Is MBAFF just interlaced?

[asarian]

I recently imported a few Continuum blu-rays from the UK. They appear interlaced (1080i50), and with TFF, and 'store method: interleaved fields.' The scan type is listed as MBAFF, though (looked kinda fancy on wiki). Can I just treat that as interlaced for QTGMC, though?

Thanks

[sneaker_ger]

MBAFF means it is encoded as interlaced. But that is no guarantee the actual content is interlaced as well. Since Continuum is a relatively modern show it is most likely progressive and does not need to be de-interlaced, though that begs the question why someone put a Canadian show on BluRay as 1080i50.

If you are unsure upload a sample of the source (~1 minute is more than enough).

[LoRd_MuldeR]

PAFF and MBAFF are just two different ways (or "modes") to encode interlaced footage (or partially interlaced footage) in H.264/AVC.

While PAFF allows switching between interlaced/progressive encoding on a per-frame basis, MBAFF allows this on a per-macroblock basis. Generally, MBAFF result in more efficient encoding, because it allows more fine-grained adaption.

This all does not say anything about whether the content is actually interlaced or progressive (or a mix therefore) at all, though!

For example: You can take a source that is 100% progressive and still encode it as either PAFF or MBAFF. That doesn't change anything about the fact that the footage is completely progressive and won't need deinterlacing ;)

(If you operate the encoder in PAFF [or MBAFF] mode, but feed it with a purely progressive source, you probably end up with all frames [or blocks] getting encoded as progressive)

__________________

As always: Look at the decoded video without any post-processing, especially with [B]no deinterlacing filter in effect, and watch out for "combing" artifacts. If and only if you see combing, then the content probably is interlaced (or Telecined).

[asarian]

MBAFF means it is encoded as interlaced. But that is no guarantee the actual content is interlaced as well. Since Continuum is a relatively modern show it is most likely progressive and does not need to be de-interlaced, though that begs the question why someone put a Canadian show on BluRay as 1080i50.

If you are unsure upload a sample of the source (~1 minute is more than enough).


Thanks. :) Here's the sample (20 secs):

https://1drv.ms/v/s!AhSxhQ9g_mrMhy08e2c7AKrt2vgr

I was afraid I might have to reencode everything (with QTGMC, at 50p), because I hate interlaced; but if I can avoid it, then I'll gladly do so, of course (as it's 4 Seasons long).

[asarian]

P.S. Thanks for the explanation, LoRd_MuldeR. :)

[sneaker_ger]

It's progressive, no QTGMC needed.

[asarian]

It's progressive, no QTGMC needed.

Thank you kindly! :)

[benwaggoner]

Typically 24p content gets sped up 4% to 25p for PAL. So most PAL DVD/Blu-ray discs of scripted US/CAN shows are 25p, although a bunch of them wind up flagged as 50i. Probably old habit from when the credits would be interlaced. In an interlaced bitstream any frame may still be encoded as progressive. Unfortunately, you can't assume the WHOLE title (particularly material at the front and end) will be progressive just because a section of the main content is interlaced.

[huhn]

the blu ray spec doesn't have 25p so it has to be 50i.

if the CAN/US BD is 23/24p than ignoring deinterlancing should be fine in this case.

you can add a fake interlanced flag to feel save if you like.

[benwaggoner]

the blu ray spec doesn't have 25p so it has to be 50i.

if the CAN/US BD is 23/24p than ignoring deinterlancing should be fine in this case.

you can add a fake interlanced flag to feel save if you like.
Although that will impact compatibility with some devices.

[huhn]

really doesn't a fake interlaced stream looks like a 50i stream for every device?

i have to say i personally don't really care about device compatibility.