Anyone succeeded in using two sound cards with libVLC?

[djdjdj]

If so, please share how you did it. I've been trying with libvlc_audio_output_device_set, but haven't been successful.

[Jean-Baptiste Kempf]

You want 2 audio outputs at the same time?

[djdjdj]

Yes. One internal and one external (USB) sound card. I can get the information of the sound cards with libvlc, but can't change the device for a media player to one or the other. The sound always comes through the default card. Detailed description is at viewtopic.php?f=32&t=82724. I would appreciate any help and clue.

[Jean-Baptiste Kempf]

I am not sure VLC's infrastructure allows that.

[djdjdj]

You mean, it is not possible to create one vlc.Instance and link it to sound card A and create another vlc.Instance and link it to sound card B?

Also, I was not successful with changing the audio output for even one media player, like (in vlc python binding) i=vlc.Instance(); mp=i.media_player_new(); mp.audio_output_device_set('waveout', 'USB Audio Codec'). Is audio_output_device_set working?

[Jean-Baptiste Kempf]

You can, but you cannot have 1 instance of VLC using 2 audio outputs.

[djdjdj]

Using two audio outputs, one for one Instance and the other for another Instance is fine with me.

I found the following difference between VLC application and libvlc.

- I have an internal sound card "Realtek" and an external sound card "USB Audio".

- In VLC application->Tools->Preferences->Audio, if I choose "Win32 waveOut extension output" as "Output module", I don't see "Device" choice. Changing the sound output is possible by using Window 7's "Sound" configuration window.
- In VLC application->Tools->Preferences->Audio, if I choose "DirectX audio output", I see "Device" choice and this has "Speakers (USB Audio)" and "Speakers (Realtek)". I can choose the audio output in this VLC configuration window.

- In libvlc, with vlc.Instance.audio_output_enumerate_devices(), I see two identical "waveout"s, with devices "USB Audio" and "Realtek" for them. However, vlc.Instance.audio_output_enumerate_devices()'s "aout_directx" does not have any associated device.

So, VLC application and libvlc behave differently. What can I do here?

[djdjdj]

By the way, with libvlc, I couldn't change audio output for an Instance. No matter what I tried, the sound always comes from the default device set by Windows.

[Kevin Hoang]

I have a question too: I need 2 play the same video on 2 windows, so I created one instance and 2 players. My question is: Can I use 2 sound devices in this case?

[djdjdj]

I can answer your question Kevin. 1 instance can have only 1 sound device. So, to use 2 sound devices you'll have to use 2 different instances.

But, my original question remains. How to use two sound cards for two different instances?

[Kevin Hoang]

In VLC 1.1.x, the audio function made for each player. But, In fact, I seen these functions does not works correctly as the meaning of them.

[cen]

If so, please share how you did it. I've been trying with libvlc_audio_output_device_set, but haven't been successful.

2. steps
libvlc_audio_output_set(name)
libvlc_audio_output_device_set(name,device)