How to change the field order dinamically
VBMizio
I'm quite new in DS programming.
I'm using VS2008 (VB) and DirectShowNet to write a playout software.
Thanks to the GMFBridge controller, I can play seamlessly some video clips,
usually some mpeg2 files.
Depending on the editing software, I can obtain a top first field file or a
bottom first field file; I need to play out the clips through a decklink
card.
Is there a way to switch the field order dinamically? Is there a transform
filter that is able to do this?
Any idea is welcome.
Thanks in advance... Maurizio
Stanza
"VBMizio" <ross...@tin.it> wrote in message
news:4b28a57b$0$30970$4faf...@reader3.news.tin.it...
> Is there a way to switch the field order dinamically? Is there a transform
> filter that is able to do this?
There are two possible ways.
You would need to buffer samples and combine odd-numbered lines with even
numbered lines from the previous input frame (i.e. the fields) or vice
versa. You would probably have to discard the first and final field aswell.
You may also have to tweak the sample timestamps because you would
effectively be shifting the frame boundary by 1 field.
An alternative simpler method is to shift in unison ALL of the lines of a
frame up or down by 1 line. You would not have to do any buffering of
samples, and would not have to tweak the sample timestamp. The only minor
disadvantage is that you would lose 1 line of detail off the top or bottom
of the frame and would have a duplicate (or black) line at the opposite edge
of the frame - this may not be a problem unless you propose to do this
several times on the same frames.
VBMizio
thanks for your answer.
...
> There are two possible ways.
[...]
> An alternative simpler method is to shift in unison ALL of the lines of a
> frame up or down by 1 line. You would not have to do any buffering of
> samples, and would not have to tweak the sample timestamp.
Do you know of some DirectShow filter ( if possible, free) that make this
possible?
Can you show me a starting point to create this filter by myself?
I'm a VB6 - VB.Net programmer, so I don't know so much about C++
programming.
Thanks again... Maurizio