handle progressive with telecined?

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rogerdpack
Posts: 13
Joined: Tue Jul 05, 2011 8:05 pm

handle progressive with telecined?

Post by rogerdpack » Wed Jul 06, 2011 3:20 am

Hello all.

I've also noticed that makemkv "total times" for DVD rips don't always seem to add up to the original DVD title times. "Typically" the makemkv output file corresponds to 29.97 fps (compared to 30 fps the commercial DVD player sum says).
Ex: commercial dvd player says the title length is 1:53:05s, the total time of output from makemkv for that title has total length 01:53:11.31 (which is right, based on 29.97 fps, which the content actually is).

But then sometimes it will be off by some amount. Like the output from makemkv will be 3s longer than that I would anticipate based on the above. Anybody know what might be going on there?

My current theory...

I know that some DVD's (many, in fact) are typically progressive 23.97 fps internally, but every so often slip into 29.97 fps mode (telecine frames I suppose). You know, for a few seconds, or for 1/3 second, then move back to progressive quickly.

So maybe makemkv isn't accomodating for this switch and is treating all internal frames as 23.97 when it puts the timestamps into the mkv file? The examples I've seen recently *might* corroborate that (example, one title is telecined for about 1s total, and the mkv file ends up being 0.2s longer [total sum] than the ts file if you extract it using tsmuxer, so the 0.2s might correspond to the extra 30 frames that were 29.97 fps but makemkv treated them as 23.97 so they inserted some extra time there.)

Thoughts/feedback?

Thanks!
-roger-

ref: http://www.mplayerhq.hu/DOCS/HTML/en/me ... ecine.html

rogerdpack
Posts: 13
Joined: Tue Jul 05, 2011 8:05 pm

Re: handle progressive with telecined?

Post by rogerdpack » Wed Jul 06, 2011 11:48 pm

I've discovered some other oddities. I'd be happy to send you original DVD's for these odd cases.

"typically" the mkv title length is (DVD_time*29.97/30). Also if you use tsmuxer and extract a .ts stream, it has the same length. Example: Other Side of Heaven DVD.

"sometimes" the mkv title length is (DVD_time*29.94/30), but if you extract a .ts stream, it has length (DVD_time*29.97/30), which is right. So the makemkv output is...too long somehow, by about 0.03 fps. Example: Snow White DVD.

"sometimes" the ts stream is right length (DVD_time*29.97/30), but makemkv mkv output is, seemingly arbitrarily, a second and a half too long.

So that's what I'm seeing. Again I'd be happy to send you some original DVD's to use for debugging purposes to see what's going on (for you to keep :)

Cheers!
-roger-

rogerdpack
Posts: 13
Joined: Tue Jul 05, 2011 8:05 pm

Re: handle progressive with telecined?

Post by rogerdpack » Wed Sep 14, 2011 6:20 pm

I'd be happy to donate to makemkv if this odd timing issue were resolved (makemkv sometimes reports a total time slightly too high, see above). I'd be happy to send a test DVD. Anything!

Until then I can't recommend makemkv to my users I guess.
Thanks.
-roger-

Romansh
Posts: 872
Joined: Sat Jan 22, 2011 7:09 pm

Re: handle progressive with telecined?

Post by Romansh » Wed Sep 14, 2011 9:16 pm

How did you determine the durations:

1) for the DVDs?

2) for MakeMKV's output?

rogerdpack
Posts: 13
Joined: Tue Jul 05, 2011 8:05 pm

Re: handle progressive with telecined?

Post by rogerdpack » Tue Jan 08, 2013 9:52 pm

handbrake yields a file with length 01:23:34.03
makemkv: 01:23:32.52

dvd advertises as 1:23:28.166

actual wall time appeared to be around 1:23:31'ish [?] so makemkv may actually be closest

So it appears in this case the DVD uses 29.97 fps MPEG stream, but then rounds the MPEG NAV packets' times *down*

I guess everybody has their opinion as to how long it should be, that may be my biggest take home lesson here (it's unclear if makemkv had any timing issues or not, as well, sorry for the noise) :)

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