Export to DVDSP

[Don Greening]

If you go to the following link below you’ll see that you’re not alone in your observations:

https://www.visiontracks.com/compressortests/

– Don

“Please take a moment to fill out your profile, including your computer system and relevant software. Help us help you.”

[Rafael Amador]

I’ve been allways exporting from the time-line (time consuming) and only recently i started to export refference movies, but after that I can see in the link I think I will keep exporting from the time-line again. let see if anybody knows something about this issue.
Cheers,
Rafael

[Rafael Amador]

Uli,
Sorry to bother you, but you are my DVD master. Please have a look to the link in this thread. Why such a difference?
Cheers,
rafael

[Terry Losardo]

Don
Thanks to all for the helpful posts. Sorry to overlook my system details. Thought they were there, but are added to my profile now.

The freeze frames in the link you provided are identical to what’s happening in my system. It’s difficult to judge which setting is “truer”. In other words, when I look at the more saturated direct export to Compressor on my computer monitor, it looks more attractive. Playing the DVD from a set top box and TV, the QT reference version looks washed out. I’m about to have thousands of DVDs replicated via glass master from the disc I’m preparing, and am unclear on this point.

Couple additional questions, if Uli joins in. I’ve read his 2005 posts to Larry Jordan’s newsletter about settings for average bit rate and peak bit rate. Generally, what I see is a recommendation to set average bit rate at 5.5 and peak at 7.2, with a proviso to stay below 7.5Mbps sum of all streams if I am to burn the discs or 10.8Mbps sum of all streams if I replicate.

1. I’m not sure I understand how to calculate the sum of all streams. An example would be helpful.

2. Does the “stay below” figure mean the average or the peak rate?

3. When a replicator prepares a glass master, do the bit rates set in Compressor transfer to that master? In other words, if one reason you want to stay below a certain bit rate is to ensure maximum playability across many brands/models of set-top players and drives, will my bit rate settings be pressed onto every replicated disc via the glass master?

In general, I’d like to provide the replicator with my highest quality disc for them to use for the master, but if this compromises playability down the line, I’d back off.

Thanks for your help.

Terry Losardo
Indigo Productions, Inc.

[Don Greening]

Hi Terry,

Your encoding questions for glass master and replication are beyond my field of expertise. I was simply the messenger for the link to that web page showing the encoding differences depending on workflow. The author did mention that exporting a reference movie and using Compressor as a stand alone app managed to mirror the FCP timeline more closely than the other method (exporting to Compressor within FCP). However, you note that your reference movie version looks washed out even though this workpath is supposed to be the closest to the FCP timeline.

I can only suggest that you encode a small test piece of your project and tweak the gamma setting in Compressor until you get the look you’re after. With a large replication job ahead you want to be sure. There are better encoders out there. One of them is Bitvice and I’ve found it to be better than Compressor i.e. more consistent with a better overall quality using similar bit rate settings. The drawbacks to using Bitvice is the price and it takes much longer to do an encode than Compressor does.

Since I’ve never had to worry about bit rates for glass master replication I can’t advise you. My peak bit rates for burning DVDs never exceed 6.5 and when you factor in the 192 bit rate for .ac3 audio I’m getting very good playability results on commercial DVD players.

Sorry I can’t be of more help.

– Don

“Please take a moment to fill out your profile, including your computer system and relevant software. Help us help you.”

[Terry Losardo]

Hey Don
That link was a huge help, so not to worry! Wll await further posts from others on the details.

Terry Losardo
Indigo Productions, Inc.

[Rafael Amador]

Terry,
The matter is to let a certain room so the lower quality DVD player can read without jumping the image. (When I make a DVD with too high data rate my chines DVD player show and image every second while the audio keeps on playing).
About the cristal masters, they have the very MPG2 file that you had got with Compressor. The imformation inside is the same but its seems that are easier to be readed than the DVDs that we get burned in our Macs.
Cheers,
Rafael

[Don Greening]

I found something at Larry Jordan’s web site that may be a partial answer to the question: ” Why is there a difference in luma and chroma levels after encoding to MPEG2 ?”

Larry states that the process of compression converts your file to a broadcast safe format. This doesn’t address the question of why exporting to MPEG2 within FCP has a different result as opposed to exporting a QT movie and using Compressor as a stand alone app, but the answer may lead to more clues down the road. I’ll continue to research this perplexing issue.

I didn’t know that the act of converting to MPEG2 resuted in a broadcast safe file. Unless I misunderstood Mr. Jordan’s article.

You can read it here (about halfway down the article)

https://www.larryjordan.biz/articles/lj_grfx_look.html

– Don:

“Please take a moment to fill out your profile, including your computer system and relevant software. Help us help you.”

[Rafael Amador]

Don,
When you make an MPG2 you get a legal PAL or NTSC by clamping the hights and the lows of the video signal. You should better set the legal levels in FC, where you can control the process, and feed Compressor with an already legal film.
Cheers,
rafael