How can I tell if a video is interlaced?

[cheerful]

I got an AVI file and would like to know if it's interlaced or progressive. I tried with MPC, GSpot and Virtualdub but could not find this information. Can anyone help me to find out?

Thanks!

[Noahtuck]

Bitrate Viewer

[jagabo]

No software will be able to tell for certain whether a video contains interlaced frames or not. You have to use your own eyes and a viewer that doesn't deinterlace.

Open your video in VirtualDub. Go to a portion of the video where there is motion. Step through several frames. If you see comb artifacts the video is interlaced.

Note you are dealing with two issues here: whether the frames contain interlaced fields (the two fields come from two different pictures or two different points in time) and whether the video was encoded as interlaced (how the encoder treated the fields internally). Anyone can take a progressive source and encode it with interlaced settings. Conversely, anyone can take an interlaced source and encode it as if it were progressive. Software usually only tells you how the video was encoded, not what the frames originally contained. If you have interlaced video that was compressed as if it was progressive you still need to handle it as interlaced. The other way around, progressive video encoded as if it was interlaced, is more forgiving.

[Noahtuck]

I usually do it by eye also, but Bitrate Viewer tells you the spec's of whether it's interlaced, top field or bottom field first, ect.

I don't know how accurate it is overall but, i've used it a few times now & it has not lied to me yet 8)

[manono]

I usually do it by eye also, but Bitrate Viewer tells you the spec's of whether it's interlaced, top field or bottom field first, ect.

To repeat; GSpot tells you how it was encoded (and incorrectly sometimes), and not if the source is interlaced or progressive. For example, the vast majority of PAL movies on DVD come from progressive sources (no interlacing showing), but are encoded as interlaced. Most NTSC progressive 30fps footage is also encoded as interlaced. If GSpot agrees with what your eyes show you, then you've been lucky so far. If it says it's interlaced, then you have either some true interlaced 30fps footage (shot with interlaced video cameras) or some hard telecined movies. But that doesn't begin to cover all that's out there.

Again, you can't count on software to tell you if you're dealing with interlaced frames (fields from 2 different points in time, with interlacing showing during motion sequences), but only your eyes.

[Noahtuck]

I usually do it by eye also, but Bitrate Viewer tells you the spec's of whether it's interlaced, top field or bottom field first, ect.

To repeat; GSpot tells you how it was encoded (and incorrectly sometimes), and not if the source is interlaced or progressive. For example, the vast majority of PAL movies on DVD come from progressive sources (no interlacing showing), but are encoded as interlaced. Most NTSC progressive 30fps footage is also encoded as interlaced. If GSpot agrees with what your eyes show you, then you've been lucky so far. If it says it's interlaced, then you have either some true interlaced 30fps footage (shot with interlaced video cameras) or some hard telecined movies. But that doesn't begin to cover all that's out there.

Again, you can't count on software to tell you if you're dealing with interlaced frames (fields from 2 different points in time, with interlacing showing during motion sequences), but only your eyes.

Okay... pay attention now... to repeat... Bitrate Viewer Bitrate Viewer
I never said anything about Gspot

[jagabo]

What does Bitrate Viewer report for this file?

https://forum.videohelp.com/images/guides/p1730321/vid.m2v

What do your eyes tell you?

Some other things to consider:

AVI files may have no information about whether the video is interlaced or progressive. Consider an uncompressed RGB AVI. Some programs may examine individual frames (TMGPEnc Plus for example) to look for interlace artifacts but they often get the interace/progressive status and field order wrong.

A single MPEG file can contain a mix of interlaced, telecined and progressive material. DGPulldown can give you more information about this. But it only tells you what the MPEG headers say. If a video is encoded incorrectly it will report incorrectly.

[manono]

Okay... pay attention now... to repeat... Bitrate Viewer Bitrate Viewer
I never said anything about Gspot

Sorry, my mistake. Exact same thing, though. Everything I said also applies to Bitrate Viewer. And ReStream, and DGIndex, and any other software that can say Interlaced and Progressive.

[Noahtuck]

Well like i said,

I usually do it by eye also, but Bitrate Viewer tells you the spec's of whether it's interlaced, top field or bottom field first, ect.

I don't know how accurate it is overall but, i've used it a few times now & it has not lied to me yet 8)

Only a few times, but i can tell by looking anyways when working on something.

And i'll check that file in a bit and see.
Did you check it yet with that program ? I just DLed it a few days ago because i saw someone mention it for something and thought i'd try it, so it's not like i did some extensive testing on it 8)

[manono]

I don't know how accurate it is overall

Do you not understand what's being said? It's pretty accurate, as far as it goes. It tells you how it was encoded. It doesn't tell you anything about the source video. Those are 2 very different things sometimes. jagabo's sample above should put to rest any notion that it does define the source video.

Here's a short 600 KB M2V from a retail DVD. Bitrate Viewer will tell you one thing and your eyes will tell you another:

http://www.mediafire.com/?ehszk1ydvnh

To answer cheerful's original question; the common AVI types, such as XviDs and DivXs, are almost always progressive. To confirm, just do as described earlier. Advance frame-by-frame during a motion sequence after opening it in something that doesn't deinterlace (VDub(Mod) is good). If you don't see interlacing, it's not interlaced.

[Noahtuck]

No, i understand, i should have said i don't know how accurate it is for telling you whether or not something is interlaced or not, instead of saying overall 8)
I was just referring to that aspect because that's what we were talking about.
But if you have the original source video it should be accurate.

OKay okay.. just use your eye's... that's what i do anyway's
Like i said, i just got it the other day and have only used it a few times.

Ewww... somebody did not clean the 20th frame on that clip