[FFmpeg-user] De-telecine, deinterlace, and filter chains

[Billy]

On 1/23/2017 10:24 AM, Andy Furniss wrote:
> Andy Furniss wrote:
>> Andy Furniss wrote:
>>
>>> Vid looks like it's scaled up from 480 height and pillarboxed, so
>>> the weave is not line for line anymore.
>>>
>>> It's probably been scaled as progressive which on strong chroma
>>> will (I think) be un-mendable. Saying that the sample can be scaled
>>> down to 480 and the weave is 1:1 again, which holds out the
>>> possibility that you could make it interlaced again with tinterlace
>>> and try to get IVTC to run on that.
>>
>> Maybe tinterlace was a crap idea as IIRC it would need field rate
>> input. Another way could be to scale down to 480 do a field rate
>> deint and drop duplicated frames.
>
> Though that's not really correct either.
>
> Whatever further processing is done, I think that scaling down to 480 is
> going to be the first step. I live in pal land, so don't have experience
> of dealing with ntsc.


Ah, so they must have used a GIGO filter.

Garbage in, garbage out.

That gives me an idea. The source video was also offered at lower resolutions. 
It looks like the high resolution download was upscaled junk, now that you 
explain what evidently happened. I will play around with other "originals" 
until I obtain one which can be detelecined or deinterlaced.

Thanks a bunch for this little clue!