[mythtv-users] aac_latm surround broken in 0.24-fixes

Jean-Yves Avenard jyavenard at gmail.com
Tue Dec 21 13:58:50 UTC 2010


Hi

On 21 December 2010 23:57, Martin <martin.rene.mortensen at gmail.com> wrote:
> Now I understand that option... I really didnt expect me to be hit by that
> option, since it used old hdmi 1.0 recievers as an example..

Well, HDMI 1.0 only mandates stereo and 48kHz support, nothing more.

The StereoPCM feature used to be called LPCM and was disabled by
default. StereoPCM has the exact opposite meaning.

This is why 5.1 used to work for you, but not anymore.

StereoPCM is to be used under the following circumstances:
- Amplifier doesn't support multi-channels PCM, and is connected via HDMI
- You are using optical/coax SPDIF, but for some reasons, ALSA shows
that more than 2 channels are available..


>
> I have a Sony STR-DH800 - I really really expected it to support
> multi-channel pcm.

yes, surprising, reading the documentation it states LPCM support. It
also supports DTS-HD MA which requires 7.1 LPCM to work (DTS-HD MA is
carried over a 8 channels, 16 bits, 192kHz connection)

>
> I have a Asrock ION 330HT - with NVIDIA ION chipset - it hasnt got a
> /proc/asound/card0/eld*

It could also very well be that something is broken in the alsa
driver, or the EDID returned by the amplifier.

The EDID can contain information on what the device connected can support.
http://www.mythtv.org/wiki/User_Manual:HDAudioPassthrough#Checking_your_TV_.2F_Amplifier_.2F_Audio_Processor_capabilities

But ion 1 / 9400M doesn't support reading it by the look of things.

Could be interesting for you to check-out the E-AC3 capabilities ; for
your audio card only check E-AC3, don't check TrueHD..
And try some samples there:
http://www.avenard.org/files/media/mediatest/audiotest/Surround/E-AC3/


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