Questions[opencv](ubuntu)

Let me explain what I had set up. I've been using pytube (Python module) to download videos from YouTube. I would then extract a few random frames from the video and save them as jpegs. I don't need the audio, nor the video.

Now, I've been downloading tens of thousands of videos and then deleting them just to grab a couple of random frames per video. This seemed wasteful and cost a fair bit too. Is there a way to just download the frames themselves without having to download the video?

I would guess something like youtube-dl combined with ffmpeg would do the trick, but I can't find an example online to do that. There is a solution to download a random sample of video which would reduce network bandwidth consumption a good deal, but I want something more efficient and less time consuming. Any help would be appreciated.

WARNING: Could not send HEAD request to https://www.youtube.com/watch\?v\=oHg5SJYRHA0: HTTP Error 404: Not Found ERROR: Unable to download webpage: HTTP Error 404: Not Found (caused by HTTPError()); please report this issue on https://yt-dl.org/bug . Make sure you are using the latest version; see https://yt-dl.org/update on how to update. Be sure to call youtube-dl with the --verbose flag and include its complete output. ffmpeg version 3.4.6-0ubuntu0.18.04.1 Copyright (c) 2000-2019 the FFmpeg developers built with gcc 7 (Ubuntu 7.3.0-16ubuntu3) configuration: --prefix=/usr --extra-version=0ubuntu0.18.04.1 --toolchain=hardened --libdir=/usr/lib/x86_64-linux-gnu --incdir=/usr/include/x86_64-linux-gnu --enable-gpl --disable-stripping --enable-avresample --enable-avisynth --enable-gnutls --enable-ladspa --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libcdio --enable-libflite --enable-libfontconfig --enable-libfreetype --enable-libfribidi --enable-libgme --enable-libgsm --enable-libmp3lame --enable-libmysofa --enable-libopenjpeg --enable-libopenmpt --enable-libopus --enable-libpulse --enable-librubberband --enable-librsvg --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libssh --enable-libtheora --enable-libtwolame --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx265 --enable-libxml2 --enable-libxvid --enable-libzmq --enable-libzvbi --enable-omx --enable-openal --enable-opengl --enable-sdl2 --enable-libdc1394 --enable-libdrm --enable-libiec61883 --enable-chromaprint --enable-frei0r --enable-libopencv --enable-libx264 --enable-shared WARNING: library configuration mismatch avcodec configuration: --prefix=/usr --extra-version=0ubuntu0.18.04.1 --toolchain=hardened --libdir=/usr/lib/x86_64-linux-gnu --incdir=/usr/include/x86_64-linux-gnu --enable-gpl --disable-stripping --enable-avresample --enable-avisynth --enable-gnutls --enable-ladspa --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libcdio --enable-libflite --enable-libfontconfig --enable-libfreetype --enable-libfribidi --enable-libgme --enable-libgsm --enable-libmp3lame --enable-libmysofa --enable-libopenjpeg --enable-libopenmpt --enable-libopus --enable-libpulse --enable-librubberband --enable-librsvg --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libssh --enable-libtheora --enable-libtwolame --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx265 --enable-libxml2 --enable-libxvid --enable-libzmq --enable-libzvbi --enable-omx --enable-openal --enable-opengl --enable-sdl2 --enable-libdc1394 --enable-libdrm --enable-libiec61883 --enable-chromaprint --enable-frei0r --enable-libopencv --enable-libx264 --enable-shared --enable-version3 --disable-doc --disable-programs --enable-libopencore_amrnb --enable-libopencore_amrwb --enable-libtesseract --enable-libvo_amrwbenc libavutil 55. 78.100 / 55. 78.100 libavcodec 57.107.100 / 57.107.100 libavformat 57. 83.100 / 57. 83.100 libavdevice 57. 10.100 / 57. 10.100 libavfilter 6.107.100 / 6.107.100 libavresample 3. 7. 0 / 3. 7. 0 libswscale 4. 8.100 / 4. 8.100 libswresample 2. 9.100 / 2. 9.100 libpostproc 54. 7.100 / 54. 7.100 -vframes: No such file or directory

I'm transitioning from Google Photos and I really liked Shotwell's features. However, face detection/recognition is very important to me because of how I manage my photos. I viewed this blog post that apparently shows how to do it, but it's very vague IMO since I'm not exactly an expert in this area. I tried doing the meson build but there were a ton of dependencies that I manually installed (maybe wasn't supposed to do that?) and one of them messed up my apt system (I ended fixing that by removing all other software in the Software app and doing a dist-upgrade which removed unnecessary packages and dependencies).

Is there a more step-by-step guide to doing this? I really like Shotwell but I must have the face detection feature (I know that it is in beta, but I saw a video that proves it works).

(I know I could use digiKam but I really like Shotwell!)

How should I solve this error in Ubuntu16.04?

    import cv2
  File "/opt/conda/envs/pytorch-py3.6/lib/python3.6/site-packages/cv2/__init__.py", line 3, in <module>
    from .cv2 import *
ImportError: libgthread-2.0.so.0: cannot open shared object file: No such file or directory

I have followed this guide to install OpenCV 2.4.8

OpenCV documentation says that I should find OpencV usr/local/include/opencv/ yet I find nothing.

Can someone tell me where to find the installed OpenCV files?

EDIT I'm not sure why the script installed OpenCV 2.4.8 instead of 2.4.9.

But I just found the files here here /usr/include/opencv and /usr/include/opencv2 I am not sure how that works but it does.

I am looking for any image viewer in ubuntu which can show the pixel coordinates and pixel value under current location of mouse other than gimp..... thanks for your help