24p on dvd at DVinfo.net

Yev Belman · April 20th, 2007, 10:08 PM

I have a couple of questions that I hope your experience can shed some light on.

What would it look like if I took a 24p comp rendered in AE and created a dvd from it directly? Is there a process during the transcoding that brings it up to NTSC standard 29.97p automatically?

When is it a good time to go progressive in my work flow? In the beginning with Fieldskit, or at the very end before rendering out the final product?

What if i have interlaced and progressive footage from the start of my project, how do I marry them in a composition. De-interlace the one, or re-interlace the other?

Does de-interlacing softens the image? by definition is it a loss of resolution?

Thanks for the help.

Douglas Toltzman · April 24th, 2007, 09:29 PM

It is my understanding that MPEG2 encoding is progressive and it's the DVD player's job to create an interlaced image for an NTSC display device. I could be wrong, as I've read varying explanations, but my experience with MPEG2 encoding is that the encoded video is progressive and that 24fps actually encodes better, because the same bit rate can yield higher quality frames.

In summary, encode the DVD directly from the 24p. I'm pretty sure you'll get pristine results. You really can't get the temporal qualities of 60 fields per second from the 24p, anyway.

Yev Belman · April 25th, 2007, 12:25 AM

Thanks for answering that. My camera only records in 60i, I then retime it with Twixtor down to 24p. It takes forever and I end up with huge files if i to stay away from recompressing to DV format. So i do the retiming sparingly, and as a result have some clips in 24p and some in original 60i.

Once i made an experiment and retimed 60i->24p and back to 24p->30p (composition within composition). That took a long time to render as can be imagined. I could then use the clip with my other 60i on the same timeline. Is this a stupid thing to do?

Frank Ladner · April 25th, 2007, 12:24 PM

This workflow sounds similar to mine, as I use Twixtor to convert to 24p.

I was also wondering about whether or not to output 24p source files to DVD. I haven't been able to test it because I'm still using an older Sony DRU-510 drive, which apparently can't write to the newer 3x and higher DVDs.

So... have to get a new drive. (Not bad considering they are around $40 or so now, compared to $250 when I purchased the Sony.)

Glad to know you should be able to output from 24p without doing pulldown to 60i.

Thanks!

April 20th, 2007, 10:08 PM	#1
Yev Belman Regular Crew Join Date: Mar 2007 Location: Charlotte, NC Posts: 27	24p on dvd I have a couple of questions that I hope your experience can shed some light on. What would it look like if I took a 24p comp rendered in AE and created a dvd from it directly? Is there a process during the transcoding that brings it up to NTSC standard 29.97p automatically? When is it a good time to go progressive in my work flow? In the beginning with Fieldskit, or at the very end before rendering out the final product? What if i have interlaced and progressive footage from the start of my project, how do I marry them in a composition. De-interlace the one, or re-interlace the other? Does de-interlacing softens the image? by definition is it a loss of resolution? Thanks for the help.

April 24th, 2007, 09:29 PM	#2
Douglas Toltzman New Boot Join Date: Feb 2007 Location: Hubert, North Carolina Posts: 16	It is my understanding that MPEG2 encoding is progressive and it's the DVD player's job to create an interlaced image for an NTSC display device. I could be wrong, as I've read varying explanations, but my experience with MPEG2 encoding is that the encoded video is progressive and that 24fps actually encodes better, because the same bit rate can yield higher quality frames. In summary, encode the DVD directly from the 24p. I'm pretty sure you'll get pristine results. You really can't get the temporal qualities of 60 fields per second from the 24p, anyway.

April 25th, 2007, 12:25 AM	#3
Yev Belman Regular Crew Join Date: Mar 2007 Location: Charlotte, NC Posts: 27	Thanks for answering that. My camera only records in 60i, I then retime it with Twixtor down to 24p. It takes forever and I end up with huge files if i to stay away from recompressing to DV format. So i do the retiming sparingly, and as a result have some clips in 24p and some in original 60i. Once i made an experiment and retimed 60i->24p and back to 24p->30p (composition within composition). That took a long time to render as can be imagined. I could then use the clip with my other 60i on the same timeline. Is this a stupid thing to do?

April 25th, 2007, 12:24 PM	#4
Frank Ladner Major Player Join Date: Aug 2003 Location: Poplarville, MS Posts: 453	This workflow sounds similar to mine, as I use Twixtor to convert to 24p. I was also wondering about whether or not to output 24p source files to DVD. I haven't been able to test it because I'm still using an older Sony DRU-510 drive, which apparently can't write to the newer 3x and higher DVDs. So... have to get a new drive. (Not bad considering they are around $40 or so now, compared to $250 when I purchased the Sony.) Glad to know you should be able to output from 24p without doing pulldown to 60i. Thanks!