Thorsten and list; On Wed, Nov 28, 2012 at 7:06 AM, Thorsten Mühlfelder <thenktor@xxxxxxxxxxx> wrote: > Hi, > > I've read a quite long discussion here about this USB Audio 2.0 chip. Apparently there have been problems when switching sample rates. > Now I have bought a cheap USB to S/PDIF interface with this chip (search for "CM6631 USB" at www.aliexpress.com) and I wonder if it is better supported now. I guess I was the last person discussing the use of this chip, in the Schiit Bifrost http://schiit.com/cart/index.php?main_page=product_info&cPath=0&products_id=7 If I'm correct, then the current situation is that the device works with Alsa, with two caveats. The first, and most annoying, is that automatic switching of sample rates and word lengths needs some manual help. For example, when playing a 96/24 music file after a 44.1/16 music file, Alsa and the DAC erroneously negotiate a rate of 88.2/24, which of course doesn't sound very good. However, stopping and restarting play establishes correct communication. The second is that "hw" does not handle the 24 bit word length, at least in this context, necessitating the use of "plughw" to get to 32 bits. Daniel gave me a kernel patch he thought might help the first problem and instructed me on its application, but that did not solve the problem. At least that is my experience. If anyone can do better, please let us know! -- Chris Hermansen · clhermansen@xxxxxxxxx C'est ma façon de parler. ------------------------------------------------------------------------------ Keep yourself connected to Go Parallel: INSIGHTS What's next for parallel hardware, programming and related areas? Interviews and blogs by thought leaders keep you ahead of the curve. http://goparallel.sourceforge.net _______________________________________________ Alsa-user mailing list Alsa-user@xxxxxxxxxxxxxxxxxxxxx https://lists.sourceforge.net/lists/listinfo/alsa-user
