[FFmpeg-user] "interlace"

[Mark Filipak]

On 09/06/2020 04:16 PM, Edward Park wrote:
> Hi,
> 
>> In the case of "interlace":
>> "It's interlaced video" -- video in which the lines alternate (i.e. are interlaced) between two (or theoretically, more) fields (e.g. odd-even-odd-even...). That employs the past participle of the verb, "interlace", as an adjective to modify "video".
>>
>> H.262 refers to "interlace video" when referring to hard telecine. But "interlace video" is a bit of a mutt. "Interlace" is clearly being used as an adjective, yet "interlace" is not a participle (past or present) -- "interlaced" is the past participle and "interlacing" is the present participle. What it would have to be is a verbal adjective (i.e. a verb used as an adjective). I may be wrong, but I don't think there exists such a thing as a verbal adjective.
> That's more or less what a participle is.
> 
>> A hard telecined video residing on a disc is clearly not interlaced. It is clearly deinterlaced (i.e. stored in fields). Since it is deinterlaced, it can be fed directly to a scanning TV (i.e. CRT) provided it is of the proper frame rate, or it can be interlaced -- a verb -- by a decoder as part of the decoding step.
> 
> Is it? Hard telecine is like telecining film and then recording it on a VCR, isn't it? And you don't need to deinterlace interlaced video to display it on an interlaced scanning TV. I think the confusion is when you deinterlace interlaced video, it is still interlaced video (or at least I think of it that way).
> 
> Regards,
> Ted Park

I have great respect for you, Ted. Tell me: What is interlaced video?