xCore-200 MC 2V0 Windows browser audio problem

Technical questions regarding the xTIMEcomposer, xSOFTip Explorer and Programming with XMOS.
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xCore-200 MC 2V0 Windows browser audio problem

Post by marijnhasebos »


I have a problem with my xCore-200 MC audio 2V0 development board. I'd like a solution strongly based on the supplied firmware for this board (2i16o16xxxxx_tdm8). I just need to get 16in/16out usb audio, nothing else.
This works like a charm with the native USB 2.0 driver. The only thing I needed to add is UAC_FORCE_FEEDBACK_EP=1build flag.

However... When using the 2i16o16xxxxx_tdm8 buildflag, Windows defaults for it's audio output to ch 1 and 2, as is the case with all the build configurations.
All system sounds play through this output, and all DAW's recognise the channels and I'm able to play/record on all of them.
What is not working is audio from a browser. (Youtube etc). In chrome I get the "Audio renderer error. Please restart your computer" error.
Non of the browsers I have tested (Firefox, chrome, opera, edge) play audio on the xmos.

I have tested this with the onboard DAC and ADC, which in TDM mode only reveive 'xDAC SD1' and 'iADC SD1' respectively in the 2i16o16xxxxx_tdm8 build.
I also have tested with our own design (two CS42248) codecs, whith 2x TDM in connected, and 2x TDM out connected. Still same problem.

A few things to note:
- This browser audio problem DOES NOT occur with the 8in/8out (2i8o8xxxxx_tdm8)

- 2i32o32xxxxx_tdm8 seems to have the same browser audio problem

- There are no other programs open during this browser audio problem

- I am uncertain if this is due to a Windows update, I'm on W10 20H2. I've tested on multiple systems, where only one W10 PC was able to play browser audio on the 16x16 config. This was W10 (1809).

- I've tested multiple samplerates/bitdepths with the define "STREAM_FORMAT_OUTPUT_1_RESOLUTION_BITS" and "DEFAULT_FREQ". All without succes.

- MAC OSX has no browser audio problems with 16i16o

Has anyone else had this problem, or maybe knows how to fix it?

Thanks in advance,


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Joined: Mon Feb 08, 2021 12:27 pm

Post by mhowle »

Hi marijnhasebos,

I too have experienced a similar problem with multiple build configurations including 2i10o10msxxxx & 2i8o8xxxxx_tdm8 (although you stated that you had no issue with this config).

I have set UAC_FORCE_FEEDBACK_EP=1 build flag.

I have this issue on both of my windows 10 machines - there is no audio from browser based audio or Spotify - but all works fine with my DAWs.

I have only just begun working on USB2.0 on XMOS and so I'm relatively new to this and I am still learning the basics of this XMOS platform.

Did you manage to find out any more about this issue or find a resolution?
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Post by marijnhasebos »

Hello mhowle,

Sadly I have not found a solution, and have to move on to different projects. But if you find something, please let me know!