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cirquit / trdrop

trdrop - a raw video analysis program
MIT License
384 stars 33 forks source link

Detect / Disallow compressed videos #77

Open cirquit opened 3 years ago

cirquit commented 3 years ago

So it seems as people have been using trdrop to analyze encoded videos, which was never the intention, so I'd like to include an option to allow these videos, but otherwise I will reject the analysis in the filepicker.

So Options -> General -> "Accept encoded videos" with a big warning label if you know what you do. I'll even consider maybe adding a watermark on the screen.

If this option is not ticked, reject the video based on the meta-data information about the video encoding.

If nobody adds to this discussion why it should not be implemented in that way, I'll add it :)

aj752 commented 3 years ago

I think this would be extremely helpful for new users. Just out of curiosity; in my case I was recording lossless at the "end-station" but it wasn't passed lossless from the capture device. So huge files (7GB/m) for 1080p60 but still not really lossless because of the capture device. Would this be able to detect this sort of cases?

cirquit commented 3 years ago

So from my naive understanding of video encoding, I'd try to do the following in that order:

  1. Detect compression in the meta-data
  2. Detect compression based on the video header (there should be something similar to magic bytes as in images?)
  3. Detect compression artifacts (that would surely create false positives on very low-resolution games, that have such artifacts build-in, think PSP games)

So I can't really say what kind of devices it will trigger, as I myself am not somebody that even has capture cards. It would be awesome if people could provide me with videos where you describe the process of how you acquired them. This would result in a wiki entry on how to correctly capture video streams with the least compression artifacts.

So a mega link / your favorite hosting service to videos you know are encoded/want to be tested is very much welcome.

aj752 commented 3 years ago

I have the Elgato HD60S+ (1080p60 no compression) and the Elgato 4K60 S+ (hardware encoder onboard, the one which passes everything though the encoder). Whenever you're ready for testing this feature, just leave me a reply here and I would be more than happy to provide you with any material needed and description how it was captured. Just let me know!

T0biasCZe commented 2 years ago

Compression isnt an issue when you increase the "pixel difference"...