• State Resolved
  • Locked Locked
  • Replies 3 replies
  • Subscribers 98 subscribers
  • Views 533 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

Does the DM648 video port support 1080p?

Eddie3909
Guru 10385 points

Hi

What is the difference between the BT.1120 and the due SMPTE 424 and 425? The vport user guide (spruem1.pdf) says it can support BT.1120, but most of the online info references SMPTE424/425 as the 1080p standard.

Can the DM648 vport support 1080p SMPTE424/425?

Also, is the BT.1120 referenced in the datasheet also the same as BT.1120-3-2005 reference in the article below?

Thx

 

About the 3Gb/s SMPTE Standard

Over the past few years, the demand for high-definition content at higher bit rates has escalated. Broadcast studios and other video production facilities have wanted to extend the life of their infrastructure by using the same hardware currently used for HD-SDI. Thus, the standards bodies, SMPTE and ITU, ratified a series of new 3Gb/s SDI standards, the SMPTE 424M (physical interface), SMPTE 425M (format mapping) and ITU-R BT.1120-3-2005, that allows for the use of the same 75-ohm coaxial cable for transmission as currently in use. This new standard, generally referred to as 3Gb/s SDI, enables higher resolution of pictures required for 1080p 50/60.

  • 0
    TI__Mastermind 41665 points

    Eddie said:
    What is the difference between the BT.1120 and the due SMPTE 424 and 425?

    I am not very familair with all of the SMPTE standards, but SMPTE 424 and SMPTE 425 are not mentioned in SPRUEM1 that I can find. The BT.1120 spec is not publicly posted, I believe you have to buy it, so it is hard to be specific about what this means (I don't have a copy), but in general my interpretation of the BT.1120 has been a BT.656 like stream that is 16 bits wide for HD resolutions. In other words the BT.1120 implies that you have a 16 bit data bus and a clock, with embedded syncs on the bus, at least this has been my interpretation.

    Eddie said:
    Can the DM648 vport support 1080p SMPTE424/425?

    Unfortunately not, the pixel clock on the DM648 can simply not go high enough to handle 1080p60 standard video.

    Eddie said:
    Also, is the BT.1120 referenced in the datasheet also the same as BT.1120-3-2005 reference in the article below?

    It probably is, however I believe BT.1120 does not really inherently imply 1080p60 support, but rather the format and timing requirements of standard HDTV (i.e. 720p60 and 1080i30) signals which are supported by DM648.

  • 0 in reply to Bernie Thompson TI
    Guru 10385 points

    Hi

    I couldn't find the BT.1120 spec either. Could it be that BT.1120 is for 1080p 30 fps rates and under, wherease SMPTE 424/425 is for 1080p50 and 1080p60?

    I guess 1080p30 (and the other frame rates of 23.98, 24, 25, 29.97) are doable?

    Cheers

     

  • 0 in reply to Eddie3909
    TI__Mastermind 41665 points

    Eddie said:
    I couldn't find the BT.1120 spec either. Could it be that BT.1120 is for 1080p 30 fps rates and under, wherease SMPTE 424/425 is for 1080p50 and 1080p60?

    That is my impression.

    Eddie said:
    I guess 1080p30 (and the other frame rates of 23.98, 24, 25, 29.97) are doable?

    This should certainly be possible, as long as the pixel clock is kept under the data sheet maximum (9.259nS period ~ 108MHz).