Interlaced encoding or deinterlacing w/ x264?

[Marsu42]

I am currently trying to backup an interlaced old BBC TV sitcom w/ mostly rather static scenes from DVD, correcting the bad AR and cropping on the way. Since x264 now supports interlaced encoding, I boldly chose this option and am wondering if this really was a good idea.

While this method certainly preserves the original fields, it takes ages to encode. Additionaly, (hq-)deinterlacing via avisynth and progressive encoding doesn't seem to be that inferior quality-wise even though this inflates the amount of raw data. And since I don't watch the stuff on a TV set, the software player has to do the (lq-)deinterlacing afterwards anyway...

Does anyone have experience on when it is a good idea to encode interlaced and when to deinterlace first? I just don't have the computing power to try out various script and encoding alternatives for myself.

[MetalPhreak]

I've never encoded anything as interlaced ever before, but there's really not much point in doing so if you're only watching on a PC monitor or any other progressive display. Interlaced encoding might be a good idea if you plan on watching on a TV.
My advice - deinterlace before encoding and encode as progressive.

[R3Z]

Interlacing should be dead. Please help kill it.

[scharfis_brain]

@R3Z: so then provide a good deinterlacer as well as tecniques to play back 1080p50 AVC coded video.

[Marsu42]

Interlacing should be dead.

Is this pure principle, or is there really no other reason to use interlaced encoding except for hd content or playback on a tv set?

The main point I was wondering about is if interlaced encoding gives higher transparency for archiving @ a given bitrate than deinterlacing first, or if the encoder throws away so many bits for the interlaced information that it is a waste of bitrate anyway.

[LoRd_MuldeR]

Is this pure principle, or is there really no other reason to use interlaced encoding except for hd content or playback on a tv set?

There is no reason to use interlaced, except old TV's. Newer TV's (LCD or Plasma) as well as all PC monitors won't display interlaced content properly without deinterlacing first. Nevertheless once deinterlaced there's no way to undo, while interlaced video can be deinterlaced at any time. Also note that there are huge differences between the different deinterlacers available...

[Marsu42]

Also note that there are huge differences between the different deinterlacers available...

... indeed, I think I tried them all but the good ones (motion-adaptive, edge enhancing) are killing off my old computer, too.

Btw, One other reason to deinterlace first is that filtering (temporal and spatial) gets much more flexible and faster this way. And resizing is possible, too.

[R3Z]

@R3Z: so then provide a good deinterlacer as well as tecniques to play back 1080p50 AVC coded video.

Whats with the agro ? :confused:

Seeing as though no hardware solutions are yet available, you would have to use a HTPC. With a decent Core 2 Duo and a medium to high end nvidia GPU you will be able to do all that.

[Jay Bee]

If the content is real interlaced you can keep it interlaced and use CoreAVC to deinterlace it with your GPU or you can deinterlace it to 50 fps before encoding which either takes a very long time or has inferior quality to GPU deinterlacing. What most people do though is deinterlace to 25 fps before encoding. I don't know why.

If the content is really progressive and was only interlaced for broadcasting then deinterlacing to 25 fps before encoding is the best method.

[Blue_MiSfit]

Look, I hate interlaced video as much as the next guy. But the fact remains that its impossible (with current AV equipment) to get more than 30 pictures per second with 1080p, as scharfis_brain said. The whole point of interlacing is to improve the appearance of motion by doubling the temporal information.

When we have bulletproof 1080p50/60, then yes, interlacing needs to die :)

I hate it so very much... but it has its place (the vast majority of the market)

~MiSfit

[Mug Funky]

bah.

first, any progressive TV worth it's salt will have a half decent deinterlacer built into it. sort of on par with kernelbob.

second, there's a fair legacy of interlaced content out there that can't be re-acquired. like about 60 years worth of it. if we all had to settle for watching stuff released in the last few years, we'd be a very culturally starved society. and i'm not big on the idea of deinterlacing archival footage either.

third, anything that's been standards converted in hardware will be interlaced. so as long as NTSC and PAL still exist as separate things (and they will... again with the legacy. broadcast equipment too often is NTSC only or PAL only. in fact in the machine room at work the only decks there that support both NTSC and PAL are the consumer VHS ones and the HDCAM SR deck).

true, it doesn't look nice on a computer (that isn't set up properly - see my comment about progressive TVs), but that's the only place it's ever looked off. i think if people can't hack dealing with interlaced video, then maybe it's time to switch hobbies/careers. if you want progressive it's probably best to just shoot it that way. if you want a "film look", then shoot on film and be prepared to pay through the nose.

and it's my opinion that any video encoder that doesn't support interlace is not fit for purpose, as "video" is by nature interlaced unless otherwise stated.

i think the only exceptions to the "keep it interlaced" rule are:

- director wants a film look. in that case think of the money and try to find a better director to work with.
- you're making stuff for streaming or download, and bitrate is important. in this case it's expected the quality will take a back seat to bandwidth, and there'll be no advantage to the extra motion and vertical detail.

[R3Z]

Look, I hate interlaced video as much as the next guy. But the fact remains that its impossible (with current AV equipment) to get more than 30 pictures per second with 1080p, as scharfis_brain said. The whole point of interlacing is to improve the appearance of motion by doubling the temporal information.

When we have bulletproof 1080p50/60, then yes, interlacing needs to die :)

I hate it so very much... but it has its place (the vast majority of the market)

~MiSfit

Bluray players handle that resolution fine :confused:

People seriously cant complain about PC's not being powerful enough can they ?

[cacepi]

Bluray players handle that resolution fine
They do?

Can you lead me to this magical device that can play back 1920x1080@60p video? Heck, I wouldn't need the 2k scanner anymore!

[R3Z]

They do?

Can you lead me to this magical device that can play back 1920x1080@60p video? Heck, I wouldn't need the 2k scanner anymore!

Sure my friend;

http://www.iq.sony.com/srvs/DocsConnect/docget.asp?manualid=70472&DL=',600,560,10,10,'Manuals'

This one does 1080i deinterlacing on the fly;

http://samsung.com/Products/Blu_ray/Blu_rayDiscPlayer/files/bd-p1200_final.pdf

The hardware is already here, time for the software to allow us to interface with it.

[Mug Funky]

Can you lead me to this magical device that can play back 1920x1080@60p video? Heck, I wouldn't need the 2k scanner anymore!

this will display it:

http://www.projectiondesign.com/Default.asp?CatID=1409

and this will shoot it:

http://www.arri.com/prod/cam/d_20/d_20.htm

but don't put away that 2k scanner just yet, as there's still plenty more to film than you'll get out of the above gear (at the moment... the D-20 looks stunning, and after grading there's not a big difference between it's pictures and super35 except for noise).

[Razorholt]

Quick question: Say that I want to minimize the storage, for a series of interlaced content (VOB). What is - technically - the best option?... knowing that I would like to watch the content on TV or my PC.

Option A: Keep the video interlaced, encode and then use a player that has an deinterlacer integrated.

Option B: Encode and deinterlace.

Again, I'm looking at a smaller video size as possible... unless there is no difference no matter what the option is.

Thanks,
- Dan

[Blue_MiSfit]

Well, if you really want to store the original content, then don't deinterlace. Unless you bob to 60/50p, you can never keep all the temporal information. In fact, you can never keep all the information when you deinterlace. Encode interlaced MPEG-4 ASP/AVC..

The difference in filesize between 29.97p and 29.97i will be small.

~MiSfit