converting an already compressed audio stream to OPUS can reduce quality slightly. Use 48–96 kbps for speech and 96–160 kbps for music or mixed screen-recording audio. Some older players and hardware do not recognize the .opus extension or Opus audio; use VLC or convert to AAC, MP3, or WAV when broader compatibility is required.