Where can I find a 160x120 bitmap 4 color TV driver? I could not find one in OBEX

Bill Henning · 2011-05-01 16:33

Hi,

I need to do some simple TV graphics, and I don't have enough memory left to use the nice one byte per pixel driver. I checked in OBEX, and no luck...

160x120 or 160x100 would be perfect, as it would only take 4800 bytes or 4000 bytes, respectively, to hold the bitmap.

Has anyone written such a driver?

The closest one I am aware of is Chip's graphics demo, but I really would like a nice simple bitmap to work with.

Thanks,

Bill

Perry · 2011-05-02 11:32

Take a look at my "Poor Mans Digital Oscilloscope" it is presently at 192x192 but can be made smaller.

I have spent a lot of time making the resolution changes easy.

Bill Henning · 2011-05-02 11:52

Thank you, that sounds great!

TV at 192x192 @ 4 colors is 9.2K, I have enough room for that in my application...

Perry wrote: »

Take a look at my "Poor Mans Digital Oscilloscope" it is presently at 192x192 but can be made smaller.

I have spent a lot of time making the resolution changes easy.

Perry · 2011-05-02 12:46

The code actually uses the standard graphics and TV drivers, but uses the spin compiler to allocate memory not statically as in the Parallax examples.

This shows you correctly how much space is left for programing

I just tried it at 160x112 and 144x112

in config.spin

  x_tiles = 9   ' 12
  y_tiles = 7     ' 10

At the lower resolutions it is nice to change the tvparams to double size
in tv_graphics.spin

                        long    20 '10              'hx
                        long    2 '1               'vx

This is a 144x112 that fills the TV screen.

Sapieha · 2011-05-02 14:41

Hi Perry.

It is possible to change it to PAL?

Perry wrote: »
The code actually uses the standard graphics and TV drivers, but uses the spin compiler to allocate memory not statically as in the Parallax examples.

This shows you correctly how much space is left for programing

I just tried it at 160x112 and 144x112

in config.spin
  x_tiles = 9   ' 12
  y_tiles = 7     ' 10
At the lower resolutions it is nice to change the tvparams to double size
in tv_graphics.spin
                        long    20 '10              'hx
                        long    2 '1               'vx
This is a 144x112 that fills the TV screen.

Bill Henning · 2011-05-02 14:51

Thanks Perry - that sounds absolutely perfect for my application!

160x112 is only 4,480 bytes - down right miserly use of memory for a display that will still look great on a 3.5" NTSC display!

Perry wrote: »
The code actually uses the standard graphics and TV drivers, but uses the spin compiler to allocate memory not statically as in the Parallax examples.

This shows you correctly how much space is left for programing

I just tried it at 160x112 and 144x112

in config.spin
  x_tiles = 9   ' 12
  y_tiles = 7     ' 10
At the lower resolutions it is nice to change the tvparams to double size
in tv_graphics.spin
                        long    20 '10              'hx
                        long    2 '1               'vx
This is a 144x112 that fills the TV screen.

Perry · 2011-05-03 06:02

Sapieha wrote: »

Hi Perry.

It is possible to change it to PAL?

Still having trouble with your two PAL monitors?

The only thing I have to test PAL is an old ATI video capture card on a junk win2000 computer (only 96M ram).
It shows and handful of PAL standards to try. I was successful with the first option (PAL-B), with some shimmering of colors!

All I did to get PAL working was:

  tv_mode |= 1     ' add this for for PAL
  tv.start(@tv_status)

Perry

Sapieha · 2011-05-03 06:21

Hi Perry.

I run them relatively good on one of Drivers people mentioned. This driver have some moire But acceptable.

It is "Poor Mans Digital Oscilloscope" I will have run on PAL with colors - Not only gray scale.

Perry wrote: »
Still having trouble with your two PAL monitors?

The only thing I have to test PAL is an old ATI video capture card on a junk win2000 computer (only 96M ram).
It shows and handful of PAL standards to try. I was successful with the first option (PAL-B), with some shimmering of colors!

All I did to get PAL working was:
  tv_mode |= 1     ' add this for for PAL
  tv.start(@tv_status)
Perry

Perry · 2011-05-13 19:42

Sapieha wrote: »

Hi Perry.

I run them relatively good on one of Drivers people mentioned. This driver have some moire But acceptable.

It is "Poor Mans Digital Oscilloscope" I will have run on PAL with colors - Not only gray scale.

In another threadhttp://forums.parallax.com/showthread.php?131552-Question-about-Propeller-RTC-emulator

Phill mentioned "creepie crawlies" on NTSC as a problem with clock accuracy.

perhaps you could improve your PAL display by adjusting the clock frequency

  _clkmode = xtal1 + pll16x
'  _xinfreq = 5_000_000   '  change this 
  _clkfreq = 80_000_000    'or this  +- 100 to get rid of "moire"

Perry

Sapieha · 2011-05-14 02:08

Hi Perry.

Will look on that.

Thanks

Dr_Acula · 2011-06-13 16:01

Does anyone know if there is such a thing as a 160x120 full color driver for TV?

I know Kye has one for VGA, and with 1 byte per pixel this uses 19200 bytes. So there should be enough ram to do the same thing for TV, right?

Rayman · 2011-06-13 16:07

I have a bitmap/video viewer for TV on my website. I think it's about that resolution.
I've adapted it to show images from my Flashpoint memory modules...

Dr_Acula · 2011-06-13 16:19

Thanks Rayman - that's a little thread that slipped under my radar! http://forums.parallax.com/showthread.php?116192

You have audio working as well? Very impressive!

I need to take a look at your code in more detail, because I wrote an automatic encoder for the 160x120 VGA movie maker, and if we combine our efforts we ought to be able to automate your movie maker.

Addit - I tried downloading the Profprop source code but something is not right - it is a 1.8Mb zip but inside is just one 6k .dat file? Any chance you would be able to post the source code? Many thanks in advance.

Rayman · 2011-06-13 16:59

I think the file is just big because of the uncompressed video... I do think the code is posted though... I'll try to find time to dig it up...

Dr_Acula · 2011-06-13 17:27

Thanks++ Rayman.

I guess big picture, VGA displays seem to be cheap if they are big (free if you want a CRT one), but once you go to QVGA they get expensive. However, these rearview TVs are a mass produced item that seems to be coming down in price.

30fps is very impressive too - I think I only managed to get the Kye video to run at about 20fps and so the audio would not quite have been in sync. I don't know how you got the audio to work too - it really is quite a clever piece of work.

Rayman · 2011-06-13 17:50

Did I really get 30fps? I seem to remember only getting 10, even with a modified FSRW...

Dr_Acula · 2011-06-13 17:52

From your thread

Just got a Propeller video player working!

Plays video on TV at 160x120 resolution and 30 fps with 22050 sample/second mono audio from SD card.

Mind you, if it is too slow, Kye's driver might fix that.

Rayman · 2011-06-13 17:57

Hmmm. Well, I hope I didn't lie...

Dr_Acula · 2011-06-13 18:01

Your thread says you got this with the v2.3. I found the files - they are in the second zip. I'm quite excited about testing this out!

Where can I find a 160x120 bitmap 4 color TV driver? I could not find one in OBEX

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