Lossless split video into 2 or more parts (best practise)

[guju]

One might think this is the first and simplest task,
but to my experience it requires some attention.

Don't use "Reset Markers" on that!
That's my first advice.

Splitting into two parts
- Navigate to the position where you want to split.
- Move to a keyframe nearby
To save 1st part:
Set Marker A (Begin marker)
==> Everything from (included) marker A to the end is selected.
Delete. Save. Fine.
To save the 2nd part:
Undo
Now: Don't use "Reset Markers" now!!
Set Marker B (End marker)
==> The interval from the previous keyframe to the next keyframe (= former split position) is marked.
Move time slider to 0.
Set Marker A (Begin marker).
Delete. Save. Fine.
-
If you "Reset Markers" (see above) then setting Marker B (End marker)
will mark from begin to one keyframe previous to the split frame.
You'll have a gap.

Splitting into several parts
is by chopping away the parts (carefully, see above).
Or by using this script
For that you have to determine the time of the split keyframes
and write them down (as AviDemux probably won't ever support multiple markers).
Still the script is anything but comfortable, and don't know
if it's reliable.

Any feedback welcome!
Maybe my way is anything but "best practise"?

[eumagga0x2a]

Splitting into two parts
- Navigate to the position where you want to split.
- Move to a keyframe nearby
To save 1st part:
Set Marker A (Begin marker)

No, set Marker B (End marker) then save.

To save the 2nd part:

Delete. Save. Done.

Splitting into several parts

Rinse and repeat from the top.

[guju]

So my speculation splitting might be done easilier was right...

I wouldn't have expected Saving would be applied on a Selection.

So that will be the "best practise" then. 

[Elstar`]

Actually, in most cases it is safe to cut when marker B is set after any P-frame. The fragment must begin on a keyframe, though. And if you will try to cut after a B-frame, avidemux will silently cut it on wrong position...