Mixer query.

[Chris Oakley]

Where am I going wrong here?

Code Select Expand

        Bass.BASS_Init(0, 48000, BASSInit.BASS_DEVICE_DEFAULT, IntPtr.Zero)
        Dim _nosoundmixerid As Integer = BassMix.BASS_Mixer_StreamCreate(48000, 2, BASSFlag.BASS_DEFAULT) 'Create mixer.
        Bass.BASS_ChannelPlay(_nosoundmixerid, False) 'Start the mixer playing.
        Bass.BASS_Init(5, 48000, BASSInit.BASS_DEVICE_DEFAULT, IntPtr.Zero)
        Dim _submixerid As Integer = BassMix.BASS_Mixer_StreamCreate(48000, 2, BASSFlag.BASS_STREAM_DECODE) 'Create mixer.
        BassMix.BASS_Mixer_StreamAddChannel(_nosoundmixerid, _submixerid, BASSFlag.BASS_DEFAULT) 'Add submixer to no sound mixer.
        Dim _streamid As Integer = Bass.BASS_StreamCreateFile("myfile.mp3", 0, 0, BASSFlag.BASS_STREAM_DECODE)
        BassMix.BASS_Mixer_StreamAddChannel(_submixerid, _streamid, BASSFlag.BASS_DEFAULT)
        BassMix.BASS_Mixer_ChannelPlay(_streamid)

I'm trying something new and I want to make a mixer on the No Sound device which is always playing. But because it's not possible to split from a non decode mixer, I need to get creative.

You see I can't have the main mixer just outputting to the physical device, because if I want to route it somewhere else too, then I can't, because I can't split.

So I'm making a _submixerid which is a DECODE and will take all the opened streams and also allow me to split.

So I'm trying to feed this submix into the _nosoundmixerid so it can be heard.

I'm getting nothing coming out though, so something isn't correct or I'm misunderstanding how this all fits.

[Ian @ un4seen]

If you would like to also play the _nosoundmixerid stream on another device then you could achieve that with a DSP function that feeds a push stream (with the same sample format) on the other device. The DSPPROC would just call BASS_StreamPutData:

Code Select Expand

void CALLBACK CloneDSP(HDSP handle, DWORD channel, void *buffer, DWORD length, void *user)
{
    BASS_StreamPutData(pushstream, buffer, length);
}

An example of doing this can be found in the MULTI.C example included in the BASS package (see its clone option).

[Chris Oakley]

Ahhh that's fine then. I was just making sure I wasn't missing something. I have used the StreamCopy feature of Bass.Net but doing this using CloneDSP may be a better option.

[Ian @ un4seen]

In case you would prefer, I think it should also be possible to achieve what you want with splitters. You would just put a splitter between the mixer (_nosoundmixerid) and each device. For example:

Code Select Expand

// initialize "No Sound" device
BASS_Init(0, 48000, 0, 0, 0);
// create the mixer
mixer = BASS_Mixer_StreamCreate(48000, 2, BASS_STREAM_DECODE | BASS_SAMPLE_FLOAT);
// create and start a splitter
split0 = BASS_Split_StreamCreate(mixer, 0, NULL);
BASS_ChannelStart(split0);
// initialize another device and start a splitter on it
BASS_Init(5, 48000, 0, 0, 0);
split5 = BASS_Split_StreamCreate(mixer, 0, NULL);
BASS_ChannelStart(split5);

If you're pre-initializing multiple devices then use BASS_SetDevice before BASS_Split_StreamCreate to set the device for the splitter.

[Chris Oakley]

What I should have mentioned as well is the No Sound mixer is the main end destination, but I want to send its output to a physical device, because if the physical device disappears, I don't want the output to stop. It needs to keep going like nothing has happened.

[Ian @ un4seen]

Yep, the "No Sound" device's splitter would continue playing the mixer as the other device's splitters come and go.

[Chris Oakley]

Thanks again Ian and Happy New Year.

I think I may have finally solved the dilema I had which meant I've been using the StreamCopy function in BASS.Net instead of using the Splits and Mixers as directed.

So essentially for every Mixer I make which is Decode, I need to split off the mixer with a Non-Decode split going to the No Sound device. This means I can then make more splits off the mixer and add other decode streams into it without issue.

For clarity, if I have another decode mixer with a non-decode split going to the No Sound device and then I split from the first mixer and add that into the second decode mixer, will the first mixer having it's own Non-Decode split cause any issues?

[Ian @ un4seen]

If I understand correctly, mixer1 has a splitter playing on the "No Sound" device, and mixer2 has a splitter plugged into mixer1. And you want to know if it'll be okay for mixer2 to also have a splitter playing on the "No Sound" device? If so, it shouldn't do any harm, but perhaps it's unnecessary? mixer2 is effectively already playing on the "No Sound" device through mixer1.

[Chris Oakley]

That's correct, but I need to actively switch things around. If the user changes the routing and mapping of the mixer 2 to a different mixer (or no mixer at all), it still needs to continue.