FreeBSD && HDMI TV
Ronald F. Guilmette
rfg at tristatelogic.com
Tue Nov 6 13:06:35 UTC 2012
In message <20121106103951.GA1502 at tiny.Sisis.de>,
Matthias Apitz <guru at unixarea.de> wrote:
>El d=EDa Tuesday, November 06, 2012 a las 02:25:46AM -0800, Ronald F. Guilmette:
>> I confess that I am somewhat shocked to learn that such things even
>> exist, and even a bit more shocked to think that people actually
>> buy them. ...
>Thanks for your helping words. I have to say that I'm completely new to
>multimedia stuff at home (I only have an old DVD player and a 20 years
I also was totally new to this stuff... up until about three weeks ago,
when I decided that I had had enough of the bugs in my LG Blu-Ray player's
firmware, and I've been on a horrendous learning curve ever since.
>I was not even thinking in VGA-HDMI
That would seem to me to more probably be the most sensible & straightforward
thing. I mean VGA is for displays, and HDMI is for displays. Both are
capable of pretty high bandwidth. USB... not so much (unless it is USB 3.0).
>and/or laptops with HDMI
>output (is this supported by X11 or just transparent for X11?)
Well...hehe... yes and no. Yes, in theory, but as I've learned, there are
a number of "issues".
Apparently, most of the work these days on X is done within (or associated
with) the Linux community, and they don't always feel the need to make life
easy on the few folks who maintain X for FreeBSD. Some dramatic changes
have happened, apparently, over the last couple of years with a lot of
key bits of what it takes to put pixels on your screen being moved into
the kernel, and that is still somewhat of a work-in-progress on the *BSD
side. There are only a grand total of about four main flavors of graphics
chips left in the market anymore, i.e. Nvidia, ATI/AMD, Intel, and then
the new kids on the block, Broadcom. I can say from personal experience
that current/recent X+FreeBSD seems to work well with Intel Graphics,
and pretty well (but with occasional small problems on older cards/chips)
in the case of ATI/AMD stuff. I know nothing about the current state
of play with respect to either Nvidia or Broadcom.
Anyway, in all of the above, I am just talking about support for X on
FreeBSD _generally_ and without even referring to HDMI output. There's
a reason for that. My impression is that if X works (on your specific
hardware) then it works, period. If you happen to have an HDMI output
for your ghaphics card/chip then that makes no real difference. If it
works it works. If it doesn't then it doesn't, and in that case it won't
matter what sort of output connectors you have... VGA or DVI or HDMI.
A whole separate set of issues arises when you try to get _sound_ working
also over your HDMI link, and these can be even thornier problems than
the problem of getting video output.
Note that you don't necessarily _have_ to do this, i.e. get your audio
out via via HDMI just because your video is coming out that way (but it
_is_ generaly more convenient if you can get both traveling together
down the same single cable).
Virtually every computer built in the past 20 years has sockets which
output plain garden variety 2 channel _analog_ audio output, and many
have a whole set of analog audio output sockets so that if you have
enough speakers & amplifiers, you can get a nice 5.1 channel or even
nicer 7.1 channel audio setup using just those outputs. The problems
start to arise if, like me, you have a fetish for things digital.
If you want to get _digital_ audio output from your computer then there
are really only two ways to do that... either you use a dedicated S/PDIF
connector and cable (which can be either optical or electrical) or else
you go with HDMI which can carry both video and audio. Most ordinary
(non-laptop) computers build within the past 10 years or more have
(I think) at least a header on the motherboard to which you can attach
a thing like this:
and then you have a digital S/PDIF audio output on your computer (both
optical and electrical kinds, in the case of the adapter shown in the
The idea behind digital audio stuff generally is that we want to get a
pure clean totally un-degraded digital representation of the sound out
of the computer and down to a modern "A/V" type receiver which will
then do a REALLY GOOD JOB of decoding and converting the digital signal
into an actual analog signal which which can be used to drive speakers.
(Even low-end receivers are generally better at doing the digital to
analog conversion than most typical computer hardware is.)
Most home audio receivers built within the past 10-15 years have at least
one and often several S/PDIF input connectors, so if you have a computer
that has an S/PDIF output (optical or electrical) and if your home A/V
receiver has S/PDIF inputs of the same kind (optical/electrical) then
you just run a simple cable from one to the other and viola! You get
pure clean digital audio out of your computer, and it goes into your
receiver which decodes it and then pumps it out to your speakers.
The latest home A/V receivers take this all one step further. They have
one or more HDMI inputs and one HDMI output. The HDMI output from the
receiver goes to your TV, and then the HDMI inputs get wired up to (1) your
cable TV or satellite TV box and (2) your DVD or Blu-Ray player and (3)
your game console (if you have one) and (4) whatever else you have that
has an HDMI output... like, for example, your computer. I myself have
one like this and they are getting less expensive all the time:
Anyway, many modern laptops and also many video cards for non-laptops
nowadays have HDMI outputs. In general, and in my experience, it is
almost always a snap and a "no brainer" to get _video_ out of those,
and then send that HDMI-carried video either directly to your TV or
else indirectly to your TV through a A/V receiver that has HDMI inputs
Getting a digital _audio_ signal to flow down that same
HDMI cable however can prove rather tricky, because the hardware and/or
the software may not feel like cooperating. And at this point I'm only
even taking about mere un-compressed 2 channel digital audio. Just
getting even that to flow down the HDMI cable can be tricky and might
not even work depending upon your specific combination of (a) computer
hardware and (b) operating system and (c) application software. All
three have to be capable of doing the Right Thing, and cooperating with
one another or else you end up with a beautiful picture and dead silence.
And God help you if you want to try advancing to the next higher level
of digital geekness, which would be getting multi-channel (>2) audio,
either compressed or not, such as 5.1 channel Dolby Digital out that
HDMI cable from your computer. If you can get your computer to send
that signal out, then the odds are good that if you have a modern A/V
receiver it will be able to properly decode that signal (and produce
beautiful surround sound for you on up to 7.1 speakers). That's the
good news. The bad news is that convincing your computer, your OS, and
your application to actually do that... e.g. send a 5.1 audio signal
out the HDMI output port... may require more fiddling and more patience
than most mere mortals possess.
I have been experimenting with all this stuff, on three different machines
and using three different operating systems, and using four or five different
applications for around the past three weeks, and the main thing I have
learned is that none of this stuff exactly qualifies as "plug and play"
(or even "click and drool") just yet. It still involves some level of
wizardry, and asking an awful lot of questions.
But I _have_ managed to get both video _and_ 5.1 Dolby Digital audio out
of the HDMI port on at least one of the two laptops I now own, and down
to my receiver (and then the video across from there to my TV). So it
is all possible... even video + 5.1 compressed audio. That's the good news.
The bad news is that so far (and I'm not done experimenting yet) I only
got 100% of this to work under... yecch... spit... Windows 7. (So far
I can't even make it all work on Windows Vista, let alone FreeBSD or
Linux. But I'm not even near giving up yet, and I have lots more stuff
>concerning the LAN board of the TV: it awaits an DLNA server in the LAN
>to show content from there and it seems that there is such a server in
>net/minidlna; will test this when I have time;
My LG BD670 Blu-Ray player also allowed browsing and playing content from
a DLNA server... or even an SMB/Samba server. I didn't realize that they
were putting this capability into TVs already.
When they start putting this capability into toasters, then that will really
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