Question about Lagarith codec

[seven_deuce offsuit]

OK, I have a quick question about this codec: is it a 16-235 range codec?

[manono]

Hi-

As near as I can tell, it gives you back whatever you send to it. I was just doing some tests that confirmed that. If your source is 0-255 and you want 16-235, then make sure you're changing it in your script. You are using an AviSynth script file, aren't you?

[seven_deuce offsuit]

I'm not using AVIsynth, but I can do that on After Effects.

[seven_deuce offsuit]

I hear most DV codecs use the 16-235 range, so I'm assuming the DVSD codec I'm using for my video is the same thing. So when I import into After Effects, do I input in the 0-255 range and then output it in the 0-235 range (using the "Levels" plugin), and then render with Lagarith? Every video I import into After Effects gives me whiter (I've heard someone say washed out images before) video.

[manono]

Someone else will have to help as I don't use After Effects and don't work with DV, but my reply will give your post a bump. I only know how to find out what you have, and that's with an AviSynth script with ColorYUV(Analyze=True) added to the bottom. There are other ways as well, I'm sure.

This looks like a job for edDV, or maybe jagabo.

[jagabo]

When lagarith converts between YUV and RGB it performs the luminance expansion/contraction as most other colorspace converters do.

If you feed it RGB and compress as RGB, the decompressed RGB is exactly the same as the input.

If you feed it RGB and have it set to store internally as YUY2 or YV12, RGB luminance from 0-255 will be converted to YUV luminance values from 16-235.

If you feed it YUY2 of YV12 and store in either of those formats the luminace range of the source is retained within the compressed data.

But, as far as I can tell, Lagarith always outputs RGB. When it converts compressed YUY2 or YV12 data to RGB it expands the luminance range from 16-235 to 0-255 RGB. If anyone knows how to get Lagarith to output YUY2 or YV12 let me know. The "always suggest RGB for output" option doesn't seem to make any differnece.

A word of warning: Lagarith assumes progressive video when it converts incoming RGB to YV12 (if that option is selected). If your source is interlaced it will mess up the chroma channels.