GOPDIT (GOP accurate eDITor) is a simple program that allows you to cut and merge MPEG2-PS files at GOP boundaries without reencoding. That's it. No other file types, no other operations! I use it mainly for removing commercials out of tv recordings.
The state of this program is more or less beta. GOPDIT project is usable, when you know, what works and when you have MPEG2 files like the ones I use.
The interface isn't much tested yet. So if you are doing something unexpected and currently nearly everything is unexpected this could result in in strange behaviour!
As for MPEG2 file formats currently I work only with two different types resulting from ATI and Hauppauge encoders. So I don't know, how this program will behave on other formats.
Encoders that encode with 'closed GOPs' are preferable, because transitions are usually smoother.
· open a mpeg2 file (file -> open ... )
· navigate to the beginning of your wanted clip
· (via playing, scrolling, keyboard accelerators - zoom in, when you're close)
· click the 'clip begin' button left below the clip table
· navigate to the end of your clip
· click the 'clip end' button right below the clip table the clip will now appear in the table
· you can repeat steps 2-5 or 1-5
· save the concatenated clips to a new mpeg2 file (file -> save as ...)
Closing a file will close the actual file (the one that is displayed below the screen) and remove ALL clips from the clip table.
Clips can be selected and then cut, copied or pasted.
In order to speed up the search for the correct cut point, you can 'zoom in': the slider will then range over a smaller section of the file.
The numbers displayed aren't GOP or frame numbers, the numbers are simply file offsets divided by a constant (1000000). They should give you some idea of where you are.
The time displayed is just the time found in the GOP structure.
If the checkbox 'I-frames' is checked, only I-frames are displayed. It helps reducing traffic, when you want to work remote (i.e. with a wireless laptop).
With the checkbox 'inclusive' you have the choice of the GOP boundry to be before (checked) or after the picture actually displayed.
You can inhibit X firing up:
# gopdit [< options >] -x [< mpegin >] < editlist > < mpegout >
< editlist > and < mpegout > can be replaced by '-', meaning stdin and stdout respectively. Parameters are read from .gopditrc, but can be overriden by options (see gopdit -h). When < mpegin > isn't specified, the editlist must contain commands for opening mpeg files.
As the cuts are done just before the pack headers, that preceed a GOP, the transition results are totally dependent on the way how mpeg2 encoding is done. In the case of Hauppauge cards, the results seem to be pretty good (especially if you have closed GOP encoding).
With other encodings transitions might look awful and before generating DVDs, some further processing (i.e. replex see 'DVB Replex' at freshmeat.net) is usually necessary.
· Crashes (please tell me about them, in order to improve stability).
· End of file handling isn't clean yet.
· Though GOPs are marked broken after clip transitions, transitions might still look awful.
· There seem to be Linux distribution, where the QT installation isn't correctly detected (I would be extremely greatful for a more complete autoconf macro than the one in autoqt-0.03).
· If you load several shows at once, they must have the same characteristics, frame size, frame rate etc - otherwise the program will probably crash.
What's New in This Release:
· This release has been upgraded to gcc 4.0.2 and can handle aspect changes in MPEG files.