r/Damnthatsinteresting • u/NoWork215 • Jul 16 '26

Video The Odyssey IMAX 70mm Setup

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u/necrophcodr Jul 16 '26

A lot of compression isn't lossless.

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u/bfodder Jul 16 '26

Please show me the compression that is lossless.

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u/necrophcodr Jul 16 '26

Well general compressions are. I don't know of any video compressions that are lossless, but I don't claim to know everything.

Edit:

Apparently there's quite a few: https://en.wikipedia.org/wiki/List_of_codecs#Lossless_video_compression

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u/LickingSmegma Jul 16 '26

FLAC, APE or WavPack for audio (in fact, iirc even WAV uses basic run-length compression). PNG or lossless Webp for static images.

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u/bfodder Jul 16 '26

I guess I should have said video compression because that was what I was meaning, but it seems those do exist anyway.

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u/LickingSmegma Jul 16 '26

Well, if you simply encode each frame as lossless webp, you already get lossless video compression.

FLAC and other lossless audio codecs apply pure mathematical compression that allows reconstructing the original stream, only they account for playback realities such as seeking. It's no surprise that the same can be done with video.

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u/justjanne Jul 16 '26

Technically™, webp is the worst format to use for this comparison, as it always converts to YUV in 4:2:0 and sRGB.

But assuming we go with e.g. cinemaDNG, that's exactly how lossless raw compression works.

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u/LickingSmegma Jul 16 '26

Yeah, I keep discovering that people have come up with lots of niche image formats in the past fifteen or so years when I wasn't actively looking at them (and, to a lesser extent, audio formats too).

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u/bfodder Jul 16 '26

Yeah. Simply.

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u/LickingSmegma Jul 17 '26

I mean, that's how animated GIF works in its simpler form. Every frame is a separate static GIF. It allows for some additional compression by replacing unchanged areas with the 'transparent' color, which gets compressed just like other areas of the same color.

I need to look into APNG, it might be a more advanced version of the same idea.