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• OpenCV 2.4.7 with FFMpeg support build with VS 2010 (x86)

  24 November 2013, by GregPhil

  I'm fighting with new version of OpenCV 2.4.7 for almost one week (prev. used 2.4.2). My motivation for the new setup is the fact that I run into problems using the Videowriter for uncompressed grayscale videos (http://answers.opencv.org/question/3603/videowriter-videocapture-and-uncompressed-avi/). In https://github.com/Itseez/opencv/pull/1516 "akarsakov" is recommending to build OpenCV without vfw support and open uncompressed video through ffmpeg. That's what I tried to do. I followed basically the instructions mentioned in this video: http://docs.opencv.org/trunk/doc/tutorials/introduction/windows_install/windows_install.html

  I had successfully build opencv with Qt 5.1.1 (http://answers.opencv.org/question/24184/how-to-compile-opencv-247-with-qt-and-ffmpeg/). But I'm not able to get the VideoWriter & VideoCapture work for me. So what I did:

  1. I downloaded the newest ffmpeg build from http://ffmpeg.zeranoe.com/builds/

  2. I generated the vs2010 project disabling VfW and enabling ffmpeg instead:

     Video I/O:
     
     
     
     Video for Windows:           NO
     
     DC1394 1.x:                  NO
     
     DC1394 2.x:                  NO
     
     FFMPEG:                      YES (prebuilt binaries)
     
       codec:                     YES (ver 55.18.102)
     
       format:                    YES (ver 55.12.100)
     
       util:                      YES (ver 52.38.100)
     
       swscale:                   YES (ver 2.3.100)
     
       gentoo-style:              YES
     
       OpenNI:                    NO
     
     OpenNI PrimeSensor Modules:  NO
     
     PvAPI:                       NO
     
     GigEVisionSDK:               NO
     
     DirectShow:                  YES
     
     Media Foundation:            NO
     
     XIMEA:                       NO

  3. I added the include directories and libs for ffmpeg to the highgui module.

  I was not able to compile OpenCV without any errors but the behaviour what I see is not what I expect:

  1. Build OpenCV 2.4.7 without VfW -> VideoWriter.open () returns always false!
  2. Build OpenCV 2.4.7 with VfW -> VideoWriter.open () returns true for the time, calling a release() and an open() on the same object returns always a false.
  3. With or without ffmpeg -> An VideoCapture.open () gives a error message asking for libiconv-2dll!

  Does some had the same problems and is able to point me to my mistake?

  Thank you in advance.
  cheers

• How do I avoid batch video transcoding error when encountering whitespaces in filename using ffmpeg [duplicate]

  20 February 2019, by russell newton

  This question already has an answer here:

  • Looping through find output in Bash where file name contains white spaces
    
    2 answers
    

  I am running a bash script to batch transcode videos on a LAMP server using find and ffmpeg

  dir="/srv/videos"
  
  for OUTPUT in "$(find $dir -iname *.AVI -o -iname *.MOV)"
  
  do
  
      ffmpeg -i "$OUTPUT" "${OUTPUT%%.*}.mp4"  -hide_banner
  
  done

  ffmpeg returns an error if file has whitespaces

   /srv/videos/file with white spaces.MOV: No such file or directory

  For files without white spaces it works fine.
  If I print the filenames inside quotes it looks as though it should be working

  for OUTPUT in "$(find $dir -iname *.MOV)"; do echo "$OUTPUT";done

  returns

  /srv/videos/file with white spaces.MOV

  What do I need to alter to avoid the error please?

  EDIT
  added "" to $OUTPUT%%.*.mp4, I get the same error and corrected extension capitalisation (mov to MOV)

• Spaces in variable

  13 April 2012, by Roger

  I am facing some problems with spaces in variables:

  ALBUM=' -metadata album="Peregrinações Alheias"'

  This command:

  ffmpeg -i $R_IMG -r 1 -b 1800 -i $SOUND -acodec libmp3lame -ab 128k "$ALBUM" -y $OUT

  Returns:

  Unable to find a suitable output format for ' -metadata album="Peregrinações Alheias"'

  And if I take out the "" from the variable:

  ffmpeg -i $R_IMG -r 1 -b 1800 -i $SOUND -acodec libmp3lame -ab 128k $ALBUM -y $OUT

  Returns:

  Unable to find a suitable output format for 'Alheias"'

  And I am sure I am missing something in the bash sintax...

  ---

  UPDATE:

  So it looks that the matter is not with spaces but with the "-metadata" argument...

  The problem is that I have many metadata and I'd like to put them in just one variable. Like this:

  META=' -metadata album="Peregrinações" -metadata title="Passeio ao PETAR" -metadata author="Rogério Madureira" -metadata date="2012" -metadata description="Áudio de um passeio ao PETAR" -metadata comment="Áudio capturado com TACAM DR-07MKII e Foto capturada com Canon PowerShot S5IS" '

  And then:

  ffmpeg -i $R_IMG -r 1 -b 1800 -i $SOUND -acodec libmp3lame -ab 128k $META -y $OUT