Is my DivX INTERLACE or PROGRESSIVE ? *PLEASE HELP*! tia.

[Comfy]

Whenever I get an AVI (DivX), and want to convert it to SVCD, I have no idea whether to set it to INTERLACE or PROGRESSIVE or not.
Is there anyway of finding out if an AVI is interlaced as VirtualDub does not give that info?
Also, I cannot understand when and when not to use the telecinc option within TMPG

Thanks so so much in advance.
Gray

[snowmoon]

99% of all avi's are progressive.

Interlacing is easy to see by just scanning the video looking for the alternating lines that are apparent on almost any motion.

[banjazzer]

100% of DivX are progressive!

[snowmoon]

Xvid just added support for interlacing.... and I doubt any movies would ever use it, but the possibility is there.

[Comfy]

Thanks so much to all of you!
Right, Everything seems to be running fine. I have encoded my DivX using progressive and with Inverse telecine on, but... do I need to do this pulldown thing?

I do not understand how the inverse telecine works with pulldown.
I have read all the 'how-tos' but would appreciate one last chunk of advice on this.

Thanks again all !!!!
Gray

[snowmoon]

NO.... no inverse telecine necessary...

Telecine is a property of INTERLACED video. Using TMPGenc and the "film" templates you do not need pulldown as TMPGenc automaticly inserts the proper flags.

Telecine is the process by which studios add fields to a video stream to bring it from 23.976 -> 29.97 for NTSC video. When you capture a movie you will see this very distinct pattern of 3 progressive 2 interlaced frames. Most DVD's use soft telecine where the video is encoded at 23.976 and little bits of information in the stream tell the DVD player to repeat the fields necessary to replicate the telecine process on the fly.

Inverse telecine is for video where the the framerate is 29.97 and a telecine pattern is present. Working properly IVTC will take out the extra fields and restore the video back to 23.976 before encoding.

Why: Mpeg encoders are better at encoding progressive materal than interlaced since their is more "similarity" for the encoder to work with.

If you use TMPGenc you can tick the settings/3:2 pulldown on playback and TMPGenc will automatically insert those bits of information back into the stream as it encodes to make it a valid 29.97 stream. If you forget that, use CCE, or another encoder you can add those bits of information with the pulldown utility. This utility will only take a video only stream and it will add the appropriate bits and output a new stream.

[Comfy]

snowmoon, your info is very valuable to me, thanks.
But. VirtualDub tells me that my video is a 23.976 video and when I use the wizrd in TMPEG it automaticly chooses the inverse telecine option!

I turned it off and converted to SVCD but the playback is strange as it plays ok for about 8 seconds, then has frame break up for about 8 seconds and carries on like that.

So, I decided to to turn inverse telecine back on and encode the SVCD and hey presto... no jaggered playback!
In all this, I kept it as progrssive.

I am trying my best to understand all this and your last reply was great, but in practice it didn;t work?

Any other ideas friends?
thanks
Gray

[Comfy]

ALSO...
There are slight jaggered line around all objects which suggests a slight interlace problem?

[Comfy]

Right, I have just done a few more tests...
I had to turn onverse telecinc on so that the frame rate runs smooth even though it is a 23.976 divx.

Anyway, I did a SVCD convert in progressive, then one using interlace.

On widescreen TV playback, they both appear the same, with the same problem...

When a character walks past some railings (for example) the motion of the camera moving past the railings causes each railing to 'comb-effect'.

WHY?????????????????

This is really bugging be now, surely there must be an easy way to encode to SVCD from DivX?

Thanks!
Gray

[banjazzer]

Since you cannot have an interlaced DivX, it sounds like your DivX may have been created incorrectly from an interlaced source...

[Comfy]

thanks banjazzer!
I have concluded the various divx I have tried should be encoded as progressive.

But, I need to use inverse telecinc otherwise the frame rate stutters every 10 seconds or so as described above!

So, I end up with the correct frame rate - no jitters... BUT, during motion scenes, I just saw another one with somebody waling past a window... you can make out the 'comb' effect along the sides of the widow and on the person walking past them.

I have used 3 completely different DivX files now and it happens the same on all of them ! ?

Oh well, I have wasted 34 discs now and counting... so am really glad of your advice and any other advice you guys can offer.

Cheers!
Gray

[Comfy]

Another snippet of info which may help you guys help me is...

The file plays fine (no combing) on my PC.
Another curious thing is that is I pause on my standalone DVD player at a combing part... and then click frame by frame advance... there is no combing... yet, when I resume the full motion play, it is back.

Damn it, I wish I knew what was wrong
Cheers!
Gray