I'm not sure everyone realizes it, but the files produced by the 1212 are an unusual format, they are h264 in an mpeg-2 transport stream container. The best thing to do is to remove the h264 data and place it into a more appropriate container, I prefer mkv - it is notably superior. This can be done best (in my hands) using tsmuxer and dgavcindex. For editing h264ts_cutter really really does work - but you must not make a cut at the start of the file - i.e., your first fragment must start with zero. This prevents audio sync issues, every time. After cutting, then using dgavcindex to demux the audio and video, mkvmerge can be used to (a) put the video/audio into an appropriate container, and (b) make your first cut - i.e., chop off the beginning of the video. A flawless file results.
You, as a hobbyist, will not be able to really understand what to do until you've played around with things - this is at least three pieces of unsupported freeware and if you intend to edit your files there is a learning process with only a few hard to find pieces of reading material to help you.
Last time I tried to be helpful all I got was criticism and questions about why I'd want to do what I want to do - half of which displayed complete ignorance of what I posted (i.e. the questioner had NOT read my post). If this happens again this will be the last time I try to help you guys. If you're polite and actually try to read what I type then I will answer any questions about this post.