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• ffmpeg | x265 VS ffmpeg

  5 octobre 2016, par Kdmeizk

  What are advantages (like a better result for example) to use

  ffmpeg -i input -pix_fmt yuv444p -f yuv4mpegpipe - | x265.exe --input - --y4m --output output

  instead of

  ffmpeg -i input -pix_fmt yuv444p -c:v libx265 output

  I saw often the first command, but with a bit of tests, the result is exactly the same for I/P/B frame numbers, and differ only of 20 B/s for I frame (plus, I assume this difference should not be taken into account).

• configure.ac : Erase default -O2 when setting -O3.

  27 juillet 2014, par Erik de Castro Lopo

  configure.ac : Erase default -O2 when setting -O3.
  Previously CFLAGS had a -O3 at the start and a -O2 at the end. According
  
  to the GCC docs :
      https://gcc.gnu.org/onlinedocs/gcc-4.9.1/gcc/Optimize-Options.html
      "If you use multiple -O options, with or without level numbers,
  
      the last such option is the one that is effective" which means that
  
      GCC doesn’t try to use SIMD to vectorize the code, etc."
  

  • [DH] configure.ac

• shell script : ffmpeg can't either read arguments or filenames, if spaces in path- or filename

  9 juillet 2014, par Nicolas

  I’m currently working on a bash shell script on OS X to get a custom tailored Pashua GUI/automatization package, using ffmpeg in the back, to transcode videos, label them, zip them, upload them, organize them and so on. Everything is working like a charm so far.

  My problem now is that I can’t make ffmpeg take files or paths that have spaces in them IF I use variables in variables. But that (I think) is a must in order to get ffmpeg to transcode multiple files at once depending on the formats and checkboxes the user ticks on.

  I made a little example snippet so you can see my dilemma.

  No spaces in path or filename / works great :

  #!/bin/bash
  
  
  
  infile='/Users/nicolas/Desktop/MASTER_[DE]_Test_140626.mov'
  
  
  
  gen_outfile () {
  
      outfile="${1/MASTER/TRANSCODE}"
  
      ffmpeg_cl="-s $2 -c:v libx264 -preset slow -crf 18 -pix_fmt yuv420p -c:a aac -b:a 240k -strict -2 $outfile"
  
  }
  
  
  
  gen_outfile "$infile" 1920x1080
  
  
  
  ./ffmpeg_stat -i "$infile" $ffmpeg_cl

  The output is as expected and the file is called "TRANSCODE_[DE]_Test_140626.mov"

  Filename variable with spaces - directly fed to ffmpeg :

  This works as well but isn’t really usable for me because I need to have the option of variable numbers of output files and arguments generated dynamically.

  #!/bin/bash
  
  
  
  infile_full='/Users/nicolas/Google Drive/encode-o-mat/MASTER_[DE] Test  140626.mov'
  
  
  
  gen_outfile () {
  
      outfile="${1/MASTER/TRANSCODE}"
  
      ffmpeg_cl="-s $2 -c:v libx264 -preset slow -crf 18 -pix_fmt yuv420p -c:a aac -b:a 240k -strict -2"
  
  }
  
  
  
  gen_outfile "$infile_full" 1920x1080
  
  
  
  ./ffmpeg_stat -i "$infile_full" $ffmpeg_cl "$outfile"

  The output is as expected and the file is called "TRANSCODE_[DE] Test 140626.mov".
  But this way is just not an option.

  This here does not work ! Filename is split up and incomplete :

  #!/bin/bash
  
  
  
  infile_full='/Users/nicolas/Google Drive/encode-o-mat/MASTER_[DE] Test  140626.mov'
  
  
  
  gen_outfile () {
  
      outfile="${1/MASTER/TRANSCODE}"
  
      ffmpeg_cl="-s $2 -c:v libx264 -preset slow -crf 18 -pix_fmt yuv420p -c:a aac -b:a 240k -strict -2 $outfile"
  
  }
  
  
  
  gen_outfile "$infile_full" 1920x1080
  
  
  
  ./ffmpeg_stat -i "$infile_full" $ffmpeg_cl

  Ffmpeg gives this error : "Unable to find a suitable output format for ’/Users/nicolas/Google’".
  Of course.

  This doesn’t work as well ! Quoting and such :

  ./ffmpeg_stat -i "$infile_full" "$ffmpeg_cl"

  If I put the $ffmpeg_cl variable in various quotes ffmpeg doesn’t understand the arguments anymore ! This is one example output :

  "Unrecognized option ’s 1920x1080 -c:v libx264 -preset slow -crf 18 -pix_fmt yuv420p -c:a aac -b:a 240k -strict -2 /Users/nicolas/Google Drive/encode-o-mat/TRANSCODE_[DE] Test 140626.mov’.
  Error splitting the argument list : Option not found
  Conversion failed !"

  It’s really important that the script can handle path- and filenames with spaces because I can’t change the environment in which that tool is supposed to run. All ideas and solutions are more than welcome !