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Old 12-03-10, 01:11 PM   #18
Stephen Warren
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Join Date: Aug 2005
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Default Re: Call for testers: HDMI pass-through

Some thoughts:

1) I believe these files are so-called "HBR" audio (High BitRate audio, name per HDMI spec)? If so, looking at our Windows driver, only a limited subset of our GPUs support this feature, based on audio codec ID:

0x000B (perhaps, based on silicon rev)
0x0011
0x0012
0x0013
0x0014
0x0018
0x0019
0x001A
0x001B
0x001C
(some of those IDs don't actually exist in production)

2) I don't recall what state the kernel driver is in for HBR support on NVIDIA codecs/controllers.

3) There are some AES control bits that I think indicate the format of the audio being sent to the receiver; I can't remember if these are bits that asound.conf needs to set or the application needs to specify when opening the ALSA device, or if they're something that's simply encoded into the SPDIF stream. Perhaps some receivers are better than others at interpreting audio if those bits aren't set correctly?
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