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• lavu/frame : Add Dolby Vision metadata side data type

  3 janvier 2022, par Niklas Haas

  lavu/frame : Add Dolby Vision metadata side data type
  In order to be able to extend this struct later (as the Dolby Vision RPU
  
  evolves), all of the 'container' structs are considered extensible, and
  
  the individual constituent fields must instead be accessed via offsets.
  
  The precedent for this style of access is set in
  
  <libavutil/detection_bbox.h>
  Signed-off-by : Niklas Haas <git@haasn.dev>
  
  Signed-off-by : Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
  

  • [DH] doc/APIchanges
  • [DH] libavutil/dovi_meta.c
  • [DH] libavutil/dovi_meta.h
  • [DH] libavutil/frame.c
  • [DH] libavutil/frame.h
  • [DH] libavutil/version.h

• FFmpeg Has A Native VP8 Decoder

  24 juin 2010, par Multimedia Mike — VP8

  Thanks to David Conrad and Ronald Bultje who committed their native VP8 video decoder to the FFmpeg codebase yesterday. At this point, it can decode 14/17 of the VP8 test vectors that Google released during the initial open sourcing event. Work is ongoing on those 3 non-passing samples (missing bilinear filter). Meanwhile, FFmpeg’s optimization-obsessive personalities are hard at work optimizing the native decoder. The current decoder is already profiled to be faster than Google/On2’s official libvpx.

  Testing
  So it falls to FATE to test this on the ridiculous diversity of platforms that FFmpeg supports. I staged individual test specs for each of the 17 test vectors : vp8-test-vector-001 ... vp8-test-vector-017. After the samples have propagated through to the various FATE installations, I’ll activate the 14 test specs that are currently passing.

  Initial Testing Methodology
  Inspired by Ronald Bultje’s idea, I built the latest FFmpeg-SVN with libvpx enabled. Then I selected between the reference and native decoders as such :

  $ for i in 001 002 003 004 005 006 007 008 009 \
   010 011 012 013 014 015 016 017
  do
    echo vp80-00-comprehensive-$i.ivf
    ffmpeg -vcodec libvpx -i \
      /path/to/vp8-test-vectors-r1/vp80-00-comprehensive-$i.ivf \
      -f framemd5 - 2> /dev/null
  done > refs.txt
  $ for i in 001 002 003 004 005 006 007 008 009 \
  
   010 011 012 013 014 015 016 017
  
  do
  
    echo vp80-00-comprehensive-$i.ivf
  
    ffmpeg -vcodec vp8 -i \
  
      /path/to/vp8-test-vectors-r1/vp80-00-comprehensive-$i.ivf \
  
      -f framemd5 - 2> /dev/null
  
  done > native.txt
  $ diff -u refs.txt native.txt
  

  That reveals precisely which files differ.

• Multiple live video outputs advice. Live stream/Record/Preview, FFMPEG, Windows, Decklink [closed]

  18 septembre 2024, par stroltz

  I am looking for advice on how best to achieve multiple live video outputs.

  


  The live source is a Decklink card on Windows. (We have a ffmpeg build working to access the card) We want 4 outputs ;

  


  


  • We want to run a preview window (low quality would be preferred) just so the user can see the video is working.

    


  


  • We want to be able to live stream - single bit rate, RTMP. (goes up to a CDN)

    


  


  • Independent from the streaming we want to be able to stop and start recording to file. Ideally using CRF. So a separate encode – but maybe we use the RTMP encode, not sure, and do 1 x encode only.

    


  


  • We also want to save a separate audio file. Stops and starts at the same time as the video file above (if required we could do this as a post process on the video file we make above)

    


  


  


  We want to keep CPU use down to as reasonable as possible. (so no high end hardware)

  


  We have had a suggestion of this with ffmpeg ;

  


  Input >> ffmpeg

  


  

  • split input to main and monitoring ;

  


  • scale monitoring stream to lower resolution

  


  • encode both streams

  


  • provide both outputs to local streaming server
ffmpeg >> local streaming server

  


  • use API to start and stop recordings (or web console, if you do it manually)

  


  • provide streams to CDN or/and provide access to your streams for end users

  


  


  recorded files >> another ffmpeg (controlled by some script that get
RECORDING COMPLETED event to start ffmpeg process)

  


  

  • extract audio from recorded file

  


  • save audio into file

  


  


  Which sounds possible, but if doing that, which local streaming server would work best (open source, API...)

  


  or open to other ideas as to the best way.

  


  https://trac.ffmpeg.org/wiki/Creating%20multiple%20outputs shows lots of ways, but I don't think you get to control the individual outputs independently.