How many GIGS... at DVinfo.net

August 22nd, 2002, 03:05 AM

For Adobe Premier - how many megabytes/minute of footage do you need, is MPEG2 compression good, and is standard premier settings DVD quality. Note, this is all for shooting on the XL1.

Rob Lohman · August 22nd, 2002, 03:57 AM

To be able to better answer your question you should try to
explain it in a bit more words so that it is clearer. I also think
you are mixing things up. I'll try to answer your question the
best way I can, bear with me here.

First. Your camera decides the resolution/quality, not your NLE
(unless you are doing stupid things). The XL1 has exactly DVD
quality, so that is no problem. MPEG2 compression can look
fantastic (just look at some of the DVD's out there)!! The trick
however is in using a good MPEG2 encoder to get that results.
The cheapest best encoder at the moment seems to be TMPGEnc
from www.tmpgenc.com. It is very slow, however.

DV (this has nothing to do with Premiere or any other NLE) has
a fixed datarate of around 3.6 MB/s. So that is what you need.
So 1 minute will be around 216 MB. 2 Gig will give you almost
10 minutes of recording time. 4 Gig will get you 20 minutes.

If you need more than that in a single file go with a NTFS file
system under Windows 2000 or XP. I usually have a different
file for each of my takes/scenes so they are never more than a
couple of minutes in length.

If you have more questions feel free to ask them, or if something
is unclear. Please try to best describe your problem/question so
that other people can better help you out.

Thank you.

August 22nd, 2002, 12:47 PM

sorry about the vague ness of that last question.

So what is the highest resolution/quality mode I can record with in the XL1? - ie dvd quality?

Thanks,

Don Palomaki · August 22nd, 2002, 06:37 PM

The highest resolution and quality mode on the XL1 is DV using movie mode, which in general will be better than MPEG., but the difference may not be visible up for some types of material.

Frame mode will have slighlty lower resolution, but you may not notice the difference unless you look for it.

Rob Lohman · August 23rd, 2002, 05:14 AM

You can only have one resolution with the XL1. And that is the
full resolution. For NTSC this is 720x480 and for PAL 720x576.
This is the EXACT SAME resolution for DVD. Don't worry, all will
be okay.

Don Palomaki · August 23rd, 2002, 05:28 PM

Perhaps a fine point but as noted by Rob the NTSC DV image area is always 480x720 pixels. The XL1 lops off a few pixels from each side in the overscan region.

However, the other aspect of image resolution is what the analog electronics, optics, CCD, and DSP do. Frame mode has somewhat different DSP forming the image which yields a slightly lower resolution representation of the shot scene in the 720x480 frame.

Kai Leibrandt · August 25th, 2002, 06:19 AM

One thing to remember is that spatial resolution (i.e. the 720x480 pixels per image for NTSC and 720x576 pixels for PAL) are not the only aspects of a video image that affect its quality.
Another very important aspect is colour resolution, which means roughly put how many time per image a colour is sampled. This is where the DV format loses out to a DVD's MPEG 2.

A DVD will sample the colour information at half the frequency of it's luminance (brightness) sampling (this is called 4:2:2, the first 4 meaning the number of luminance samples, the other two meaning the samples for red and blue, green is simply the remainder got by substracting these from eachother).

MiniDV however samples only at 4:1:1 (NTSC) or 4:2:0 (PAL), which are basically just two different strategies of sampling the colour information a quarter as many time as the luminance samples per image.

You may ask "why is this important?". Well, it means that you get blocking of colour information, and these blocks are called compression artifacts. You may have seen them in a really badly compressed jpeg image, they're there for a different reason but the result is quite similar.

For everyday filming these compression artifacts really pose no great problem, but as soon as you want to do any kind of digital processing, you will run into problems as the colours of the image may appear slightly offset, or halo-ed. This is especially problematic when doing compositing, and though it kinda-works, a pro will never use 4:2:0, or, worse, 4:1:1 material for compositing. This is where DVCPro50 is better off (4:2:2 at 50mbit/s), and Beta or DigiBeta are better still...

Woops. Way over the top. Sorry. I hope this is helpful or even interesting to the original poster tho.

Kai.

PS: For those that are really interested, there's lots of info at http://www.adamwilt.com/DV.html.

Don Palomaki · August 25th, 2002, 06:28 AM

Of course DVD/MPEG2 have other artifacts to deal with which make it less suitable for editing.

And going to 4:2:2 gets one out of the XL1 price point range of products.

August 22nd, 2002, 03:05 AM	#1
ameria.net Posts: n/a	How many GIGS... For Adobe Premier - how many megabytes/minute of footage do you need, is MPEG2 compression good, and is standard premier settings DVD quality. Note, this is all for shooting on the XL1.

August 22nd, 2002, 03:57 AM	#2
Rob Lohman RED Code Chef Join Date: Oct 2001 Location: Holland Posts: 12,514	To be able to better answer your question you should try to explain it in a bit more words so that it is clearer. I also think you are mixing things up. I'll try to answer your question the best way I can, bear with me here. First. Your camera decides the resolution/quality, not your NLE (unless you are doing stupid things). The XL1 has exactly DVD quality, so that is no problem. MPEG2 compression can look fantastic (just look at some of the DVD's out there)!! The trick however is in using a good MPEG2 encoder to get that results. The cheapest best encoder at the moment seems to be TMPGEnc from www.tmpgenc.com. It is very slow, however. DV (this has nothing to do with Premiere or any other NLE) has a fixed datarate of around 3.6 MB/s. So that is what you need. So 1 minute will be around 216 MB. 2 Gig will give you almost 10 minutes of recording time. 4 Gig will get you 20 minutes. If you need more than that in a single file go with a NTFS file system under Windows 2000 or XP. I usually have a different file for each of my takes/scenes so they are never more than a couple of minutes in length. If you have more questions feel free to ask them, or if something is unclear. Please try to best describe your problem/question so that other people can better help you out. Thank you. __________________ Rob Lohman, visuar@iname.com DV Info Wrangler & RED Code Chef Join the DV Challenge \| Lady X Search DVinfo.net for quick answers \| Buy from the best: DVinfo.net sponsors

August 23rd, 2002, 05:14 AM	#5
Rob Lohman RED Code Chef Join Date: Oct 2001 Location: Holland Posts: 12,514	You can only have one resolution with the XL1. And that is the full resolution. For NTSC this is 720x480 and for PAL 720x576. This is the EXACT SAME resolution for DVD. Don't worry, all will be okay. __________________ Rob Lohman, visuar@iname.com DV Info Wrangler & RED Code Chef Join the DV Challenge \| Lady X Search DVinfo.net for quick answers \| Buy from the best: DVinfo.net sponsors

August 22nd, 2002, 12:47 PM	#3
ameria.net Posts: n/a	sorry about the vague ness of that last question. So what is the highest resolution/quality mode I can record with in the XL1? - ie dvd quality? Thanks,

August 22nd, 2002, 06:37 PM	#4
Don Palomaki Wrangler Join Date: Sep 2001 Location: Northern VA Posts: 4,487	The highest resolution and quality mode on the XL1 is DV using movie mode, which in general will be better than MPEG., but the difference may not be visible up for some types of material. Frame mode will have slighlty lower resolution, but you may not notice the difference unless you look for it.

August 23rd, 2002, 05:28 PM	#6
Don Palomaki Wrangler Join Date: Sep 2001 Location: Northern VA Posts: 4,487	Perhaps a fine point but as noted by Rob the NTSC DV image area is always 480x720 pixels. The XL1 lops off a few pixels from each side in the overscan region. However, the other aspect of image resolution is what the analog electronics, optics, CCD, and DSP do. Frame mode has somewhat different DSP forming the image which yields a slightly lower resolution representation of the shot scene in the 720x480 frame.

August 25th, 2002, 06:19 AM	#7
Kai Leibrandt Regular Crew Join Date: Apr 2002 Location: Munich, Germany Posts: 70	One thing to remember is that spatial resolution (i.e. the 720x480 pixels per image for NTSC and 720x576 pixels for PAL) are not the only aspects of a video image that affect its quality. Another very important aspect is colour resolution, which means roughly put how many time per image a colour is sampled. This is where the DV format loses out to a DVD's MPEG 2. A DVD will sample the colour information at half the frequency of it's luminance (brightness) sampling (this is called 4:2:2, the first 4 meaning the number of luminance samples, the other two meaning the samples for red and blue, green is simply the remainder got by substracting these from eachother). MiniDV however samples only at 4:1:1 (NTSC) or 4:2:0 (PAL), which are basically just two different strategies of sampling the colour information a quarter as many time as the luminance samples per image. You may ask "why is this important?". Well, it means that you get blocking of colour information, and these blocks are called compression artifacts. You may have seen them in a really badly compressed jpeg image, they're there for a different reason but the result is quite similar. For everyday filming these compression artifacts really pose no great problem, but as soon as you want to do any kind of digital processing, you will run into problems as the colours of the image may appear slightly offset, or halo-ed. This is especially problematic when doing compositing, and though it kinda-works, a pro will never use 4:2:0, or, worse, 4:1:1 material for compositing. This is where DVCPro50 is better off (4:2:2 at 50mbit/s), and Beta or DigiBeta are better still... Woops. Way over the top. Sorry. I hope this is helpful or even interesting to the original poster tho. Kai. PS: For those that are really interested, there's lots of info at http://www.adamwilt.com/DV.html.

August 25th, 2002, 06:28 AM	#8
Don Palomaki Wrangler Join Date: Sep 2001 Location: Northern VA Posts: 4,487	Of course DVD/MPEG2 have other artifacts to deal with which make it less suitable for editing. And going to 4:2:2 gets one out of the XL1 price point range of products.