Nelson's log

Blu-Ray to x265

I am super excited about the Vinegar Syndrome re-release of Liquid Sky. One of my favorite movies from the 80s, most of us watched it on crappy 3rd generation VHS tapes or if we were lucky, a low quality DVD. Vinegar Syndrome remastered it and put out a beautiful Blu-Ray with gorgeous color and lots of extra features. Only problem: it’s a disc. Who can play discs these days? So I ripped it. (For myself only, I respect Vinegar Syndrome far too much to give out copies.)

Blu-Ray discs are encrypted so most computer tools can’t read them. But MakeMKV can. It’s a straight up rip; it copies all the tracks off of the Blu-Ray and puts them in MKV containers on your hard drive. No re-encoding so the 2 hour movie is like 29 GB.

Re-encoding it to a smaller file is easy. Handbrake will do the job fine but for some reason was running slowly for me, so I used ffmpeg instead. Here’s the command:

ffmpeg -hwaccel auto -i title00.mkv
-map 0:v -c:v libx265 -crf 26 -preset slow -tune grain
-map 0:a:0 -c:a:0 aac
-map 0:a:1 -c:a:1 copy
-map 0:s:0 -c:s copy
ls.mkv

I’m doing this the complicated way with -map options so I can pick and choose audio tracks. Track 0 is the main audio, track 1 is director’s commentary. There’s also a track 2 which is the sound without dialog, but I decided not to include it. Just the one video track of course, and one subtitle track.

I transcoded the main audio. The source is in 768kbps DTS, overkill particularly since the audio is mono (as the original film was). So I’m re-encoding it to AAC. I have no idea what bitrate that was going to give me. The result is about 150kbps which seems reasonable, if generous.

I also transcoded the video to H.265, the result is about 3300kbps for 1920×1080. crf 26 is higher quality than the default crf 28. Preset slow trades off CPU time for higher quality / smaller video. And “tune grain” tweaks the encoder to try to preserve film grain, something abundantly visible in the source disc.

I wanted to transcode the subtitles to SRT but that didn’t work for me, ffmpeg threw an error.

The metadata mostly came through but then some of it is wrong; bitrates and stuff were copied from the Blu-Ray. Chapter marks did come through from the original source.

All told it took about 18 hours or about 0.1x real time speed. That slow preset really makes it slower, something like 4x slower.