really interlaced?

[ficofico]

I'm testing videos from sony nex camera, when I open in virtualdub mts file from other camera I see interlacing in 1 second... with this file, that mediainfo say interlaced TFF, I cannot see any kind of interlacing...
Here an example

http://www.vimeo.com/download/video:...c28ed177e47e70

[Guest]

"You have to be logged in to download videos."

Ain't gonna happen.

[LoRd_MuldeR]

I cannot access you file:

Permission denied
You have to be logged in to download videos.

However you need to understand that MediaInfo can only tell you how the video was encoded, but it cannot tell you the actual nature of the content.

Progressive footage can be encoded as interlaced. It's unnecessary and it hurts compression for no benefit, but it is possible. And it's not unusual at all in reality, i.e. in television broadcast.

Therefore the only reliable way to check whether the the video is interlaced or not is looking at the unprocessed/unscaled content with your own eyes...

[ficofico]

A ok

http://216.18.212.226/PRODS/NEX5/FUL...VCHD_00004.MTS

[Guest]

Did you try with your own eyes?

It's progressive encoded as fields.

[LoRd_MuldeR]

Originally Posted by ficofico

A ok

http://216.18.212.226/PRODS/NEX5/FUL...VCHD_00004.MTS

Clearly not interlaced:
http://i48.tinypic.com/2qv4gw1.jpg

Explanation already given in my previous post.

[ficofico]

why this kind of encoding?

[LoRd_MuldeR]

Originally Posted by ficofico

why this kind of encoding?

Because it's more "safe", if you are uncertain about the nature of the content you are encoding.

Encoding progressive footage as interlaced works okay. It's not as efficient as it could be, but it certainly isn't a huge problem either.

Doing it the other way around, encoding interlaced footage as progressive, is an absolute no-go! It would destroy the interlacing and thus screw up the content.

Also: If your footage was encoded by a hand-held camera, I assume the hardware encoder chip they use simply is "hardwired" to interlaced encoding

Maybe your camera even has different capturing/encoding modes, like 1080i60 -vs- 1080p30 ???

[Guest]

Who or what encoded it? A video camera? If so, you have to ask the manufacturer. Maybe the hardware encoder chip they use only does field encoding. Or the manufacturer decided to do it that way for some reason. There's no good reason to encode *known* progressive content with fields that I know of. If you don't know the content, however, ...

[ficofico]

There's no good reason to encode known progressive content with fields that I know of. If you don't know the content, however, ...

.... there are 2 model,
nex3 (720 30p)
nex5 (1080 50i)

but now we have seen that it's impossible to ricreate very 50p with some boobber from this source file....I think that it's better nex3 now.... I


For ""deinterlacing"" what I've to write in avs file?

assume TFF()
FieldDeinterlace()

?

[LoRd_MuldeR]

Originally Posted by ficofico

.... there are 2 model,
nex3 (720 30p)
nex5 (1080 50i)

Well, as the footage you posted was 1920x1080 at 29.97 fps and clearly is progressive, the "1080 50i" mode turned out to be a "1080 30p" mode

(But if the camera really did offer progressive and interlaced capturing modes, it indeed would make sense to have the encoder chip work interlaced in order to handle both cases)

Originally Posted by ficofico

For ""deinterlacing"" what I've to write in avs file?

If the footage is progressive, then there is nothing to deinterlace. Hence you don't have to write anything. Yes, it's that simple

(Applying a deinterlacer on progressive content would destroy detail for zero benefit!)

[Guest]

It's 1080p29.97 so neither nex3 or nex5 (as you describe them) could have created this clip. Why not actually answer my question? What camera made that clip?

The clip is progressive! You don't have to deinterlace it.

[Guest]

Isn't it nice to get your answers in stereo?

[ficofico]

Originally Posted by neuron2

It's 1080p29.97 so neither nex3 or nex5 (as you describe them) could have created this clip. Why not actually answer my question? What camera made that clip?

The clip is progressive! You don't have to deinterlace it.

Clip are from nex5... here a review with spec and more sample

http://www.imaging-resource.com/PROD.../NEX5VIDEO.HTM

[LoRd_MuldeR]

Originally Posted by ficofico

Clip are from nex5... here a review with spec and more sample

http://www.imaging-resource.com/PROD.../NEX5VIDEO.HTM

With a frame rate of 60 fields-per-second (interlaced), the Sony NEX-5 produces smooth motion, although it isn't clear whether the frame rate of the sensor is actually 60 fields-per-second, or if it's a 30 frames-per-second readout that's being interlaced to 60i. Looking at the Sony NDX-5's video in slow-motion playback (a feature we found ourselves using a surprising amount when viewing fast action), the motion certainly looks smooth enough that it could in fact be 60 fields-per-second at the sensor level.

What the heck are they talking about? Given that the "AVCHD" sample file really came directly from that camera and also given they didn't process (e.g. deinterlace) the file after exporting it from the camera, they could have easily found out that the content obviously is not interlaced! It's 1080p30, encoded as interlaced (progressive segmented frame). Why are they speculating about "motion smoothness" when the facts are that clear? The sample clip contains 29.97 full frames per second there's no doubt about that. And hence there is no way to get more than ~30 "snapshots" per second of temporal resolution out of that...

[ficofico]

The title It's because this......

[LoRd_MuldeR]

Originally Posted by ficofico

The title It's because this......

My assumption would be that the "reviewers" used a televsion screen with built-in deinterlacer rather than a PC screen.

Thus it's hard (if not impossible) for them to decide between interlaced and progressive content, as you always get to the see the progressive/deinterlaced version, no matter what the source content was.

Things get even messier if they use one of those fancy "100 Hz" or "200 Hz" television screens that will add artificial intermediate images to the actual content...

[ficofico]

All sample in web are similar.... not only this from imaging review... they are all progressive but encoded as flield

[LoRd_MuldeR]

Originally Posted by ficofico

All sample in web are similar.... not only this from imaging review... they are all progressive but encoded as flield

So the situation is quite clear

[ficofico]

High Def, Not Half Def
Many cameras take HD movies, but not so many offer the same Full HD 1080-line resolution as most broadcast HD networks4. And very few have the same 60i frame rate for fluid, natural motion. In fact, this is the world's first interchangeable lens digital still camera with 1080/60i HD movies1.

This is from sony.com about nex5