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• ffmpeg slower than downloading

  7 août 2017, par Krylic

  When trying to get a clip of a video from a remote source
  Input source :
  

  ffprobe version 3.3.2-static http://johnvansickle.com/ffmpeg/  Copyright (c) 2007-2017 the FFmpeg developers
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'http://website.com/video.mp4':
 Metadata:
   major_brand     : mp42
   minor_version   : 0
   compatible_brands: mp42mp41
   creation_time   : 2017-07-13T15:44:58.000000Z
 Duration: 00:57:32.42, start: 0.000000, bitrate: 1939 kb/s
   Stream #0:0(eng): Video: h264 (Main) (avc1 / 0x31637661), yuv420p(tv), 720x480 [SAR 10:11 DAR 15:11], 1745 kb/s, 29.97 fps, 29.97 tbr, 29970 tbn, 59.94 tbc (default)
   Metadata:
     creation_time   : 2017-07-13T15:44:58.000000Z
     handler_name    : Mainconcept MP4 Video Media Handler
     encoder         : AVC Coding
   Stream #0:1(eng): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 189 kb/s (default)
   Metadata:
     creation_time   : 2017-07-13T15:44:58.000000Z
     handler_name    : Mainconcept MP4 Sound Media Handler

  Current command :
  ffmpeg version 3.3.2-static
  ffmpeg.linux -threads 2 -y -ss 3273 -i "http://website.com/video.mp4" -an -movflags +faststart -preset veryfast -codec copy /outputfolder/trimmed_video.mp4
  This 5m35.102s to create a 45mb 2min file.

  If I download the file using wget it takes 28s and using ffmpeg only takes 0.243s

  If I add -vn OR -an to the output portion of the command it completes the trim in about 2.101s. Meaning it’s faster to download the two stream and merge them myself.

  Can anyone explain this behaviour and why my first command takes so long when on a lot of other video files it’s very fast ?

• ffmpeg http slower than downloading first

  9 août 2017, par Krylic

  When trying to get a clip of a video from a remote source
  Input source :
  

  ffprobe version 3.3.2-static http://johnvansickle.com/ffmpeg/  Copyright (c) 2007-2017 the FFmpeg developers
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'http://website.com/video.mp4':
 Metadata:
   major_brand     : mp42
   minor_version   : 0
   compatible_brands: mp42mp41
   creation_time   : 2017-07-13T15:44:58.000000Z
 Duration: 00:57:32.42, start: 0.000000, bitrate: 1939 kb/s
   Stream #0:0(eng): Video: h264 (Main) (avc1 / 0x31637661), yuv420p(tv), 720x480 [SAR 10:11 DAR 15:11], 1745 kb/s, 29.97 fps, 29.97 tbr, 29970 tbn, 59.94 tbc (default)
   Metadata:
     creation_time   : 2017-07-13T15:44:58.000000Z
     handler_name    : Mainconcept MP4 Video Media Handler
     encoder         : AVC Coding
   Stream #0:1(eng): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 189 kb/s (default)
   Metadata:
     creation_time   : 2017-07-13T15:44:58.000000Z
     handler_name    : Mainconcept MP4 Sound Media Handler

  Current command :
  ffmpeg version 3.3.2-static
  ffmpeg.linux -threads 2 -y -ss 3273 -i "http://website.com/video.mp4" -an -movflags +faststart -preset veryfast -codec copy /outputfolder/trimmed_video.mp4
  This 5m35.102s to create a 45mb 2min file.

  If I download the file using wget it takes 28s and using ffmpeg only takes 0.243s

  If I add -vn OR -an to the output portion of the command it completes the trim in about 2.101s. Meaning it’s faster to download the two stream and merge them myself.

  Can anyone explain this behaviour and why my first command takes so long when on a lot of other video files it’s very fast ?

• 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.