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• Using "volume" argument in ffmpeg volume audio filter

  3 septembre 2018, par xylophagous

  I wish to "silence" the background noise in an audio, without removing the silence entirely - so as to keep the length of the audio constant. I am trying to use volume filter in ffmpeg like

  ffmpeg -i input.flac -filter:a "volume='if(lt(volume,-8dB),0,1)':eval=frame" output.flac

  but this seems to output the same file as input. I checked this by seeing the volumedetect output and it is identical for input.flac and output.flac.

  I am new to ffmpeg so sorry if this is preliminary ; quick help or pointers to relevant examples appreciated. Thanks !

• Revision ba70f16011 : Add early termination in transform size search In the full-rd transform size se

  12 août 2014, par Yunqing Wang

  Changed Paths :
   Modify /vp9/encoder/vp9_rdopt.c

  
   Modify /vp9/encoder/vp9_speed_features.c

  
   Modify /vp9/encoder/vp9_speed_features.h

  
  
  Add early termination in transform size search

  In the full-rd transform size search, we go through all transform
  sizes to choose the one with best rd score. In this patch, an
  early termination is added to stop the search once we see that the
  smaller size won’t give better rd score than the larger size. Also,
  the search starts from largest transform size, then goes down to
  smallest size.

  A speed feature tx_size_search_breakout is added, which is turned off
  at speed 0, and on for other speeds. The transform size search is
  turned on at speed 1.

  Borg test results :
  1. At speed 1,
  derf set : psnr gain : 0.618%, ssim gain : 0.377% ;
  stdhd set : psnr gain : 0.594%, ssim gain : 0.162% ;
  No noticeable speed change.
  3. At speed 2,
  derf set : psnr loss : 0.157%, ssim loss : 0.175% ;
  stdhd set : psnr loss : 0.090%, ssim loss : 0.101% ;
  speed gain : 4%.

  Change-Id : I22535cd2017b5e54f2a62bb6a38231aea4268b3f

• VeriSilicon and WebM Support

  24 janvier 2011, par noreply@blogger.com (John Luther)

  Guest blogger Tomi Jalonen is Director of Product Marketing for Hantro video IP at VeriSilicon

  2011 is shaping up to be an exciting year at VeriSilicon Holdings in terms of WebM support. With the new year upon us, I want to share some updates about the work we are doing at VeriSilicon to move the WebM platform forward.

  VeriSilicon has been a longtime partner of On2/Hantro (Hantro is the video IP brand that Google acquired with On2 Technologies) and we were among the first hardware partners to commit to WebM video when the codec was open-sourced last year. After promoting WebM to the semiconductor industry during 2010, we’re excited that at CES 2011 the first tablet supporting WebM with full 1080p resolution was demonstrated. VeriSilicon licensed the WebM IP to this tablet manufacturer and provided engineering support to bring the technology to the showroom floor.

  In addition to licensing IPs, this year we’ll be taking the WebM experience a step further by taping out several application processor chips—including the WebM video IP for Android phones, xPad, and Google TV—to accelerate the deployment of WebM and HTML5 video playback into the market.

  The entire VeriSilicon team is very excited about the future of WebM. We believe that the availability of high-quality, optimized WebM hardware video IP, combined with other VeriSilicon audio and multimedia IP, will be a key ingredient for semiconductor companies to create competitive consumer products. After the launch of WebM, the interest in hardware-accelerated WebM video has been immense and we will continue working with the WebM Project to enable WebM and VP8 in many more chips in 2011.