Question on rpm for ffmpeg

yzhang738@hotmail.com · 11-26-2010, 04:39 PM

I have a rpm to install ffmpeg on linux, but I don't quite understand how it works. Please help me. Here is the spec for rpm:

Code:

Summary: Custom FFmpeg RPM
Name:ffmpeg
Version: 1.1.0
Release: 1
License: GPL
Group: Development/Tools
Source: ffmpeg-1.1.0.tar.gz
BuildRoot: %{_builddir}/%{name}-root
%description
Custom FFMPEG RPM.
%prep
%setup -c -q
%build
%install
cp -a ./ $RPM_BUILD_ROOT
%clean
rm -rf $RPM_BUILD_ROOT
%files
%defattr(-,root,root)
/usr/lib/libfaac.so.0
/usr/lib/libmp3lame.so.0
/usr/lib/libfaad.so.0
/usr/lib/libxvidcore.so.4
/usr/lib/libxvidcore.so.4.1
/usr/bin/ffmpeg
/usr/lib/libvorbisenc.so.2
/usr/lib/libogg.so.0
/usr/lib/libvorbis.so.0
%doc

The questions are:
1. What is and how to set the value of _builddir?
2. What is and how to set the value of $RPM_BUILD_ROOT?
3. This rpm is supposed to be built in BuildRoot, what is the value of BuildRoot?
4. How does it copy binary of ffmpeg to /usr/bin and libraries to /usr/lib?
5. What is the meaning of /usr/lib/libfaac.so.0... under %defattr(-,root,root)? Are they libraries to be built or already exist and to be linked?

Thanks.

unSpawn · 11-27-2010, 12:50 PM

Quote:

Originally Posted by yzhang738@hotmail.com

I have a rpm to install ffmpeg on linux, but I don't quite understand how it works.

If you don't then you are probably better off installing the standard software. In addition no answer will make you understand things the way you could by reading your distributions package building documentation, http://wiki.centos.org/PackageManagement/Rpm, http://fedoraproject.org/wiki/Docs/D...gPackagesGuide, http://www.rpm.org/wiki/Docs#PackagerDocumentation, rpm5.org/docs/rpm-guide.pdf and rpm5.org/docs/max-rpm.pdf.

Quote:

Originally Posted by yzhang738@hotmail.com

What is and how to set the value of _builddir?

%_builddir as set in your ~/.rpmmacros or package.spec file and shown by 'rpmbuild --showrc' (also see "%%dump").

Quote:

Originally Posted by yzhang738@hotmail.com

What is and how to set the value of $RPM_BUILD_ROOT?

%BuildRoot.

Quote:

Originally Posted by yzhang738@hotmail.com

This rpm is supposed to be built in BuildRoot, what is the value of BuildRoot?

That depends on what "%{_builddir}" expands to. One good reason to NOT build packages as root account user.

Quote:

Originally Posted by yzhang738@hotmail.com

How does it copy binary of ffmpeg to /usr/bin and libraries to /usr/lib?

See the %install section. This package simply runs 'cp -a ./ $RPM_BUILD_ROOT' (while ffmpeg comes with a 'make' script that has an "install" target).

Quote:

Originally Posted by yzhang738@hotmail.com

What is the meaning of /usr/lib/libfaac.so.0... under %defattr(-,root,root)? Are they libraries to be built or already exist and to be linked?

The %files section lists files (to be) installed that belong to this package. This .specs %files section lists libraries that on a sane system belong to several other packages, meaning problems with dependency resolution, updating, de-installation, RPMDB corruption and whatnot may all be yours for free if you install this package. (Saying the person who wrote this spec file needs to read a few docs is an understatement.)

yzhang738@hotmail.com · 12-03-2010, 11:55 PM

My qustion is: how to create rpm for ffmpeg that builds other libraries too. For example, we need to build libfaac, libxvidcore, libx264, libogg, libvorbis and etc. How to build these libraries along with ffmpeg because ffmpeg need them to run?

yzhang738@hotmail.com · 12-04-2010, 03:06 AM

If x264, lame, ogg, ... are installed through separate rpm, how in rpm to install ffmpeg know if they are installed already?

unSpawn · 12-04-2010, 04:23 AM

Quote:

Originally Posted by yzhang738@hotmail.com

If x264, lame, ogg, ... are installed through separate rpm, how in rpm to install ffmpeg know if they are installed already?

By the %requires tag. BTW did you read any of the docs I linked to?

yzhang738@hotmail.com · 12-04-2010, 03:28 PM

Yes, I have read the pdf file about rpm that is the best I've seen. Many thanks unSpawn. My understanding is that separate rpm to install x264, ogg, vorbis, ... should be created and put to ffmpeg.spec as:

Code:

%require x264-.rpm
%require ogg-.rpm
...

So ffmpeg rpm is dependent on other rpms, right?

My question is:
1. If x264-.rpm is not installed, can it detect in ffmpeg rpm?
2. In order to install ffmpeg.rpm, other rpms must be installed separately. Is it possible to create a single rpm to install everything?
3. Can multiple rpms be installed at same time, eg rpm -i x264-rpm ogg-rpm...?