At Sun, 7 Aug 2011 21:17:46 +0200, Andrée 'Glaucous' wrote:
Hello.
I'm wondering if there's any ongoing development on multichannel sound support for HDMI - LPCM/5.1/7.1, not bitstreamed audio such as DTS/AC3 (which works). I've tried both a AMD HD 4870 and AMD HD 6870, on both 2 channel and bitstreamed audio works with ALSA, but not LPCM. LPCM works perfectly (5.1, 7.1) on Windows.
According to the mailing list there seem to have been some activity in this area (January or so), but no success. I'd gladly try out patches.
Check whether your HDMI codec chip is processed via patch_generic_hdmi() in patch_hdmi.c. Some ATI codecs are via patch_atihdmi() and it doesn't support multi-channel LPCM.
If it's through patch_generic_hdmi(), basically it should work as is, since the very same function is used by Intel and Nvidia HDMI, too, and LPCM works on them. Of course, some unknown ATI-specific things might be missing. But first check whether ELD validity is set, i.e. whether the video driver passes the right ELD to HDMI auido side.
Takashi