Port all GStreamer tutorials

[sdroege]

Code can be found here: https://cgit.freedesktop.org/gstreamer/gst-docs/tree/examples/tutorials
Text with explanations here: https://gstreamer.freedesktop.org/documentation/tutorials/index.html

Would be nice to port these to Rust

[sdroege]

Start of this can be found here: https://github.com/sdroege/gstreamer-rs/tree/master/tutorials

Write here if someone wants to work on porting a specific tutorial

[Jouan]

I can try porting basic-tutorial-2.

[sdroege]

I can try porting basic-tutorial-2.

That would be great, thanks! Let me know if you have questions

[sdroege]

basic-tutorial-2 is also done. Someone wants to do basic-tutorial-3? There's code in the examples that is almost like this already (decodebin.rs)

[sireliah]

Hey, I can try to write the third one. I'll use previous examples as a base.

[sdroege]

Thanks, that would be great :)

[sdroege]

Tutorial 3 is available here now: #38

[lovebug356]

I also tried basic-tutorial-4. The query part works, but it is not clear how to write GST_SEEK_FLAG_FLUSH | GST_SEEK_FLAG_KEY_UNIT in rust?

lovebug356@0c9d36d

[sdroege]

@lovebug356 This should work gst::SeekFlags::FLUSH | gst::SeekFlags::KEY_UNIT (if you use master, which uses bitflags 1.0. With 0.9 it was gst::SEEK_FLAG_FLUSH IIRC).

[lovebug356]

Fyi, I'm working on tutorial-6, but I'm struggling a bit with adding bindings for StaticPadTemplate (gir does not build on my system due to a problem with git2-rs).

[raytiley]

Figured I would comment on this issue rather than open a new one. Just looking into gstreamer, and have been wanting to a reason to learn a bit more about rust, so I figured I would check this project out.

I cloned the repo and ran cargo build inside the tutorials directory and received errors:

error: associated constants are experimental (see issue #29646)
   --> /Users/raytiley/.cargo/registry/src/github.com-1ecc6299db9ec823/bitflags-1.0.0/src/lib.rs:441:17
    |
441 |                 pub const $Flag: $BitFlags = $BitFlags { bits: $value };
    |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    | 
   ::: /Users/raytiley/.cargo/registry/src/github.com-1ecc6299db9ec823/bitflags-1.0.0/src/example_generated.rs
    |
4   | bitflags! {
    | - in this macro invocation

Can anyone point me in the right direction? Is there a "Getting Started" for these tutorials somewhere?

Thanks for any guidance.

[raytiley]

Ok.. so did some googling and figured out I had an outdated version of rust. Got everything to build but running tutorial-1 panics.

🍻 RUST_BACKTRACE=1 ./basic-tutorial-1                                                                              master 08c30a0
thread 'main' panicked at 'called `Result::unwrap()` on an `Err` value: Error(Boxed { inner: ForeignOwned(0x7ffba4d146a0) })', src/libcore/result.rs:906:4
stack backtrace:
   0: std::sys::imp::backtrace::tracing::imp::unwind_backtrace
   1: std::panicking::default_hook::{{closure}}
   2: std::panicking::default_hook
   3: std::panicking::rust_panic_with_hook
   4: std::panicking::begin_panic
   5: std::panicking::begin_panic_fmt
   6: rust_begin_unwind
   7: core::panicking::panic_fmt
   8: core::result::unwrap_failed
   9: <core::result::Result<T, E>>::unwrap
  10: basic_tutorial_1::main
  11: __rust_maybe_catch_panic
  12: std::rt::lang_start
  13: main

[sdroege]

Fyi, I'm working on tutorial-6, but I'm struggling a bit with adding bindings for StaticPadTemplate (gir does not build on my system due to a problem with git2-rs).

I can add it tomorrow if that helps, should be a matter of 5 minutes and boring :) You probably don't want to fight with libgit2 just for that :)

[sdroege]

@raytiley A backtrace with line numbers would be useful (and for the other thing, you need Rust 1.20 at least because of latest bitflags). My guess is that you're missing a GStreamer plugin or your GStreamer installation is otherwise incomplete/broken (the tutorial has no error handling at all to first focus on the actual GStreamer bits).

[raytiley]

A backtrace with line numbers would be useful (and for the other thing, you need Rust 1.20 at least because of latest bitflags). My guess is that you're missing a GStreamer plugin or your GStreamer installation is otherwise incomplete/broken (the tutorial has no error handling at all to first focus on the actual GStreamer bits).

@sdroege I'll look into how to generate a more useful backtrace and confirm my gstreamer install. I'm on a mac and just used brew install gstreamer. Not sure how to verify it installed properly but I'll poke around.

[sdroege]

@raytiley You also need at least gst-plugins-base and gst-plugins-good installed. I don't know if homebrew is splitting those up into separate plugins or have them as single packages with all the plugins.

[raytiley]

You also need at least gst-plugins-base and gst-plugins-good installed. I don't know if homebrew is splitting those up into separate plugins or have them as single packages with all the plugins.

@sdroege Awesome! Thanks for helping out. I found the the other homebrew formulas.. (Also needed gst-libav for the codecs).

[sdroege]

@lovebug356 The bindings are there now, hopefully all that is needed 9206ddb . Had to be written manually unfortunately due to those types being a bit special (no constructor, no copy/ref/free/unref, etc).

[sireliah]

I wrote wrote some code before sireliah@344f4ef but I didn't have much time to finish it. Then I found you already have tutorial-3 ready here: https://github.com/sdroege/gstreamer-rs/blob/master/tutorials/src/bin/basic-tutorial-3.rs. Well, I guess that there is nothing more to do with third one?

[sdroege]

@sireliah If you have any suggestions for improving the existing tutorial, please submit a PR. I'm sure there are ways for making it nicer still :) Thanks for your effort in any case

Also it would be good if anybody working on another tutorial would write a short comment here so that people don't work on the same tutorial and duplicate work.

[sdroege]

This is now tracked at https://gitlab.freedesktop.org/gstreamer/gstreamer-rs/issues/32