@maxman,
depends of what you want to do,
if you want to only cut the video in sections, Avidemux cuts a video without encoding or re-encoding
but the clips can't be cut "frame -accurate" there are always about 12 to 20something frames between "keyframes" on videos, depending on their encoding parameters
one more thing , when cutting, trimming, joining videos without re-encoding, the chunks or videos to be joined have to share the exact same encoding characteristics, example:
you can join any 2 video files encoded by youtube, or any 2 video files encoded by your cell phone or tablet (same resolution and frame-rate, of course)
formats like AVI or a barely compressed mp4 or carefully compressed .h264 can feature frame-acurate cuts and edits, but they would have big sizes
there are some video editors that feature "smart encoding" that will only re-encode the first or last few frames of the video leaving the rest intact, but i have found that those types of editors have a cost -
re-encoding also has the disavantage of taking a while , while programs that do not recode the video are pretty much doing a "copy " paste of sorts of the original file
smart encoding or smart rendering program (this is the one that si mostly mentioned)
TMPGEnc MPEG Smart Renderer 5 is a high-speed video cutting tool focusing on MPEG video file formats. The product is designed so that you can cut videos with great speed and detail, and also incorporates the Smart Rendering function which makes super-fast output with practically no loss in quality.
tmpgenc.pegasys-inc.com
cutting videos without re-code
avidemux:
Edita, comprime y convierte vídeos gratis
avidemux.uptodown.com
now if you want to do transitions, fades & other stuff, then what you are doing is taking videos , adding elements and re-encoding, so adobe premiere and the windows movie makers and such are the right tools, just make sure that the source videos are as
Uncompressed and as high quality as you can get
ffmpeg is another option, and it has guis out there, but i have not found commands for "smart rendering"