HM100 recorded interlaced footage when in progressive mode

[Keith Moreau]

To Elvis and Andy:

If set to progressive, the HM100 should be recording native progressive and saving the data in the XDCAM EX format.

The XDCAM EX codec progressive mode is true progressive, it's not an interlaced format that combines or skips frames like some of the tape-based DV and HDV codecs which was an artifact and limitation of tape transport recording.

I personally use 1080 30P and this is where I experienced my problem, which is that it seems there is interlacing artifacts embedded into file that should be 'progressive.' Whether this is happening in the camcorder and is part of the actual video data or it's incorrectly recording interlaced and marking it as progressive, something is going wrong at the camcorder end.

[Leonid Yegoshin]

Anthony,

I looked into your clip. It looks like it is not a pure interlaced issue. The grass blades in front plane out of focus have clear light-green/dark-green long lines which lasts a couple of frames. But it should not be at all because grass is out-of-focus. Moreover, lines with interlacing problem should exist only 1 or 2 frames at the same place but not more.

It is more interesting look into original clip because this one has a trace of some re-encoding, it has Format profile: Main@High-1440 which is not available for MP4 shooting. That may underline the problem.

[Anthony Shera]

Originally Posted by Leonid Yegoshin

Anthony,

I looked into your clip. It looks like it is not a pure interlaced issue. The grass blades in front plane out of focus have clear light-green/dark-green long lines which lasts a couple of frames. But it should not be at all because grass is out-of-focus. Moreover, lines with interlacing problem should exist only 1 or 2 frames at the same place but not more.

It is more interesting look into original clip because this one has a trace of some re-encoding, it has Format profile: Main@High-1440 which is not available for MP4 shooting. That may underline the problem.

Leonid, please understand (and trust me) that if you had watched that clip as 1080p25, it would have looked IDENTICAL. I don't want to upload the whole, original file because then it would be about 200 MB in size, and I don't have a fast internet connection. The next best thing I can do is upload a shorter MPEG-2 file in 1080p25 mode. I have played the same original clip in the JVC ProHD Clip Manager and it looks exactly as the clip you now see. I will upload that version soon.

Also, about the file format being "Main@High-1440" -- I just realised that that was the "Level" that was set as the default in Adobe Media Encoder. I could have just chosen "High".

Originally Posted by Keith Moreau

I tried seeing if putting the clip into a XDCAM EX 60i timeline to see if I could fix it, and it didn't for me. It looks like the interlacing is embedded into progressive video, there's no way to 'deinterlace it.' so the footage is junk. It seems that the problem is not just that you have interlaced instead of progressive, it's that you have interlaced footage put into progressive frames. You can't fix it in post. If you had an important shoot with a lot of movement, you'd be screwed.

Yes this is what I was trying to convey in my original post about the interlacing being essentially "hard wired" into the progressive frames.

Interesting that FCP couldn't solve the problem by placing it into a 1080i timeline. Premiere Pro doesn't have a problem fixing it for me. Maybe you should try Premiere? I know Premier can handle .mov files. (I also use a Mac, btw, but prefer Premiere since it integrates so well with After Effects and Encore, which I use frequently.)

The problems I've had have all happened using battery power. It has only remained for two or three successive clips, then goes away on its own, even if the first clip in which the problem no longer exists is only a matter of a minute or two after the previous problem clip. I can't think what I've done between those clips to correct the problem. I doubt I have turned the camera off in that intervening time. From now on, when recording certain clips, I'm going to announce to the camera the main settings I have and what I've changed. That way when the problem inevitably arises again, I can see if there's a pattern.

Originally Posted by Elvis Ripley

1. Are we testing for 24p, 25p, and 30p in 1080 mode?
It seems like his were 25p I have seen my own under 24 but I shoot a lot under that and only noticed it when and HDMI cable was also plugged in. I am talking about the 24p the camera recorded, not what came out of the cable.

2. Does the HM100 capture 24p natively (24 frames, not 24p over 60i)
Native
3. Does the HM100 capture 30p natively (30 frames, not 30p over 60i)
Native

I thought the JVC captured 30p over 60i. This would explain why I can drop a 1080p30 clip into a 1080i60 timeline in Premiere Pro and no rendering is required, because Premiere can "see" the separate fields.

[Tim Nielsen]

This is a fascinating thread, has anyone contacted JVC about this, maybe they know exactly what is going on, who knows, maybe this is something slated already to be fixed in the firmware update? But it sure seems like someone should contact them, as the camera certainly shouldn't be operating in this way, right?

Tim

[Doug Tessler]

I called today so they now know about the issue .So I will hopefully hear from their engineers
Doug

[Leonid Yegoshin]

Originally Posted by Anthony Shera

Leonid, please understand (and trust me) that if you had watched that clip as 1080p25, it would have looked IDENTICAL.

Anthony, it is not a matter of trust, I believe you have seen something wrong. It is all about localizing the problem and find the way around it.

What puzzles me - there are 3 unexplained issue to mark the problem as "interlaced".

1) Long zigzag lines in front plane grass blades. In frame-by-frame advance it seems that blades moves slowly and it's edges are out-of-focus. However, zigzag lines are long and clear.

2) Zigzag lines and spaces between them consist from TWO pixels width. But fields actually interleave each other pixel line, that is a definition. I double check with my 1920x1080 clips and yes, zigzag lines in progressive still shot (postprocess from interleaved i60) are only one pixel width.

3) You said you downconverted a 1080 clip. But in most of downconverting procedures the zigzag lines will be blurred away because of a resolution drop (from 1080 to 720 - it is a 50%). In my knowledge the only downconverting procedure which could keep interleaved zigzags is the downconverting from interleaved stream and converting it to progressive. In some ways it may downgrade separately fields and turn to progressive later.

Now, because you are shooting in MP4 and I can't successfully analyze Keith's MOV files I have some interest in your original clip - that is a reason. I browsed through my shots (1+ month) but I don't see this problem. However, my experience with p30/p25 is limited because I shoot in i60 and use 720p60 for room/evening shots.

[Anthony Shera]

Leonid, would a 1080p25 clip in MPG format suffice? Adobe Media Encoder only allows me to output such a clip in the MPEG-2 format.

On the other hand, I have a 53 MB clip which is 12 seconds long that has this interlacing issue (or whatever you prefer to call it). I could upload this clip, completely unaltered, for you to analyse. But be warned that there is not a lot of movement in this clip so it is harder to see the problem than in the clip you've already seen.

[Leonid Yegoshin]

Originally Posted by Anthony Shera

I have a 53 MB clip which is 12 seconds long that has this interlacing issue (or whatever you prefer to call it). I could upload this clip, completely unaltered, for you to analyse. But be warned that there is not a lot of movement in this clip so it is harder to see the problem than in the clip you've already seen.

That would be great! Just point us to approximate time of trouble.

[Anthony Shera]

Leonid, here is the link of the unchanged MP4 file: http://dl4.rapidshare.ru/1126863/66133/000_0063_01.MP4

It is only 12 seconds long. Like I said before, the artefacts are not as easy to see as in the previous clip, though they are definitely there. Also the clip is pretty noisy because I think I forgot to turn the ND filter off.

[Simon Lucas]

Originally Posted by Anthony Shera

Leonid, here is the link of the unchanged MP4 file: http://dl4.rapidshare.ru/1126863/66133/000_0063_01.MP4

It is only 12 seconds long. Like I said before, the artefacts are not as easy to see as in the previous clip, though they are definitely there. Also the clip is pretty noisy because I think I forgot to turn the ND filter off.

Anthony,
I can confirm the interlaced image issue. Like you, that's what i'm calling it – as the evidence from my camera is very compelling. I looked at your footage and could see the same thing I have seen with my HM100. It's hard to see in your footage as there's little movement in your shot but it is there nonetheless.

I have had it in all files of 2 out of 4 shooting sessions that I have used the camera when I had it set to 1080 30p.

See my full size frame grab exported directly from a file opened in QT Player. No processing of any kind apart from jpg-ing it for upload. You can see the pronounced lines which are one pixel high:

http://www.flickr.com/photos/zenless...77140/sizes/o/

JVC have my camera for this and other reasons and I hope to hear from them about the interlacing problem any day.

[Jack Walker]

Does this happen in only 30p, or in 60p and 24p, too.

Please let us know what JVC says and if we need press for a recall.

There is something strange about. And suddenly word is silent on the training DVD that is past due coming out (with a single copy turning up on Australian Ebay).

It will be interesting to see what the announced firmware fix will be at the end of the month... or if news on that just goes silent, too.

[Simon Lucas]

Originally Posted by Jack Walker

Does this happen in only 30p, or in 60p and 24p, too.

.

I've only really tested the camera in 30p. The camera does 60i not p.

I'll keep you posted.

[Shaun Roemich]

Originally Posted by Simon Lucas

The camera does 60i not p.

The camera DOES do 720P60...

[Tim Dashwood]

Originally Posted by Keith Moreau

So Tim, JVC or others, if you are listening, please, please investigate. If you want I can upload some files to one of your FTP sites so you can investigate further.

I've been trying to replicate the issue but haven't been able to. Did anyone else stumble upon a sure-fire way to do it?

Originally Posted by Jack Walker

There is something strange about. And suddenly word is silent on the training DVD that is past due coming out (with a single copy turning up on Australian Ebay)

The delay on the release of the DVD has nothing to do with this. The DVD's were replicated over a month ago. The delay was simply in getting the free tutorials uploaded and the sales site built and implemented, which went live late yesterday. http://www.dvinfo.net/prohd You will start to see the DVDs pop up on ebay and on dealer websites this week. There's no conspiracy with JVC and I'm sure they have likely read this thread and are looking into it themselves.

[Jack Walker]

Originally Posted by Tim Dashwood

The delay on the release of the DVD has nothing to do with this. The DVD's were replicated over a month ago. The delay was simply in getting the free tutorials uploaded and the sales site built and implemented, which went live late yesterday. http://www.dvinfo.net/prohd You will start to see the DVDs pop up on ebay and on dealer websites this week. There's no conspiracy with JVC and I'm sure they have likely read this thread and are looking into it themselves.

Thank you for the update. I have ordered a DVD!