We had a recent shoot that used a Tentacle with a GoPro 4. Media Composer is unable to read the LTC that was recorded, although it is visible/audible. When we pulled the file into Pro Tools, we noticed that the LTC waveform looked unusual. Is it possible that it was distorted? See image below; waveform in question is green; the pink and blue are LTC tracks from other successfully-read GoPro shoots.
we experienced the same behavior (malformed LTC waveform) with all GoPro cameras. The reason for this is that all GoPro cameras do kind of heavy highpass-filtering the input signal. This is good for filtering out wind noise. The bad thing is that this filtering does have an negative effect on square wave signals like LTC. As your waveforms do show, the information is still in it, but AVID’s LTC reading algorithm is not able to read it.
Tentacle Sync Studio for macOS and Tentacle Timecode Tool for PC have special LTC reading algorithms to read even these distorted LTC signals. So I would recommend you to use our software to read audio timecode from GoPro files. Our software can read audio-tc and embed the read timecode as real metadata timecode into the file so that AVID and other editing systems can read it. It is also possible to transcode the GoPro footage to a more editing friendly codec on the fly.
Hope that helps!