MKV - interlaced or not tool?

[JorgeO]

Hello,

Is there a tool that will let one know if a MKV file is interlaced or not?

Thanks,

[RickA]

Greets,

MediaInfo provides alot of useful info about your .mkv files. There is also a Matroska Shell Info program but I do not think it is as verbose as MediaInfo.

Cheers,
Rick

[poisondeathray]

Some automated tools may detect incorrectly.

The only (almost) sure way is to use your eyes. Open the .mkv in avidemux and advance frame by frame.

[jagabo]

There are no programs that reliably report interlace for any file type. You have to examine unprocessed frames for interlace comb artifacts. Software that reports interlace vs. progessive generally only tells you whether the codec treated the frames as interlaced video when it compressed them, not whether the frames themselves really contain interlaced video.

[JorgeO]

Thanks, guys.

I usually use GSpot - if it shows fileds=2X frames, I take it as interlaced.
But GSpot shows very little on MKV files...

Edit - Just found out that in text mode MediaInfo gives info re interlaced or not.

Question -
I play a MKV in Avidemux (V2.4) frame by frame (as suggested by poisondeathray) and the video looks like progressive.
But if I convert the same MKV file to MPG (no deinterlacing), GSpot shows fields=2X frames (some MKV - not all).

I'm at a loss here (but will check with MediaInfo also).

[jagabo]

Question -
I play a MKV in Avidemux (V2.4) frame by frame (as suggested by poisondeathray) and the video looks like progressive.
But if I convert the same MKV file to MPG (no deinterlacing), GSpot shows fields=2X frames (some MKV - not all).

I'm at a loss here (but will check with MediaInfo also).

GSpot only shows you how the video was encoded (ie, if the MPEG encoder was told to use interlaced mode or progressive mode; this effects how the video is handled internally) not whether the frames contain interlaced or progressive data.

Since you are probably working with PAL video I suspect you simply took a progressive MKV file and told the MPEG encoder to use interlaced mode. This will smear the colors a bit compared to using progressive mode.

[PuzZLeR]

Tools will only report how the file was encoded, not how it is. You can have progressive looking frames in an interlaced video, or even vice-versa. No info there.

Short answer: MeGUI is usually very good at analyzing a clip for you in AviSynth Script Creator. Use the middle tab and wait till it does its analysis.

Longer more detailed answer if you use your eyes:
Not sure how perfect MeGUI can be particularly with mixed sources, but even better - load the file into VirtualDub directly (or via AviSynth script). Advance frame-by-frame during a motion scene and look for a pattern (or no pattern) and look for raking lines. You will pick it off in about 10-15 frames.

Here's my rule of thumb:

-If it's NTSC and you see a pattern such as P P P I I P P P I I P P P I I... where P is a progressive frame and I is an interlaced frame, this is what they call 3:2 pulldown (3 progressive and 2 interlaced frames every 5). The video is telecined from a film source. To deinterlace, you need to eliminate a repeated frame every 5 with a method called IVTC and reduce the fps to 23.976fps.

-If you see interlacing but no pattern then this is a true interlace. You can use Yadif or TomsMoComp to deinterlace. (This may apply to you more if you use alot of PAL content.)

-Seeing no interlacing, all progressive frames. The video is indeed progressive.

-Seeing no interlacing, all progressive frames in NTSC video BUT seeing one frame repeated every 5: You need to decimate to save bandwidth and remove the jerky motion if "deinterlacing". You'd be surprised that some movie companies don't encode efficiently in the first place. You would need a script like the following to "clean it up" and reduce it to 23.976fps.

ColorMatrix(hints=true, interlaced=true)
TDecimate(cycleR=1)

[JorgeO]

Thanks again, guys

Among you now I can find out if a file is interlaced or not.
For some reason, my VirtualDub will not open an MKV file, but Avidemux will.

Up to now the info I get from Media Info, MeGUI and Avidemux is the same for the few files I've tested.

[PuzZLeR]

Among you now I can find out if a file is interlaced or not.
For some reason, my VirtualDub will not open an MKV file, but Avidemux will.

You may need to demux the contents first from the MKV file using MKVExtract or TSMuxeR and then just use a simple AviSynth script pointing to the video file/stream for VirtualDub input. You can even test a deinterlacing script into VirtualDub as well by moving it frame-by-frame. (Then again, not an expert on AviDemux if it's a better viewing method.)

Up to now the info I get from Media Info, MeGUI and Avidemux is the same for the few files I've tested.

Try this with MeGui:

1) Tools-> AviSynth Script Creator (to create your script)
2) Options tab: load your video stream (or D2V file if it's MPG)
3) Filters tab (middle one): Analyze

MeGui will determine a deinterlacing method for you, whether it's a hybrid, true interlace, IVTC, decimation, or to do nothing with a progressive stream. It's not perfect, but it's the only automated tool that is quite accurate.

I still say the best way is moving it frame-by-frame with VirtualDub and using your eyes. It's easy after a bit of practice.