New, also help on dealing with multiple audio streams using gstreamer-rs

[Michael Johnson]

Ahhh I think I see, so then how do you go about emitting that signal
without using it from playbin for these action signals

On Thu, 17 Dec 2020, 14:04 Michael Johnson, <liquidmikerrs at gmail.com> wrote:

> Regardless, if you want to press a button to change audio stream surely
> you emit when the button is pressed, which then causes the callback to run
>
> Without that it only emits on startup and close. And that's not helpful
>
> Thank you for all your help so far, it's been highly appreciated
>
> On Thu, 17 Dec 2020, 13:50 Michael Johnson, <liquidmikerrs at gmail.com>
> wrote:
>
>> Oh wait I see what you mean about the first point. My eyes can't see a
>> minus sign apparently :P
>>
>>
>>
>> On Thu, 17 Dec 2020, 13:49 Michael Johnson, <liquidmikerrs at gmail.com>
>> wrote:
>>
>>> All those warnings are related to not handling the None type, I didn't
>>> think that would have any bearing.
>>>
>>> Wait. You're not supposed to use emit? Then why does it exist? Surely
>>> you emit a signal to then be caught by the connect. By the logic of setting
>>> the value of 2 every them then current audio should go -1,-1,2 not
>>> -1,-1,-1. It yields 2 on exit. Which was my point
>>>
>>> What is the alternative to using emit then, and why does the alternative
>>> still relate to connect?
>>>
>>> On Thu, 17 Dec 2020, 13:36 Sebastian Dröge, <sebastian at centricular.com>
>>> wrote:
>>>
>>>> On Thu, 2020-12-17 at 12:28 +0000, Michael Johnson wrote:
>>>>
>>>> As requested a toy example,
>>>> Here we see that the audio-changed emit never activates the connect,
>>>> maybe because it emits before the video has began playing?
>>>>
>>>> I'm probably doing something very wrong
>>>>
>>>>
>>>> Yeah, you're ignoring compiler warnings here that tell you that you're
>>>> ignoring potential errors :)
>>>>
>>>> Make sure to at least `unwrap()` `Result`s instead of ignoring them,
>>>> then you immediately know if you did something wrong there.
>>>> In this case the emitting of the "audio-changed" signal fails because
>>>> of the wrong number of arguments.
>>>>
>>>> But that also doesn't matter here: that signal is supposed to be
>>>> emitted by playbin whenever something changes, not by you.
>>>>
>>>> After removing that line what I get is
>>>>
>>>> current audio track is -1
>>>> number of audio tracks is 1
>>>> current audio track is -1
>>>> number of audio tracks is 2
>>>> current audio track is -1
>>>> number of audio tracks is 3
>>>>
>>>> That looks as expected. Every signal emission you're setting the
>>>> current audio track to 2, but only the last time there actually is a 3rd
>>>> (0, 1, 2) audio track available.
>>>> So in the end it should use the 3rd audio track.
>>>>
>>>> If you change it for example to set it to 1 then you'll see that during
>>>> the last signal emission the current audio track is 1.
>>>>
>>>>
>>>> For getting state into the signal handler closure, take a look at the
>>>> overlay-composition.rs example and what it does with the
>>>> DrawingContext inside the Arc<Mutex<_>> there.
>>>>
>>>> --
>>>>
>>>> Sebastian Dröge, Centricular Ltd · https://www.centricular.com
>>>> <http://www.centricular.com>
>>>>
>>>> _______________________________________________
>>>> gstreamer-devel mailing list
>>>> gstreamer-devel at lists.freedesktop.org
>>>> https://lists.freedesktop.org/mailman/listinfo/gstreamer-devel
>>>>
>>>
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