Mediaplayer SDK, Avalonia - Unable to play Karaoke CDG & zip files

thanks, I'll add the package and give it a try.

I've looked at that sample, It appears to be for winforms, I'm using Avalonia?

Just added the package, restarted the project and I'm still getting the same errors.

No, the WinForms Karaoke demo worked without issue.

Hi Roman,
Thanks for the demo, It works fine in Windows, however it cannot play Karaoke files running on Linux. I've yet to try it on macOs yet as I haven't had time.

I get the following debug data when trying to play the files:

[MediaBlocksPipeline[MediaPlayerCoreX]][DisposeAsync] Starting async disposal...
[MediaBlocksPipeline[MediaPlayerCoreX]][Dispose] Pipeline graph saved to pipeline_dispose_20260122_122312.dot
[MediaBlocksPipeline[MediaPlayerCoreX]][Dispose] Starting managed resource cleanup...
[MediaBlocksPipeline[MediaPlayerCoreX]][Dispose] Video view cleared.
[MediaBlocksPipeline[MediaPlayerCoreX]][Dispose] Media blocks cleaned up and collections cleared.
[12:23:12 INF] [SafeElementLinker][CleanupManagedCapsFilters] Cleaned up 0 managed capsfilters
[MediaBlocksPipeline[MediaPlayerCoreX]][Dispose] SafeElementLinker capsfilters cleaned up.
[MediaBlocksPipeline[MediaPlayerCoreX]][Dispose] Pipeline NULL state achieved: Null
[MediaBlocksPipeline[MediaPlayerCoreX]][Dispose] Bus disposed after pipeline NULL state.
[MediaBlocksPipeline[MediaPlayerCoreX]][Dispose] Pipeline context disposed.
[MediaBlocksPipeline[MediaPlayerCoreX]][Dispose] Callback delegates cleared.
[MediaBlocksPipeline[MediaPlayerCoreX]][Dispose] Event handlers cleared.
[MediaBlocksPipeline[MediaPlayerCoreX]][Dispose] Managed resource cleanup completed.
[MediaBlocksPipeline[MediaPlayerCoreX]][Dispose] Dispose completed successfully.
[MediaBlocksPipeline[MediaPlayerCoreX]][DisposeAsync] Async disposal completed.
[12:23:12 INF] [MediaPlayerCoreX][CreatePipeline] CreatePipeline
[MediaBlocksPipeline[MediaPlayerCoreX]][Constructor] Creating new MediaBlocksPipeline: MediaPlayerCoreX
[MediaBlocksPipeline[MediaPlayerCoreX]][AddBlock] Successfully added block 'Queue' to pipeline.
[MediaBlocksPipeline[MediaPlayerCoreX]][AddBlock] Successfully added block 'CDGSource' to pipeline.
[MediaBlocksPipeline[MediaPlayerCoreX]][Connect] Successfully connected CDGSource.[CDGSourceBlock] Out Audio to Queue.[QueueBlock] In Auto
[MediaBlocksPipeline[MediaPlayerCoreX]][AddBlock] Successfully added block 'AudioEffects' to pipeline.
[MediaBlocksPipeline[MediaPlayerCoreX]][Connect] Successfully connected Queue.[QueueBlock] Out Auto to AudioEffects.[AudioEffectsBlock] In Audio
[MediaBlocksPipeline[MediaPlayerCoreX]][AddBlock] Successfully added block 'AudioRenderer' to pipeline.
[MediaBlocksPipeline[MediaPlayerCoreX]][Connect] Successfully connected AudioEffects.[AudioEffectsBlock] Out Audio to AudioRenderer.[AudioRendererBlock] In Audio
[MediaBlocksPipeline[MediaPlayerCoreX]][AddBlock] Successfully added block 'Queue' to pipeline.
[MediaBlocksPipeline[MediaPlayerCoreX]][Connect] Successfully connected CDGSource.[CDGSourceBlock] Out Video to Queue.[QueueBlock] In Auto
[MediaBlocksPipeline[MediaPlayerCoreX]][AddBlock] Successfully added block 'OverlayManager' to pipeline.
[MediaBlocksPipeline[MediaPlayerCoreX]][Connect] Successfully connected Queue.[QueueBlock] Out Auto to OverlayManager.[OverlayManagerBlock] In Video
[MediaBlocksPipeline[MediaPlayerCoreX]][AddBlock] Successfully added block 'VideoEffects' to pipeline.
[MediaBlocksPipeline[MediaPlayerCoreX]][Connect] Successfully connected OverlayManager.[OverlayManagerBlock] Out Video to VideoEffects.[VideoEffectsBlock] In Video
[MediaBlocksPipeline[MediaPlayerCoreX]][AddBlock] Successfully added block 'VideoRenderer' to pipeline.
[MediaBlocksPipeline[MediaPlayerCoreX]][Connect] Successfully connected VideoEffects.[VideoEffectsBlock] Out Video to VideoRenderer.[VideoRendererBlock] In Video
[12:23:12 INF] [MediaPlayerCoreX][Play] Using async API.
[MediaBlocksPipeline[MediaPlayerCoreX]][CreatePipeline] Building 8 media blocks...
[12:23:12 ERR] [CDGSource][Init] Unable to create cdgparse.
[12:23:12 ERR] [CDGSourceBlock][Build] Unable to build CDGSourceBlock.
[12:23:12 ERR] [MediaBlocksPipeline[MediaPlayerCoreX]][CreatePipeline] Failed to build block 'CDGSource'.
[12:23:12 ERR] [MediaBlocksPipeline[MediaPlayerCoreX]][Open] Unable to create some pipeline elements.

Alan

I've read and installed everything from the guide before I started...

The "gst-inspect-1.0 --version" command returns:
gst-inspect-1.0 version 1.24.2
GStreamer 1.24.2


attached is a screen grab of the installed packages.

It's Mint 22, so yes.

Thank you, the update is working on Linux now.

Hi Roman,
I have most of what I need working, however I cannot get the audio effects to work and I’ve tried on both Linux and Windows, for example following does nothing:

var effect = new KaraokeAudioEffect();
effect.FilterBand = 220;
effect.FilterWidth = 100;
_player.Audio_Effects_AddOrUpdate(effect);

Also I cannot get the pitch control working for (non-CDG) audio and video, however it works for .cdg files.
I’m using the following to set the pitch on audio & video files:

private PitchShiftAudioEffect _pitch;
.....
_pitch = new PitchShiftAudioEffect(0);

then

..... else if (_cdg == false)
{
var semitones = (int)tbPitch.Value;
_pitch.Pitch = semitones;
_player.Audio_Effects_AddOrUpdate(_pitch);
}

I’m probably doing something wrong and I have one other thing I’m probably going to need some assistance with, however one step at a time!!

Thanks again.

Alan

Thank you, I have checked.....
The Karaoke effect now works, however the pitch still isn't working for straight audio and video files.

/// <summary>
/// The current CDG source settings.
/// </summary>
private CDGSourceSettings _currentSettings;

/// <summary>
/// Pitch shift for non-CDG Files
/// </summary>
private PitchShiftAudioEffect _pitch;


private async void MainWindow_Activated(object sender, EventArgs e)
{
.....
.....

/// <summary>
///create and initialize a new instance of _pitch
/// </summary>
_pitch = new PitchShiftAudioEffect(0);

.....
}


/// <summary>
/// Handles the pitch slider scroll.
/// </summary>
private void tbPitch_Scroll()
{
if (lbPitch == null || tbPitch == null || _player == null)
{
return;
}

var semitones = (int)tbPitch.Value;
lbPitch.Text = $"Pitch: {semitones:+#;-#;0}";

// Change pitch during playback
if (_currentSettings != null && _cdg == true)
{
_currentSettings.PitchSemitones = semitones;
}
else if (_cdg == false)
{
_pitch.Pitch = semitones;
_player.Audio_Effects_AddOrUpdate(_pitch);
}
}

Thank you, that works.

I have one final question....
Some CD+G audio file are multiplexed (dual mono), for example they will have music only on the left hand channel of the source track and Music plus vocals on the right, (the left and right may be the other way around), so my question is:

Is it possible to take either the left or right audio from the source and feed it to both left and right audio outputs?

Ideally it would be good to be able to pan from the left to the right of the source audio so the user can adjust the level of vocal in the mix, however if this is not possible switching between the source left, right and stereo would suffice.

Thank you, It may be a week or two, but basically yes.... I'm working on a potential new product, It isn't actually a traditional Karaoke application, but needs to be able to play Karaoke files.

Roman, if you need a multiplexed MP3+G file let me know and I'll send you over one.

Regards

Alan.

see attached

The zip won't attach so I've emailed the file to you, if you don't get it (it may be to large for email) let me know and I'll put if on my ftp for you to download.

Thank you, Tested... works very well.

Hi Roman,
Sorry to be a pain, I've just found an issue, the rate/speed control is only working with video files, It doesn't do anything with audio files (MP3 Flac etc.) and Karaoke files (MP3+G / Zip) it stops the audio playback. it works fine with video files (mp4 etc).
Currently I have only checked on Linux so don't know the situation with widows or Mac.

Using the code below, its straight from the media player demo:

private async void tbSpeed_Scroll()
{
if (_player == null)
{
return;
}

await _player.Rate_SetAsync(1 + (tbSpeed.Value / 100.0));
}