4K to BD-50

[robvalentino81]

Sometimes when converting BD-66 discs to BD-50 size it makes the folder too small for a 50GB disc, like around 35GB. Is there any setting change that can fix this? For BD-100 discs it converts find to around 46-47GB.

[jdobbs]

Sometimes when converting BD-66 discs to BD-50 size it makes the folder too small for a 50GB disc, like around 35GB. Is there any setting change that can fix this? For BD-100 discs it converts find to around 46-47GB. Not sure about your case, but sometimes when that happens it is because the quality has been maximized (if using constant quality), or the bitrate has hit its maximum.

I have seen originals that even have sectors filled with zeros or other junk just to make it seem as if it requires more than a standard BD-R.

[robvalentino81]

Thanks for the info. So am I not losing any quality by having a 58GB movie only file compress to 35GB as opposed to being compressed to 47GB to take up an entire BD-50 disc?

[jdobbs]

Thanks for the info. So am I not losing any quality by having a 58GB movie only file compress to 35GB as opposed to being compressed to 47GB to take up an entire BD-50 disc?If what I proposed is the case, yes.

Which method are you using for encoding? Constant quality, or a fixed bitrate?

If constant quality, can you look at the log and see value was used? If bitrate, you should be able to get that from the log as well.

[robvalentino81]

My encoder is on Automatic Quality Settings. Is there something else I should change it to?

[jdobbs]

My encoder is on Automatic Quality Settings. Is there something else I should change it to?No. That's fine.

Can you cut-and-paste the portion of your BD-REBUILDER.LOG (in the Working Path) that applies to that job? I'm just interested to see if it looks like it maxed out the quality settings.

Usually you'll see something similar this if it is using constant quality (this one used QSVEnc):

- Auto Quality: Very Good (Very Fast), ICQ
...
- [07:23:24] Performing ICQ Prediction...
- Analyzing 5.00 8.00 7.00 [8.00]

or this if using VBR:

- Auto Quality: Very Good (Very Fast), 1-Pass VBR
...
- Bitrate: 35,000 Kbs

With UHD the bitrate might be as high as 48,000 Kbs.

[robvalentino81]

Yes the bitrate is 48,000 kbs, see below log.

----------------------
[09/14/24] BD Rebuilder v0.62.12
[23:18:27] Source: THE_STRANGERS_UNRATED_00002
- Input BD size: 58.14 GB
- Approximate total content: [01:27:28.625]
- Target BD size: 46.26 GB
- Windows Version: 6.2 [9200]
- MOVIE-ONLY mode enabled
- Auto Quality: Very Good (Very Fast), 1-Pass VBR
- UHD-BD source detected.
- Decoding/Frame serving: NVENCC
- Audio Settings: AC3=0 DTS=0 HD=1 Kbs=448
[23:18:28] PHASE ONE, Encoding
- [23:18:28] Processing: VID_00000 (1 of 1)
- [23:18:28] Extracting A/V streams [VID_00000]
- [23:20:27] Reencoding video [VID_00000]
- Source Video: HEVC, 3840x2160
- Rate/Length: 24.000fps, 125,967 frames
- Bitrate: 48,000 Kbs
- [23:20:27] Reencoding: VID_00000, Pass 1 of 1
- [23:55:10] Video Encode complete
- [23:55:10] Processing audio tracks
- Track 4352 (eng): Keeping original audio
[23:55:10]PHASE ONE complete
[23:55:10]PHASE TWO - Rebuild Started
- [23:55:10] Rebuilding BD file Structure
[23:56:31] - Encode and Rebuild complete
[23:56:31] JOB: THE_STRANGERS_UNRATED finished.

[jdobbs]

Yes the bitrate is 48,000 kbs, see below log.

----------------------
[09/14/24] BD Rebuilder v0.62.12
[23:18:27] Source: THE_STRANGERS_UNRATED_00002
- Input BD size: 58.14 GB
- Approximate total content: [01:27:28.625]
- Target BD size: 46.26 GB
- Windows Version: 6.2 [9200]
- MOVIE-ONLY mode enabled
- Auto Quality: Very Good (Very Fast), 1-Pass VBR
- UHD-BD source detected.
- Decoding/Frame serving: NVENCC
- Audio Settings: AC3=0 DTS=0 HD=1 Kbs=448
[23:18:28] PHASE ONE, Encoding
- [23:18:28] Processing: VID_00000 (1 of 1)
- [23:18:28] Extracting A/V streams [VID_00000]
- [23:20:27] Reencoding video [VID_00000]
- Source Video: HEVC, 3840x2160
- Rate/Length: 24.000fps, 125,967 frames
- Bitrate: 48,000 Kbs
- [23:20:27] Reencoding: VID_00000, Pass 1 of 1
- [23:55:10] Video Encode complete
- [23:55:10] Processing audio tracks
- Track 4352 (eng): Keeping original audio
[23:55:10]PHASE ONE complete
[23:55:10]PHASE TWO - Rebuild Started
- [23:55:10] Rebuilding BD file Structure
[23:56:31] - Encode and Rebuild complete
[23:56:31] JOB: THE_STRANGERS_UNRATED finished.Yes. Then it confirms my suspicions. The disc is smaller than the target size because even the use of the maximum bitrate and selecting the fastest encode method (which typically creates larger output) couldn't make it that large.

[robvalentino81]

Ok cool thanks for your assistance

[stonesfan129]

Does this process also convert HDR to SDR or does it just remove that metadata all together and not do any color space conversion? Typically when converting 4K SDR to 1080 SDR, I have to use Vidcoder and set the colorspace to output BT.709.