image artefacts on qtgmc-ing .MTS files

[i4004]

LWLibavSource+HardwareDecoding: no artifacts
DGDecNV: no artifacts
FFVideoSource: no artifacts
BestSource: artifacts
LWLibavSource: artifacts
-> probably a bug in libav handling interlaced avc (same with some interlaced vc-1 source).

let's revisit this a bit: i'm having no such luck with decoding this: i mean i see everything is ok when i don't use bob in qtgmc (which again points to failed laced avc decoding).
if i remove hardware assisted decoding from your list of working solutions, i'm left with ffvideosource, but that also doesn't produce ok (bobbed) video for me, ie this:

clip = core.ffms2.Source(source="C:/Video/netwr0k video cache/00139_tripod stabi.MTS",cachefile="C:/Users/i4004/AppData/Local/Temp/mts_86e907c30f0d55f4cfd8878628d58f35_853323747.ffindex",format=vs.YUV420P8,alpha=False)

also produces artefacts. did u use bob mode in qtgmc? 

the "saving grace" seems to be that only first few frames are usually affected....