[Sound-open-firmware] Question about topology with mixer

[Ranjani Sridharan]

On Tue, 2020-05-19 at 16:06 +0000, Daniel Baluta wrote:
> Hello everyone,
> 
> Is there any topology that mixes two PCM streams that
> we can take as an example to start with?
> 
> We would like to do something like this:
> 
> PCM0 ----> volume ----------------+
>                                                    |-- LL mixer ----> 
> volume ---->DAI
> PCM1 ----> volume ----> SRC --+
> 
> Also, should this result in 1 sound card with 2 sub devices, right?
Hi Daniel,

We already have a pipeline similar to this that we use in our
topologies. Take for example sof-apl-pcm512x.m4.
It uses the "pipe-low-latency-playback" pipeline for PCM0 pipeline 1
and the "pipe-pcm-media" pipeline (pipeline 5) is connected to the
mixer in pipeline 1. Hope this helps.


> 
> Is there a plan to write a topology GUI tool? Writing m4 files
> is not really easy 🙂.

We dont have a GUI yet for writing topologies but there's a tool to
visualize the topologies that you build with m4 for now. 

THanks,
Ranjani