Taglib Library

[jsulm]

@lucas_1603 Did you build the lib by yourself?
If you downloaded it: from where and which compiler was used to build it?

[Lucas_1603]

@jsulm I downloaded taglib from taglib.org and used cmake to build it. After successfully built, I got a .dll and a .dll.a file. What I have to do next to link taglib to my project? I'm new in Qt so guide me step-by-step, please.
Thanks a lot

[jsulm]

@lucas_1603 There should be a .lib file as well as @raven-worx said.
Also, the way you use LIBS in pro file is wrong: remove .dll from file name (again, like @raven-worx suggested). When adding libs using -l the "lib" prefix and file extension (.lib, .so, ...) must be removed. Example: if lib is called libfoo.lib you add "-lfoo" to your pro file.

[Lucas_1603]

@jsulm I actually cannot find any .lib files. I built taglib following the guidelines of this tutorial. After building process completed, it just generated 2 files more, one is .dll and the other is .dll.a as I said before. I don't know whether I built taglib right or wrong, or there were something I don't well aware of :((

[jsulm]

@lucas_1603 Then fix LIBS in your pro file as described before and try again.

[Lucas_1603]

@jsulm I tried to fix it to LIBS += -L$$PWD/taglib -ltag as you suggested but it raised "cannot find -ltag" error!

[jsulm]

@lucas_1603 What is the exact file name of the lib?
Also, $$PWD/taglib is a relative path - are you sure it is correct (you can check the linker output to see what exactly is passed to -L.

[Lucas_1603]

@jsulm I would like to describe more details for you to understand my problems clearly

---

This is exactly what I have tried :

After downloading taglib (version 1.11.1) from taglib.org, I built it with cmake and got a .dll and a .dll.a file. Then I brought taglib folder to where my Qt project folder is in and named it 'myTaglib' as this picture

When I go to 'myTaglib' folder, I'll get these items

Now jumping into .pro file, I tried to link to taglib:

QT += quick multimedia core
CONFIG += c++11
INCLUDEPATH += $$PWD/myTaglib
DEPENDPATH += $$PWD/myTaglib
LIBS += -L$$PWD/myTaglib -ltag

And in header file, I included necessary files and using namespace TagLib like this:

#include <tag.h>
#include <fileref.h>
#include <mpeg/id3v2/id3v2tag.h>
#include <mpeg/mpegfile.h>
#include <mpeg/id3v2/id3v2frame.h>
#include <mpeg/id3v2/id3v2header.h>
#include <mpeg/id3v2/frames/attachedpictureframe.h>
using namespace TagLib;

After all, I built my project and got some errors:

...
undefined reference to `__imp__ZN6TagLib8FileNameC1EPKc' in player.cpp - line 94
undefined reference to `__imp__ZN6TagLib7FileRefC1ENS_8FileNameEbNS_15AudioProperties9ReadStyleE' in player.cpp - line 94
undefined reference to `__imp__ZNK6TagLib7FileRef3tagEv' in player.cpp - line 95
undefined reference to `__imp__ZNK6TagLib6String10toCWStringEv' in player.cpp - line 97
undefined reference to `__imp__ZNK6TagLib6String10toCWStringEv' in player.cpp - line 96
...

Then, I checked these lines but it didn't show something like underlined error or red text or something like that, you can see this picture

[jsulm]

@lucas_1603 Can you show the linker call? Either it can't find the lib or the lib is not compatible.

[Lucas_1603]

@jsulm You mean this one (sorry if I misunderstood what you mean):

[jsulm]

@lucas_1603 Yes, your taglib is not compatible with the compiler you're using.
Do you really use exact same compiler you used to compile taglib?

[Lucas_1603]

@jsulm I built taglib with MinGW and in this project I think it also built with MinGW

[jsulm]

@lucas_1603 I'm not a Windows expert, but I think you really need .lib file on Windows at build time, not .dll

[Lucas_1603]

@jsulm Yes, I'll try to find it out. Anw, thank you so much for your time, you helped me a lot

[SGaist]

Hi,

One other thing that you can try is to link directly to the static .a library. Use the full path to that file using $$PWD.

[raven-worx]

@lucas_1603
rename taglib.dll.a to taglib.a

Also read this

[Lucas_1603]

@sgaist I tried this:

LIBS += -L$$PWD/myTaglib -llibtag.dll.a

But the linker said "cannot find -llibtag.dll.a"

[SGaist]

As already suggested, try with LIBS += -l$$PWD/myTagLib/libtag.dll.a

[Lucas_1603]

@raven-worx
After rename, I got these:

And in .pro file, I wrote:

INCLUDEPATH += $$PWD/myTaglib
DEPENDPATH += $$PWD/myTaglib
LIBS += -L$$PWD/myTaglib -ltag

But I still got some errors:

[raven-worx]

@lucas_1603 said in Taglib Library:

But I still got some errors:

your problem is not that it can't find the lib but that it finds it already and says it is incompatible.
So you need to change the compiler in either of your 2 compilations.