[pulseaudio-discuss] [PATCH] Add HDMI Surround 7.1 profiles

[David Henningsson]

On 2014-07-16 12:59, Alexander E. Patrakov wrote:
> 15.07.2014 22:28, Alexander E. Patrakov wrote:
>> 13.07.2014 18:12, Tanu Kaskinen wrote:
>>> Someone (not me, at least any time soon) could write a simple
>>> patch that measures and logs (at error level - measurements shouldn't be
>>> done at debug log level) the time that the probing takes. Then test it
>>> on your development machine, and if the time seems negligible, try also
>>> e.g. plugging in a USB sound card to a Raspberry Pi.
>>
>> Done. See the attachment.
>
> Here is some data from the PC that I have to use at work: 0 = onboard
> analog audio, 1 = NVIDIA HDMI (with 4 outputs, out ow which only one
> corresponds to a physical connector), 2 = Logitech USB Headset H340
> (borrowed from a colleague).
>
> I guess I need to redo the patch, because the numbers don't add up,
> especially for the USB headset. I.e. there is significant latency that
> is not covered by tv_this_profile.

Cool, thanks for all the tests.

So, given this the only place where extra 7.1 profiles actually take 
some time to consider is this one (NVIDIA HDMI). Where adding 7.1 
profiles to all four devices would probably lead to an additional 
startup delay of 100 - 150 ms.

All other places we probably get stopped in userspace, which means less 
than a ms delay.

My gut feeling would say that it would be okay to merge default.conf and 
extra-hdmi.conf, add the 7.1 profiles to the result, and add up to 8 
HDMI devices.

What do you think?

> E: [pulseaudio] alsa-mixer.c: Checking for profile output:hdmi-stereo
> took 18385 usec
> E: [pulseaudio] alsa-mixer.c: Checking for profile output:hdmi-surround
> took 23026 usec
> E: [pulseaudio] alsa-mixer.c: Checking for profile
> output:hdmi-stereo-extra1 took 35001 usec
> E: [pulseaudio] alsa-mixer.c: Checking for profile
> output:hdmi-surround-extra1 took 23027 usec
> E: [pulseaudio] alsa-mixer.c: Checking for profile
> output:hdmi-stereo-extra2 took 35028 usec
> E: [pulseaudio] alsa-mixer.c: Checking for profile
> output:hdmi-surround-extra2 took 23040 usec
> E: [pulseaudio] alsa-mixer.c: Checking for profile
> output:hdmi-stereo-extra3 took 35022 usec
> E: [pulseaudio] alsa-mixer.c: Checking for profile
> output:hdmi-surround-extra3 took 22996 usec
> E: [pulseaudio] alsa-mixer.c: Checking for all profiles on device 1 took
> 255536 usec in total

-- 
David Henningsson, Canonical Ltd.
https://launchpad.net/~diwic