HowTo: Load H.264 Videos With dvbcut
Almost a decade ago, in September 2012, we began our work on a personalized TV app. The project is like IPv6 which means a rathervery long-term project. However, we still learned a lot about Linux + DVB-S which was very useful back then. Nowadays things are a little easier, but when it comes to editing recorded movies via DVB-S2 not that much has changed. There are video editors but if all you want is a cutter, those apps feel a bit overloaded for the task.
A little elaboration first: We modified gnutv to support H.264 streams which still works like a charm. The output of the gnutv program is a MPEG-TS container that can be viewed with mplayer/mpv without any problems. And for ordinary MPEG-2 videos in the container, dvbcut is the first choice, if you just want to quickly edit a movie to remove some parts or to adjust begin and/or end.
So far everything is fine, but since nowadays people record stuff in high definition, formely H.264 and higher, those media cannot be loaded into dvbcut. We did a quick research about the status quo, but found no real solution. Instead, we use the swiss army knife for media ffmpeg to convert the media instead.
The number of options for ffmpeg can be intimidating, but all you have to do is:
ffmpeg -i your_h264_media_file.mpeg -c:v mpeg2video -qscale:v 2 -c:a mp2 -b:a 192k /tmp/output.ts
The last part is the audio stuff: MP2 with 192K/s and the first one re-encodes the h264 video into the good old mpeg2 format. But since the operation is no simple copy, it takes a lot of time for longer videos and thus does not come for free.
Bottom line, the proper solution would still be to implement the feature directly into dvbcut but since we have no time for this, the only option -we are aware of- is this lengthy kludge.
Personalized TV on single-board computers 