23.976 fps encodes play at incorrect speed when authored.

DVD-lab, DVD-lab Studio and DLP2
Post Reply
lalittle
Posts: 8
Joined: Sun Feb 27, 2011 7:37 am

23.976 fps encodes play at incorrect speed when authored.

Post by lalittle »

I encoded a 23.976 fps project in Cinema Craft Encoder Basic. When I import this into DVD Lab Pro 2 and author a DVD, the video plays too fast, and the audio is not in sync. Looking at the time counter on my DVD player and doing the math, I can see that the video plays 25% faster than it should, which is the exact difference between 24 and 30 fps. The audio plays at what appears to be the correct speed, and cuts off when the video ends.

In other words, DVD Lab Pro does not appear to be recognizing that the video is 23.976 fps, and the result is that the video plays at the full 29.976 fps without any pulldown being added, which means that the video is playing 25% too fast.

I found some reports from other people having the same issue with DVD Lab Pro, but so far I haven't been able to find a solution. I also saw reports from people saying that this issue was discussed on the mediachance forums, but it looks like the current mediachance forums only go back a few months, so I cannot find these posts. Some people said that they had to stop using DLP because of this, but I really like the program, and would very much like to continue using it.

Is there any way to fix this? I don't see any settings in CCE Basic that would effect this, and I'm using the settings that are recommended for CCE with 23.976 material. Also, given the other reports saying that the issue is unique to DLP, and that the same encoded files do not have this problem with other authoring apps, this appears to be a DLP issue.

Thanks for any feedback on this,

Larry

Vapymid
Posts: 291
Joined: Wed Oct 27, 2010 4:38 am
Location: London, UK

Re: 23.976 fps encodes play at incorrect speed when authored

Post by Vapymid »

I've done numerous DVDs with 23.976fps videos in DVDLab.

If you try to import such video into the assets bin, DVDLab will recognise it and won't let the import without pulldown (which it will offer to do for you). However, I mostly prefer to do the pulldown before DVDLab, using other utilities (e.g. pulldown.exe).

It appears that CCE does not put the correct fps value in your video file's header. Check the file's parameters with something like ReStream to confirm if that is the source of the problem.

Regards

lalittle
Posts: 8
Joined: Sun Feb 27, 2011 7:37 am

Re: 23.976 fps encodes play at incorrect speed when authored

Post by lalittle »

I'm not sure what happened at this point, but after closing and reopening CCE and loading/applying the same saved settings profile and re-encoding the file, I'm no longer seeing this issue. DVDlab did indeed ask to apply pulldown, which I let it do, and the clip now plays at the correct speed.

What does the DVDlab pulldown process actually do? Does it simply add some sort of flags to the frames, or does it alter the stream in more significant ways? Is there any particular reason that you prefer to do this with pulldown.exe instead of just letting DVDlab do it?

What about using something like Procoder instead of CCE? Procoder appears to take care of the pulldown during the encode since DVDlab does not need to alter the file when it's imported.

Thanks,

Larry

Vapymid
Posts: 291
Joined: Wed Oct 27, 2010 4:38 am
Location: London, UK

Re: 23.976 fps encodes play at incorrect speed when authored

Post by Vapymid »

Does it simply add some sort of flags to the frames?
Yes, the Repeat First Field flags + changes the timecode. Both operations completely reversible and do not change the actual encoded data in any way.
Is there any particular reason that you prefer to do this with pulldown.exe instead of just letting DVDlab do it?
Simply because I prefer to import ready-made assets into DVDLab and to control the filenames and locations before I do so.
Procoder appears to take care of the pulldown during the encode since DVDlab does not need to alter the file when it's imported.
Because it is such a simple operation the pulldown must be a secondary consideration to other things - like quality of the encoding. For all other things being equal, though, why not use what is the most convenient?

Just be sure that Procoder does not actually alter the fps during encoding (i.e. encoding with 29.97 full frames per second rather than 23.976 + RFF flags).

Regards

neilwilkes
Posts: 78
Joined: Mon Nov 15, 2010 12:50 pm
Location: London, England
Contact:

Re: 23.976 fps encodes play at incorrect speed when authored

Post by neilwilkes »

I'll be checking CCE-SP3 doing this in a few minutes time - in this, the pull options are either 2-3 or 3-2.
There is also an inverse pull option too.
Just trying on a new project right now and will poist back - if it is a CCE Basic bug, Cinemacraft will fix it very quickly indeed in my experience with them.

EDIT.
Imported the M2V file, encoded in CCE-SP3, from 23.976 source with 3:2 pull added in the encoder, and DLP has picked this up as a 29.97 file with pulldown applied.
http://www.opusproductions.com
http://www.so-audio.com
high resolution and surround sound specialists

lalittle
Posts: 8
Joined: Sun Feb 27, 2011 7:37 am

Re: 23.976 fps encodes play at incorrect speed when authored

Post by lalittle »

neilwilkes wrote:I'll be checking CCE-SP3 doing this in a few minutes time - in this, the pull options are either 2-3 or 3-2.
There is also an inverse pull option too.
Just trying on a new project right now and will poist back - if it is a CCE Basic bug, Cinemacraft will fix it very quickly indeed in my experience with them.

EDIT.
Imported the M2V file, encoded in CCE-SP3, from 23.976 source with 3:2 pull added in the encoder, and DLP has picked this up as a 29.97 file with pulldown applied.
Unfortunately, there is no option for CCE Basic on the Cinemacraft support form, so I can't submit a support request. On top of that, there hasn't been an update to the "Basic" version of the program for over 4 years now. They appear to have stopped support for the Basic version, so I have serious doubts that they'd fix the issue even if I was able to get a report to the right people. It really doesn't surprise me that SP3 doesn't have this issue given that updates for that version are still active, with the most recent one being only a little over a month ago.

Thanks for your help,

Larry

neilwilkes
Posts: 78
Joined: Mon Nov 15, 2010 12:50 pm
Location: London, England
Contact:

Re: 23.976 fps encodes play at incorrect speed when authored

Post by neilwilkes »

Hey Larry.

Update from this end - CCE-SP3 does not output a file that DLP seems to like!
Even though the file plays fine in a Media Player, it looks terrible when compiled in DLP - looks like a really bad day at the field order office....
Yet the exact same source when encoded with MainConcept encoder (straight out of Premiere Pro CS5.5, and *not* through the AME interface) it works flawlessly.
So it seems that CCE-SP3 is adding flags that DLP is not liking.
Tried both 2:3 and 3:2 pulls.

Trying to get a fix, but they cannot see a problem with my settings, so until they can repro this there will be no fix (boo).
Also, I suspect they check the output with a Media PLayer, and it works in the player - just not on the final DVD.
Cannot be the source files or DLP, or else it would not work from same source but with a different encoder.

I've had regular issues with ProCoder output too - it seems to crush the blacks really easily (Apple ProRes source).
Makes everything look like "The Godfather" almost!
http://www.opusproductions.com
http://www.so-audio.com
high resolution and surround sound specialists

lalittle
Posts: 8
Joined: Sun Feb 27, 2011 7:37 am

Re: 23.976 fps encodes play at incorrect speed when authored

Post by lalittle »

Neil -- Thanks for the update.

It sounds like you may be experiencing the same issue I am, which would mean that both CCE Basic and SP3 share the same issue. Perhaps they'll fix it in Basic if they figure out why it's doing it in SP3.

Regarding Procoder, this has become my new go-to encoder, and I'm definitely NOT getting crushed blacks. I'm actually REALLY sensitive to contrast and black level issues (I've run into them before), so I know what you're talking about, but my ProCoder encodes do not have any such problems. I would recommend not giving up on PC just yet. If you play with some settings in ProCoder and do a series of test encodes, I feel that there is an excellent chance that you could figure out how to avoid the issue. There are often settings in encoders that seem counter-intuitive, and it sounds like a 16-235 vs 0-255 setting is incorrect somewhere.

Note that I've run into encoders that automatically do color space re-mapping even when they're set NOT to, so the settings for this can be really confusing. This could definitely lead to crushed blacks. Note that it would also lead to crushed whites, but this is much less obvious than crushed blacks. Have you tried re-mapping the color space with the 601 correction filters in PC? You could also try playing with the color space settings on your source output. I use Avid, and with some encoders I need to change the QTRef color space output setting in order to get it to work. Other encoders can take either output and encode it correctly.

One thing I've done in the past to chase down this issue is to create a project in avid that consists of 15 seconds or so of color bars with the black level PLUGE bars. I output 2 QTRefs from this project, one using 16-235, and one remapped to 0-255. I then do encode tests on these files and check for black level issues, which the PLUGE pattern easily points out. Note that it takes some time to do these tests, especially since I like to go all the way to a burned DVD played in a regular DVD player hooked to a TV. This is the only way to positively confirm that the final output will be correct.

Please let us know what happens, and thanks again for posting to this thread. It's nice to know that I'm not the only one seeing this issue.

Larry

neilwilkes
Posts: 78
Joined: Mon Nov 15, 2010 12:50 pm
Location: London, England
Contact:

Re: 23.976 fps encodes play at incorrect speed when authored

Post by neilwilkes »

Hi Larry - it's actually Rhozet Carbon Coder that gave me the problem and I suspect it was caused by the Source file.
The ProRes looks different to the MOV so the encoder gets the all-clear (I rechecked everything after reading your excellent post)

NO issues with the 16-235 settings, and no problems with the settings in CCE-SP3.
They reckon they cannot replicate the issue though, so I am sending them a whacking great big file to look at.
No way will it upload inside a week, so easier to send on disc in the mail.
They usually fix this stuff, and the same file encoded beautifully in Premiere Pro, believe it or not, and played at the correct pitch & speed.
As it ought to.

Fingers crossed for the fix.
http://www.opusproductions.com
http://www.so-audio.com
high resolution and surround sound specialists

Post Reply