View Single Post
Old 12th January 2023, 03:58   #46  |  Link
flossy_cake
Registered User
 
Join Date: Aug 2016
Posts: 605
This thread was very informative, thank you.

There is however one problem still: my Sony DVD player, when playing soft telecine content which contains 95% film, is able to do something DVD2AVI's "force film" cannot do: detect those 5% combed frames by looking at frame flags. I believe our current tools only allow this to be done by analysing pixels for combing patterns. Obviously it would be better to use the frame flags since that is more reliable (well, assuming the post company or software they used didn't muck it up )

It appears that LWlibavVideoSource(repeat=false) is able to get those frame flags in real time as it updates the _FieldBased frame property every frame. But LWLibAVVideoSource is bugged and cannot play back the video at correct speed when doing this - it's some sort of bug, it plays 23.976 at around 24.1. I have mentioned it on the git issues thread here.

DirectShowSource has a similar problem - it gets it right for a while, but then after a while audio sync goes out (or it just randomly starts stuttering really badly, depending on convertfps=true/false setting).

So for now the only 2 real-time options for handling soft telecine seem to be:

Option 1: use FFmpegSource2(rffmode=2) which uses DVD2AVI's "force film" mode which outputs 95% progressive frames (23p) at the correct speed. Then for the 5% combed frames, manually detect & deint them with IsCombedTIVC (or whatever your preferred filter is for detecting combed frames).

Option 2: use LWlibavVideoSource(repeat=true) or FFmpegSource2(rffmode=1) , which will convert it to hard telecine (29i). Then use TFM.TDecimate to convert it back to 23p.

Here is a test clip recommended as short clips I find tend to have broken frame flags and led me to numerous false conclusions https://drive.google.com/file/d/1xz_...usp=share_link . This is MPEG2 remux from the NTSC DVD and hasn't been clipped or altered in any way apart from putting it inside a mkv container.

Last edited by flossy_cake; 12th January 2023 at 04:11.
flossy_cake is offline   Reply With Quote