How to resize with x264? and audio query

[DoomNlNE]

Hi,

I want to encode and resize a video to 1080p.
How can I do this?

This is my current command for compressing video
x264 --preset veryslow --crf 0 --demuxer lavf --threads 8 "in.avi" -o "output.mkv"

I also want to encode using lossless audio (I have FLAC installed).
The x264 build that I use also compresses audio to AAC. Is there a way to compress audio to FLAC or another lossless format?

(I don't want to encode audio and video separately)

[Temuthril]

http://mewiki.project357.com/wiki/X264_Settings#resize
For example:--video-filter resize:1920,1080,1:1,method=spline

[DoomNlNE]

http://mewiki.project357.com/wiki/X264_Settings#resize
For example:--video-filter resize:1920,1080,1:1,method=spline
and how to keep the same aspect ratio as the source (so it doesn't look stretched out)?

[Groucho2004]

and how to keep the same aspect ratio as the source (so it doesn't look stretched out)?

You'll have to tell us a bit more about the source file (frame size, PAR, etc.).

[Snowknight26]

--vf resize:1920,1080,,both,,

That will resize the video to 1920x1080 box, keeping the aspect ratio correct. Hopefully you're not upscaling the video, though.