HD resolutions… Correct forum?

[Micah Mcdowell]

720 at 59.94 would mean likely mean 720p, which is 59.94 full progressive frames per second.

The 1080i HDV you’ve been working in is 60i, meaning 59.94 interlaced fields per second, which corresponds to a “framerate” of 29.97. Does that answer your question?

[John Sharaf]

Jason,

Because progressive frame rates do not have “half” frames (otherwise known as “fields”) there are now 60 frames per second instead of 30 frames. This is why some observers think that 720/60p creates a “smoother” action than interlaced formats.

When you specify 720/30p, each of the distinct 30 frames are repeated one time to create the 60 frames that are consumed each second. At this frame rate the “action” looks more “filmic” because it includes a 2:2 pull down cadance.

Hope this helps,

JS

[Jason Brown]

OK…I think I got it…I’ve worked with NTSC D1 interlaced Betacam SD video for a LONG time…so I fully understand interlacing.

Question about 720p…so I can do 720p at 29.97…right? I know I’ve naively rendered things to the 720 resolution at 29.97 progressive. (played back on a media box…worked correctly)

I think I was mosly confused by the fact that 1080 is listed at 60i sometimes…but I’ve never heard the listing 60p…wouldn’t that be the correct way to refer to 720p footage?

1920×1080 60i would be 30 frames per second interlaced.
1280x720p could be called 60p? Correct?

Thanks for helping me understand this guys…

-Jason

[Bram Desmet]

To avoid confusion it is generally a really good idea to list both the native resolution and native frame rate. You would not want to refer to 1280x720p60 as just 60p because there is also a 1920x1080p60 broadcast format, albeit at almost 3Gbps bandwidth. You also have the less common 480p60 (flavor of EDTV) formats so 60p could be misleading as it does not necessarily imply 1280x720p60.

Bram Desmet
FSI (Flanders Scientific, Inc.)
http://www.FlandersScientific.com

[Jason Brown]

Does the 720 format come in other flavors or is the standard 60fps?

I may be asking a loaded question, because I’m guessing that delivery is dependent upon “standard” … I’m not referring to broadcast…only blu-ray and what monitors would support playing back from a media box type of delivery.

-Jason

[Bram Desmet]

Yes, 720 does come in other flavors. 720p24/25/30/50/60. If we were talking about broadcast this would actually be simpler as the number of transmission formats are generally much more limited, but when we start talking about playback from DVD, BluRay, digital media players, etc. these other formats may be more prevalent. Also, you are much more likely to run into 1080p60 with the type of equipment you describe, which again reinforces the idea that it is quite important to list the native resolution along with the frame rate to avoid confusion.

Bram Desmet
FSI (Flanders Scientific, Inc.)
http://www.FlandersScientific.com

[Jason Brown]

OK…GREAT information…I appreciate it!

My experience and understanding was that 720p @ 60fps was intended as slo motion footage…it can be played back like that, correct?

If you play back 60 fps video at 30 (29.97) it will be half speed at 30p, right? That’s always how I’ve seen it used.

-Jason

[Richard Herd]

It’s also worth keeping in mind the difference between:
— electronic signal processing &
— computer programming

There’s so much information on all of it, it’s hard to know exactly where to start, so here’s a place: https://lurkertech.com/lg/fields/ It’s written from the point of view of a computer programming trying to make software to turn a video signal into a video editing platform (like Final Cut Pro). This guy Mr. Lurkertech wrote specs for QuickTime. He’s an authority worth reading.

[Jason Brown]

Bram mentions later that the format exists of 1080p60 which would be 1920×1080 frame size at 60 progressive frames per second…wouldn’t that essentially kill 720p?

-Jason

[Jason Brown]

wow…that’s a pretty good read! I’ll take a look at work tomorrow…that may be well above my head! 🙂

Thanks for the good information…

Can anyone speak to the idea of using 720 60p as half speed footage? That’s the only application I’ve ever seen it used in…I don’t think I’ve ever seen anyone (editing) with 720 at 60 frames per second. (In my small circle of video professionals)

-Jason