How to take video screenshots for codec comparison?

[zmejce]

The title says it.
I want to take screenshots of few video formats, the screenshots must be taken at same frame for comparison. The containers I will use: mkv, mp4 & avi; codecs DivX 6, mp2, h264 & x264.
Which application does it on (windows & mac os x)?

[detmek]

I use MPC-HC for that: File - Save Image. Save as PNG as JPEG is lossy and degrades image quality. Avisynth and its ImageWriter is also an option.

[zmejce]

Im wondering how are people making those screen samples as in the link? Perhaps the same program makes a separate screenshots for codec comparison?

http://iceimg.com/i/d4/21/bf50c028ff.jpg

[sneaker_ger]

In MPC-HC: File -> Save Thumbnails...

[StainlessS]

To save the FULL SCREEN image to clipboard, just hit the Prt Scrn/SysRq key (next to scroll lock),
load in eg Paint (CTRL-V ie paste).
I think it behaves differently depending on eg CTRL/SHIFT/ALT.
Yep, just tested, CTRL copies just the active window, other key combos not tested.