[FFmpeg-user] When to determine frames are progressive or interlaced ?

[Tim Nicholson]

On 19/12/12 10:36, Carl Eugen Hoyos wrote:
> tank pranav <akshar_tank <at> yahoo.com> writes:
> 
>> I would like to know when to determine frames are 
>> progressive or interlaced ?
>

When, or how?

The various flags can come from container/stream flags, which may, or
may not be interpreted correctly, and may, or may not, have been
correctly set in the first place by the coder.

AVFrame->interlaced_frame holds a frame by frame flag of what ffmpeg
thinks the current state is....

> (Depending on how you define "interlaced" frames:)
> To the best of my knowledge, only visual inspection 
> tells you, but there is a filter named "idet" that 
> tells you if the video is interlaced.
> 

idet makes a "statistical guess" and can quite often return a result of
"don't know" especially when movement is slight so your mileage may vary.

> Carl Eugen
> 
>[..]


-- 
Tim