Avisynth Linear to sRGB?

[SameSelf]

As the title says, is there a way within Avisynth to bake in gamma for a linear image sequence, specifically iec61966_2_1? So far my web searches indicate the short answer is, no, not easily, which is shocking since a single switch does the trick in ffmpeg, and I have always heard that Avisynth was the bees knees. If worse comes to worse, I will just re-export my linear sequence with gamma baked in, but it would be nice to be able to avoid that for this and future projects. TAA

[poisondeathray]

What kinds of operations are you doing that requires avisynth ?

vapoursynth can do it with the built in zimg library

It should almost be possible in avisynth+ when the zimg plugin gets completed . The current version cannot, or at least I couldn't get it to do it correctly. avisynth+ supports additional higher bitdepths and colorspaces natively instead of that workaround stacked format

[sneaker]

Can dither tools do it?

[SameSelf]

Hi, pdr. Thanks for the reply. Normally, I encode .mp4 or .264 streams using ffmpeg, and a linear sequence only requires -apply_trc iec61966_2_1—ridiculously simple. But, I needed to author a DVD using HCenc which requires Avisynth (maybe I am mistaken about that?). Anyway, after crawling the web, it seems one has to jump through hoops to get Avisynth working. And unfortunately, I just can't muster the inertia to learn vapoursynth, but even if I did, would that solve my problem of frameserving to HCenc? Since nobody responded, I just re-exported my seq with gamma baked in.

So, there you go. My problem: a linear, half float exr sequence that needs to be encoded for DVD using HCenc. How would you go about doing that?

[poisondeathray]

AFAIK, HCEnc only accepts avs and d2v .

It's not just linear => sRGB . Presumably you're going to resize for DVD , and you're going to need YUV 4:2:0, BT.601 etc... If it's 59.94p => interlaced you need special treatment , lowpass all that fun stuff

I don't think dither tools can do it, it doesn't have as much control as fmtconv (by the same author) in vpy . And dither tools hasn't been re-written to support the native formats, only the stacked formats. You can convert to/from stacked in avisynth+ but dither tools only support "RGB48" as separate 16bit stacked YUV channels, not the native 16bit RGB formats (either interleaved, or planar). But don't think it can specify transfer function in /out like fmtconv or zimg in vpy . At least you can load interleaved 16bit RGB with Imagesource() in avisynth+ now (not just 8bit like in "avisynth minus" ), but I don't think it can deal with converting from linear yet, until either zimg plugin gets updated, or dither tools gets updated to fmtconv functionality

Avisynth+ has vapoursource to load vpy scripts, so it should be able to solve frameserving to HCEnc. VSImport() works but I only have 64bit installed and tested. HCEnc is 32bit, so you would need 32bit Avisynth+ , 32bit VSImport(). It should work but I didn't test it

But you can use AVFS with 64bit vpy as a "virtual file" (virtual file can bridge 32bit/64bit) , and then 32bit avisynth or avisynth+ with AVISource(), and HCEnc will accept

Or just use ffmpeg (or other program) to create intermediate as you have been.

[SameSelf]

Yeah, there was other stuff in my script, but rather pointless to mention unless I could bake in gamma first somehow.

It sounds like if there is a will there is a way, but outside of a simple plugin, yeah, generating new intermediates is much easier. However, I can say that only because by sheer luck I had already exported my AE menu sequence with gamma baked in due to some strange color issues when exported as linear. But, if I had had to re-export that, oh man, I would have shot myself. This is a good reminder that if I ever plan to take my video to DVD, then I really need to export the sequence with gamma.