Introducing gst-conan

Thu Oct 4 15:25:02 UTC 2018

Oops ... In the prior email, I was talking about "ldconfig" where I meant
to say "make install && ldconfig".

Just to elaborate on this some more:  I have some example projects which
consume gst-editing-services.  In order to run the executable build output,
I need to use a script which defines a few environment variables.  The
script file is automatically generated by gst-conan:

#!/bin/bash

thisFolder="$( cd "$( dirname "${BASH_SOURCE[0]}" )" >/dev/null && pwd )"

export GST_PLUGIN_PATH=/home/ding/.conan/data/gst-editing-services/1.14.3/my_conan_user/my_conan_channel/package/fca34e783d0d7fe020f0afd08ea6cec145c5e7f8/plugins:/home/ding/.conan/data/gst-plugins-good/1.14.3/my_conan_user/my_conan_channel/package/fca34e783d0d7fe020f0afd08ea6cec145c5e7f8/plugins:/home/ding/.conan/data/gst-plugins-bad/1.14.3/my_conan_user/my_conan_channel/package/fca34e783d0d7fe020f0afd08ea6cec145c5e7f8/plugins:/home/ding/.conan/data/gst-plugins-ugly/1.14.3/my_conan_user/my_conan_channel/package/fca34e783d0d7fe020f0afd08ea6cec145c5e7f8/plugins:/home/ding/.conan/data/gst-libav/1.14.3/my_conan_user/my_conan_channel/package/fca34e783d0d7fe020f0afd08ea6cec145c5e7f8/plugins:/home/ding/.conan/data/gst-plugins-base/1.14.3/my_conan_user/my_conan_channel/package/1010277bd962c74fe8b33f2280b3c0af94266416/plugins:/home/ding/.conan/data/gstreamer/1.14.3/my_conan_user/my_conan_channel/package/69f10d1e6d78c1962fbe8fb80440f32b1fdf8423/plugins
export GST_PLUGIN_SCANNER=/home/ding/.conan/data/gstreamer/1.14.3/my_conan_user/my_conan_channel/package/69f10d1e6d78c1962fbe8fb80440f32b1fdf8423/bin/gst-plugin-scanner
export LD_LIBRARY_PATH=/home/ding/.conan/data/gst-editing-services/1.14.3/my_conan_user/my_conan_channel/package/fca34e783d0d7fe020f0afd08ea6cec145c5e7f8/lib:/home/ding/.conan/data/gst-plugins-good/1.14.3/my_conan_user/my_conan_channel/package/fca34e783d0d7fe020f0afd08ea6cec145c5e7f8/lib:/home/ding/.conan/data/gst-plugins-bad/1.14.3/my_conan_user/my_conan_channel/package/fca34e783d0d7fe020f0afd08ea6cec145c5e7f8/lib:/home/ding/.conan/data/gst-plugins-ugly/1.14.3/my_conan_user/my_conan_channel/package/fca34e783d0d7fe020f0afd08ea6cec145c5e7f8/lib:/home/ding/.conan/data/gst-libav/1.14.3/my_conan_user/my_conan_channel/package/fca34e783d0d7fe020f0afd08ea6cec145c5e7f8/lib:/home/ding/.conan/data/gst-plugins-base/1.14.3/my_conan_user/my_conan_channel/package/1010277bd962c74fe8b33f2280b3c0af94266416/lib:/home/ding/.conan/data/gstreamer/1.14.3/my_conan_user/my_conan_channel/package/69f10d1e6d78c1962fbe8fb80440f32b1fdf8423/lib:$LD_LIBRARY_PATH

exec $thisFolder/consume-ges "$@"

On Wed, Oct 3, 2018 at 4:50 PM David Ing <ding at panopto.com> wrote:

> By the way, I am planning to record a video tutorial of Conan and
> gst-conan ... but we are a couple months away from that.  For now, I'll
> give you my long-winded analysis:
>
> I think Cerbero uses AutoTools and perhaps ldconfig, whereas gst-conan and
> gst-build both both use Meson.
>
> Cerbero is better than Gst-Conan in many important ways.
>
>    - Cerbero can build for Windows and Mac (Gst-Conan is Linux only ...
>    for now ... although Conan works on any platform)
>    - Cerbero can do cross-compilation (Gst-Conan might be able to do this
>    ... with some coaxing ... I'm not sure right now)
>    - Cerbero can produce debian and rpm packages (Gst-Conan has a roadmap
>    ... we might produce `snap` packages if we get around to it ... distant
>    future)
>
> But, gst-conan is special because it uses Conan to organize packages on
> any machine.  Conan behaves a bit like `ldconfig` in that sense, but Conan
> is more sophisticated (in my opinion).  For example, when I created the
> "gstreamer" package, I gave Conan a whole bunch of options which identify
> that package.
>
> name = gstreamer
>
> version = 1.14.3
>
> user = my_conan_user
>
> channel = my_conan_channel
>
> os = linux
>
> arch = x86_64
>
> build_type = Debug
>
> compiler = gcc
>
> ... (you can define as many options as you want)
>
>
> Conan stores the package on my system in a very specific location (where
> the first 4 options are explicitly part of the package path, and the
> remaining options are hashed):
>
>
> ~/.conan/data/gstreamer/1.14.3/my_conan_user/my_conan_channel/package/69f10d1e6d78c1962fbe8fb80440f32b1fdf8423
>
> Now that Conan has built the "gstreamer" package and installed it onto my
> system, I can simply reference the package from another project using the
> same identifying information (as given above).  I can even change one of
> the options (e.g. `compiler = clang`) and Conan will try to build the
> package from a recipe that it stored with the package.  My original recipe
> was here:
> https://github.com/Panopto/gst-conan/blob/master/packages/gstreamer/conanfile.py
>
> But Conan remembers the recipe in a specific location ...
>
>
> ~/.conan/data/gstreamer/1.14.3/my_conan_user/my_conan_channel/export/conanfile.py
>
>
> ... and so it can try to rebuild the package using different options.
>
> There are also common conan packages (e.g. zlib, openssl, boost, poco,
> ffmpeg, etc ...) that people have built packages for already.  Conan will
> automatically search https://bintray.com/ for those recipes so you don't
> even need to worry about building them yourself.
>
> Now I can create my own project (or Meson, AutoTools, whatever) and Conan
> will expose the dependencies into that build system.
>
>    - cmake example:
>    https://github.com/Panopto/gst-conan/tree/master/examples/consume-ges-cmake
>    - meson example:
>    https://github.com/Panopto/gst-conan/tree/master/examples/consume-ges-meson
>
> If you look at the "conanfile.py" in each example, you will notice that it
> contains this:
>
> # This is how we declare our dependencies to Conan.  GES will come with transitive dependencies.
> # We also need to handle the pkg_config_paths in the `build(self)` method.
> requires = ( f"gst-editing-services/{GST_CONAN_VERSION}@{GST_CONAN_USER}/{GST_CONAN_CHANNEL}",
>                  f"gst-plugins-good/{GST_CONAN_VERSION}@{GST_CONAN_USER}/{GST_CONAN_CHANNEL}",
>                   f"gst-plugins-bad/{GST_CONAN_VERSION}@{GST_CONAN_USER}/{GST_CONAN_CHANNEL}",
>                  f"gst-plugins-ugly/{GST_CONAN_VERSION}@{GST_CONAN_USER}/{GST_CONAN_CHANNEL}",
>                         f"gst-libav/{GST_CONAN_VERSION}@{GST_CONAN_USER}/{GST_CONAN_CHANNEL}")
>
> Unlike with ldconfig, Conan is suported by https://bintray.com/ ... so
> packages can be easily fetched from the internet as needed.  (This is
> similar to Maven and NuGet.)  This makes it easy to integrate with other
> packages (e.g. zlib, boost, etc.).  Although Cerbero does a beautiful job
> of defining recipes (allowing 1-off patches and everything), it doesn't
> have the support of bintray, and it doesn't offer the same elegant model
> for package management (as described above).
>
> I would love to see the Cerbero folks take an interest in Conan.  I am
> happy to help in any way I can.
>
> On Wed, Oct 3, 2018 at 3:42 PM Nicolas Dufresne <nicolas at ndufresne.ca>
> wrote:
>
>>
>>
>> Le mer. 3 oct. 2018 17 h 57, David Ing <ding at panopto.com> a écrit :
>>
>>> Gstreamer Community,
>>>
>>> I am pleased to present you with a new open-source project:
>>>
>>> https://github.com/Panopto/gst-conan
>>>
>>>
>>> It is basically a set of Python scripts for creating Conan packages for
>>> Gstreamer.
>>>
>>> If you have never heard of Conan before, I think of it as `Maven` or
>>> `pip` for native code (https://conan.io/).  We have been using Conan at
>>> my company for a couple years and we are very impressed with it.
>>>
>>
>> That seems nice. Maybe you could give a brief comparison between Conan
>> and let's say Cerbero ? Obviously it's not the same, but it does a similar
>> task.
>>
>>
>> _______________________________________________
>>> gstreamer-devel mailing list
>>> gstreamer-devel at lists.freedesktop.org
>>> https://lists.freedesktop.org/mailman/listinfo/gstreamer-devel
>>>
>> _______________________________________________
>> gstreamer-devel mailing list
>> gstreamer-devel at lists.freedesktop.org
>> https://lists.freedesktop.org/mailman/listinfo/gstreamer-devel
>>
>
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