[Tod Hopkins]

[Daniel Low] “Well you obviously can’t go straight from 1080i to 480i, you have to deinterlace first. Why don’t you go straight to 480p??”

Apparently not obvious to all of us. You don’t NEED to deinterlace when scaling down from 1080i to 480i, but I realize that most scalers DO deinterlace before scaling, especially software scalers. I’m sure you are right. And in order to maintain temporal resolution, it would have to deinterlace at 1080, prior to scaling. Ouch. No wonder it takes so frigging long.

By the way, I am testing 480p, but I don’t like to lose the temporal resolution. I like 60 fields. Looks smooooooth. Upside is that going progressive does cut the compression time dramatically!

Thanks. Consider me educated!

Tod Hopkins
Hillmann & Carr Inc.
Washington, DC

[Tod Hopkins]

Yes, resizing 1080i to 480i, MPEG2 for DVD. With deinterlace set to fast, the four minute show takes 1 hour. Set to “best” it estimates 50+ hours. I let that run for one hour and the estimate did not go down.

From what I read, the time estimates I get fit other people’s experience with this setting. It’s just that it logically should not happen when fields are set to “same as source.” I presume it’s just an oversight in the programming, but I was curious if someone knows better. I could not find anything on line. It’s not really a problem as long as you leave it at “fast” when you set to “same as source.”

Tod

Tod Hopkins
Hillmann & Carr Inc.
Washington, DC

[Tod Hopkins]

[jaime abramson] “if any of you super smart people were to tell a not-so-tech-savvy client the kinds of compressed files you’d accep”

Don’t. Handle all conversion at your end. That’s what I do. It’s the only way. You’ve already told me the client can’t handle it.

tod

Tod Hopkins
Hillmann & Carr Inc.
Washington, DC

[Tod Hopkins]

[Nat Rovit] “Please help, is there any way to download new codecs for use in Quicktime?”

Sometimes. It depends on the codec. Frequently the only proper way is to install an app that includes the codec. In this case, FCP. In other cases, the codec is available seperately (ProRes) or as an add-on (MPEG0). And I believe you can copy the codec file in the library from one machine to another, but I’m not certain about that.

Tod Hopkins
Hillmann & Carr Inc.
Washington, DC

[Tod Hopkins]

[Daniel Low] “If you are going from interlaced to interlaced, then you’d set ‘Same as source’ and ignore the deinterlace setting. Compressor only deinterlaces jobs that need it.”

Yes, that’s what the manual says, but it’s clearly not what the app does. That’s why I ask. Compressor definitely does NOT ignore that setting. If you set deinterlace to fast, fine. Set it to best and your encode times will increase 50-fold! So… why? If compressor is ignoring the setting, why do the compression times skyrocket.

tod

Tod Hopkins
Hillmann & Carr Inc.
Washington, DC

[Tod Hopkins]

[Jeremy Garchow] “The same happens to DVCPRo HD. 100mbps is the highest bit rate (1080i60), once you start getting to 720p23.98, it drops down to about 40mbps. DVCPro HD is smaller than ProRes, you will just have to trust me on that, I know it’s hard sometimes. :)”

I’m a trusting kinda guy. I know that DVCProHDpn24 (the so-called “native” framerate)is lower bitrate.

Well, duh! Here it is right on the same Apple chart. I just didn’t look for it.

Cheers,
tod

Tod Hopkins
Hillmann & Carr Inc.
todhopkins-at-hillmanncarr.com

[Tod Hopkins]

According to Apple:

1280x720p23.98 target datarate is 59mbps and 88Mbps at HQ.

1280x720p59.97 target datarate is 147Mbps and 220Mbps at HQ

Framerate makes a huge difference.

Cheers,
tod

On Oct 29, 2008, at 10:16 AM, Apple Final Cut Pro wrote:

ProRes is 145 mb/sec and ProResHQ is 220 Mb/sec, now those will get smaller depending on frame size and frame rate, but they are still larger than DVCPro HD. DVCPro HD @ 720p23.98 is about 5 MB/sec. It’s about double dv25.

Jeremy

————————————————–

Tod Hopkins
Hillmann & Carr Inc.
todhopkins-at-hillmanncarr.com

[Tod Hopkins]

Oops. 88Mbps is HQ. Regular is lower at 59Mbps.

Tod Hopkins
Hillmann & Carr Inc.
todhopkins-at-hillmanncarr.com

[Tod Hopkins]

ProRes does have a lower “target” rate (88mbps) than DVCProHD at 100Mbps. Whether that’s enough to justify conversion…

If you truly want off-line, go DV25. Reconform later.

Cheers,
tod

Tod Hopkins
Hillmann & Carr Inc.
todhopkins-at-hillmanncarr.com

[Tod Hopkins]

Yes, it will if the monitor has been told to display the signal as 16:9. Remember that a monitor can’t actually tell if the signal is meant to by displayed 4:3 or 16:9. You have to tell it (assuming the monitor can do both). There is no “flag” or marker in the video itself. The change from 4:3 to 16:9 happens only at the display. The question is whether the image in the signal is meant to be displayed as is, or to be stretched out to 16:9.

This gets a bit trickier with file-based playback, dvd, or dtv broadcast because these formats do have a variety of flags and parameters that control playback, but a simple NTSC analog video signal only comes in one form.

Cheers,
tod

P.S. One warning. I’m not as familiar with PAL as I am NTSC. I believe the two are the same in this particular regard, but I might be wrong.

Tod Hopkins
Hillmann & Carr Inc.
todhopkins-at-hillmanncarr.com