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• x86 : hevc_mc : split differently calls

  24 août 2014, par Christophe Gisquet

  x86 : hevc_mc : split differently calls
  In some cases, 2 or 3 calls are performed to functions for unusual
  
  widths. Instead, perform 2 calls for different widths to split the
  
  workload.
  The 8+16 and 4+8 widths for respectively 8 and more than 8 bits can’t
  
  be processed that way without modifications : some calls use unaligned
  
  buffers, and having branches to handle this was resulting in no
  
  micro-benchmark benefit.
  For block_w == 12 (around 1% of the pixels of the sequence) :
  
  Before :
  
  12758 decicycles in epel_uni, 4093 runs, 3 skips
  
  19389 decicycles in qpel_uni, 8187 runs, 5 skips
  
  22699 decicycles in epel_bi, 32743 runs, 25 skips
  
  34736 decicycles in qpel_bi, 32733 runs, 35 skips
  After :
  
  11929 decicycles in epel_uni, 4096 runs, 0 skips
  
  18131 decicycles in qpel_uni, 8184 runs, 8 skips
  
  20065 decicycles in epel_bi, 32750 runs, 18 skips
  
  31458 decicycles in qpel_bi, 32753 runs, 15 skips
  Signed-off-by : Michael Niedermayer <michaelni@gmx.at>
  

  • [DH] libavcodec/x86/hevcdsp_init.c

• doc/filters : add geq diagonal split screen example

  12 février 2016, par Lou Logan

  doc/filters : add geq diagonal split screen example
  Also remove similar but confusing and less useful example.
  Based on geq expression by Patrick Race <raceink at gmail>.
  Signed-off-by : Lou Logan <lou@lrcd.com>
  
  Signed-off-by : Michael Niedermayer <michael@niedermayer.cc>
  

  • [DH] doc/filters.texi

• Use FFmpeg to split a video into equal-length segments

  11 janvier 2017, par amateur3057

  I need to split many videos of unknown length into 2-minute chunks. I can use the accepted answer from http://unix.stackexchange.com/questions/1670/how-can-i-use-ffmpeg-to-split-mpeg-video-into-10-minute-chunks to do this, but this would require copying, pasting, and modifying many lines and manually calculating how many 2-minute parts are in each video (not a big deal for a few videos, but after a while it gets really tedious).

  I have used code in the past in which all I have to do is specify the input video, the start time, segment length, and the output name and by running it in a .sh file in the same folder as the input video it generates all the necessary separate videos which are labeled "output_video01," "output_video02," etc. However, somehow it doesn’t want to work on my new computer. Other answers which claim to be able to do this don’t work for me, either (when run as either a .bat or .sh file). I believe the code I previously used was :

  ffmpeg -i "input_video.MTS" -ss 164 -f segment -segment_time 120 -vcodec copy -reset_timestamps 1 -map 0:0 -an output_video%d.MTS

  Another suggestion that doesn’t work for me but apparently works for others (see http://superuser.com/a/820773/313829) :

  ffmpeg -i input_video.MTS -c copy -map 0 -segment_time 8 -f segment output_video%03d.MTS

  I currently have Windows 10 with the anniversary update build in which I have enabled Bash, but for some reason it doesn’t want to work. I can’t even see the error it gives me because the window closes so abruptly.