2 pass encoding in winmenc what does it do?

see title for question

It's to have a better quality, but it takes more time. I Think one pass is enough to have a very good quality.

My experience is that it produce a noticeable better quality... but, probably because the bitrate gets sometimes too high, the video on the miniplayer becomes a bit choppy.

No jbl2012, it uses the same bitrate (same filesize) but results in a better video.

Can miniPlayer play it or is the CPU too slow (so it's choppy) ?

It is the same thing. Same bitrate, same filesize. Just better video because more time was taken in converting. Why wouldn't miniPlayer play it?

More to compute I think

Using multipass technique when encoding video into another format means basically that the video encoder analyzes the video many times from the beginning to the end before the actual encoding process. While scanning the file, encoder writes information about the original video to its own logfile and uses that log to determine the best possible way to fit the video within the bitrate limits user has set for the encoding process -- this is why multi-pass encoding is only used in VBR encoding (the CBR encoding doesn't offer any flexibility for the encoder to determine the bitrate for each frame). Best way to understand why this is used is to think of a movie -- when there are shots that are totally, absolutely black, like scene changes, normal 1-pass CBR encoding uses the exact same amount of data to that part as it uses for complex action scene. But by using VBR and multi-pass, encoder "knows" that this piece is Ok with lower bitrate and that bitrate can be then used for more complex scenes, thus creating better quality for those scenes that require more bitrate.

In what way? Bitrate, codec and screen resolution are the only variables in video playback @ Meizu M6. If their all constant, why would anything change?

Edit: Thanks Tipsytc for the explanation.

When I convert flac to LAME-mp3 there's a big difference in time consumption depending on the compression rate the flac was ripped.
I think two-pass encoding will take more CPU time to decompress, too.
Seems that I have to explore it by myself because two answers say different things

Originally Posted by Err0r

No jbl2012, it uses the same bitrate (same filesize) but results in a better video.

Error: same filesize only means same average bitrate

Originally Posted by Tipsytc

But by using VBR and multi-pass, encoder "knows" that this piece is Ok with lower bitrate and that bitrate can be then used for more complex scenes, thus creating better quality for those scenes that require more bitrate.

That's why I think that complex scenes require sometimes too high bitrate for the Meizu.

Yes but basicaly you have to chose your min bitrate and the max bitrate. Then the encoder chose according to the scene a bitrate between [min bitrate ; max bitrate]

The result is that you have the best quality video for a smaller size.

Sorry for my bad english :s