[uwp] audio graph with 2 media files, the second starts later

John Torjo 861

Hi,

I'd like to create an audio graph to play on the default sound card. It has 2 media (.mp3) files.
The first one has 2 minutes, while the second one has 10 seconds.

I want to play the first media for 25 seconds, then play the second media along with first media (10 seconds), then continue with first media only.
There are some audio effects that I will apply to each , but I will be able to manage that.

How do I do the above? Thanks!

Richard Zhang-MSFT 6,936 Reputation points

2020-04-28T03:13:26.73+00:00

Hi, In AudioGraph, there is AudioSubmixNode to provide a mix of two audio files, here is an example. Considering your situation, you can create a DispatcherTimer, stop short audio when the audioGraph starts playing, and start timing, then play the short audio at 25s.
John Torjo 861 Reputation points

2020-04-28T07:25:16.25+00:00

Thanks! I'll play with it in a bit, and see if that works.
Richard Zhang-MSFT 6,936 Reputation points

2020-04-29T01:55:41.73+00:00

Hello, is this solution work for you?
John Torjo 861 Reputation points

2020-04-29T11:15:59.79+00:00

Well, it's far from ideal, but I'll try it as a start. My plan is to work on it next week, since this will be part of a much bigger module.

I was hoping for a .Position of the audio graph, which would then tell me where I am in the whole mix, and then that would work even when saving my mix to an audio file.
Or, an audio effect that would generate basically "silence" for 25 seconds, then play my media, then generate "silence" again.
Richard Zhang-MSFT 6,936 Reputation points

2020-04-30T02:06:16.213+00:00

Mixing two kinds of audio like this, maybe consider using MediaClip, you can control multiple audio tracks, or you can delay one of the audio tracks. For more information, please refer to this [document](https://learn.microsoft.com/en-us/windows/uwp/audio-video-camera/media-compositions-and-editing#add-a-background- audio-track-to-a-composition)
John Torjo 861 Reputation points

2020-05-01T08:29:09.767+00:00

Thanks. Yeah, that sounds doable. I was hoping I could avoid doing that, but I'll take a stab at it.
I'm just hoping it's fast and reliable enough, since it needs to be playing in parallel with a win2d video (created by me, realtime) playing.

I will test all the above and see which can fit my app's needs. Will report back here - I suspect 2 weeks or so from now.
This is basically my next task, after I finish my current one (which I hope to be next Wed :))
Richard Zhang-MSFT 6,936 Reputation points

2020-05-04T01:03:41.127+00:00

Ok, I look forward to your test results. If you find a solution after the test, you can post it as an answer, which will help more people with the same problem.