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Hello,
I read this webpage : http://answers.opencv.org/question/40425/opencv-build-fails-because-i-cannot-download-icv-on-our-build-farm/ but it does not help me.
I am new in opencv, I am on ubuntu 14.04, I have done exactly this in my terminal as said on this webpage http://docs.opencv.org/2.4/doc/tutorials/introduction/linux_install/linux_install.html#linux-installation :
sudo apt-get install build-essential
sudo apt-get install cmake git libgtk2.0-dev pkg-config libavcodec-dev libavformat-dev libswscale-dev
sudo apt-get install python-dev python-numpy libtbb2 libtbb-dev libjpeg-dev libpng-dev libtiff-dev libjasper-dev libdc1394-22-dev
git clone https://github.com/Itseez/opencv.git
cd opencv
mkdir release
cd release
cmake -D CMAKE_BUILD_TYPE=RELEASE -D CMAKE_INSTALL_PREFIX=/usr/local ..but after a long wait of downloading, I have this output :
-- ICV: Downloading ippicv_linux_20151201.tgz...
CMake Error at 3rdparty/ippicv/downloader.cmake:73 (file):
file DOWNLOAD HASH mismatch
for file: [/home/pauka/opencv/3rdparty/ippicv/downloads/linux-808b791a6eac9ed78d32a7666804320e/ippicv_linux_20151201.tgz]
expected hash: [808b791a6eac9ed78d32a7666804320e]
actual hash: [f166287239920c4a16e6f8870e15ef79]
I thought that it was an error of downloading so I retry, but hashes are always different. Why are they always different ? And where this file is located on the internet ? I do find it to download it manually (the 20151201 version).
I hope that I am not alone with this issue.
Thanks for your work 👍
Activity
alalek commentedon Jan 15, 2016
The first "expected" hash should be always same (for specific OpenCV code version).
The second "actual" hash is a signature of received data. And this received data is just broken due some reasons (firewall policy restrictions / other network problems / other software problems, like legacy CMake (2.8.7+ works fine) ): you may try to open file in "mc" editor and check it, sometimes there are messages like "403 forbidden", "timeout", "connection lost".
There are some discussion for the similar problem here (but about ffmpeg): #5546 #5895
So there are two options:
-DWITH_IPP=OFF)paul-mesnilgrente commentedon Jan 16, 2016
Thank you very much, I have downloaded the file and place it in the directory and the compilation has worked !
I tried on my laptop which is on ubuntu 15.10 in my university (not on my local network I mean), and it worked without to do this. I don't know if the network is has an influence...
vojdan commentedon Jul 24, 2016
I re-ran the command and (for some strange reason) it continued
smartcai commentedon Dec 28, 2016
You can download the file"ippicv_linux_20141027.tgz" from the website
https://sourceforge.net/projects/opencvlibrary/files/3rdparty/ippicv/
then, you can copy it and replace the old one.
tttor commentedon Jan 20, 2017
Put the ippicv_linux...tgz under
<...>/opencv-3.2.0/3rdparty/ippicv/downloads/linux-808b791a6eac9ed78d32a7666804320e/
exophoric commentedon Jan 28, 2017
This error could also mean that your CMake is not built with OpenSSL support. (It cannot resolve HTTPS addresses without the OpenSSL).
To fix this, rebuild CMake from source, but before doing so make sure to install the openssl-devel package of your distribution.
If you get hash d41d8cd98f00b204e9800998ecf8427e (which is the md5 for an empty file), that should be the problem you are facing. Unless you have internet connectivity issues.
achaiah commentedon Feb 7, 2017
Actually, this is still a big problem as the precompiled version of ippicv_linux is built for 32-bit architectures. Even when you correctly include it with OpenCV the build errors out with:
Any ideas on what can be done here? Links to 64-bit ippicv?
Thanks
nguyenbc commentedon Jul 27, 2018
If you get hash d41d8cd98f00b204e9800998ecf8427e (which is the md5 for an empty file), that should be the problem you are facing. Unless you have internet connectivity issues.
... Solution for this:
open the log: CMaeDownload.txt file:
for example, my PC:
#check_md5 "D:/OpenCV/opencv/sources/.cache/ippicv/0421e642bc7ad741a2236d3ec4190bdd-ippicv_2017u3_win_intel64_general_20170822.zip"
#mismatch_md5 "D:/OpenCV/opencv/sources/.cache/ippicv/0421e642bc7ad741a2236d3ec4190bdd-ippicv_2017u3_win_intel64_general_20170822.zip" "d41d8cd98f00b204e9800998ecf8427e"
Then you will rename the downloaded file to: 0421e642bc7ad741a2236d3ec4190bdd-ippicv_2017u3_win_intel64_general_20170822.zip and save to this folder.