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• truehd_core : Switch to in-place modifications

  6 juillet 2019, par Andreas Rheinhardt

  truehd_core : Switch to in-place modifications
  The truehd_core bitstream filter decreases the sizes of the
  
  major_sync_info structure (if present), of the
  
  substream_directory and of the substreams themselves. As a consequence,
  
  there is enough space available in front of the actual substream data
  
  for the new header, so that one only needs to modify the header in front
  
  of the actual data (which apart from shrinking is left untouched) and
  
  the packet's size and buffer pointer (after having made sure that the
  
  packet is writable).
  This and switching to bsf_get_packet_ref also removed the need for
  
  having separate packets for in- and output.
  Even if the input is not writable, there are noticable performance
  
  improvements : The average of 10 iterations of processing a file with 262144
  
  runs each (inlcuding about 20 skips per iteration) went down from 5669
  
  to 4362 decicycles. If the input is writable, it goes down to 1363
  
  decicycles.
  Signed-off-by : Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
  

  • [DH] libavcodec/truehd_core_bsf.c

• HTML5 transparent video with the greatest cross-browser/system support

  22 juin 2022, par Will Ashworth

  I'm encountering an issue getting videos with alpha transparency to reliably load and play on a web page. After some thorough research, this is where I ended up as a means of video encoding to accomplish transparent video which isn't over a solid background color.

  


  Hoping the general community has insight into why we're noticing weirdness with MacOS Monterey in Safari 15 🤷‍♂️

  


  Note : We tried Lottie as an option for the animations, but what we found was that the DOM was excessively bloated ; which would inevitably cause performance issues for the website. So we went back to video as an option.

  


  Convert to HEVC with alpha

  


  ffmpeg -i "source.mov" -c:v hevc_videotoolbox -allow_sw 1 -alpha_quality 1 -vtag hvc1 output.mov


  


  Convert to VP9 with alpha

  


  ffmpeg -i "source.mov" -c:v libvpx-vp9 output.webm


  


  HTML5 method of serving these files to the browser

  


  <video autoplay="autoplay" loop="loop" muted="muted" playsinline="playsinline" class="tmpl-front-page__transition-item tmpl-front-page__transition-item--0 tmpl-front-page__transition-item--banner-video">&#xA;    <source src="path/to/video.mov" type="&#x27;video/mp4;" codecs="hvc1">&#xA;    <source src="path/to/video.webm" type="video/webm">&#xA;</source></source></video>&#xA;

  


  How it works

  


  Essentially, we've learned the following :

  


  

  • Safari supports HEVC with alpha, Chrome does not

  


  • Chrome supports VP9 with alpha, Safari does not

  


  


  Now we let the browser choose which version it wants to use.

  


  There are issues

  


  There's inconsistency in how reliably this works in reality. For example, I'm currently running MacOS Catalina with Safari 14.0.2, and the videos started loading for me when using the above method.

  


  While testing MacOS Monterey with Safari 15.1 inside a Parallels VM, the video doesn't load at all when I test that way. That said, another developer on our team did take the plunge and upgraded to Monterey and has Safari 15.1 ; and he can see the videos loading just fine.

  


  This is getting a little silly, and I'm not sure what else to try. Thanks for any help !

  


• tests/Makefile : Redo how to keep intermediate FATE-files

  4 mai 2022, par Andreas Rheinhardt

  tests/Makefile : Redo how to keep intermediate FATE-files
  Extend the ordinary mechanism to signal KEEP for this.
  
  This also allows to remove the keep-parameter from enc_dec,
  
  transcode and stream_remux, so that several empty parameters
  
  '""' could be removed.
  Signed-off-by : Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
  

  • [DH] tests/Makefile
  • [DH] tests/fate-run.sh
  • [DH] tests/fate/acodec.mak
  • [DH] tests/fate/caf.mak
  • [DH] tests/fate/cover-art.mak
  • [DH] tests/fate/ffmpeg.mak
  • [DH] tests/fate/filter-video.mak
  • [DH] tests/fate/id3v2.mak
  • [DH] tests/fate/image.mak
  • [DH] tests/fate/matroska.mak
  • [DH] tests/fate/mov.mak
  • [DH] tests/fate/mxf.mak
  • [DH] tests/fate/oma.mak
  • [DH] tests/fate/seek.mak
  • [DH] tests/fate/vcodec.mak