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• ffmpeg not letting me use variables in place of actual urls or start and stop times to download a portion of a video

  25 novembre 2020, par sathu-beep

  so I have been trying to download some videos using ffmpeg. Im using the subprocess.call('ffmpeg -i $(youtube-dl -f 133 --get-url  l) -ss 0.4 -to 5.5 -c:v copy -c:a copy happy.mp4',shell=True) command, however, It works fine when I replace the l after "get url" with an actual url, but when I set l as a variable that points to a url, it takes l literally, and says that l is an invalid url. How do I get ffmpeg to recognize that l is a variable and use the url stored in it. Ive tried putting quotes, turning it into a string, and nothing works. Any help is appreciated. It also wont let me use variables for stop and start times

  


• How to compile FFmpeg with bash on Windows 10 ?

  10 août 2017, par user2980183

  In the Creators Update (1703), the Windows 10 bash linux (WSL) can run native windows tools. So, under Windows 10, you can now compile FFmpeg with Visual Studio and the required linux utilities, natively, without having to install MinGW or other interop crap software.

  Here is how I tried to compile FFmpeg (using MSVC 2017 toolchain) :

  • I started the bash shell from "Developer Command Prompt for VS 2017" to set PATH variable to find the MSVC compiler/linker.

  • I installed the "make" tool with the following command : "sudo apt-get install make".

  • To call Windows program from the bash shell, I have to type the command with its .exe extension. So, I must adapt the "configure" and "compat/windows/makedef" files to add ".exe" at the end of "cl", "link" (no confusion possible with the /usr/bin/link), "dumpbin" and "lib" executables :

  configure

  cl_major_ver=$(cl 2>&1 | sed -n 's/.*Version \([[:digit:]]\{1,\}\)\..*/\1/p')
  
      if [ -z "$cl_major_ver" ] || [ $cl_major_ver -ge 18 ]; then
  
          cc_default="cl.exe"
  
      else
  
          cc_default="c99wrap cl"
  
      fi
  
      ld_default="link.exe"
  
      nm_default="dumpbin.exe -symbols"
  
      ar_default="lib.exe"

  compat/windows/makedef

  lib.exe -out:${libname} $@ >/dev/null
  
  
  
  arch=$(dumpbin.exe -headers ${libname} |
  
     tr '\t' ' ' |
  
     grep '^ \+.\+machine \+(.\+)' |
  
     head -1 |
  
     sed -e 's/^ \{1,\}.\{1,\} \{1,\}machine \{1,\}(\(...\)).*/\1/')
  
  
  
  dump=$(dumpbin.exe -linkermember:1 ${libname})

  I hope the FFmpeg build tool chain will be adapted in the future to support natively compiling on bash on Windows...

  • If you want to set an absolute path for YASM in the "configure", you have to use the following pattern /mnt/[letter_partition]/path/yasm.exe.

  ./configure --toolchain=msvc --yasmexe='/mnt/e/Home/Important/Development/Toolkit/Tools/yasm-1.3.0-win32.exe' [all other settings you need]

  • The make command should generate the lib as expected.

  • I tried to type make install but I get the following error :
    No rule to make the target "libavutil\x86\x86util.asm", needed for "libavutil/x86/cpuid.o".

  I don’t know what is wrong...

  As you can see, building FFmpeg on bash under Windows is not very developer friendly yet. Compiling FFmpeg in Windows should be as easy as Linux. Do you know if there is an easier way to proceed ? Do you know if this compilation scenario will be officially supported in next versions of FFmpeg (I don’t find any roadmap) ?

  Thanks.

• Using ffmpeg with subprocess python

  23 décembre 2018, par Vincent

  I am trying to download videos from Wistia and I managed to download them but in .bin&amp format ; I’d like to convert them to .mp4 in order to use OpenCV. For this I am calling ffmpeg with subprocess on Python but I get 1 as the value for the return code, meaning the process has failed. Any idea why, and how I can change this...?

  Code is the following :

  import subprocess
  
  
  
  infile = filename #a bin&amp file
  
  outfile = filename[:-7]+'mp4'
  
  
  
  subprocess.run(['ffmpeg', '-i', infile, outfile],shell=True)

  I get :

  CompletedProcess(args=['ffmpeg', '-i', '58c63bccfcc1c150646c261caad97a58ced4b5e3.bin&amp', '58c63bccfcc1c150646c261caad97a58ced4b5e3.mp4'], returncode=1)

  Also, it works in the command prompt...

  Thank you for your help,

  Sincerely,