First pass and second pass

[Fire Foxer]

hi
why when im coding a movie it always doing first pass and also second pass
which both actions are the same?
can i choose it to do only one pass? or it must doing 2 passes?

[minidv2dvd]

a little itsy bit more info might help. what program are you using to encode with?

also the source and output specs would come in handy.

[Fire Foxer]

GK

[guns1inger]

The first pass is an analysis pass. The encoder looks at the video and works out how best to distribute the allowed data (bitrate) across the video. The second pass refines this analysis and encodes the video. You can skip the first pass and do a single pass encode, however you won't get the best distribution of data, and therefore are likely to get inferior quality.

Generally, single pass encodes are done either with a constant bitrate, where the analysis pass isn't necessary, and a defined filesize can still be achieved, or as a quality based encode, where the image quality is the key, and the file size is not a preset factor.

[manono]

And Gordian Knot doesn't allow for running just a single pass. It's 2-pass for a defined file size always. If you want to run 1-pass Q-based encodes, then either encode manually (perhaps after making the .avs using GKnot) or use AutoGK.

[Fire Foxer]

ok thanks
got it