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• How do I apply the fade filter after a CUDA-powered scale with ffmpeg ?

  7 novembre 2017, par Peter W.

  I’m trying to apply a fade out filter to a video that is being encoded with the h264_nvenc encoder.

  This :
  ffmpeg -hwaccel cuvid -c:v h264_cuvid -i input.mp4 -c:v h264_nvenc -c:a copy -vf scale_cuda=-1:720,hwdownload,fade=t=out:st=24:d=0.5,hwupload -y output.mp4

  fails with this error message :

  [hwdownload @ 0000028b4c8c7ea0] Invalid output format yuv420p for hwframe download.
  
  [Parsed_hwdownload_1 @ 0000028b4d833620] Failed to configure output pad on 
  
  Parsed_hwdownload_1
  
  Error reinitializing filters!
  
  Failed to inject frame into filter network: Invalid argument
  
  Error while processing the decoded data for stream #0:0
  
  Conversion failed!

  I haven’t really worked with ffmpeg’s hardware acceleration features before, and apparently no one else has, either. At least no one has bothered documenting them.

  I’d be incredibly grateful for any help with this problem.

• Create poster with overlay and scale

  16 juillet 2017, par timgavin

  I’m working on creating a thumbnail from a video and adding an overlay. The following is working great ; it outputs a JPG with the PNG overlay.

  ffmpeg -ss 15 -i input.mp4 -i play-button.png \
  
  -filter_complex overlay='(main_w-overlay_w)/2:(main_h-overlay_h)/2' \
  
  -vframes 1 poster.jpg

  However, I’d like to scale the thumbnail down, so I tried adding scale='min(640\, iw):-1'

  ffmpeg -ss 15 -i input.mp4 -i play-button.png \ 
  
  -filter_complex overlay='(main_w-overlay_w)/2:(main_h-overlay_h)/2' \
  
  -vframes 1 scale='min(640\, iw):-1' poster.jpg

  But when doing that I receive errors

  Unable to find a suitable output format for 
  
  'scale=min(640\, iw):-1' scale=min(640\, iw):-1: Invalid argument

  I’ve tried qscale and adding image2, and playing around with a lot of different options but just can’t find the one that works.

  Edit

  This is what I was previously using to create my poster image, I just needed to add an overlay. But when trying to combine the two it all fell apart.

  ffmpeg -ss 15 -i input.mp4 -f image2 -vf scale='min(640\, iw):-1' \
  
  vframes 1 poster.jpg

• mdct15 : remove redundant scale argument to imdct_half

  11 juillet 2017, par Rostislav Pehlivanov

  mdct15 : remove redundant scale argument to imdct_half
  The only use of that argument was for Opus downmixing which is very rare
  
  and better done after the mdcts.
  Signed-off-by : Rostislav Pehlivanov <atomnuker@gmail.com>
  

  • [DH] libavcodec/aacdec_template.c
  • [DH] libavcodec/mdct15.c
  • [DH] libavcodec/mdct15.h
  • [DH] libavcodec/opus_celt.c