I have seen Lagarith's use mentioned dozens of times not just in the forums, but in the guides as well.
Lagarith cannot ever be recommended for archival or editing purposes. Using Lagarith at any point
in the workflow is irresponsible and reckless at best. Video-corrupting errors have existed in nearly every revision of this encoder. This is not just conjecture, this is by the developer's own admission.
Imagine the bugs we don't know about!!
These are just the most recent three such fatal
flaws. Viewing the changelog there are over a dozen such instances. This is simply unacceptable by any measure.
Version 1.3.27 released on 12-08-2011
Restored a table entry in the Fibonacci coder I accidently deleted; this would cause video corruption or crashes when playing back high-resolution video.
Version 1.3.26 released on 09-25-2011
Fixed an error that caused certain solid color frames from 1.3.20 and earlier to be corrupted.
Version 1.3.24 released on 4-10-2011
Fixed a bug in the SSE & MMX median restoration routines for RGB video that caused corrupted video.
Suggested alternatives to Lagarith include: UT Video, HuffYUV
, MagicYUV. It is possible there are more, but as far as I can tell these are the best / most popular.