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• avcodec/mips : Improve hevc uni-w copy mc msa functions

  21 septembre 2017, par Kaustubh Raste

  avcodec/mips : Improve hevc uni-w copy mc msa functions
  Load the specific destination bytes instead of MSA load and pack.
  
  Pack the data to half word before clipping.
  
  Use immediate unsigned saturation for clip to max saving one vector register.
  Signed-off-by : Kaustubh Raste <kaustubh.raste@imgtec.com>
  
  Reviewed-by : Manojkumar Bhosale <Manojkumar.Bhosale@imgtec.com>
  
  Signed-off-by : Michael Niedermayer <michael@niedermayer.cc>
  

  • [DH] libavcodec/mips/hevc_mc_uniw_msa.c
  • [DH] libavutil/mips/generic_macros_msa.h

• sending variables to subprocess call with spaces - python 2.7

  24 novembre 2015, par Tandy Freeman

  I want to add ffmpeg options to a variable and later use it in a subprocess call. If the variable contains one word, all is well, but if it contains more than one, I get errors. I am working on a larger script and I will need to have extra options such as this for certain codecs. How can I get this working ?

  The following works perfectly for me :

  import subprocess
  
  import sys
  
  
  
  video_codec = 'libx264'
  
  output = sys.argv[1] + '.mkv'
  
  subprocess.call(['ffmpeg',
  
              '-i',sys.argv[1], 
  
              '-c:v',video_codec,
  
              '-c:a','copy',         
  
              output])    

  Once I introduce new options/spaces to video_options as such :

  video_codec = "'libx264', '-pix_fmt', 'yuv420p'"

  I get an ffmpeg error :

  Unknown encoder ''libx264', '-pix_fmt', 'yuv420p''

  If I remove the double quotes and just use
  video_codec = ’libx264’, ’-pix_fmt’, ’yuv420p’

  I get a python error :

  Traceback (most recent call last):
 File "testo.py", line 10, in <module>
   output])<br />
 File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/subprocess.py", line 524, in call
   return Popen(*popenargs, **kwargs).wait()
 File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/subprocess.py", line 711, in __init__
   errread, errwrite)
 File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/subprocess.py", line 1308, in _execute_child
   raise child_exception
TypeError: execv() arg 2 must contain only strings
</module>

• Simples loop to iterate over files and send them to ffmpeg

  25 octobre 2019, par user2752471

  I want to do a shell script that will iterate over several video files in a directory, send everyone of them to ffmpeg, that will then reencode each one, producing a reencoded file that will have the same name as the original, except with .avi extension instead .mkv or .mp4.

  I found a fairly simple script in another topic here on SO, tried to change it slightly to take into account the file extension and the destination directory.

  However my script only produces countless "anything : No such file or directory"

  Here is it :

  $ for f in $(find -type f -name *.mkv); do ffmpeg -n -i "$f" -c:v copy ".$f" ; done

  And these is the ffmpeg command that I usually use :

  ffmpeg -y -i  -vf scale=720:-2 -c:v mpeg4 -vtag xvid -b:v 969k -pass 1 -an -f avi /dev/null && ffmpeg -i -c:a libmp3lame -b:a 48k -ac 1 -vf scale=720:-2 -c:v mpeg4 -vtag xvid -b:v 969k -pass 2  .avi

  So I need to identify what is incorrect in the first script, that is considering each small word of the file’s name as a file, and then change it as to add all these ffmpeg parameters.

  Somethings that I do not understand in the script :

  1)Are the -type and f in find command necessary. From what I read of the documentation, all it does is to tell find that it shall look for normal files, something that seems irrelevant for my case. When I use find, I do : find starting dir -name filename. So do I have to keep it ?

  2)What -n means for ffmpeg ? I am currently without a man entry for ffmpeg. Is it necessary for my needs ?

  3)Do I need to have "" around $f ? What it does ?

  4)As far as I understand $ denotes a variable. But what the "f" after it does ? Do I need it ?

  5)The " ;" after the closing ")" and the ".$f" are necessary ? The first is used to indicate the end of the for loop,and the second the end of the ffmpeg command ?

  6)The "do" and the "does" are also necessary for the same motives behind the " ;"

  Here is my attempt of the ffmpeg part of the script. Please tell me what to change on it, as in the find part of it.

  do ffmpeg -n -y -i "$f.mkv" -vf scale=720:-2 -c:v mpeg4 -vtag xvid -b:v 969k -pass 1 -an -f avi /dev/null && ffmpeg -n -i "$f" -c:a libmp3lame -b:a 48k -ac 1 -vf scale=720:-2 -c:v mpeg4 -vtag xvid -b:v 969k -pass 2  ".$f.avi" ; done

  If I would like the script to also look for ".mp4" besides ".mkv" how I would need to change it ?

  Thanks for any input.