The VideoLAN Forums

Posted: **15 Mar 2019 07:51**

Hello,

I'm using VLCKit in MacOS to play some audio streams and now I'm looking for a way to meter the audio. Is it possible to add the AudioBarGraph filter? This is what I'm trying in Swift:

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        var outputPlayer: VLCMediaPlayer = VLCMediaPlayer()
        let videoURL = URL(string: theURL)
        let media = VLCMedia(url: videoURL!)
        media.addOptions([AnyHashable("--audio-filter=audiobargraph_a") : NSNull()])
        media.addOptions([AnyHashable("--audiobargraph_a-bargraph=1") : NSNull()])
        media.addOptions([AnyHashable("--sub-source=audiobargraph_v") : NSNull()])
        outputPlayer.media = media
        outputPlayer.delegate = self
        outputPlayer.drawable = self.OutputPlayerView
        outputPlayer.play()

The player plays the stream from the URL, but I don't see an audiobargraph showing. Am I adding the options incorrectly or is this a feature that is not implemented in VLCkit?

Thanks,

Streamin'

Posted: **16 Mar 2019 19:09**

Look at the logs. But I don't think you should pas the Options with --

Posted: **17 Mar 2019 00:09**

Thanks for getting back to me on this. I don't see anything in the logs about these options. I've gotten rid of the "--" with the same result. I had high hopes for doing it this way:

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        var outputPlayer: VLCMediaPlayer = VLCMediaPlayer()
        let videoURL = URL(string: theURL)
        let media = VLCMedia(url: videoURL!)
        media.addOptions([AnyHashable("audio-filter") : "audiobargraph_a"])
        media.addOptions([AnyHashable("audiobargraph_a-bargraph") : 1])
        media.addOptions([AnyHashable("sub-source") : "audiobargraph_v"])
        outputPlayer.media = media
        outputPlayer.delegate = self
        outputPlayer.drawable = self.OutputPlayerView
        outputPlayer.play()

but I still get the video with no audio bar graph showing up. Any ideas?

Posted: **17 Mar 2019 11:55**

Use

Code: Select all

:

instead of

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--

Posted: **17 Mar 2019 21:11**

You mean like this:

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media.addOptions([AnyHashable(":audio-filter=audiobargraph_a") : NSNull()])
media.addOptions([AnyHashable(":audiobargraph_a-bargraph=1") : NSNull()])
media.addOptions([AnyHashable(":sub-source=audiobargraph_v") : NSNull()])

or like this:

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media.addOptions([AnyHashable(":audio-filter") : "audiobargraph_a"])
media.addOptions([AnyHashable(":audiobargraph_a-bargraph") : 1])
media.addOptions([AnyHashable(":sub-source") : "audiobargraph_v"])

Just tried both ways. Still no bar graph.

Posted: **17 Mar 2019 22:45**

Just tried doing it this way:

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let myPlayerOptions = ["audio-filter=audiobargraph_a","audiobargraph_a-bargraph=1","sub-source=audiobargraph_v"]
outputPlayer = VLCMediaPlayer.init(options: myPlayerOptions)

Still no bar graph. Interestingly... if I do it this way:

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let myPlayerOptions = ["--audio-filter=audiobargraph_a","--audiobargraph_a-bargraph=1","--sub-source=audiobargraph_v"]
outputPlayer = VLCMediaPlayer.init(options: myPlayerOptions)

I end up getting a crash with this in the logs:

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vlc: unknown option or missing mandatory argument `--audiobargraph_a-bargraph=1'

While all other methods of supplying those options that I've tried go seemingly unnoticed, this method has gotten some attention and made a crash. Even more interesting is that it is the second parameter that is causing grief. Does that mean that the first parameter was accepted? Strange.

Posted: **18 Mar 2019 19:55**

Did you recompile VLCKit?

Posted: **18 Mar 2019 21:21**

Hmm... I'm not sure, actually. I added the framework to my Xcode project using a POD file. When I built my app for the first time, I'm not sure if it compiled VLCKit or just used a pre-compiled framework. I suspect that it was pre-compiled and I've never recompiled it. Are there changes that I need to make to the framework itself?

Posted: **20 Mar 2019 08:17**

Maybe, and that is hard.

Posted: **20 Mar 2019 10:06**

I don't know VLCKit, but for your "unknown or missing mandatory argument --audiobargraph_a-bargraph=1" error, you could try passing "--audiobargraph_a-bargraph" and "1" as separate options.

However...

I was just testing this In my own bindings and I can get an empty audio bar-graph to appear, but it does not receive data to render the levels.

I think I remember reading somewhere on these forums or in the Trac, that things like audio filters don't (can't?) work this way through LibVLC. IIRC someone wanted to use the audio compressor module and it was stated that it wouldn't work.

And then there's the usual caveat of using these options/arguments/switches via libvlc_new is not supported anyway.

I just found the related post here https://forum.videolan.org/viewtopic.php?t=143056.

So maybe you're stuck.

Posted: **20 Mar 2019 17:39**

Ok, thank guys. I'm going to pull this feature from my app requirements for the time being. I went into this thinking that it might be an easy, supported option to just turn on and this does not appear to be the case. I'll keep checking in on VLCKit development from time to time and if things change, I'll add this feature into my app.

Thanks again for the help and guidance.

Posted: **21 Mar 2019 19:40**

You should open a bug, though, on VLCKit repo.

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