Doctor M said:

Probably a stupid question, but did you try dgdecod with the cpu > 4?

I've had pretty good success and it's fairly fast.

cpu: 0 to 6 (default: 0)
Post-Processing Quickset Options.
(Y=luma, C=chroma, H=horizontal, V=vertical)
- 0: DISABLE POST-PROCESSING
- 1: DEBLOCK_Y_H
- 2: DEBLOCK_Y_H, DEBLOCK_Y_V
- 3: DEBLOCK_Y_H, DEBLOCK_Y_V, DEBLOCK_C_H
- 4: DEBLOCK_Y_H, DEBLOCK_Y_V, DEBLOCK_C_H, DEBLOCK_C_V
- 5: DEBLOCK_Y_H, DEBLOCK_Y_V, DEBLOCK_C_H, DEBLOCK_C_V, DERING_Y
- 6: DEBLOCK_Y_H, DEBLOCK_Y_V, DEBLOCK_C_H, DEBLOCK_C_V, DERING_Y, DERING_C

You can use cpu2 if you want to disable/enable specific options (such as the strong deblocking).

Yes. the Deblocking in dgdecode in not necessary on these sources, and the de-ringing is not very effective and blurs quite a bit.

-G