libavcodec 56 not found even though it is installed

[Luo__Eric]

I keep getting this error message: warning: libavcodec-ffmpeg.so.56, needed by /opt/intel/computer_vision_sdk_2018.3.343/opencv/lib/libopencv_videoio.so.3.4.3, not found I also get similar error messages for: libavformat-ffmpeg.so.56, libavutil-ffmpe.so.54, and libswscale-ffmpeg.so.3. However, when I type ffmpeg in the terminal, I get: ffmpeg version 2.7.7 Copyright (c) 2000-2016 the FFmpeg developers built with gcc 7 (Ubuntu 7.3.0-27ubuntu1~18.04) configuration: libavutil 54. 27.100 / 54. 27.100 libavcodec 56. 41.100 / 56. 41.100 libavformat 56. 36.100 / 56. 36.100 libavdevice 56. 4.100 / 56. 4.100 libavfilter 5. 16.101 / 5. 16.101 libswscale 3. 1.101 / 3. 1.101 libswresample 1. 2.100 / 1. 2.100 Hyper fast Audio and Video encoder I have all the correct versions. The ffmpeg is in /usr/local/bin. Why can't OpenVino see it? Any advice will be appreciated, thanks in advance!

[Luo__Eric]

I was able to resolve this error message by compiling the 2.8.15 version here: https://www.ffmpeg.org/download.html#release

I unzipped the tar, then did the following:

./configure --enable-shared --build_suffix=-ffmpeg

It stopped complaining about the *.so files not existing. However I'm still getting error messages similar to the one below:

/opt/intel/computer_vision_sdk_2018.3.343/opencv/lib/libopencv_videoio.so.3.4.3: undefined reference to `av_write_trailer@LIBAVFORMAT_FFMPEG_56'

[Severine_H_Intel]

Glad you could solve the issue. 

[Maksim_S_Intel · Accepted solution]

Eric, you should modify all *.ver files in FFmpeg distribution to produce same symbol versions: LIBAVFORMAT_56 -> LIBAVFORMAT_FFMPEG_56

I don't know if there is a build configuration switch for this.

[Luo__Eric]

I decided to downgrade my Ubuntu to 16.04, so I didn't continue with this route. If anyone else has been able to get OpenVino to work on 18.04 please do share how you guys got it to. Thanks everyone!

[Chen__Alex_G]

I get it worked with 18.04 after download and compile the latest OpenCV4.0. you need to modify the Setupvars.sh to make it refer to the OpenCV link you installed.