Bitrate-limitations when burning UHD on BD-R?

[Dr. Cooper]

Hey guys,

I ran into a weird issue lately: The short version is I tried to remux a retail-UHD and burn it back on a BD-R DL 50 GB which all worked fine, but when I'm trying to play it on my Panasonic UBP-824 or the PS 5, it starts to stutter as soon as the bitrate exceeds 60 MBit/s.

Now the more detailed version of what I did:
First I authored a normal 1080p-Blu-ray with menu etc. using Encore CS 6. For the video I just used a proxy-encode in 1080p, just to get it integrated into the menu-structure. Then I replaced it as described here. Then I updated the BD-profile to level 3.00 with BDedit and burned it using ImgBurn (UDF 2.5 and whatever settings it used automatically after it recognized the BD-structure). The player recognizes it as UHD and the menu etc. are all ok. The film starts, but soon as the bitrate exceeds 60 MBit/s it starts to stutter.

I also added a Dolby Vision-layer from a Web-DL (the original disc only has HDR10), but that's not the issue - I also tried to burn it without the Dolby Vision-layer and the results were the same. What might also be important to know is that I also completely swapped the audio-tracks. The original disc had 10 audio-tracks with (according to BD info) a total bitrate of 6879 kBit/s, mine has 8 DTS-HD MA-tracks with a total of 12079 kBit/s.

Are there any limitations with self-burned BD-R discs or is there something in the burn-settings or the BD-structure that needs to be changed, so it also plays fine on the UHD-player? When trying to play the burned disc with VLC it also works fine, so it's not an issue with the disc itself. The Blu-ray white-paper mentions something about 72 MBit/s or 92 MBit/s for 50 GB-discs and 92, 123 or 144 MBit/s for 66 and 100 GB-discs. But somehow I can't quite figure it out whether this is my bottleneck or what else I am doing wrong.

What worries me is that I can't find any other reports about issues like this. When someone asks about burning UHD-discs, it's just recommended to use common 50 or 25 GB-discs since the BD-R XL-discs won't play on most standalone-players. But nothing about bitrate-limitations etc.

Anyone here knowing what might help to get this solved or is it just impossible what I'm trying to do here?
Thanks in advance for your help!

[Stamper]

Isn't Encore only really compatible with Mpeg2? I saw some posts online.
It seems too ancient to continue creating Blu-ray discs with it.

[Dr. Cooper]

No, it also works with AVC. It has its limitations, e.g. HD-audio doesn‘t work, you can‘t mix WAV and AC3/DTS on the same disc, but I startet just using shitty proxy-encodes for the authoring-process and then swapping them for the proper encodes with tsMuxeR and BDedit afterwards. Works fine and as you can see it even opens up the opportunity for UHD.

I just don‘t know why the playback on the standalone-players starts to stutter, soon as the bitrate goes higher than 60 MBit/s. We once had this thread about H.265 encoder-settings for UHD-BD and there spoRv mentioned a maxrate of 64000 kbit/s for BD50 which matches with the issue I‘m having here. So it seems like there really are limitations with the self-burned discs, I just can‘t find any other info about this. Everytime someone wants to burn UHD, the recommendations are just to use normal BD-R instead of the XL-discs as they won‘t play on most standalone-players. But nothing about bitrate-limitations etc.

[Dr. Cooper]

I tried to do a reencode using these settings in a command-line:

Code:

"ffmpeg.exe" -probesize 100MB -i "input.m2ts" -pix_fmt yuv420p10le -an -f yuv4mpegpipe -strict -1 - | "x265-10b.exe" --y4m --fps 24000/1001 --input-csp 1 --input-depth 10 --output-depth 10 --no-interlace --preset slow --vbv-maxrate 60000 --vbv-bufsize 60000 --uhd-bd --bitrate 50000 --pass 1 --slow-firstpass --sar 1 --hrd --aud --chromaloc 2 --hdr-opt --colorprim bt2020 --transfer=smpte2084 --colormatrix bt2020nc --max-cll "1000,400" --master-display "G(13250,34500)B(7500,3000)R(34000,16000)WP(15635,16450)L(10000000,1)" - -o nul

"ffmpeg.exe" -probesize 100MB -i "input.m2ts" -pix_fmt yuv420p10le -an -f yuv4mpegpipe -strict -1 - | "x265-10b.exe" --y4m --fps 24000/1001 --input-csp 1 --input-depth 10 --output-depth 10 --no-interlace --preset slow --vbv-maxrate 60000 --vbv-bufsize 60000 --uhd-bd --bitrate 50000 --pass 2 --sar 1 --hrd --aud --chromaloc 2 --hdr-opt --colorprim bt2020 --transfer=smpte2084 --colormatrix bt2020nc --max-cll "1000,400" --master-display "G(13250,34500)B(7500,3000)R(34000,16000)WP(15635,16450)L(10000000,1)" - -o "output.hevc"

The vbv-maxrate and vbv-bufsize were actually supposed to limit the bitrate to 60 MBit/s, but for whatever reason the final result still exceeds the limit in several scenes and if it sums up in a couple of seconds, it starts to stutter again on the UHD-player.

It‘s a lot better than before, I got from a mostly unwatchable film to 5-6 stuttering scenes, but how can I get the encoder to respect the limitation through the entire film, so it‘ll play smoothly on the UHD-player?