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Re: The great Netflix vpn debacle! (geofeeds)


From: Owen DeLong via NANOG <nanog () nanog org>
Date: Wed, 1 Sep 2021 16:08:52 -0700



On Sep 1, 2021, at 15:17 , Warren Kumari <warren () kumari net> wrote:



On Wed, Sep 1, 2021 at 2:28 PM <bzs () theworld com <mailto:bzs () theworld com>> wrote:

Every time I've read a thread about using TVs for monitors several
people who'd tried would say don't do it.

And everytime I see an email thread about the difference or not between monitors and TVs I'm taken over by an all 
consuming rage...
I have a **monitor**.... I purchased it from Dell, and it clearly said "monitor" on the box, it identifies itself 
somewhere display settings as a "monitor", and even says "monitor" in small letters somewhere on the back.... It's a 
MONITOR dagnabit... but, for some unfathomable reason it has some tiny little speakers in it, and every time I 
connect it via HDMI to my Mac laptop, the machine decides to completely ignore the fact that I've told it that I want 
to use a specific sound output, and starts playing all audio though the monitors speakers. Oh, and because this is 
HDMI, and Apple apparently follows the HDMI spec, the Mac volume controls won't work ("This device has no audio level 
control" or something...) and I have to go scrummaging around in some horrendous on-screen monitor menu to make it 
less obnoxiously loud...

Yes, it’s not clear why Apple doesn’t implement more of the HDMI spec and send it CEC commands to control the volume 
when it’s connected to an HDMI device with sound output.

Interestingly, my Apple TV does implement that part of the spec and my Amp that it is connected to dutifully obeys and 
everything works as expected… Display on the monitor (TV if you prefer), sound from the 7.1 speakers through the amp as 
expected, and control of the playback through the Apple TV all from the single elegant Apple TV Remote. So clearly, 
Apple has mastered the skills necessary to make this possible. Why they don’t bring them to MacOS yet remains a mystery 
to me.

All attempts to get this less stupid result in Apple pointing at the HDMI spec and saying that if a device advertises 
audio capabilites they list it as an output device, and Dell pointing out that they simply advirtise the fact that 
the device has a speaker, and, well, shrug, not thier issue if things try and use it.

Listing it as an output device doesn’t require them to auto switch to that output device upon connection… You might 
want to point out to Apple that an ability to override this less than desirable behavior would be sufficient to cure 
your issue without violating the HDMI spec.

It pains me to say this, but Dell is right. The HDMI spec doesn’t allow for them to have a (useful) implementation of a 
speaker (or speakers) in an HDMI monitor that can some how say “I have a speaker, but don’t use it unless the user 
specifically tells you to.”. OTOH, Dell could (and I’ve seen monitors and even televisions that do) add a user control 
to “Disable HDMI audio negotiations” or something to that effect.

There used to be a good webpage that had some instructions along the lines of:
Step 1: Open /System/Library/Extensions/AMDRadeonX6000HWServices.kext/Contents/PlugIns/AMDRadeonX6300HWLibs.kext in a 
hex editor
Step 2: Change the byte at offset 931 to 0xED, offset 12323 to 0xFD, offset 94 to 0x00 and offset 42 to 0x03. 
Step 3: ???
Step 4: The HDMI capabilities parser no longer understands the audio capability message, and so the Mac will never 
try to use HDMI audio ever again.... well, until you upgrade... oh, this is perfectly safe, trust us, nothing could 
possibly go wrong here...

Unfortunately this was only for a specific version of a specific kext on a specific model of Macbook, but it did 
work... 

I suppose, if you’re willing to never have the ability to use HDMI Audio Output from your laptop (which wouldn’t work 
well for me).

I will say that it’s annoying to have to do it each time you connect to the monitor, but it is relatively trivial to 
change the audio output back after the monitor and laptop finish their whole HDMI negotiation and the various auto 
switches have finished screwing up your system settings.

System Preferences->Audio->Output — Select the output you want instead of the HDMI monitor.

All I want is to be able to reliably inform my computer that the thingie on my desk is "just" a monitor and not a 
TV/HiFi system/similar... is that too much to ask!?!!?!!?!??!! <sob>

I’m reminded of a certain advertising slogan…
        “Dude! You got [stuck with] a Dell.”

(Actually, this used to annoy me enough that I purchased one of bunnie Huang's NeTV 
(https://www.bunniestudios.com/blog/?cat=17 <https://www.bunniestudios.com/blog/?cat=17>) devices, which allows 
taking in HDMI, munging it and sending it out (e.g to do text overlays). My plan was to repurpose it as a straight 
data passthrough, but overriding the HDMI profile info, but as with most of these sorts of projects I got sidetracked 
into playing with the build environment instead, and now the hardware is buried under a pile of other abandoned 
projects somewhere on my workbench)

I can’t relate to this one bit… Nope, not at all…

Thank you all, I feel much better now...

Glad we could collectively help.

Owen



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