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Re: Radeonhd audio

Posted: Mon Jul 11, 2016 9:15 am
by salass00
@LyleHaze

Is that scanning really necessary though?

Can't you just send audio and if the thing that's on the other end of the HDMI cable ignores it or there is nothing connected then so be it?

I'm just wondering since the only two computer-like systems that I have that have HDMI (a PS3 and a PS4) only allow to select between using either HDMI or optical out for audio and AFAICT I don't get any different choices depending on what I have the HDMI cable connected to.

Re: Radeonhd audio

Posted: Mon Jul 11, 2016 12:00 pm
by LyleHaze
Can't you just send audio and if the thing that's on the other end of the HDMI cable ignores it or there is nothing connected then so be it?
Honest answer: I'm just not sure.

In an ideal specification there would be a set of base capabilities / channels / sample rates that all devices are required to support.
If such a definition exists for HDAudio over HDMI then I have missed it somehow (quite possible)

Since "HDAudio over HDMI" _IS_ by definition HDAudio, perhaps the last detail does not matter.

When adding support for "optical audio out" to a working X1000 audio driver, I bought a simple optical to analog adapter to test my work.
It had a much narrower list of available sample rates, which complicated the options GUI, since AHI never considered that changing option
"A" might affect the choices available in options "B".

After release, the optical out was found to fail with certain devices that assume certain levels of compression would be required, and that was just another "gotcha" I had not considered.

Dolby is another issue there, I assume it requires some sort of licensing.

So making the driver smarter.. I started by something fool-proof. On startup, search for all available outputs. On my X1000 it responded with the (static) list I expected. On Radeon it failed.
But now I am back to the beginning of the topic. :)

Nothing is insurmountable. But every advance in technology takes us further from the simpler PCI based sound cards of the past, which AHI was tailored around.

Re: Radeonhd audio

Posted: Tue Jul 12, 2016 6:30 am
by RobMattin
LyleHaze wrote:What it you are "playing" into an HDMI recorder?
How do you poll the output device for abilities if it is not connected at the time?
I don't know anything about the standards but if recording devices identify themselves as such then you should be able to send the audio signal and it will be recorded.

Re: Radeonhd audio

Posted: Tue Jul 12, 2016 11:05 am
by Belxjander
LyleHaze wrote:
Can't you just send audio and if the thing that's on the other end of the HDMI cable ignores it or there is nothing connected then so be it?
Honest answer: I'm just not sure.

In an ideal specification there would be a set of base capabilities / channels / sample rates that all devices are required to support.
If such a definition exists for HDAudio over HDMI then I have missed it somehow (quite possible)

Since "HDAudio over HDMI" _IS_ by definition HDAudio, perhaps the last detail does not matter.

When adding support for "optical audio out" to a working X1000 audio driver, I bought a simple optical to analog adapter to test my work.
It had a much narrower list of available sample rates, which complicated the options GUI, since AHI never considered that changing option
"A" might affect the choices available in options "B".

After release, the optical out was found to fail with certain devices that assume certain levels of compression would be required, and that was just another "gotcha" I had not considered.

Dolby is another issue there, I assume it requires some sort of licensing.

So making the driver smarter.. I started by something fool-proof. On startup, search for all available outputs. On my X1000 it responded with the (static) list I expected. On Radeon it failed.
But now I am back to the beginning of the topic. :)

Nothing is insurmountable. But every advance in technology takes us further from the simpler PCI based sound cards of the past, which AHI was tailored around.
This seems like an updated ahi.device where plugins provide the card specifics and the HD_Audio specification is directly baked into the device itself with the plugins providing AHI_PLUGIN_HDAUDIO_ENABLED or some such extension marker.

That way ahi checks for simple devices when loading the plugin and includes additional HDaudio support extras and caps query support when actually available.

Would that be a way to go for the required support or is that over-complicating things?

Ahi loads, detects sound cards(performs caps queries and registers HDaudio caps for timed updates?)
DevOpen and DevClose trigger updating the HDaudio caps presence and allow for garbage-collection?
Use of a cap would also require confirmation of existence as well?

Would THAT work? With any RadeonHD_Audio plugin then using the extended HDaudio caps options?

But this still requires some means of getting a response from the HDaudio hardware attached to the card for intended playback.

The only example I have of this would be the HDMI feed off the RaspberryPi machines I have and an extra RadeonHD 5450 PCI Express card I can't currently use without some kind of adapter in my sam440.

Would extending ahi.device itself with HDaudio support possibly help? Or just add HDaudio through a separate library/resource?

Re: Radeonhd audio

Posted: Thu Jan 19, 2017 9:34 am
by tlosmx
hi all sorry for my late reply but i was forget about this my thread.
RadeonHd have inside it intel_hd audio chip.
im using only my radeond inside my x5000 on linux and i have audio full working thru hdmi.
for more info you can check the linux kernel src probably can help
http://cateee.net/lkddb/web-lkddb/SND_HDA_INTEL.html