- Posts: 1
- Joined: Mon Dec 11, 2017 3:59 pm
Hi everyone,
I'm not really a video guy, so I could really be asking beginner questions here: sorry about that, but still I think I need a little help from you:
In my company we are building a software that will output SDI video using a DeckLink Duo 2 card.
Those video streams should contain KLV data in some "VANC line".
And so, what I noticed is that:
A. When I use a video format such as 720p@60Hz or 1080p@30Hz, then I can configure everything as desired and then put some date on the "line 25"
B. If I try to use an interlaced format instead such as 1080i@59.94Hz of 1080i@50Hz: Then even if I can setup everything as desired, then I can't retrieve that line 25 for writting. The call to the following function will fail:
anc1->GetBufferForVerticalBlankingLine(startLine, (void**)&buffer)
Actually, I also tried all possible values for "startLine" above in the range [0,59] and none of them can be retrieved with the interlaced video formats (while all of them can be retrieved with the progressive formats).
=> So the question I have is: is this normal and expected ?
- I actually see a few options here:
A. I couldn't find any standard document stating that we could have "VANC" lines with interlaced formats, so maybe this is just not supported at all ?
B. Or maybe this is a limitation due to the current Decklink card we are using ?
C. Maybe it's a driver issue somehow ?
D. Or maybe I'm dong something terribly wrong :-S...
Thanks for your help and clarification on this point!!
Cheers,
Emmanuel.
I'm not really a video guy, so I could really be asking beginner questions here: sorry about that, but still I think I need a little help from you:
In my company we are building a software that will output SDI video using a DeckLink Duo 2 card.
Those video streams should contain KLV data in some "VANC line".
And so, what I noticed is that:
A. When I use a video format such as 720p@60Hz or 1080p@30Hz, then I can configure everything as desired and then put some date on the "line 25"
B. If I try to use an interlaced format instead such as 1080i@59.94Hz of 1080i@50Hz: Then even if I can setup everything as desired, then I can't retrieve that line 25 for writting. The call to the following function will fail:
anc1->GetBufferForVerticalBlankingLine(startLine, (void**)&buffer)
Actually, I also tried all possible values for "startLine" above in the range [0,59] and none of them can be retrieved with the interlaced video formats (while all of them can be retrieved with the progressive formats).
=> So the question I have is: is this normal and expected ?
- I actually see a few options here:
A. I couldn't find any standard document stating that we could have "VANC" lines with interlaced formats, so maybe this is just not supported at all ?
B. Or maybe this is a limitation due to the current Decklink card we are using ?
C. Maybe it's a driver issue somehow ?
D. Or maybe I'm dong something terribly wrong :-S...
Thanks for your help and clarification on this point!!
Cheers,
Emmanuel.