[HN Gopher] AV1 Video Codec
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       AV1 Video Codec
        
       Author : doener
       Score  : 28 points
       Date   : 2022-05-09 21:18 UTC (1 hours ago)
        
 (HTM) web link (aomedia.org)
 (TXT) w3m dump (aomedia.org)
        
       | deadmutex wrote:
       | What is new here?
        
         | jonny_eh wrote:
         | I assume it's because this hit the front page:
         | https://news.ycombinator.com/item?id=31317989
        
           | mawise wrote:
           | Given that discussion around licensing, what's the licensing
           | story around AV1?
        
             | lynguist wrote:
             | > non-sublicensable, perpetual, worldwide, non-exclusive,
             | no-charge, royalty-free, irrevocable
             | 
             | According to its license which is very short and can be
             | read here:
             | 
             | https://code.videolan.org/videolan/dav1d/-/blob/master/doc/
             | P...
        
       | yjftsjthsd-h wrote:
       | What's the state of encoding? I'd like to try moving some videos
       | to AV1, but I'm not willing to wait... IIRC, it was literally
       | days of encode time for minutes of video last time I tried.
        
         | mikenew wrote:
         | With ffmpeg 5 using libaom it's actually reasonable. Obviously
         | it depends on quality and whatnot, but I'm able to get about
         | .25X of realtime playback speed with AV1 encoding. The magic
         | switch is setting -cpu-used to something higher than the
         | default of 1, which is go-on-vacation-and-maybe-it-will-finish
         | slow.
         | 
         | Rough example: `ffmpeg -i video.mkv -c:v libaom-av1 -cpu-used 5
         | av1_test.mkv`
        
         | out_of_protocol wrote:
         | https://people.videolan.org/~unlord/SVT-AV1_BD-rate.png
         | 
         | Comparation between codecs and encoder presets. At the same
         | speed SVT-AV1 gives better quality vs h264, h265. M10-M8 look
         | like nice spot
        
         | kasabali wrote:
         | AFAIK state of the art is using fast presets of SVT-AV1,
         | combined with Av1an [0] for parallelism.
         | 
         | [0] https://github.com/master-of-zen/Av1an
        
         | lynguist wrote:
         | See here for performance benchmarks on dav1d (av1 encoder):
         | 
         | https://openbenchmarking.org/test/pts/dav1d#results
         | 
         | Edit: It's false! This is just a decoder, not an encoder! I
         | just learned it.
         | 
         | Here is the link for the performance benchmarks for SVT-AV1,
         | the most popular encoder as I just learned:
         | 
         | https://openbenchmarking.org/test/pts/svt-av1
        
           | cogman10 wrote:
           | dav1d is an av1 decoder
        
             | ______-_-______ wrote:
             | We just need to hold out hope for the release of dav1e
        
               | lynguist wrote:
               | Does Team Videolan have anything like it on their
               | roadmap?
        
               | sp332 wrote:
               | It's not a videolan project, but is rav1e the kind of
               | thing you're looking for?
        
         | post-factum wrote:
         | svt-av1 is pretty fast. Well, depending on crf/preset etc of
         | course, but in general, the more cores you have, the easier it
         | is to get realtime encoding with decent quality. You may want
         | to try ab-av1 first, and then go and play with ffmpeg manually
         | if the result does not satisfy your needs.
         | 
         | For other encoders that do not do parallel encoding that well
         | there are things like av1an.
        
         | cogman10 wrote:
         | The current preferred encoder is SVT-AV1 [1]. It has pretty
         | good CPU/space tradeoffs, so you can pick how long you are
         | willing to wait for a video to encode.
         | 
         | [1] https://github.com/AOMediaCodec/SVT-AV1
        
           | Ameo wrote:
           | I've used this with FFmpeg with great success. Encoding time
           | and video quality is comparable to other encoders, and file
           | size almost always smaller.
        
           | SemanticStrengh wrote:
           | This chart is well know, has kt been reproduced on other
           | datasets?
        
       | causality0 wrote:
       | I'm all for people forging ahead on AV1, but I'm not personally
       | bothering with it yet. Most of my library is currently in HEVC
       | and I'm not going to switch until I don't even have to think
       | about whether all my equipment supports hardware AV1 decoding.
        
         | pkulak wrote:
         | The more stuff you store away in a format that you can't decode
         | for free, the worse off you're gonna be, trust me. I recently
         | started self-hosting my family's photos and videos, and the
         | HEVC and HEIF stuff was a huge pain in my ass to deal with.
         | Lucky for me everything before 2016 was untainted, any no one
         | had yet bothered to turn on 4k-60p on any of their phones
         | (making transcoding on my poor NAS's CPU nearly impossible), or
         | I'd have been in real trouble.
        
           | SemanticStrengh wrote:
           | The world bloats storage by 50% which harm user experience
           | and ecology. That's a lot of regress while all it take is one
           | symbolic dollar for a lifetime license..
        
       | stingraycharles wrote:
       | I find it incredibly difficult to find out from this site what
       | exactly differentiates AV1 from, say, x264/5.
       | 
       | The introduction appears to only be a legal disclaimer?
        
         | brigade wrote:
         | Relative to VP9, https://arxiv.org/pdf/2008.06091.pdf is a good
         | reference. The technical details on the official AOM site are
         | pretty much just the raw specs and code.
        
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