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Interested in 1080P black and white output to DVI or HDMI for a line graph — Parallax Forums

Interested in 1080P black and white output to DVI or HDMI for a line graph

nmz787nmz787 Posts: 24
edited 2012-01-31 09:05 in Propeller 1
Just saw this thread on the potential for DVI:
http://forums.parallax.com/showthread.php?108444-DVI-out-from-Prop-with-TFP410

I figure I really don't care about color, but do want high-res to display the data from a 3648 pixel CCD array as a line graph (i.e. ADC value == height of black pixel).

I figure with some code trickery, I could use an array 1920 shorts, each storing the height from 0-1080, to output the high bits at the right pixels.

There's this chip, ~$4 that looks OK... as for GPIO pins... the config lines, control lines, and 1 line for black/white (all 24 color bits tied to one pin)... should be about 15 pins max (probably less).
http://www.analog.com/en/audiovideo-products/analoghdmidvi-interfaces/ad9389b/products/product.html


comments? suggestions? has this been done before?

Comments

  • RaymanRayman Posts: 14,845
    edited 2012-01-30 04:31
    I could be wrong, but I think it would be relatively easy to do 1080p in 6-bit color.
    I'm pretty sure you can do it right now (30 fps) out of VGA. Some TVs will accept that.
    If that works, then inserting the DVI encoder chip should make it work over HDMI.
    I think all TVs accept 1080p at 30 fps over hdmi...
  • SONIC the HedgehogSONIC the Hedgehog Posts: 321
    edited 2012-01-30 07:46
    Alot of tv commercials say like 250mHz on them or something, and i know this is the refresh rate, and my tv at home is 60mHz, but would that mean my tv couldn't read inputs under 60fps? And 30fps plus 6bit color is definitely worth the resolution. Plus alot of tvs now a days already have VGA input, so I don't think an encoder would be to necessary unless you did use DVI out or HDMI.
  • groggorygroggory Posts: 205
    edited 2012-01-30 11:12
    If you do get this working please let us know. It would be really cool to have a daughter board that outputs HDMI. Even better if you make the daughter board take audio input too that slips into the HDMI stream.

    I'd love to make some propeller based boxes that output audio and video to a modern, high-def TV screen.
  • Toby SeckshundToby Seckshund Posts: 2,027
    edited 2012-01-30 13:50
    I would be wary about assuming that all LCD or plasma screens are 1080p. A lot of screens are labled as being "HD ready" which usually means that they are 1366 pixels wide rather than 1920, they will have ago at scaling a 1080 input (probably just the interlaced version).

    True 1080p requires just short of 3Gb input rate ( here in 50Hz areas ).
  • groggorygroggory Posts: 205
    edited 2012-01-30 15:22
    Toby Seckshund wrote: »
    I would be wary about assuming that all LCD or plasma screens are 1080p. A lot of screens are labled as being "HD ready" which usually means that they are 1366 pixels wide rather than 1920, they will have ago at scaling a 1080 input (probably just the interlaced version).

    True 1080p requires just short of 3Gb input rate ( here in 50Hz areas ).

    True, but if we had a helper chip that we could feed it at a reasonable rate and it did the refreshes at those rates for us that would make me happy.
  • RaymanRayman Posts: 14,845
    edited 2012-01-30 15:28
    I've been meaning to do an HDMI board for a while... I've got the chip to do it, just haven't had the time...
  • groggorygroggory Posts: 205
    edited 2012-01-30 15:31
    Rayman wrote: »
    I've been meaning to do an HDMI board for a while... I've got the chip to do it, just haven't had the time...

    Which chip are you referring to?
  • SONIC the HedgehogSONIC the Hedgehog Posts: 321
    edited 2012-01-30 15:32
    I read on Wikipedia that the HDMI standard has to include the sRGB modes from DVI, which in turn is a major upscale VGA. I think a good place to start would be to use a DVI driver and upscale here and there....
  • RaymanRayman Posts: 14,845
    edited 2012-01-30 15:46
    Well, I did DVI with a TPS410. I want to explore other options though...
  • nmz787nmz787 Posts: 24
    edited 2012-01-30 15:50
    Toby Seckshund wrote: »
    I would be wary about assuming that all LCD or plasma screens are 1080p. A lot of screens are labled as being "HD ready" which usually means that they are 1366 pixels wide rather than 1920, they will have ago at scaling a 1080 input (probably just the interlaced version).

    True 1080p requires just short of 3Gb input rate ( here in 50Hz areas ).

    ~3Gbps (bits, not bytes) if you're using RGB at 8 bits per channel... 24bits*1920*1080 pixels * 60fps / 8(bits/byte) / 1,000,000 = 373.248 megabytes per second @ 60fps

    for black and white its 1bit *1920*1080*60 /8 /1,000,000 = 15 megabytes per second @ 60fps (124.416Mbps)

    So I don't think 60FPS is realizable with the propeller, but I think 30 would be.

    I was thinking about the scaling problem last night, and wasn't sure if the TV handled scaling, the parallel to HDMI/DVI chip handled scaling, if video just got cut off (or black bars added if you weren't pumping out enough pixels to fill the TV's resolution)... or if there is some communication that goes back and forth between the TV to the converter chip, which the controller is then expected to talk with and change the output resolution.
  • RaymanRayman Posts: 14,845
    edited 2012-01-30 16:37
    Just as an aside... I was thinking for a while that this wouldn't be worth the effort, with Prop2 coming any day (month or year) now...

    But, it seems that Prop2 won't even be fast enough for HDMI or DVI output. So, I'm still motivated to do this for Prop1...

    While I'm at it... One main driver for me is a new, affordable, monitor with built in USB touchscreen.
    So, what I really want is a Prop board that has DVI plus USB to talk to it...
  • nmz787nmz787 Posts: 24
    edited 2012-01-30 16:45
    Rayman wrote: »
    Just as an aside... I was thinking for a while that this wouldn't be worth the effort, with Prop2 coming any day (month or year) now...

    Or as my roommate just mentioned, the raspberryPi @ $25-35 (or $30-35...) would probably be better for my case (displaying a graph is one thing, interacting with it, zooming (interpolating/compressing data) is a good amount more processing)

    That said, I still am interested in this idea.
  • RaymanRayman Posts: 14,845
    edited 2012-01-30 17:13
    Yes, any PC could do it. But sometimes, you want the simplest solution for a given problem. For a lot of my problems, the Prop turns out to be the simplest solution...
  • SONIC the HedgehogSONIC the Hedgehog Posts: 321
    edited 2012-01-30 17:15
    Actually, the prop 2 would be able to handle it with twice the MIPS, but I think you should stock with 30 fps. And what I meant was use the drver and setup you did with DVI, but, instead wire HDMI, not DVI. So if you get that working then you know you got the pinout rightnand start upgrading to 720p, i think that might be more feasable and more thank likely wouldn't over load the prop. If youre shooting for true high-def(which would be awesome) try 1080i, because progressive scan with colors might just be too much. But i could be wrong.
  • SONIC the HedgehogSONIC the Hedgehog Posts: 321
    edited 2012-01-30 17:19
    But the prop is also a fun solution!
  • RaymanRayman Posts: 14,845
    edited 2012-01-30 17:24
    nmz787, actually now that I read your first post again, this might be close to what you want:
    http://forums.parallax.com/showthread.php?106118

    Only problem is that I had to graph top-bottom instead of the left-right that I wanted...
  • nmz787nmz787 Posts: 24
    edited 2012-01-31 09:05
    Rayman wrote: »
    nmz787, actually now that I read your first post again, this might be close to what you want:
    http://forums.parallax.com/showthread.php?106118

    Only problem is that I had to graph top-bottom instead of the left-right that I wanted...


    Thanks Rayman, I'll take a look at the code in the next few days. I don't have any idea of how VGA works, so I'll need to look at that too... haven't investigated the video generators on the prop yet either. The Analog Devices HDMI part I listed earlier just has parallel digital RGB, but I think VGA is analog, maybe I'm wrong.
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