VideoInfo::IsParityKnown? It is?

[Ebobtron]

At the risk of being slapped, I revisit a tried subject, hopefully from a different point of view.

While info() displays "Parity: Top Field First"
{
VideoInfo::IsParityKnown() == FALSE;
VideoInfo::IsTFF() == FALSE;
}

While info() displays "Parity: Assumed Top Field First"
{
VideoInfo::IsParityKnown() == TRUE;
VideoInfo::IsTFF() == TRUE;
}

I understand that while the function “Info()” may display information about field parity, I also understand that it may be incorrect.

When I “Assume(TTF)” in my script, “Info()” "assumes" parity is top field first as well.

Ok, I get that.

Questions:
May I assert that "VideoInfo::IsParityKnow()" will only return true when the script author assumes field parity in their script?

Or should I assume that in the future the current implementation of VideoInfo class functions "IsParityKnow()", "IsTFF()" and "IsBFF()" may change?

:)

Thanks
http://members.aol.com/avsfilmcutter

[IanB]

They may change slightly. There are some ""inconsitancies"" that are being thought about (and sometimes argued about ;) ) Feel free to add your 2 cents worth.

[Ebobtron]

I can maybe add a couple of cents, but I doubt that I will add any sense to the conversation.

I am working to add a “script output prosperities list” to a preview feature in avsFilmCutter, much like the data derived from AviSynth’s Info() function.
This feature has a video preview window and script editor in one, with the list displayed next to the video window. As the user builds their script, they may select to update the video display and properties list. This may not improve the process of writing scripts but it will not hurt the process either.

As I was working and noticed the behavior of the functions I was disappointed that the field parity functions did not track the data provided by Info(). :(

The thought occurred to me that the current implementation would allow the user to pass field parity data to an enterprising application like FilmCutter or HC. This application could look at the info, realizing that the author declared the field parity and make use of this information accordingly.

As I write this it comes to me that if the “IsTFF()” and “IsBFF()” where allowed to track whatever flag “Info()” used we could leave “IsParityKnown()” to track the script authors assumptions. End result would be the same. Except I could show the user the field parity that AviSynth assumed without the user having to use the function “Info()” in their script.

if(VideoInfo::IsParityKnown())
check for which
else
don’t check because the parity is truly assumed.

Edit: Its about two hours later and I notice an error in my assumptions, but it changes not my suggestion and prompts the question.

Why should "VideoInfo::IsParityKnown()" return TRUE only if the script contains either "AssumeTFF" or "AssumeBFF" and is field based?
Is not the parity known when either field or frame based. To me it would seem at least as important in frame based content.

Field, frame it all begins to blend together after awhile. :)


I guess that is more like 5 cents worth.
:thanks:
Thanks Ian for listening and may I assert that this is a very small pimple on a very big rear end.

p.s. If you could find the time and look at http://forum.doom9.org/showthread.php?p=761663#post761663 DSS halts FilmCutter on MCIWndClose() or even when the MCIWindow is distroyed. I also have a question about devIL.dll, but I don't have the question yet.