GZip/deflate appears to be surprisingly good for compressing mostly compressed stuff...

Compressing [CoalGuys] B Gata H Kei - 01 [531DF322].mkv with 7-Zip 9.12:

(LZMA/2 use a 64MB dictionary, 2 threads, 64 bytes word size)


Original size: 374,233,074 bytes

.7z
Store:         374,233,256 bytes
LZMA:          377,964,947 bytes
LZMA2:         373,963,350 bytes
BZip2:         374,750,452 bytes

.gz
Deflate        373,694,877 bytes

.xz
LZMA2          373,963,224 bytes


But LZMA2 does appear to be a superior algorithm in general.

(This post was last modified: 03/05/2010 02:03 AM by ZiNgA BuRgA.)