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    8. Detect video noise using FFMpeg

      ~comp Text 429 words
      Hi Folks I've been working on an autoconversion Bash script to pick up videos and convert them to AV1. Yes, I know converting a source to another source means degradation and yada yada yada, but...

      Hi Folks

      I've been working on an autoconversion Bash script to pick up videos and convert them to AV1. Yes, I know converting a source to another source means degradation and yada yada yada, but it's something I can live with as most of my sources are of very high quality to begin with, and I'm going for space-saving. Plus, my eyes aren't what they once were.

      The conversion into AV1 I'm mostly happy with. I'm currently going through some old 90s shows which are of lesser quality, so they would need a little help to look better with AV1 by adding some natural film grain, else AV1 makes them look a little bit too clean.

      I can easily pop into the script and enable film grain in the variables, or add in a simple option, but that's boring and tedious. Why do that when we can automate the world :)

      Where I have got to is using the signalstats filter. The issue I have is I don't know how to analyse it's output enough to work out whether I should or shouldn't enable film grain or not. I know it's subjective either way.

      Does anyone have experience with this? The output per frame looks like:

      frame:1438 pts:59977 pts_time:59.977
      lavfi.signalstats.YMIN=0
      lavfi.signalstats.YLOW=0
      lavfi.signalstats.YAVG=60.6913
      lavfi.signalstats.YHIGH=149
      lavfi.signalstats.YMAX=239
      lavfi.signalstats.UMIN=91
      lavfi.signalstats.ULOW=108
      lavfi.signalstats.UAVG=121.955
      lavfi.signalstats.UHIGH=131
      lavfi.signalstats.UMAX=148
      lavfi.signalstats.VMIN=124
      lavfi.signalstats.VLOW=128
      lavfi.signalstats.VAVG=134.535
      lavfi.signalstats.VHIGH=146
      lavfi.signalstats.VMAX=154
      lavfi.signalstats.SATMIN=0
      lavfi.signalstats.SATLOW=0
      lavfi.signalstats.SATAVG=9.74682
      lavfi.signalstats.SATHIGH=27
      lavfi.signalstats.SATMAX=43
      lavfi.signalstats.HUEMED=147
      lavfi.signalstats.HUEAVG=162.949
      lavfi.signalstats.YDIF=0.737433
      lavfi.signalstats.UDIF=0.642897
      lavfi.signalstats.VDIF=0.162755
      lavfi.signalstats.YBITDEPTH=8
      lavfi.signalstats.UBITDEPTH=8
      lavfi.signalstats.VBITDEPTH=8

      I'm happy to analyse a random 60-second segment and then grab an average from a couple of these outputs, but I'm not sure if this is a good method or not. I'm asked a couple of the biggest LLMs, they have come back with older ways that no longer exist in ffmpeg 7.1.

      I'm trying not to use too many other pieces of software in this script. The dependencies are fairly simple with ffmpeg, awk, grep, etc., the kind of thing you get on nearly every distro of Linux. Any thoughts and/or ideas?

      8 votes

    29. Tildes Video Thread

      ~misc Ask
      Find yourself watching tons of great videos on [insert chosen video sharing platform], but also find yourself reluctant to flood the Tildes front page with them? Then this thread is for you. It...

      Find yourself watching tons of great videos on [insert chosen video sharing platform], but also find yourself reluctant to flood the Tildes front page with them? Then this thread is for you.

      It could be one quirky video that you feel deserves some eyeballs on it, or perhaps you've got a curated list of videos that you'd love to talk us through...

      Share some of the best video content you've watched this past week/fortnight with us!

      7 votes