[Imagine] I have a compressed video file. How it's better to slightly change it? What software should I use?
Examples of tasks:
- Make the video slowdown on some moment + draw a circle or freehand line on some part of image.
- Blur some parts of video (e.g. censor it).
- Fix something minor in it (manually erasing or drawing things in frames).
Features that should the video editor have:
- Reading and demuxing compressed files (desirable without creating large temporaries).
- Ability to "pass-throught" compressed stream without decoding+endoding it. Slight quality loss (because of reencoding) is acceptable only near the frames that was actually modified.
- Have couple of effects that can be applied to parts of picture of complex shape. If "curve editor" is obvious thing that needn't be mentioned separately.
- Ability to invoke fully-fledged external picture editor (like Gimp) for some parts of video (both spatially and temporally delimited).
- Mux and write output files, reusing parts of compressed streams from input.
FOSS is strongly preferred. Target system is GNU/Linux (Wine is allowed). It needn't be one big intergated environment, it can be set of tools.