[davilla]

Home movies in MOV format, hehe. Smells like GoPro or badly or no audio/video packet intervening.

I've come across a few of these causing issues. The problem is the 1st level of buffering/caching. Default handling fails if the interleave is large and the buffering ends up constantly flushing and filling as the demuxer has to do large seek offsets to fetch audio, then video packets.

For example, there are (ahm) tools that can remove itunes DRM. Some of these tools also remux audio/video with no interleave. That is all audio packets at beginning, followed by subs, then video. The internal buffering scheme is epic fail with such content. Apple native players have no issues playing the content but others can have issues.

Remuxing the content into a mkv container will provide proper a/v interleave. If you just remux the content and not convert, the operation will be fast.

Desktop boxes tends to make a bad reference platform. You don't see the issue on desktop because desktop typically has the ponies and resources to hide a lot of issues by brute force.