HDMI screens/monitors and high rez audio

I've recently been writing a program to 'probe' HDMI monitors or screens to
see what audio modes they accept. The results have prompted me to wonder
about their limits.

I've only seen results from a few. But all the ones I've got data on only
work for LPCM sample rates up to 48k max. Which would leave 'high rez'
audio out in the cold. (And when sent 44.1k the seem to dumbly resample it
48k upon reception).

That gives me the feeling that the expectation in TV is that 48k is the
'standard', so they cannae be bothered, 48k rules.

Afraid the program I'm using only works on RISC OS. So it would be for
others to say how you'd check this using other approaches. But I'd be
interested to know what people can find out here. Any TVs/monitors that
accept 96k/24 LPCM?

Please note that it may be possible to 'play' a 96k/24 file and hear
audio, but it is working because the actual transfers are being downsampled
and sent as 48k. So simply being able to play such a file over HDMI and
hear it doesn't show it is actually being sent and played as 96k.

Note also that I'm not concerned here with non-LPCM formats or their
bitrates. Just with stereo LPCM.

Jim

--
Please use the address on the audiomisc page if you wish to email me.
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
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Audio Misc http://www.audiomisc.co.uk/index.html

Jim Lesurf wrote:

I've recently been writing a program to 'probe' HDMI monitors or screens to
see what audio modes they accept.

My "3K" miniDP monitor only claims to support 16/20/24bit audio
at 32/44.1/48kHz, it's more convenient to plug the speakers in there
than into the PC. The PC's soundcard does claim 96/192kHz but I doubt I
could tell the difference on el-cheapo speakers ...

In article , Andy
Burns
wrote:

My "3K" miniDP monitor only claims to support 16/20/24bit audio at
32/44.1/48kHz, it's more convenient to plug the speakers in there than
into the PC. The PC's soundcard does claim 96/192kHz but I doubt I
could tell the difference on el-cheapo speakers ...

My suspicion is that 16/20/24 bit is accepted because that reflects the way
the spdif spec was extended fairly early on. In effect, it covers the
various bit-clock rates to be expected for the sample rates up to 48k.

Indeed. out (Panasonic) TV seems to send out 48k 20bit via its optical
output.

Jim

--
Please use the address on the audiomisc page if you wish to email me.
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html
Audio Misc http://www.audiomisc.co.uk/index.html

On Sat, 30 Jan 2016 13:11:55 +0000 (GMT), Jim Lesurf
wrote:

I've recently been writing a program to 'probe' HDMI monitors or screens to
see what audio modes they accept. The results have prompted me to wonder
about their limits.

I've only seen results from a few. But all the ones I've got data on only
work for LPCM sample rates up to 48k max. Which would leave 'high rez'
audio out in the cold. (And when sent 44.1k the seem to dumbly resample it
48k upon reception).

That gives me the feeling that the expectation in TV is that 48k is the
'standard', so they cannae be bothered, 48k rules.

Afraid the program I'm using only works on RISC OS. So it would be for
others to say how you'd check this using other approaches. But I'd be
interested to know what people can find out here. Any TVs/monitors that
accept 96k/24 LPCM?

Please note that it may be possible to 'play' a 96k/24 file and hear
audio, but it is working because the actual transfers are being downsampled
and sent as 48k. So simply being able to play such a file over HDMI and
hear it doesn't show it is actually being sent and played as 96k.

Note also that I'm not concerned here with non-LPCM formats or their
bitrates. Just with stereo LPCM.

Jim

You'll be coming across the EDID/HDCP issue with HDMI.

So called Hi-res audio is only supposed to be allowed to be dealt with
by an HDCP compliant receiving device so you can't be naughty and
extract it at full bit depth and sample rate. If the right EDID data
is not returned to the originating device it is only supposed to
deliver 48kHz 16 bit stereo to the receiving device. (Which will be
down sampled if neccesary.)

I've been trying to extract multi-channel audio from PC produced HDMI
with an Atlona AT-HD570 and come up against this problem. My Epson
projector doesn't present any audio EDID data, so the de-embedder only
delivers stereo. Trying it with either of the 2 cheap HDMI TVs that I
have, MonInfo says that they will accept any of the multi-channel
formats that the HDMI interface will handle and the Atlona delivers
multi channel audio. Unfortunately it still needs a kludge in the form
of an HDMI splitter to keep telling the Atlona de-embedder that it can
deliver multi-channel output when the projector is reconnected.

One of the TVs is an old Goodmans GTVL20W7HD and MonInfo says that it
will handle these audio formats:

CE audio data (formats supported)
LPCM 2-channel, 16/20/24 bit depths at 32/44/48/88/96/176/192 kHz
LPCM 8-channel, 16/20/24 bit depths at 32/44/48/88/96/176/192 kHz
AC-3 6-channel, 640k max. bit rate at 32/44/48 kHz
AAC 6-channel, 480k max. bit rate at 44/48 kHz
DTS 7-channel, 1536k max. bit rate at 44/48/88/96 kHz
SACD 6-channel at 44 kHz
DD+ 8-channel at 44/48 kHz
DTS-HD 8-channel, 16-bit at 44/48/88/96/176/192 kHz
DVD-A 8-channel at 44/48/88/96/176/192 kHz

The much newer Hitachi says the same. What they actually do with the
audio is a different matter, but it does produce sound when presented
with 24bit multi channel audio. (Haven't got any high sample rate
files.)

Isn't copy protection wonderful? Especially as it all seems to have
been cracked now.

On Saturday, 30 January 2016 13:12:17 UTC, Jim Lesurf wrote:
I've recently been writing a program to 'probe' HDMI monitors or screens to
see what audio modes they accept. The results have prompted me to wonder
about their limits.

I've only seen results from a few. But all the ones I've got data on only
work for LPCM sample rates up to 48k max. Which would leave 'high rez'
audio out in the cold. (And when sent 44.1k the seem to dumbly resample it
48k upon reception).

That gives me the feeling that the expectation in TV is that 48k is the
'standard', so they cannae be bothered, 48k rules.

Afraid the program I'm using only works on RISC OS. So it would be for
others to say how you'd check this using other approaches. But I'd be
interested to know what people can find out here. Any TVs/monitors that
accept 96k/24 LPCM?

Please note that it may be possible to 'play' a 96k/24 file and hear
audio, but it is working because the actual transfers are being downsampled
and sent as 48k. So simply being able to play such a file over HDMI and
hear it doesn't show it is actually being sent and played as 96k.

Note also that I'm not concerned here with non-LPCM formats or their
bitrates. Just with stereo LPCM.

Jim

Interesting question.

In my lounge I have a Sony AV amp - this can support all sorts of formats dynamically and briefly displays what it is getting (and you get quite a selection from satellite). OTOH most programs are 48k [2,0] i.e. just stereo.

My PC's main monitor is an Iiyama 4K one. Windows tells me it supports 32, 44.1, 48, 88.2 96, 176.4 and 192k, but they don't all work when tested, so it is set to 48k. In any event the speakers in the monitor are not really hi-fi.

I recently bought a [cheap] soundbar from Aldi to get better sound. It is connected using digital optical [fibre]. The sound is a lot better. This supports some modes, but not 192k and the DTS comes out as mush. Currently it is set to 96k.

In article , Bill Taylor
wrote:
You'll be coming across the EDID/HDCP issue with HDMI.

So called Hi-res audio is only supposed to be allowed to be dealt with
by an HDCP compliant receiving device so you can't be naughty and
extract it at full bit depth and sample rate. If the right EDID data is
not returned to the originating device it is only supposed to deliver
48kHz 16 bit stereo to the receiving device. (Which will be down sampled
if neccesary.)

Interesting for two reasons, one short, t'other longer.

Short: Even 44.1k seems to be *upsampled* to 48k on TVs I've tested.

Longer:

I've not taken any interest in this area until now as my main interest is
audio without any video. So I just play audio out via USB when using a
computer, or when needed via spdif for CD players, etc.

However I do have a number of 'home made' 96k/24bit LPCM recordings I've
made from ancient LPs. Stored either as plain vanilla LPCM wave files or
tagless plain flac files.

If I tried playing these via an HDMI monitor that admitted it could accept
96k/24 would it refuse to play them at all because my machine or the file
lacked some magic 'permission' key which doesn't exist for these files?

i.e. do the monitors, etc, take for granted that any 96k/24 audio
*requires* such permission if I want to have the monitor pass out the
96k/24 via spdif?

If so, it's a dead parrot so far as I'm concerned. And raises the question
of why manfacturers should presume such a blanket control over what I
choose to record and play back.

Jim

--
Please use the address on the audiomisc page if you wish to email me.
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html
Audio Misc http://www.audiomisc.co.uk/index.html

On Sunday, 31 January 2016 13:11:45 UTC, Jim Lesurf wrote:
In article , Bill Taylor
wrote:
You'll be coming across the EDID/HDCP issue with HDMI.

So called Hi-res audio is only supposed to be allowed to be dealt with
by an HDCP compliant receiving device so you can't be naughty and
extract it at full bit depth and sample rate. If the right EDID data is
not returned to the originating device it is only supposed to deliver
48kHz 16 bit stereo to the receiving device. (Which will be down sampled
if neccesary.)

Interesting for two reasons, one short, t'other longer.

Short: Even 44.1k seems to be *upsampled* to 48k on TVs I've tested.

Longer:

I've not taken any interest in this area until now as my main interest is
audio without any video. So I just play audio out via USB when using a
computer, or when needed via spdif for CD players, etc.

However I do have a number of 'home made' 96k/24bit LPCM recordings I've
made from ancient LPs. Stored either as plain vanilla LPCM wave files or
tagless plain flac files.

If I tried playing these via an HDMI monitor that admitted it could accept
96k/24 would it refuse to play them at all because my machine or the file
lacked some magic 'permission' key which doesn't exist for these files?

i.e. do the monitors, etc, take for granted that any 96k/24 audio
*requires* such permission if I want to have the monitor pass out the
96k/24 via spdif?

If so, it's a dead parrot so far as I'm concerned. And raises the question
of why manfacturers should presume such a blanket control over what I
choose to record and play back.

HDMI does include copy protection. You must have set it on your own recordings.


Jim


PS IMO not much point making hi-res copies off worn vinyl. Years ago I read the comparison (so no link) and basically CD's objectively ****ed on vinyl on all measurements, but especially dynamic range (96dB on CD). Subjectively it was the same - when CD's first came out Signal Radio ran a program with mostly tracks on CD's - Signal used professional vinyl decks and I could easily tell the difference between vinyl and CD (before the DJ announced it) listening to program in my while driving up the M6 at er 70mph - i.e. with a radio segment, relatively poor speakers and road noise in the mix so to speak.

In article , R.
Mark Clayton wrote:

If I tried playing these via an HDMI monitor that admitted it could
accept 96k/24 would it refuse to play them at all because my machine
or the file lacked some magic 'permission' key which doesn't exist for
these files?

i.e. do the monitors, etc, take for granted that any 96k/24 audio
*requires* such permission if I want to have the monitor pass out the
96k/24 via spdif?

If so, it's a dead parrot so far as I'm concerned. And raises the
question of why manfacturers should presume such a blanket control
over what I choose to record and play back.

HDMI does include copy protection. You must have set it on your own
recordings.

I haven't even tried playing high rez via HDMI. The above was asking
questions for that reason. All the monitors/TVs I've probed so far only
report accepting rates up to 48k, so I can't even try it.


Jim


PS IMO not much point making hi-res copies off worn vinyl. Years ago I
read the comparison (so no link) and basically CD's objectively ****ed
on vinyl on all measurements, but especially dynamic range (96dB on CD).
Subjectively it was the same - when CD's first came out Signal Radio
ran a program with mostly tracks on CD's - Signal used professional
vinyl decks and I could easily tell the difference between vinyl and CD
(before the DJ announced it) listening to program in my while driving up
the M6 at er 70mph - i.e. with a radio segment, relatively poor speakers
and road noise in the mix so to speak.

The point is to give some head/elbow room when making the recording.

e.g .1 When recording LPs I set the levels so that +18dB(RIAA) will give
0dBFS for the digital recording. That means I can leave the levels alone
disc-after-disc without too much worry about any recorded peaks clipping
the digital recording. If I were recording 44.k1/16 I'd be more concerned
that I was under-recording and want to fiddle with the level each time.
96k/24 is 'fire and forget'.

Using 96k/24 means that doesn't later on mean the results may end up
affected by the levels being recorded too low and minimises any loss of
captured dynamic range or detail if I decided to scale the gain or alter
the balance, etc. I also find it makes finding clicks and doing 'inaudible
mends' easier, but that may just be me.

e.g.2 Running at 96k makes life easier for DACs. You rely less on the
design getting reconstruction right as the nyquist is that much higher
above the clearly audible range.

At first I did spend time processing down to get well scaled lower rate
files. But after a while I decided, why bother, saves time to simply store
and play the 96k/24.

And not all old vinyl is 'worn'. My own LPs have mainly only been played
with a V15/III. Although 2nd-hand ones I've bought recently are more
pot-luck, some are amazingly good. Seems to depend on genre - pop music
gets trashed, jazz seems to have been played less often and on good kit
with care. Old classical seems to depend on the label. If its EMI it
probably emerged damaged from the factory. 8-]

OTOH the recent issues of the Beatles in Mono on LP and a Shadows double LP
issued a couple of years ago are stunningly good.

The problems with Audio CD in the real world are simple. The music biz
often produce crap, regardless of the media. Many examples documented on my
audiomisc website. Almost every way to spoil digital audio exampled from
real commercial CDs. Poor ADCs, scaled by integer multipling with no dither
or shaping, etc, etc.

And, yup, they do it with their high rez downloads as well. I have a few
superb high rez downloads. But I still happily buy *good* Audio CDs. The
problem is Sturgeon's Law, innit. :-/

Jim

--
Please use the address on the audiomisc page if you wish to email me.
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html
Audio Misc http://www.audiomisc.co.uk/index.html

It has nothing discernible to do with anyone called Sturgeon ...

There are many debates about life north of the border that would
benefit from a good and vibrant political opposition, but your cheap
and irrelevant jibes in this forum are a good example of the sorts of
reasons why such an opposition doesn't exist, and probably won't until
rather more political maturity is shown by followers of other
political persuasions.

On Sun, 31 Jan 2016 18:55:07 +0000 (GMT), Jim Lesurf
wrote:

And, yup, they do it with their high rez downloads as well. I have a few
superb high rez downloads. But I still happily buy *good* Audio CDs. The
problem is Sturgeon's Law, innit. :-/
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On Sun, 31 Jan 2016 19:42:26 +0000, Java Jive
wrote:

It has nothing discernible to do with anyone called Sturgeon ...

There are many debates about life north of the border that would
benefit from a good and vibrant political opposition, but your cheap
and irrelevant jibes in this forum are a good example of the sorts of
reasons why such an opposition doesn't exist, and probably won't until
rather more political maturity is shown by followers of other
political persuasions.

On Sun, 31 Jan 2016 18:55:07 +0000 (GMT), Jim Lesurf
wrote:

And, yup, they do it with their high rez downloads as well. I have a few
superb high rez downloads. But I still happily buy *good* Audio CDs. The
problem is Sturgeon's Law, innit. :-/

Maybe you should try Google before jumping to irrelevant conclusions!