How to determine optimum size for a BD rip?

[JimmyBarnes]

Interested in starting to back-up my BD discs to AVI/Xvid in high ("near BD") quality but so as to occupy much less space.

With DVDs I would use VDM/Xvid and quantizer 2.0 to determine what I called the "natural size" of a rip for a given resolution. Then a 2-pass run using 75-80 % of the "natural size" as target would virtually always guarantee a good rip, but with optimal size.

I have my own ideas on what to try but would be interested in what other users have found to work from actual (preferably extended) experience...

:thanks: IA

[Guest]

What do you mean by "optimal size"?

[Inspector.Gadget]

Why on earth would you transcode Blu-ray to ASP?

[JimmyBarnes]

What do you mean by "optimal size"?

The smallest size for the particular resolution while still maintaining "near BD" quality

You can probably convert say a 20GB BD into a 15GB AVI but that hardly seems a great saving in space. It should be possible to save perhaps as much as 80 % of the original size - obviously for a reduced resolution e.g. 1280x544 or 960x408

[JimmyBarnes]

Why on earth would you transcode Blu-ray to ASP?

It amuses me to so do

[Guest]

The smallest size for the particular resolution while still maintaining "near BD" quality
That is as vague as your original formulation.

[prOnorama]

The smallest size for the particular resolution while still maintaining "near BD" quality

You can probably convert say a 20GB BD into a 15GB AVI but that hardly seems a great saving in space. It should be possible to save perhaps as much as 80 % of the original size - obviously for a reduced resolution e.g. 1280x544 or 960x408

If you downscale 1080p to 720p or lower you can get a far bigger size reduction and still maintain really good quality (like 1/4 or 1/3 of the original size), try it with x264 :)

[RunningSkittle]

Use this command and watch x264 do its magic ;)

x264 --preset veryslow --crf 18 <input> -o <output>

http://mewiki.project357.com/wiki/X264_Settings#crf
or read --hullhelp

[Guest]

He said he wants ASP output!

[RunningSkittle]

Once he sees x264 do its black magic, he might change his mind ;)

[BigDid]

The smallest size for the particular resolution while still maintaining "near BD" quality
...
It amuses me to so do

Hi,

Some similarities with this thread (SD conversion but for ASP also):
http://forum.doom9.org/showthread.php?p=1393686#post1393686

Same recommendations would go for x264: do a CRF 18 encode for comparison. Good and easy GUI if needed: Ripbot or StaxRip.

Try to achieve same visual quality (transparent) with a Q2 xvid encode. Change would be: no high bitrate matrix needed for HD.

Reminds me of a thread 3 years ago or so, in which Sharktooth (if I recall well) was saying that for HD encode is V3-LR or even V3-ULR matrix was good enough :rolleyes:

No link for that thread but Sharktooth matrixes can be found here:
http://forum.doom9.org/showthread.php?s=&threadid=83125

And in the end, even if x264 wins ;) you would have had fun trying ASP.

Did

[Atak_Snajpera]

The smallest size for the particular resolution while still maintaining "near BD" quality
define "near BD" quality !

[JimmyBarnes]

That is as vague as your original formulation.

Dude, have u ever ripped a BD? If so, how do you determine "target size" and "acceptable quality"?

[JimmyBarnes]

I concur, good sirs. This is a crime worthy of capital punishment. OFF WITH HIS HEAD, I SAY!

BTW what is "ASP"? (u can see I'm a noob)

Association of Surfing Professionals
Appalachia Service Project
Active Server Pages
American Society of Primatologists (quit monkeying around..)
Astronomical Society of the Pacific (nah!)

[Guest]

(u can see I'm a noob) Moving to Newbies forum.

[Guest]

If so, how do you determine ... "acceptable quality"? I look at it and if it is acceptable, I accept it.

[JimmyBarnes]

I look at it and if it is acceptable, I accept it.

Precisely. With lossy compression there is always some degradation of quality, so a subjective judgment needs to be made.

And "target size", do you concern yourself with that?

[JimmyBarnes]

Hi,

Some similarities with this thread (SD conversion but for ASP also):
http://forum.doom9.org/showthread.php?p=1393686#post1393686

Same recommendations would go for x264: do a CRF 18 encode for comparison. Good and easy GUI if needed: Ripbot or StaxRip.

Try to achieve same visual quality (transparent) with a Q2 xvid encode. Change would be: no high bitrate matrix needed for HD.

Reminds me of a thread 3 years ago or so, in which Sharktooth (if I recall well) was saying that for HD encode is V3-LR or even V3-ULR matrix was good enough :rolleyes:

No link for that thread but Sharktooth matrixes can be found here:
http://forum.doom9.org/showthread.php?s=&threadid=83125

And in the end, even if x264 wins ;) you would have had fun trying ASP.

Did

Thanx for these details, some very useful feedback...

Try to achieve same visual quality (transparent) with a Q2 xvid encode. Change would be: no high bitrate matrix needed for HD.

Could you elaborate on these:
* What do you mean by "transparent"?
* Q2 Xvid = quantizer =2.00 correct?
* "no high bitrate matrix needed for HD" - so when doing a BD rip, the difference from a DVD rip is..??

TIA

[RunningSkittle]

ASP=Advanced Simple Profile=Xvid/Divx

opposed to AVC=H.264

If your just playing back on PC use AVC instead of ASP (use x264 :) )

[JimmyBarnes]

ASP=Advanced Simple Profile=Xvid/Divx

opposed to AVC=H.264

Thanx for that. What does AVC mean?

If your just playing back on PC use AVC instead of ASP (use x264 :) )

why?

[RunningSkittle]

AVC (Advanced Video Codec)!

Why? Because its WAY better. No reason not to unless your device doesnt support it.

[BigDid]

Thanx for these details, some very useful feedback...
Could you elaborate on these:
* What do you mean by "transparent"?
* Q2 Xvid = quantizer =2.00 correct?
* "no high bitrate matrix needed for HD" - so when doing a BD rip, the difference from a DVD rip is..??
TIA
Hi,

You are welcome, H264 newbies are often not enough considered by those having experience (or claiming so) in that domain :devil:

Back on the subject
- lossless is no loss of quality relative to the original; transparent is no (or nearly no) visual loss of quality relative to the original
- Correct for Q2
- What is needed to achieve visual transparency for SD-ASP encode may not be the same in HD; see my link to the SD-ASP thread.
For SD-ASP (IMO) you need a Q2 encode AND a high-bitrate matrix.
For HD-ASP you may well use the same standard (as SD) BUT, if you can achieve same transparency with another matrix at lower bitrate, why not?

x264-CRF18 for HD may be a good start (or lesser CRF to achieve transparency) for a near BD quality; depends (as asked by Atak) what you mean by near BD quality and/or interpretation of neuron2 answer: is visual (quality) acceptable for your needs? if yes it is acceptable.

Target size is usually not a concern anymore with x264-CRF (there is also a 2 pass encoding mode if needed). If it is for you, there are workarounds like a comptest of 5 or 10% encode for adjusting the CRF and/or avisynth script to a median size like near 4/4.3 GB (720P) or near 8Gb (1080P) etc...

Once again give x264 (and Ripbot) a chance; make a CRF18 encode and compare to ASP; you will really be surprised!

Did

[Guest]

And "target size", do you concern yourself with that? No, because I make only multi-program transport streams for injection via a packet injector/modulator. I have to concern myself with the transport bitrate.

[CWR03]

Because x264 offers better compression than Xvid/DivX. You should be able to get a Blu-Ray of 50GB down to 4GB 1080p using x264 with barely noticeable loss in quality. You can't do that with Xvid - there will always be artifacts introduced into areas of similar color like fire, blue sky, smoke or fog, and it's worse at lower bitrates. The artifacts are still there with x264 but they're nearly transparent.

[Atak_Snajpera]

Advanced Video Codec

why?
Because it is more advanced than Simple Profile :)

[JimmyBarnes]

Because x264 offers better compression than Xvid/DivX. You should be able to get a Blu-Ray of 50GB down to 4GB 1080p using x264 with barely noticeable loss in quality. You can't do that with Xvid - there will always be artifacts introduced into areas of similar color like fire, blue sky, smoke or fog, and it's worse at lower bitrates. The artifacts are still there with x264 but they're nearly transparent.

Another reply that actually teaches me something instead of implying that I am an idiot incapable of learning.. many :thanks:

Actually I have been ripping DVDs to Xvid/AVI for some years and very early on, I became aware those "artifacts" were a major flaw in the result. That was going on the rule that a "good" rip should be some 67-75 % of quantizer=2 rip size. I eventually found that if one used 80 % (or possibly 75 %-80 %) instead, the artifacts were absent, even in areas where they were most likely to appear: walls, sky, backlit uniform smoke haze in a room. The only area where sometime artifacts are seen slightly is in some underwater scenes looking towards the surface light. Again we are talking lossy compression so "transparent" "acceptable quality" "near-DVD" "near BD" are highly subjective, but I pride myself on being a good judge in that area and always watch my encodes throughout carefully.

[JimmyBarnes]

Advanced Video Codec

Because it is more advanced than Simple Profile :)

For a given MTS and resolution, what improvement in compression (give your estimate in percent) for the same visual quality can I expect?

[JimmyBarnes]

Hi,

You are welcome, H264 newbies are often not enough considered by those having experience (or claiming so) in that domain :devil:

Careful, that sort of talk will get you excommunicated..

Back on the subject
- lossless is no loss of quality relative to the original; transparent is no (or nearly no) visual loss of quality relative to the original
- Correct for Q2
- What is needed to achieve visual transparency for SD-ASP encode may not be the same in HD; see my link to the SD-ASP thread.
For SD-ASP (IMO) you need a Q2 encode AND a high-bitrate matrix.
For HD-ASP you may well use the same standard (as SD) BUT, if you can achieve same transparency with another matrix at lower bitrate, why not?

x264-CRF18 for HD may be a good start (or lesser CRF to achieve transparency) for a near BD quality; depends (as asked by Atak) what you mean by near BD quality and/or interpretation of neuron2 answer: is visual (quality) acceptable for your needs? if yes it is acceptable.

Target size is usually not a concern anymore with x264-CRF (there is also a 2 pass encoding mode if needed). If it is for you, there are workarounds like a comptest of 5 or 10% encode for adjusting the CRF and/or avisynth script to a median size like near 4/4.3 GB (720P) or near 8Gb (1080P) etc...

Once again give x264 (and Ripbot) a chance; make a CRF18 encode and compare to ASP; you will really be surprised!

Did

Thanx for the above.

You have convinced me to try RipBot/x264. So far I have had 2 problems:

* FLV playback in ThumbsPlus7 gets disabled, I keep having to reinstall K-Lite Code pack 5.9 to reenable it (nothing to do with encoding I know, but if you have any suggestions..)

* I added an MTS, but after RipBot did stream demuxing, it gave: "Script error: there is no function named "DirectShowSource" (G:\temp\RipBot264temp\job1\getinfo.avs, line 2)

Your suggestions pls

[Atak_Snajpera]

* I added an MTS, but after RipBot did stream demuxing, it gave: "Script error: there is no function named "DirectShowSource" (G:\temp\RipBot264temp\job1\getinfo.avs, line 2)

http://forum.doom9.org/showthread.php?p=1387495#post1387495

BTW. AviSynth installed?

[7ekno]

For a given MTS and resolution, what improvement in compression (give your estimate in percent) for the same visual quality can I expect?

I suggest you have a read thru the MSU Codec comparison 2009 (http://compression.ru/video/codec_comparison/mpeg-4_avc_h264_2009_en.html) testing document ;) Specifically the table at bottom of page 22 that show for the same "quality" metric, XviD needs 51% more bitrate (or filesize) to achieve the same "quality" as x264 ;)

This years comparison should be even better with mb-tree and b-pyramids finally sorted ...

7ek

[JimmyBarnes]

I suggest you have a read thru the MSU Codec comparison 2009 (http://compression.ru/video/codec_comparison/mpeg-4_avc_h264_2009_en.html) testing document ;) Specifically the table at bottom of page 22 that show for the same "quality" metric, XviD needs 51% more bitrate (or filesize) to achieve the same "quality" as x264 ;)

This years comparison should be even better with mb-tree and b-pyramids finally sorted ...

7ek

Now that's what I call some hard evidence - quantitative comparison..

Many thanx

[Forteen88]

You should be able to get a Blu-Ray of 50GB down to 4GB 1080p using x264 with barely noticeable loss in quality.I'd say at least 8GB in 1080p is needed for a normal film for that, 4GB might be OK for 720p.

[JimmyBarnes]

I'd say at least 8GB in 1080p is needed for a normal film for that, 4GB might be OK for 720p.

Surely it depends on the particular movie, some compress well (esp. ones with lots of dark scenes) whereas some relatively short movies full of bright scenes and "fast motion" don't (speaking from an Xvid/AVI perspective anyway)

[Ghitulescu]

One should also need to define a normal movie: duration, action/static, dark/light etc.

[JimmyBarnes]

One should also need to define a normal movie: duration, action/static, dark/light etc.

Is there any utility which can determine the compressibility of a BD movie, the same as Enc and other utils can do for DVDs?

[BigDid]

Is there any utility which can determine the compressibility of a BD movie... ?
Hi,

I use avisynth internal SelectRangeEvery() as comptest.

For 10%: SelectRangeEvery(300,30)
For 5%: SelectRangeEvery(300,15)

If to be used within Ripbot editor, see:
http://forum.doom9.org/showthread.php?p=1397665#post1397665
Resulting size is a bit optimistic; substract 5 to 10% to get more accurate final size and bitrate.

Example:
- 10% comptest gives me a length of 248.392Kb
- Final should be x10= 2.483.920Kb
- minus 5% (124.196)= 2.359.724Kb
The real encode is 2.326.315Kb (Avatar CRF22, 720width, with deblock =-2-2)
Bitrate calculation is similar:
10% comptest is 2054kbp/s; final is 1925kbp/s.

Did

Edit: for beginners; edit whatever avisynth script ( for Ripbot= JobX.avs) is used in your encoding app
and add the SelectRangeEvery() at the end of the script as last command.
From avisynth tutorial:
"SelectRangeEvery (clip, int "every", int "length", int "offset", bool "audio")
This filter is available starting from v2.5. The filter selects length number of frames every n frames, starting from frame offset. Default values are: Select 50 frames every 1500 frames, starting with first selection at frame 0. (every = 1500, length = 50, offset = 0).
Starting from v2.55, SelectRangeEvery will also process audio. To keep the original audio, use audio = false. "