[mythtv] Lossless MPEG2 editing!
Nigel Pearson
nigel at ind.tansu.com.au
Wed Jan 19 21:54:51 EST 2005
A fellow Australian, Greg Frost, has coded a utility to cut the
edit blocks from a recording. It is, in his own words, a bit crude,
and has only been tested on DVB recorded MPEG2 streams, but it works!
http://knoppmythwiki.homelinux.org/index.php?page=CrudeMPEG2cutForDVB
If some brave souls could test it on PVR[23]50 recorded MPEG2 streams,
ATSC, MPEG-4 and RTJPEG, and I will summarise results.
I would like to put it in contrib ASAP, but decided that a little
discussion was probably in order:
1) The program creates a new file that has the edit blocks removed.
It uses the recordedmarkup table to locate the byte boundaries.
It also creates a new recorded table entry for the new file
2) Now, I assume that a recordedmarkup entry will always correspond
to a sequence header or keyframe, but I am not sure if the
audio and video blocks or packets will always align to these
byte offsets.
If that _is_ the case, then this utility should
be safe with any stream type, right?
3) I would eventually like to make this a program like mythtranscode,
(e.g. mythchop/mythcut/mythedit) that is invoked from the menu
while watching/editing a recording, or the contextual menu in the
Watch/Delete Recordings screens.
It could also be an inactive item if the recording has no cutlist.
The alternative would be to shoehorn it into mythtranscode,
with a new "lossless" profile for the stream types it supports.
Given that it doesn't actually transcode, I prefer having
a separate program and set of UI actions for it. Thoughts?
--
Nigel Pearson, nigel at ind.tansu.com.au | "Gentlemen,
Telstra BI&D, Sydney, Australia | you can't fight in here
Office: 8255 4222 Fax: 8255 3153 | - this is the war room!"
Mobile: 0408 664435 Home: 9792 6998 | Dr Strangelove
More information about the mythtv-dev
mailing list