Recherche avancée

Sur d’autres sites (6415)

• OpenCV Cmake unable to find ffmpeg lib

  29 juillet 2016, par URMISH THAKKER

  I am trying to compile OpenCV with ffmpeg support for ARM Platform on a x86 host.

  I downloaded and compiled ffmpeg for arm platform (both static - FFMPEG_ARM_LIB and dynamic libs - FFMPEG_ARM_LIB_SO)

  When I run cmake in opencv, it gives the following -

  --   Video I/O:
  
  --     DC1394 1.x:                  NO
  
  --     DC1394 2.x:                  NO
  
  --     FFMPEG:                      **NO**
  
  --       codec:                     NO
  
  --       format:                    NO
  
  --       util:                      NO
  
  --       swscale:                   NO
  
  --       gentoo-style:              YES
  
  --     GStreamer:                   NO
  
  --     OpenNI:                      NO
  
  --     OpenNI PrimeSensor Modules:  NO
  
  --     PvAPI:                       NO
  
  --     GigEVisionSDK:               NO
  
  --     UniCap:                      NO
  
  --     UniCap ucil:                 NO
  
  --     V4L/V4L2:                    NO/YES
  
  --     XIMEA:                       NO
  
  --     Xine:                        NO

  I changed the following flags to point to the lib paths of both ffmpeg static and dynamic libs-

  1. LD_LIBRARY_PATH
  2. C_INCLUDE_PATH
  3. CPLUS_INCLUDE_PATH
  4. PKG_CONFIG_PATH
  5. PKG_CONFIG_LIBDIR
  6. PATH
  7. CMAKE_LIBRARY_PATH
  8. CMAKE_INCLUDE_PATH

  However, the opencv is still not able to recognize the ffmpeg libs.

  My FFMPEG compilation command was

  ./configure --enable-shared --disable-static\
  
   --cross-prefix=arm-linux-gnueabi- --arch=armv7a\
  
   --target-os=linux --prefix=<path>
  
  </path>

  What am I doing wrong here ?
  1. Am I compiling the ffmpeg with the wrong option ?
  2. Am I missing some element in CMake which would make it point to the compiled ffmpeg lib for ARM on my system ?

• OpenCV Cmake unable to find ffmpeg lib

  22 février 2018, par URMISH THAKKER

  I am trying to compile OpenCV with ffmpeg support for ARM Platform on a x86 host.

  I downloaded and compiled ffmpeg for arm platform (both static - FFMPEG_ARM_LIB and dynamic libs - FFMPEG_ARM_LIB_SO)

  When I run cmake in opencv, it gives the following -

  --   Video I/O:
  
  --     DC1394 1.x:                  NO
  
  --     DC1394 2.x:                  NO
  
  --     FFMPEG:                      **NO**
  
  --       codec:                     NO
  
  --       format:                    NO
  
  --       util:                      NO
  
  --       swscale:                   NO
  
  --       gentoo-style:              YES
  
  --     GStreamer:                   NO
  
  --     OpenNI:                      NO
  
  --     OpenNI PrimeSensor Modules:  NO
  
  --     PvAPI:                       NO
  
  --     GigEVisionSDK:               NO
  
  --     UniCap:                      NO
  
  --     UniCap ucil:                 NO
  
  --     V4L/V4L2:                    NO/YES
  
  --     XIMEA:                       NO
  
  --     Xine:                        NO

  I changed the following flags to point to the lib paths of both ffmpeg static and dynamic libs-

  1. LD_LIBRARY_PATH
  2. C_INCLUDE_PATH
  3. CPLUS_INCLUDE_PATH
  4. PKG_CONFIG_PATH
  5. PKG_CONFIG_LIBDIR
  6. PATH
  7. CMAKE_LIBRARY_PATH
  8. CMAKE_INCLUDE_PATH

  However, the opencv is still not able to recognize the ffmpeg libs.

  My FFMPEG compilation command was

  ./configure --enable-shared --disable-static\
  
   --cross-prefix=arm-linux-gnueabi- --arch=armv7a\
  
   --target-os=linux --prefix=<path>
  
  </path>

  What am I doing wrong here ?
  1. Am I compiling the ffmpeg with the wrong option ?
  2. Am I missing some element in CMake which would make it point to the compiled ffmpeg lib for ARM on my system ?

• Bash - Get time difference from ffmpeg - Audio and Video merge

  30 janvier 2018, par arjuncc

  I am building an an application using ffmpeg. In which I need to subtract start time of two files(there are only two files as input). following is my code.

  #!/bin/bash
  
  mkvarray=()
  
  mkvarray_name=()
  
  for video_name in *.mkv; do
  
  output=$(ffprobe -v error -show_entries format=start_time -of default=noprint_wrappers=1:nokey=1 "$video_name")
  
  mkvarray+=($output)
  
  mkvarray_name+=("$video_name")
  
  done 
  
  
  
  arraylength=${#mkvarray[@]}
  
  for (( i=0; i<${arraylength}; i++ ));
  
  do
  
    echo ${mkvarray_name[$i-1]} "------>  " ${mkvarray[$i-1]}
  
  done
  
  
  
  max_number=0
  
  if [[ ${mkvarray[0]} < ${mkvarray[1]} ]]; then
  
    echo "first-------------"
  
  
  
    max_number = ${mkvarray[0]} - ${mkvarray[1]}
  
    echo "first " $max_number
  
  else
  
     echo "second-------------"
  
     max_number = ${mkvarray[0]} - ${mkvarray[1]}
  
     echo "second " $max_number
  
  fi
  
  
  
  echo $max_number

  OUTPUT

  $ ./ffmpeg_updated.bash RTda01986c816052106c00f417387a83ff.mkv ------>
  2.040000 cc.mkv ------> 2.040000 RT4bafb05e1b36885c75d7d67a16f5e3b2.mkv ------> 4.086000
  first------------- ./ffmpeg_updated.bash : line 24 : max_number : command
  not found first 0 0

  from this I understood that, floating point arithmetic is not possible. So Is there any suggestion to proceed from this. I am pretty much new to bash. Or is there any alternative way to get things done in ffmpeg ?