BD-RB Quick Mode Question

[ron spencer]

When is it the "right time" to use the quick mode (BD-25) that BD-RB offers? For example, would it be appropriate for so-called "simpler" re-encodes? For example, if the source is 27-28 gig and you want to re-encode to 25 gig. This is a very small change in quality, so is the "quick BD-25" mode suitable? Or is it not as good as an overnight encode?

thanks for such a good proggy!!!

[jdobbs]

I use it most of the time. It does a single-pass CRF encode for the "insignificant" files with an "ok" setting. You can decide what "ok" is if you set "QUICK_CRF=" It saves time, and it reallocates space from low priority streams (most of the time) to the feature.

The time NOT to use it is on series discs.

[ron spencer]

Thanks. So for movie only and minimal change in original movie size (to bd25) I will use it. Thanks!!

[jdobbs]

It does nothing for Movie-Only -- there are no extras. As for "minimal change" -- there's no advantage. In fact it would probably make more sense to use it when there are significant changes -- especially when there are a lot of extras.

[ron spencer]

Hmmm. I am a bit confused. What is a recommended setting for movie only bd25 then? I gather the quick mode is wrong for movie only bd25 then?

[Willobee]

I use the high quality setting when doing a movie only to bd25. The quality of the movie is identical to the original as far as I can tell. It does take some time so I run it overnight. Using quick mode does not make a difference when rebuilding only the movie.

As jdobbs mentions use the quick mode for BD25 when you are rebuilding the entire blu-ray disk especially if there are many extras since quick mode only works quick on the extras.

Also do not use quick mode when rebuilding a series disk. Why? With a series disk there are many videos that make up the disk rather than a main movie and the extras. I would guess BD rebuilder would not be able to determine which video is the main movie and which ones are the extras based on thier size.

[ron spencer]

thanks alot for the explanation!!!

[sidneysides]

I'm still a little confused with that. I like to do full backups as I like to keep menus and extras (not bothered about the quality of these though). Does quick mode do only a 1 pass of the main movie? If so, how different is it to a movie that has gone through 2 passes? Don't want to waste too many discs trying it out!

[jdobbs]

I'm still a little confused with that. I like to do full backups as I like to keep menus and extras (not bothered about the quality of these though). Does quick mode do only a 1 pass of the main movie? If so, how different is it to a movie that has gone through 2 passes? Don't want to waste too many discs trying it out!No. It does a single CRF pass on extras only (small files that aren't a part of a larger playlist). The main-movie is done with whatever you have chosen under "Encoder Settings" (which could be one-pass, but only if you've chosen to do so).

[sidneysides]

So in your experience, if I was doing a full disc backup to 25GB BD-R, I should be OK with one pass CRF OR one-pass CRF and High Speed?
Not fussed about extras quality so don't mind high speed for those.

[siratfus]

I use it most of the time. It does a single-pass CRF encode for the "insignificant" files with an "ok" setting. You can decide what "ok" is if you set "QUICK_CRF=" It saves time, and it reallocates space from low priority streams (most of the time) to the feature.

The time NOT to use it is on series discs.

I've read this whole thread and like others, I'm a little confuse. Let me ask you this jdobbs, would it be correct to make this statement?

"If you are making a full-disc back-up onto a BD-25, and you don't care about the quality of the extras (menus, features), then you should select "High Speed Option BD-25" under the encoder setting. Because this option only affects the quality of the extra features. The quality of the main movie is the same no matter which encoder setting you choose."

Would that be a true statement?

Someone from another board told me the high speed option is useless because he can tell the quality difference of the movie between high quality vs high speed. If high speed option only affects the quality of the extras then is he imagining things? I was happy using high speed until this person said it was useless. Then I got paranoid and went back to high quality.

I thought there may be some validity to his statement because using my dual core processor, my time is cut down from 40 hrs to about 10 to 15 hrs just by switching high quality to high speed. I thought surely my main movie is also being processed quicker, thus, equal poorer quality.

But if you say this has no affect on the main movie, then I'm going back to high-speed. Please advise.

[jdobbs]

"If you are making a full-disc back-up onto a BD-25, and you don't care about the quality of the extras (menus, features), then you should select "High Speed Option BD-25" under the encoder setting. Because this option only affects the quality of the extra features. The quality of the main movie is the same no matter which encoder setting you choose."No. That would be completely inaccurate and the opposite of what I've said.

The setting that "only affects the quality of extra features" is "Quicker Encode for Extras" on the MODE menu. When you select "High Speed Option BD-25", you are saying "use the fastest encode speed" for everything -- including the feature -- and that will have a direct impact on quality.

The quality of the main movie is always affected by which option you choose under SETTINGS/Encoder Settings.

Whoever made the "useless because he can tell the quality difference" statement apparently doesn't understand encoding. You can't make broad statements -- ever. The quality isn't determined just by the X264 settings (which is what changes with "Encoder Settings") -- but also bitrate and the complexity of the source. At very high bitrates you very probably couldn't tell the difference between the settings (for example if you were doing only a couple of hours or so to a BD-25).

Now -- with that said -- I personally use the default "High Quality" setting for most encodes. Why? Because then I don't have to worry about it. I know I'm getting a good encode at any bitrate. Since I do most of my encodes while I'm sleeping -- the amount of time spent isn't that important to me.

[siratfus]

No. That would be completely inaccurate and the opposite of what I've said.

The setting that "only affects the quality of extra features" is "Quicker Encode for Extras" on the MODE menu. When you select "High Speed Option BD-25", you are saying "use the fastest encode speed" for everything -- including the feature -- and that will have a direct impact on quality.

The quality of the main movie is always affected by which option you choose under SETTINGS/Encoder Settings.

Whoever made the "useless because he can tell the quality difference" statement apparently doesn't understand encoding. You can't make broad statements -- ever. The quality isn't determined just by the X264 settings (which is what changes with "Encoder Settings") -- but also bitrate and the complexity of the source. At very high bitrates you very probably couldn't tell the difference between the settings (for example if you were doing only a couple of hours or so to a BD-25).

Now -- with that said -- I personally use the default "High Quality" setting for most encodes. Why? Because then I don't have to worry about it. I know I'm getting a good encode at any bitrate. Since I do most of my encodes while I'm sleeping -- the amount of time spent isn't that important to me.

Okay got it!

Here's another scenario to help me better understand the various relationships. Would this statement be true?

A movie that is backed up to a Dvd dual layer (BD-9) using the "high quality" encoder setting will yield poorer quality than the same movie being backed up to a BD-25 using "high speed" encoding.

Would that be true?

[jdobbs]

Okay got it!

Here's another scenario to help me better understand the various relationships. Would this statement be true?

A movie that is backed up to a Dvd dual layer (BD-9) using the "high quality" encoder setting will yield poorer quality than the same movie being backed up to a BD-25 using "high speed" encoding.

Would that be true?Again, no. You just can't make absolute statements. It all depends on the complexity of the source and the bitrate in addition to the settings. Honestly in most cases it's hard (or impossible) to distinguish the difference between a BD-9 encoded at "high quality" and the original -- so how could it, when compared to a BD-25 backup at any setting be considered "poorer quality"?

[sidneysides]

so you could have High Quality (default) and one-pass, and High-Speed BD25 and one-pass and get very different results?

[siratfus]

Again, no. You just can't make absolute statements. It all depends on the complexity of the source and the bitrate in addition to the settings. Honestly in most cases it's hard (or impossible) to distinguish the difference between a BD-9 encoded at "high quality" and the original -- so how could it, when compared to a BD-25 backup at any setting be considered "poorer quality"?

Life would be so much easier if we can follow absolute statements. :) Well, I'll just use High Quality and not worry about anything.

It's just my dual core takes about 30 to 45 hrs in high quality. Need to upgrade my pc soon.