Could you upload your .cube file somewhere?

Try to get raw video from that camera, that hex translated to ASCII is GRYB so it might be uncompressed or not.

Yes, should be resolved.

I wrote demuxer for dav files, feel free to test it.

Can you explain in detail?

Should be fixed.

Use -max_muxing_queue_size 512 before -c copy.

Forever, because there is @pause at end, just press any key.

If you use libavfilter, you can call av_frame_get_buffer()
You first need to allocate AVFrame with function from libavutil and set some parameters in newly allocated AVFrame, as explained in doxy.
The function to allocate AVFrame is av_frame_alloc().

That message is just informal one, and should not have any impact on output.