Lossless cutting video (MPEG-4) Is it possible to lossless clip out the video file (MPEG-4/H.264) that result chunks will be equivalent to the same of raw footage? I want to reduce size of the source (raw) material by cutting off the unnecessary, but desire to have remaining clips in the same quality as initial video.
This is possible with the FFmpeg command ffmpeg -i input.mp4 -ss 0 -c copy -t 60 output.mp4. This would cut the video from the beginning -ss 0 to second 60 -t 60.

Be aware that -ss is and offset which -t is based upon. So -ss 10 and -t 60 would result in cutting to second 70 and removing the first 10. You can use the -to option to cut at a fixed time unrelated to -ss.

I'm not exactly sure how ffmpeg will handle GOPs but I think it will cut at the nearest GOP at the specified time.

Relevant question on SU: https://superuser.com/questions/138331/using-ffmpeg-to-cut-up-video