HCenc - Encode 24p with pulldown as interlaced

[hwjohn]

As the title suggests, I was wondering if there was a way to make HCenc encode a 23.967 fps clip with a 3:2 pulldown as interlaced. The GUI automagically forces progressive if you select 3:2, since it is expecting progressive film material as the input.

Since I know it will be asked , I do have a good reason. I am using HCenc to encode a test pattern that consists of alternating, single pixel height, horizontal black/white lines, and interlaced encoding increases the quality while decreasing the file size (significantly). We want to use 24p with pulldown because the disk is for HD playback devices (HD DVD/Blu-ray) and, more importantly, more playback devices can get a film mode deinterlace correct than the motion adaptive deinterlace that is required if we use 29.97 fps (no pulldown).

Any ideas would be greatly appreciated.

[manono]

Hi-

Any ideas would be greatly appreciated.

While I didn't quite understand all that you wrote, why can't you encode your 23.976fps progressive source as interlaced but without applying pulldown in the encoder. Then when all done, apply pulldown using DGPulldown.

http://neuron2.net/dgpulldown/dgpulldown.html

[hwjohn]

Originally Posted by manono

Hi-

While I didn't quite understand all that you wrote, why can't you encode your 23.976fps progressive source as interlaced but without applying pulldown in the encoder. Then when all done, apply pulldown using DGPulldown.

http://neuron2.net/dgpulldown/dgpulldown.html

Thanks manono, I didn't realize that DGPulldown existed. That seems like it would work. I'll try that and report back. Thanks again, and thanks to neuron2 for writing DGPulldown, wherever he is.

[Guest]

Originally Posted by hwjohn

thanks to neuron2 for writing DGPulldown, wherever he is

I'm right here, having just returned from my vacation. DGPulldown was inspired by Xesdeeni, the main work by me and valuable contributions by Jetlag and timecop. Please feel free to suggest improvements.

[hwjohn]

Originally Posted by neuron2

I'm right here, having just returned from my vacation. DGPulldown was inspired by Xesdeeni, the main work by me and valuable contributions by Jetlag and timecop. Please feel free to suggest improvements.

Thanks to all for DGPulldown, it appears to have worked correctly.

The material I used DGPulldown on is a 1920x1080 HD stream. The file plays fine after the pulldown, and WMP 11 deinterlaces the pattern correctly using a reverse 3:2. I have not had time to look at all the flags to double check things, but would DGPulldown change any other flags besides the 3:2 pulldown and drop frame? I just want to make sure that it wouldn't change any other flags to match DVD specs instead of HD DVD (bitrate, VBV size, etc).

Thanks again.

[Guest]

In addition to the TFF/RFF flags and drop frame, it also sets progressive frame in the picture coding extension and clears progressive sequence in the sequence extension. These are required for field pulldown to work properly. Nothing else is changed.

[hwjohn]

Originally Posted by neuron2

In addition to the TFF/RFF flags and drop frame, it also sets progressive frame in the picture coding extension and clears progressive sequence in the sequence extension. These are required for field pulldown to work properly. Nothing else is changed.

That should be fine. We have a couple of patterns that really benefit from using field encoding instead of frame, and we wanted to stay with field encoding while using a 3:2 pulldown. DGPulldown worked great for that. Now the pattern can be field encoded with an avg. quantizer of 1, average bitrate of just over 1000, and be deinterlaced by a film mode deinterlacer to produce a virtually perfect pattern. Thanks again!

P.S. - Is it against forum rules to post a link to a thread in another forum? I thought I might post a link to the disc we are working on so that those with HD players could take advantage of it if they are interested in calibrating their display (most patterns require a colorimeter to use, but we have a basic section that only requires a few gel color filters like those commonly distributed with commercial cal discs). Is this ok?

[Guest]

It is OK.