On 10/13/14, 7:49 PM, Andrej Falout wrote:
On Tue, Oct 14, 2014 at 11:56 AM, Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com mailto:pierre-louis.bossart@linux.intel.com> wrote:
On 10/11/14, 1:33 AM, Andrej Falout wrote: Hello, <...snip...> 5. Note that as far as I know, no proprietary drivers on Windows (ATI/AMD, Nvidia, Intel) support this; It will be the first time a device that is not a SACD player outputs DSD over HDMI, on any OS. I am assuming that this has nothing to do with hardware limitations of the HDMI chips used for video outputs (I could not find any reference for such assumption in any HDMI chips I examined specs for). Therefore, I assume that implementing this has no hardware prerequisites. HDMI controllers typically don't support DSD in the PC space. It'd be easier to convert to high-res PCM (HBR).Hello Pierre-Louis,
Thank you for your comment.
What are you basing your assessment that "HDMI controllers typically don't support DSD in the PC space"? I looked, but could not find any evidence for this.
I am basing my judgement on first-hand experience with silicon.
Certainly, DSD is not a part of HDMI hardware implementation (such as for example, CEC). From all info I have, DSD is simply multiplexed into HDMI data stream, just as DST-HD or AC3 is.
This multiplexing is typically not implemented - mainly because this isn't a format used outside of niche markets and there was no real format to convey DSD over PCM frames until the DOP format was created in 2012. DTS-HD and AC3 use a PCM format which is rather straightforward to implement but there's quite a few cases where these modes have been dropped. HDMI only requires 48kHz 2ch really. Note that the facts don't mean any negative judgement on quality, i was at AES this week-end where I heard outstanding DSD/DXD recordings. You will have more luck with a USB DAC, there are multiple USB DSD products available.
The goal here is to have a native DSD transport, so conversion to PCM is not an option.
Thanks, Andrej Falout