24 bit RGB for DVI output

Danillo Graziosi

Other Parts Discussed in Thread: DM3730

Hi,

I am currently working on a AM/DM37X Mistral evaluation board (DVSDK 04.03.00.06), and trying to output plain 8-bit RGB video using the DVI output.

I adapted the video playback exercise (lab07c) from the "linux embedded system design workshop". I was able to successfully change the UYVY output to RGB565, but when I change to RGB888 the program fails on the first Display_put() and then hangs on the next Display_get() function.

Is there any limitations to the color depth output on a DM3730 ? Can I program the device to use 24 bit RGB colorspace (all the functions in the DMAI library use 16bit YUV default values) ?

My ultimate goal is to output plain RGB video with 2Kx2K video resolution at 60 frames per second, but now I can just work with lower resolutions (like 1280x720). I want to have a playback application running, to verify decoding of my compression algorithm.

I appreciate your help.

Best regards,

Danillo

over 11 years ago

0 Margarita Gashova over 11 years ago

TI__Guru* 80190 points

Hello,

I am not familiar with your board and DVSDK but you could check in the TRM for the supported formats:

http://www.ti.com/lit/ug/sprugn4r/sprugn4r.pdf

Chapter 7. Display Subsystem

Hope this helps.

Margarita

0 Cvetolin Shulev-XID over 11 years ago

TI__Guru 65405 points

Hi Danillo,

The display subsystem supports programmable pixel display modes with 1, 2, 4, 8, 12, 16, and 24 bits per pixel. Therefore the maximum color depth of display output is 24 bits per pixel. You can obtain some additional information from the Technical Reference Manual section - 7.4.2.1 Display Modes at the link:

http://www.ti.com/lit/ug/sprugn4r/sprugn4r.pdf

About resolution and frame rate the maximum pixel rate of DM3730 is 75 MHz. This means that at resolution 1280x720 max supported frame rate is 60 fps (pixel clock = 74.25 MHz) but with 2Kx2K video resolution the max frame rate should be around 17 fps.

Tsvetolin Shulev

0 Danillo Graziosi over 11 years ago in reply to Margarita Gashova

Intellectual 480 points

Hello,

thanks for the quick answer. The document was very useful, and I can see that there are two pipelines, a graphics pipeline and a video pipeline. For the case of the video pipeline, only three input formats are supported: UYVY, YUV420 and RGB565 (all 16-bit formats). I guess this is an specification of the DM3730, is that right ?

Is there any other chip that supports higher bit-depth in their video pipeline (such as YUV444 or even RGB24) ?

If I want to use the graphics pipeline instead of the video pipeline, is there any examples that show how to program that, using codec engine, or are the codecs only to be used by the video pipeline ?

Thanks,

Danillo