qcomp - what is it?

[TheLastOfThem]

For your source it doesn't. It's usually meant for sources with a lot of interlacing when you want to make the source progressive for one reason or another. It turns each field into its own frame. It won't do you any good at all. You'll double the framerate but also double the number of duplicate frames.

Thank you manono! I figured something like that... a lot of people claim they see "smoother motion" going from an interlaced 29.97 source to 50fps compared to keeping the deinterlacer in Mode 0 (not doubling the FPS). I figured if it just duplicates frames...how on earth would that lead to "smoother motion"

[jagabo]

True interlaced 29.97 fps video has 59.94 unique fields per second. Each field represents a different point in time. So (smart) bobbing to 2x fps gives much smoother motion. Not everything is shot on film at 24 fps. Live sports, most news, some TV shows are shot at 59.94 fields per second.

[TheLastOfThem]

True interlaced 29.97 fps video has 59.94 unique fields per second. Each field represents a different point in time. So (smart) bobbing to 2x fps gives much smoother motion. Not everything is shot on film at 24 fps. Live sports, most news, some TV shows are shot at 59.94 fields per second.

True interlaced 29.97 meaning no 3:2 pulldown? How do you know something is 29.97 true interlaced?

[Selur]

bob the content if you got a change between each frame your content is interlaced and not telecined.

[TheLastOfThem]

bob the content if you got a change between each frame your content is interlaced and not telecined.

Why would this be the case?

[pandy]

True interlaced 29.97 fps video has 59.94 unique fields per second. Each field represents a different point in time. So (smart) bobbing to 2x fps gives much smoother motion. Not everything is shot on film at 24 fps. Live sports, most news, some TV shows are shot at 59.94 fields per second.

True interlaced 29.97 meaning no 3:2 pulldown? How do you know something is 29.97 true interlaced?

Interlace is technique for bandwidth compression (lossy) - video is captured (but also in case of animation or generally CG) draw/created with field rate, in interlace video frame is build from two fields as such frame rate is a half of the field rate.
Usually there is progressive acquisition (so camera sensor) aquire frames with full resolution, later half lines (odd or even) is selected to form field, two fields combined, new frame (interlaced) created.
To know if there is fake or true interlace you need analyse fields - if there is difference between fields (motion) then it is interlaced, no difference means progressive.

bob the content if you got a change between each frame your content is interlaced and not telecined.

Why would this be the case?

easier to perform visual delta so comparing fields - no change=progressive, change= interlace

[TheLastOfThem]

True interlaced 29.97 fps video has 59.94 unique fields per second. Each field represents a different point in time. So (smart) bobbing to 2x fps gives much smoother motion. Not everything is shot on film at 24 fps. Live sports, most news, some TV shows are shot at 59.94 fields per second.

True interlaced 29.97 meaning no 3:2 pulldown? How do you know something is 29.97 true interlaced?

Interlace is technique for bandwidth compression (lossy) - video is captured (but also in case of animation or generally CG) draw/created with field rate, in interlace video frame is build from two fields as such frame rate is a half of the field rate.
Usually there is progressive acquisition (so camera sensor) aquire frames with full resolution, later half lines (odd or even) is selected to form field, two fields combined, new frame (interlaced) created.
To know if there is fake or true interlace you need analyse fields - if there is difference between fields (motion) then it is interlaced, no difference means progressive.

bob the content if you got a change between each frame your content is interlaced and not telecined.

Why would this be the case?

easier to perform visual delta so comparing fields - no change=progressive, change= interlace

So you're just talking about anything with 3:2 pulldown here? Because that has 2 interlaced frames out of every 3?

[Selur]

Applies to all pulldown, if you got a mix of interlaced and progressive frames you should be able to see the pattern (looking for changes) once you bob the content,...

[TheLastOfThem]

Applies to all pulldown, if you got a mix of interlaced and progressive frames you should be able to see the pattern (looking for changes) once you bob the content,...

So basically any source that's 3:2 pulldown (before bob) benefits from 50fps deinterlace?

[Selur]

No clue where that comes from,...
Normally you wouldn't bob a source which a pulldown was applied to, you would apply the reverse pulldown to recreate the original progressive frames.
Bobbing would just create lots of duplicates and waste bandwidth.
You normally use bob on pulldowned content only during the analysis of the source to be sure what/if pulldown was applied,...

[TheLastOfThem]

No clue where that comes from,...
Normally you wouldn't bob a source which a pulldown was applied to, you would apply the reverse pulldown to recreate the original progressive frames.
Bobbing would just create lots of duplicates and waste bandwidth.
You normally use bob on pulldowned content only during the analysis of the source to be sure what/if pulldown was applied,...

Ah I see. So something that just has purely interlaced frames and no 3:2 pattern? So if I have a TV Episode recorded with a capture device in interlaced....but the original animation was duplicated to be 24p by company ...does it still help for "smoother motion"

[Selur]

If you got an interlaced source you would apply a bobbing to keep all the motion information from the source and not loose half of it using same-frame-rate interlacers.
(for non-sport / high motion clips most folks use a same-frame-rate interlacer, since there often isn't that much additional motion information that could get lost)

[TheLastOfThem]

I see! Thank you Selur! I just realized manono already answered the question about my animation and bobbing to 50fps not helping.

Seems bobbing only helps for shows that are essentially shot for 60 fields/sec like TV Shows

[TheLastOfThem]

True interlaced 29.97 fps video has 59.94 unique fields per second. Each field represents a different point in time. So (smart) bobbing to 2x fps gives much smoother motion. Not everything is shot on film at 24 fps. Live sports, most news, some TV shows are shot at 59.94 fields per second.

Manono mentioned

" It's usually meant for sources with a lot of interlacing when you want to make the source progressive for one reason or another. It turns each field into its own frame. It won't do you any good at all. You'll double the framerate but also double the number of duplicate frames. "

Can you please give an example of possibly what shows are shot at 60i?

[Selur]

No clue if any tv show is shot at 60i since I live in a country where PAL and not NTSC is used as default.
But like jagabo I would guess that your best show is with a live sports event.

[pandy]

Seems bobbing only helps for shows that are essentially shot for 60 fields/sec like TV Shows

Nope - bob converting interlaced frames (consisting two, half vertical resolution fields) to "full" vertical resolution frames with field rate - i.e. bob converting fields to frames - missing vertical lines are created by interpolation.
It is valid for any interlace source.
Side to this nowadays almost there is no camera capable to "shot" in interlace format - first camera acquire full frame so progressive video and then during video signal processing interlace frames are created.
Same process for 50 and 60 fps, movie (film/cinema) is special case where different framerate (24 fps) is converted to TV compatible way - this is so called pulldown - it can be performed by 3:2 pattern in NTSC area but in PAL area this approach will fail and you need different patterns/methods.
But once again pulldown is not interlace - this is crude (but clever) way to convert or rather match cinema framerate with different than cinema TV framerate.