BD Rebuilder and File Sizes, Bit Rates, etc.

[larrsz]

JDobbs + all:

I need some ideas on how much BDRB can reduce a BD file without too much (OK, I know this may be subjective) evidence of compression. This has nothing to do with making a backup disc, but rather a backup file, so I am not tied to a disc size, but I also want to be able to keep my backups on a hard disc which means I do have at least SOME space issues at some point. Is there a rule of thumb to keep from experimenting to death with each file? I have had no issues with a BD9 of an original feature that is 20+/- GB for example (even on a projection system), but I am not sure how far to push it as a rule of thumb as I have some movies that (just the feature) are 35-40GB. And, what if I am also willing to go to 720p from 1080i/p Or, should I pay attention to bit rates, etc. instead?

I'd love to have some thoughts as I am thinking of backing up my collection of HD movies (most are 1080i HD files from my DVR, burned to BDs) on a raid server rather than discs and keep my discs in storage.

[jdobbs]

You can't really depend on original size -- as you don't know how challenged the original encode was. Bitrate is probably the best indicator of how well it will come out. On the other hand, if you always want to have the backup that encodes at a set level of quality and don't care about output sizing control, you can do a fixed CRF encode. That way it will use whatever rate is need to get the quality level you select. You do that by selecting "One Pass CRF Encoding" and adding the "FIXED_CRF=n" to the INI file (see FIXED_CRF in HIDDENOPTS.TXT). A good starting point might be FIXED_CRF=23. As the number gets lower the quality gets higher (and the output size gets bigger).

[jdobbs]

I should also add that using "Automatic Quality" will adjust the settings based on source characteristics to give you fairly consistent level of output quality. You can also tweak it with AUTO_BIAS (see HIDDENOPTS.TXT).

[larrsz]

As a general rule of thumb, if I am more interested in a lack of breakups during action, etc than I am sheer resolution, should step one be to reduce the resolution to 720p before worrying about bit rates with a 1080 encode?

From my experimentation, it seems that a 720p BD9 encode is superior to a 1080 BD9 encode in this respect.

[laserfan]

I have never seen a "breakup" using x264, and this with a 120" screen and 1080p projector. One of my earliest encodings (just pre-BD-RB iirc) was "Live Free or Die Hard" which if you haven't seen it has more than its share of complex action scenes. I'd done it mostly for fun, as a test, and was astonished at the high quality of it. And it was only encoded to 3500kbps to fit a DVD-5!

Yeah I'll use a DVD-9 if the movie is >2hours or an effects spectacular, or a BD-25 if I'm lazy and just want to back-up the original disc, but I can't imagine why anyone would encode to 720p.

[Sharc]

....., but I can't imagine why anyone would encode to 720p.
Well, for example much shorter encoding time.
In many cases no real loss of details (or hardly visible) compared to the 1080p original.

Or if the source is 1080i one can apply double rate deinterlacing (bobbing) to avoid loss of temporal resolution and encode to 720p/50 (or 720p/60) for blu-ray compliance.
(Although with the recent MBAFF improvements of x264 encoding to 1080i is a strong option)

[larrsz]

[QUOTE=Sharc;1501093]Well, for example much shorter encoding time.
In many cases no real loss of details (or hardly visible) compared to the 1080p original.

QUOTE]

Based on my trial and error, I find this to be the case (both points). I don't see enough loss to worry me, and when watching on my largest screen, I use the BD anyway.

[Mike Rogers]

Hi I'm new to the forum and have been trying BDRB for the past couple of weeks. May I say that you've written an impressive bit of software however I hope you can advise on a problem I'm having that might well be related to the recent threads on file sizes and bit rates. I've searched the forum for a specific answer but unsuccessfully. My objective has been to rip multiple episodes of a tv series from a single Blu-Ray disk to MKV. BDRB makes this process very easy using the Movie only/Alternate Movie Only Output mode and the ripping process has produced excellent quality MKV's with Encoder Quality Settings set to to Automatic using the MKV Container Output 1920x1080 Intact Audio. Each movie episode runs for about 50mins and produced file sizes of around 6gb using an average CRF of 20. The files play perfectly in Home Cinema Media Player/Power DVD 10, however when written to Blu-Ray disk and played on my LG 3570 BR player, picture breakup/pixilation occurs. I've tried a lower CRF (16) to improve the quality but on playback the same pixilation displays. MKV's usually play perfectly on the LG3570 so is this problem related to bitrates or something else perhaps? Also slight jerkiness on panned shots happens from time to time. Could this also be related?

[jdobbs]

Hi I'm new to the forum and have been trying BDRB for the past couple of weeks. May I say that you've written an impressive bit of software however I hope you can advise on a problem I'm having that might well be related to the recent threads on file sizes and bit rates. I've searched the forum for a specific answer but unsuccessfully. My objective has been to rip multiple episodes of a tv series from a single Blu-Ray disk to MKV. BDRB makes this process very easy using the Movie only/Alternate Movie Only Output mode and the ripping process has produced excellent quality MKV's with Encoder Quality Settings set to to Automatic using the MKV Container Output 1920x1080 Intact Audio. Each movie episode runs for about 50mins and produced file sizes of around 6gb using an average CRF of 20. The files play perfectly in Home Cinema Media Player/Power DVD 10, however when written to Blu-Ray disk and played on my LG 3570 BR player, picture breakup/pixilation occurs. I've tried a lower CRF (16) to improve the quality but on playback the same pixilation displays. MKV's usually play perfectly on the LG3570 so is this problem related to bitrates or something else perhaps? Also slight jerkiness on panned shots happens from time to time. Could this also be related? I doubt that it could be the encoding. A CRF of 20 should return a virtually perfect picture. I don't think I can visualize exactly what you're describing by "picture breakup". It plays back fine on the computer? That means it isn't very likely that the video itself is the problem -- but instead the playback.

That doesn't mean I'm saying your player is at fault -- only that something in the playback is causing issues (it could be bitrate etc.). I've done a lot of tests using MKV playback, though, and have never experienced anything like what you are describing.

[StanHere]

I'm a new kid on the block when it comes to BluRay ...but learning fast as a polished veteran of years with DVD!

While it's an important issue with DVD re-authoring\burning and addressed frequently elsewhere as to BluRay disk quality.....

How come specific BluRay writer reliability & BluRay media quality and their history with Mike have not been ruled
IN or OUT as a possible playback issue?

If Mike has a "proven" BR burner AND known, good quality disks, then I feel for his frustration, given J Dobbs feedback!

ARRRGH!

[jdobbs]

I'm a new kid on the block when it comes to BluRay ...but learning fast as a polished veteran of years with DVD!

While it's an important issue with DVD re-authoring\burning and addressed frequently elsewhere as to BluRay disk quality.....

How come specific BluRay writer reliability & BluRay media quality and their history with Mike have not been ruled IN or OUT as a possible playback issue?

If Mike has a "proven" BR burner AND known, good quality disks, then I feel for his frustration, given J Dobbs feedback!

ARRRGH! You make a good point. It's very possible that the problem could be in the media.

[Mike Rogers]

I doubt that it could be the encoding. A CRF of 20 should return a virtually perfect picture. I don't think I can visualize exactly what you're describing by "picture breakup". It plays back fine on the computer? That means it isn't very likely that the video itself is the problem -- but instead the playback.

That doesn't mean I'm saying your player is at fault -- only that something in the playback is causing issues (it could be bitrate etc.). I've done a lot of tests using MKV playback, though, and have never experienced anything like what you are describing.

StanHeres point about media quality has got me thinking so I'm going to try an alternative BD-R in case this is the culprit. In the meantime the attached images show the pixilation /breakup I've been getting on LG3570 playback together with the Media Info on both one of the input M2TS files and the MKV output file. This may help you to evaluate whether the data files are any way contributing to the problem.

I'll come back on the media question.

I've now tried alternative recording media and the same playback breakup occurs so it would appear that something in the MKV file itself is causing the display problem. Out of interest, MKV files I have produced from other BD ripping software play OK but the quality is nowhere near in the same class as BDRB, hence my interest and preference for using it. I would be interested to hear if the Media Info dumps provided any clues.

[jdobbs]

Hmmm... the picture doesn't look like a bitrate issue at all, and the bitrate is very tame (under 14Mbs with a max set at 15Mbs). Instead, the picture looks like total confusion on the part of the playback device, and loss of references. Interesting how the blocks seem to move to the right horizontally as they progress vertically down. Maybe one of the X264 experts will recognize that pattern and comment.

Do you have any documentation on what the rules are for MKV playback on that unit?

[Mike Rogers]

This is the info from the LG370 manual.
Div X file requirements, resolutions and playable codecs:-
DivX 3 to DivX6, 720x576 (DivX6 standard playback only)
XVID, H.264/MPEG4 AVC 1920x1080

DivX File extensions supported: .avi .divx .mpg .mpeg .mp4 .mkv

The player supports H.264/MPEG-4 profile Main,High at level 4.1. Option available to play at higher level also.

I've not included the audio requirements as these seem to play OK

[jdobbs]

This is the info from the LG370 manual.
Div X file requirements, resolutions and playable codecs:-
DivX 3 to DivX6, 720x576 (DivX6 standard playback only)
XVID, H.264/MPEG4 AVC 1920x1080

DivX File extensions supported: .avi .divx .mpg .mpeg .mp4 .mkv

The player supports H.264/MPEG-4 profile Main,High at level 4.1. Option available to play at higher level also.

I've not included the audio requirements as these seem to play OK Hmmm... the output to MKV is H.264/MPEG-4 High Profile at level 4.1.

[Mike Rogers]

Hi JD. I think I've found the source of this particular problem and it's nothing to do with BDRB. A faulty USB port somehow caused the picture degradation when BDRB was encoding the MKV to an external drive. I've re-encoded to an internal drive and all is well. Many thanks for your comments. BDRB is a gem.

[Mike Rogers]

Hi JD. I think I've found the source of this particular problem and it's nothing to do with BDRB. A faulty USB port somehow caused the picture degradation when BDRB was encoding the MKV to an external drive. I've re-encoded to an internal drive and all is well. Many thanks for your comments. BDRB is a gem.

Well, just as I'd thought the gremlins had gone away, back they came. Having established what I thought had caused the BD/MKV playback problem (ie USB hardware) it seems that wasn't the case. Using an internal destination drive worked OK encoding two MKV titles with good playback display but on two others it didn't so back to the drawing board. So what had I done that was different? The two successful titles I rebuilt singly (output BD9) and the two unsuccessful ones in a batch (output BD25). I decided to do few additional tests to see if this was replicated in other variations of single and batch and you will see from the results attached that the target output size BD25 was the common denominator generating the problem.