HDMI output from Beagle board

Hi Guys

This is confusing.

We have a Phillips with 4 HDMI connectors on the back.

The beagle board has a HDMI connector. But it doesnt provide HDMI
output? The output is DVI, which cant be used to drive the HDMI input
of the phillips LCD TV.

Am I correct or am I missing something??

Thanks

Denis

Yes, BeagleBoard does not support the HDMI interface and is used to provide the DVI-D interface only

Ashwin Athani <ashwin.athani@gmail.com> writes:

Yes, it appears that DVI and HDMI are the same w.r.t video. I was not aware of this fact. I just remembered reading the reference manual (rev 0.1); which mentions this on page 19.

Warm regards
Ashwin

Hi Guys

Thanks for clearing that up. So I just need a HDMI cable to go to the
TV and Im set.

Are there certain resolutions, frame rates supported? Or do I need to
configure this?

Regards

Denis

HDMI and DVI are the same wrt video, HDMI has the option to encode extra data (e.g. sound) in the blanking intervals and do things like HDCP.

regards,

Koen

Koen Kooi <koen@beagleboard.org> writes:

HDCP is possible both over HDMI and DVI.
See e.g. http://en.wikipedia.org/wiki/High-bandwidth_Digital_Content_Protection

And HDMI is not DVI without audio. You might perhaps say HDMI = DVI-D
+ audio.
But HDMI does not carry any analog signal, so do not expect a DVI-A
source to display on a TV using a DVI <-> HDMI cable.
Also it is my understanding (but I am not an expert in this area) that
DVI-D might support more resolutions than HDMI.

Coming back to the original question of Denis:
Beagle output is DVI-D. If you put it in the proper resolution your TV
can display it (using a regular HDMI cable)
It depends on the TV type what resolutions it can handle, but I would
expect things to work if you boot the beagle and use 720p60 as video
resolution.
Note that this does not give you audio. Of course you can connect an
amplifier or so to your beagle.
It might be possible that your TV allows you to display video from
HDMI and audio from another input, but I would not be too surprised if
this is not possible as normally the TV would expect audio on the same
connector as the video.

Frans.

Hello Frans

Again thanks for the replies.

Below the specification from our LCD TV.

Supported display resolutions

• Computer formats

Resolution Refresh rate
640 x 480 60Hz
800 x 600 60Hz
1024 x 768 60Hz
1920 x 1080i 60Hz
1920 x 1080p 60Hz

• Video formats
Resolution Refresh rate
480i 60Hz
480p 60Hz
576i 50Hz
576p 50Hz
720p 50Hz, 60Hz
1080i 50Hz, 60Hz
1080p 24Hz, 25Hz, 30Hz
1080p 50Hz, 60Hz

Do we think that one of these will work straight away?

Thanks

Denis

Frans Meulenbroeks <fransmeulenbroeks@gmail.com> writes:

HDCP is possible both over HDMI and DVI.
See e.g. http://en.wikipedia.org/wiki/High-bandwidth_Digital_Content_Protection

And HDMI is not DVI without audio. You might perhaps say HDMI = DVI-D
+ audio.
But HDMI does not carry any analog signal, so do not expect a DVI-A
source to display on a TV using a DVI <-> HDMI cable.
Also it is my understanding (but I am not an expert in this area) that
DVI-D might support more resolutions than HDMI.

HDMI type A (the one used on the Beagle and all TVs I've ever seen) is
electrically identical to single-link DVI-D. This means that both
links can carry exactly the same resolutions. HDMI type B (which I
have never seen used) is equivalent to dual-link DVI-D.

Måns, thanks for your update.
Electrically there is indeed not a difference, I was only not sure
whether HDMI has a more restricted range of resolutions that they
support. Eg. it is unlikely that a HDMI device will support UXGA. Then
again, I haven't verified it in the specs or checked with our experts.

Denis, I'm fairly sure 720p60 will work (720p, 60hz).
See also: http://www.elinux.org/BeagleBoardFAQ#Display_resolutions_.231
Feel free to ping me if you cannot get it working. I have a Philips TV
too (only with 2 hdmi interfaces) so I might be able to do some
testing (haven't done so).

Frans

Many thanks Frans

Ill let you know my results.

Denis

Note that resolution and refresh rate are not the only things that matter.
There are also the horizontal and vertical timings. OMAP cannot produce
signal with high enough timings for many standard modes. If I recall
right, hsync and vsync max is 64 with OMAP, for the rest max is 256.

However, I believe all the reduced blanking modes should be possible. And
that's what the 'R' is for when using modedb to define video modes with
DSS2.

  Tomi

Tomi Valkeinen <tomba@bat.org> writes:

This is a tangent, but what video mode should be used for the splash screen in u-boot that is shipped on the board (to know that the display is alive)? I'd ideally like it to work with both the pico projector and HDTVs (as well as DVI monitors), but I don't believe that is possible. Any ideas?

You could have uboot detect the pico (0x1b) and switch to 640x480 when it encounters that. For the rest a 720p would be most likely to work.

regards,

Koen

Note that resolution and refresh rate are not the only things that
matter.
There are also the horizontal and vertical timings. OMAP cannot
produce
signal with high enough timings for many standard modes. If I recall
right, hsync and vsync max is 64 with OMAP, for the rest max is 256.

However, I believe all the reduced blanking modes should be
possible. And
that's what the 'R' is for when using modedb to define video modes
with
DSS2.

All the HDMI modes except 1080p50/60 should be possible as well.

This is a tangent, but what video mode should be used for the splash
screen in u-boot that is shipped on the board (to know that the
display is alive)? I'd ideally like it to work with both the pico
projector and HDTVs (as well as DVI monitors), but I don't believe
that is possible. Any ideas?

You could have uboot detect the pico (0x1b) and switch to 640x480 when
it encounters that. For the rest a 720p would be most likely to work.

What are the actual HSYNC possibilities. The table 15-121 at page 2305 is
inconsistent I.e. the text is inconsistent to the actual number of bits
assigned to the fields in the graphics (8,8,6 bits contra 12,12,8 bits).

I can see, that the VSYNC table on the next page has been updated compared
to the TRM for OMAP3430. Should the HSYNC table had been updated as well, or
is the text in the description field wrong? In case the text is wrong I
think the OMAP might support (much) more non-reduced blanking modes than (at
least I) expected… :slight_smile:

Anybody being able to check the actual size of the registers? Either by
measurements or by checking internally with the TI design team?

Best regards and thanks in advance
  Søren

I agree, but not all TV's do support all res. E.g. mine does not do
1080p. Apparently the hdmi chip cannot handle it (the panel is 1080p,
and 1080i also sort-a works.

720p seems to be the best supported format, that's why I suggest
starting with that one

FM

hi guys,

im trying to connect my RevC5 beagle board using a VGA-VGA cable to a normal PC monitor,nothing is appearing. I am actually powering the board from the 5v USB. Is that fine? Or should i be using the HDMI output?..Please advise. Thanks

Hi Denis,
Could you please give the result of your investigation?
you were able to connect Beagle board xm to HDMI TV?

Regards,
Abdul.