What CRF Level Do You Use?

[Anakin]

I have movie that overall bitrate of videotrack is bit bellow 8000kbps, but sometimes comes to close 10000kbps only FullHD resolution. But it is grainy and you can easily notice that grain isn't as it can be for example on UHD version. The movie is of course in HEVC. Much more efficient compression. I recorded it from air DVB-T2 with no recompression. Usualy they use bitrate around 4500kbps and for clean or restaured content it is enough. Of course it also depend on other encoder settings. Better (in terms of quality) encoding will last longer.

100% agree with jagabo + you will spend instead say 100min encoding 200min of encoding.
CRF is faster, with expectional quality. 2pass i good to fit medium. CD or DVD or BD. Otherwise waste of bits or not enough bits. But this already states Jagabo.


Edit: I had TV that supported just 4.0 with USB so 4.1 wasn't playable so you will have to test it.



Bernix

I’m trying The Last Jedi with 2 pass, 8000kbps and maximum of 36mbps. 1920x1080. Should it look ok?

[_Al_]

whoa, what a U-turn in this thread

CRF (space does not matter) to 2pass -5hour video

[LigH.de]

Whether you use CRF or an average bitrate, use the VBV values recommended for Blu-ray discs in addition.

[jagabo]

I’m trying The Last Jedi with 2 pass, 8000kbps and maximum of 36mbps. 1920x1080. Should it look ok?

Nobody can tell you how any particular video will look at 8000 kbps. That's been the whole point of this discussion about CRF.

[Bernix]

Hi,
only think I know is if it ran 1sec at 36mbps it for example has to run somewhere else for say 2000kbps for 6sec. or in better case 36sec at 7000kbps. So where are bits added in bits expensive scenes, so these bits has to be somewhere taken from video. That is disadvantage of 2pass and advantage of CRF. CRF put as many bits as needed for given CRF value.

But encoding quality depends also on other settings, my favorite motion estimation and subpixel refinement. But of course there are much much more option that final quality depends on. Minimal and maximal distance of keyframes, number of P and B frames, and others with more or less impact on speed and quality.
If you don't know what which parameter means there are predefined presets. I suggest you for good result at given CRF or 2pass preset slow or slower. Placebo is not usable because encoding speed is very slow and difference in quality is very low if there is any


Please correct me, if I'm as usual wrong



Bernix

[_Al_]

To ask if 8000 is enough for a video using 2pass is an absolute non-scientific inquiry, because final result depends , not only on a content but also on a lenght of certain content. Imagine encoding movie twice. Once as a whole, second time in two parts. If using 2pass to the same average, you get different results for the same scene. And we are talking same movie here! Bitrate distribution can radically change. This is just to visualize what we are asking here.

[JVRaines]

CRF 18 at Slow preset for everything. Then I go worry about something else.

[_Al_]

Yap, it is pretty much simple as that. Using --vbv-bufsize 30000 --vbv-maxrate 30000 to be overcautious. If encoder gets to cut off those peaks, those are the scenes, you'd not going to notice anyway. 4k resolution perhaps yes. But for 4k, CRF perhaps could be higher if encoding with x264, but that's about it. SD video, on the contrary 16-17, because every bit gets blown-up, so it better be good, especially gradients, low light, so SD video does not look like google earth map.

Just encode those movies like that and then put them on disk as data ,combined accordingly so you use space somehow more efficiently, just using simple math. So you encode bunch of them and only then you burn them in some number, one , two or three depending on size. That is somehow scientific. To try to press one movie at a time to the same bucket is not.

[Bernix]

Thats exactly how I do it. So I have one 8 season serie on several disk, burned them as they comes. Once in week. When I have enough data to BD 25, so I burned. Therefore I demanded software that can combine files to exact size (BD) sort them to use BD capacity as much as possible (in other thread here). But there is none good enough. So I do it manualy. When for example I get to situation that data is little bit over limit few MB's, just recompress audio bit in some crapy fairy tale or in some crap. I will not watch but sound is still good. If there is for example 0,5 GB remaining I use this space as backup for some files. For example some my gameplay or so. But if there is more than 1GB remaining i don't burn, waiting for others recording and recombine them in other way.
So now I'm facing problem of catagolize it. There is good program called Playtime, something like mediainfo but can read from folders and subfolders and export in cvs name codecs video audio bitrate etc. Then will try Ant movie catalog. It can import/export cvs.
I'm writting this because burning random stuff on one CD/DVD/BD there is need to catagolize it. Otherwise you will end in terrible mess. Just print list can't help if you are looking for something particular. Probably somebody suggested me p.m. some good free solution for cataloging better than mentioned.



Bernix

[_Al_]

you'd need to catalogue a place - title correlation , something like a database where search "Ex Machina" would return:

upper shelf, third drawer, sci-fi category, hoping you did not borrow it to your brother
regards Siri

eh, typical foreign English mistake - borrow <> lend

[Anakin]

Whether you use CRF or an average bitrate, use the VBV values recommended for Blu-ray discs in addition.

TMPGEnc’s Blu Ray Standard Profile has a VBV of 3662. Would that be enough to use CRF 21?

[jagabo]

Whether you use CRF or an average bitrate, use the VBV values recommended for Blu-ray discs in addition.

TMPGEnc’s Blu Ray Standard Profile has a VBV of 3662.

That's ridiculously low unless it's expressed as KBytes/sec rather than Kbits/sec.

[Bernix]

[QUOTEyou'd need to catalogue a place - title correlation , something like a database where search "Ex Machina" would return:
Code:
upper shelf, third drawer, sci-fi category, hoping you did not borrow it to your brother regards Siri


eh, typical foreign English mistake - borrow <> lend ][/QUOTE]


Here is it same with borrow vs lend.


I know it was irony, but say I have now 10 BD in one case. So where is disc 1-10 i know. But what is on which disc I can't remember. There is also SD content that i recompress, so it is over 100 movies/videos. So when looking for something, it is really difficult at this small amount of discs. I can't memorize it. Checked Ant movie catalog and will use hardly 2% of fields. There is only field borrower, so they believe that humans are honnest.


@Anakin
In full hd with x264 you will with CRF 21 easily get over 3662kbps. But on Doom9 where the link redirects it states max bitrate 40000kbps. It is about (can be wrong) 5MB/s and I think you will not get over this.

--vbv-bufsize 30000 --vbv-maxrate 40000 is allowed

BD-5 BD-9 should be DVD-5 DVD-9 <- im wrong.


Bernix

[Anakin]

Whether you use CRF or an average bitrate, use the VBV values recommended for Blu-ray discs in addition.

TMPGEnc’s Blu Ray Standard Profile has a VBV of 3662.

That's ridiculously low unless it's expressed as KBytes/sec rather than Kbits/sec.

I’ll be home in a few hours. I’ll take a picture of the settings. I can’t remember.

[Anakin]

These are the settings that TMPGEnc uses.


[Attachment 46674 - Click to enlarge]

[jagabo]

They use a capitol B in kB so that probably means kBytes. 3662 kB is 29296 kbits, a reasonable number for Blu-ray compatible VBV.

[_Al_]

tmpgenc manual says:
- Maximum Bitrate [--vbv-maxrate]
- VBV Buffer Size [--vbv-bufsize]

so most likely tmpgenc in your case uses:
--vbv-maxrate 35000 --vbv-bufsize 29296

[poisondeathray]

Inconsistent GUI in that screenshot. Poor design choice swapping bytes vs. bits notation .

I would double check with small test run to see what actually gets passed

[Anakin]

They use a capitol B in kB so that probably means kBytes. 3662 kB is 29296 kbits, a reasonable number for Blu-ray compatible VBV.

So, if I did use CRF 21 with that VBV, would it be ok for Blu Ray players?

[LigH.de]

CRF 21 is pretty low, you will probably notice a quality loss. If you want "visual transparency" (hardly any loss to notice), I would recommend a CRF below 18. But only you will know how much loss you will accept and trade off for squeezing another movie onto your Blu-ray discs.

By the way, how do you author your discs containing several movies?

[Anakin]

CRF 21 is pretty low, you will probably notice a quality loss. If you want "visual transparency" (hardly any loss to notice), I would recommend a CRF below 18. But only you will know how much loss you will accept and trade off for squeezing another movie onto your Blu-ray discs.

By the way, how do you author your discs containing several movies?

I use TMPGEnc Authoring Works. I create a menu that lets me select the film.

[Anakin]

Would you guys ever use 1440x1080 over 1920x1080? I’m using 1920, but I’d just like your opinions. Do any of you use it? If so, why?

[Bernix]

Hi,
1440x1080 is 4:3 ratio, so some older videos can be transmited with 1920x1080 but with black bars on side. Best is to not reencode. If you need it and remove black bars, you end up with this or very similar number to 1440. But reencoding means lower quality (if not lossless)

I do removing those bars, because prefer full screen video. So remove black bars. But most prefer correct aspect ratio. So leave it with black bars. Those black bars doesn't need much bits in whole movie. So no need to get rid of them. Or do virtual crop in mkvtoolnix and is supported with many renderers in potplayer. Not sure about MadVR.

I do this in one series that is filmed in 4:3 and convert from 1080p to 720p. Horrible for someone but for me good.


Bernix

[Anakin]

Hi,
1440x1080 is 4:3 ratio, so some older videos can be transmited with 1920x1080 but with black bars on side. Best is to not reencode. If you need it and remove black bars, you end up with this or very similar number to 1440. But reencoding means lower quality (if not lossless)

I do removing those bars, because prefer full screen video. So remove black bars. But most prefer correct aspect ratio. So leave it with black bars. Those black bars doesn't need much bits in whole movie. So no need to get rid of them. Or do virtual crop in mkvtoolnix and is supported with many renderers in potplayer. Not sure about MadVR.

I do this in one series that is filmed in 4:3 and convert from 1080p to 720p. Horrible for someone but for me good.


Bernix

The Blu Ray standard has 1440x1080 as 16:9.

[Bernix]

So it made up 1/3 of whole picture. 1440x1080 is 4:3 aspect ratio. Probably you have on your tv or bluray player automatic conversion to 16:9. Do not believe it much. Bluray should be Full HD support.

Edit: https://en.wikipedia.org/wiki/Blu-ray_Disc#Video

Bernix

[Anakin]

So it made up 1/3 of whole picture. 1440x1080 is 4:3 aspect ratio. Probably you have on your tv or bluray player automatic conversion to 16:9. Do not believe it much. Bluray should be Full HD support.

Edit: https://en.wikipedia.org/wiki/Blu-ray_Disc#Video

Bernix

My apologies. I thought it was like 480x576 back in the SVCD days! Long time ago! I think I will stick with 1920x1080 anyway.

[Anakin]

Hey guys. I have had great success with using CRF17, but I am always looking at putting more on a disc. If I use CRF21 on the slowest setting, would I be able to tell the difference on a 42 inch TV?

[jagabo]

Hey guys. I have had great success with using CRF17, but I am always looking at putting more on a disc. If I use CRF21 on the slowest setting, would I be able to tell the difference on a 42 inch TV?

It's certainly possible to see the difference. But whether you can see the difference or not only you can say. Most of the difference will be a loss of small, low contrast detail (film grain, wood grain, fuzz on a sweater, etc.) which will lead to posterization at times.

[Anakin]

Hey guys. I have had great success with using CRF17, but I am always looking at putting more on a disc. If I use CRF21 on the slowest setting, would I be able to tell the difference on a 42 inch TV?

It's certainly possible to see the difference. But whether you can see the difference or not only you can say.

Thank you for the reply. What I should be asking is, is going from Blu Ray to CRF 21 going to be a huge loss or a small loss?

[LigH.de]

You are asking the same question over and over; the answer will always be: Try it, look at it, decide for yourself how obvious the loss is to you, personally. We can't look through your eyes.