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• lavc/qsv_hevc : correct QSV HEVC default plugin on Windows

  12 décembre 2018, par Zhong Li

  lavc/qsv_hevc : correct QSV HEVC default plugin on Windows
  1. Old logic meaned : everywhere, except Windows, ffmpeg has to use HW
  
  acceleration, but on Windows ffmpeg has to use (unavailable) software
  
  HEVC by default
  
  2. Software HEVC is available only if you provide corresponding
  
  software MediaSDK library, which isn't provided with ffmpeg. More
  
  information could be found in
  
  https://github.com/Intel-Media-SDK/MediaSDK/blob/master/doc/samples/readme-encode_linux.pdf
  
  3. HW HEVC decoding/encoding are available on Windows in the driver by default
  Note : Default case should be the most common case but this change still has potential risk
  
  on windows if HW path is not supported(or doesn't work as expection).
  
  (See the historical disscution : https://lists.libav.org/pipermail/libav-devel/2016-November/080419.html).
  
  In such case, two options suggested :
  
  1. Use the option "-load_plugin hevc_sw" to switch SW path manually.
  
  2. Or report bug to Intel windows driver if your GPU can support HEVC HW codec.
  
    (HEVC decoding is supported since Braswell, and encoding supported since Skylake)
  Patch started by Landgraph. Add similar change for hevc decoder and bump a new version.
  Reviewed-by : Mark Thompson <sw@jkqxz.net>
  
  Reviewed-by : Maxym Dmytrychenko <maxim.d33@gmail.com>
  
  Signed-off-by : Landgraph <me@landgraph.ru>
  
  Signed-off-by : Zhong Li <zhong.li@intel.com>
  

  • [DH] libavcodec/qsvdec_h2645.c
  • [DH] libavcodec/qsvenc_hevc.c
  • [DH] libavcodec/version.h

• Working with raw output from ffmpeg 'gdigrab' on Windows

  7 mars 2023, par jugglingcats

  I'm trying to capture high quality screen recording with the minimum CPU load (what we're recording is already CPU intensive and suffers slowdown if encoding is being done at the same time as screen recording).

  


  I'm using this command :

  


  ffmpeg -f gdigrab -t 00:00:05 -i desktop -pix_fmt yuv420p -vcodec copy -y testing.avi


  


  When I open this in Windows Media Player or VLC it sort of works. It's the right size and duration, but the pixels are messed up, as shown below.

  


  

  


  Ultimately I'd like to be able to re-encode this to something smaller, again using ffmpeg, but I can't find the right ffmpeg incantation/options for this given the raw input file generated by the first command.

  


• HEVC with Alpha Encoding on Windows

  14 juillet 2023, par CodeVortex

  I know, this question has been asked before, but most of the answers to them are very old.

  


  Actually, I am developing a website which uses transparent videos. So, I am using .webm format for them. However, as you know it is not possible to run .webm with transparency on Apple products. So, after researching on internet(stackoverflow etc), I found a solution that I should convert my video into a series of PNGs and then convert them into HEVC with alpha channel. However, according to the research I done, only the Apple hardware can properly encode HEVC with alpha channel.

  


  I am a newbie to these codecs and formats stuff. So, I think that I read somewhere that latest versions of FFMPEG can also encode HEVC with alpha. However, being a noob I can't figure out any way to write a command for this purpose. Being a beginner with almost non-existent skills in this field of expertise, it is nearly impossible for me to understand the documentations correctly. I also tried using shutterencoder and some other tools but failed.

  


  Although, there is a quicktime .mov solution but with that the file size becomes too large for my 10 sec video, almost 334 mb and as you know this size is too large for a animation video on a landing-page style basic website.

  


  So, now my question is there any way to properly encode HEVC with alpha on Windows or Linux to maintain transparency ?

  


  If this is not possible, then is there any other way to create such transparent videos on Windows or Linux which can be played on browsers of Apple devices ?

  


  I am stuck on this for 3 days, So, any type of help is greatly regarded. I am also providing the link to my videos, if someone wants to take a closer look on codes and formats of these videos : Videos Link

  


  P.S : if anyone with a mac device can encode these transparent videos for me, then that would be best and I shall be very grateful to you