[FFmpeg-user] Trying to Reduce Sizes of Movies Ripped with MakeMKV

[Ted Park]

Hi,

> I have been using the following command to recompact the Blu-Ray MKV files:
> 
> ffmpeg -y -hwaccel cuvid -c:v h264_cuvid -vsync 0 -i in.mkv -map 0 -codec:v
> h264_nvenc -codec:a copy -codec:s copy -max_muxing_queue_size 4096 out.mkv
> 
> That command does two things for me. Since I have a halfway decent graphics
> card (Nvidia geforce RTX 2060), it gives me the hardware acceleration I
> desire. It also retains all subtitles when recompacting the files.

I wonder if the BD/DVD ripping software you are using can be made to transcode so you wouldn’t have to do this. (Since it doesn’t sound like digitizing an exact lossless copy isn’t a priority)

> That command works very well for Blu-Rays. It can reduce a 40-50GB MKV file
> to about 7GB. The problem is, that only works on files produced by ripping
> Blu-Rays. If I try it on DVD files, I get errors.

Does this happen with all DVD files?

> I am using ffmpeg version n4.1.4 on a Ubuntu Mate 20.04 system, Intel X64
> PC. Everything is up-to-date (I run apt update/upgrade regularly).

The “up-to-date” release in most distros package manager default sources are usually at least a few months old, try downloading a static build if you can’t seem to build for some reason. https://www.ffmpeg.org/download.html#build-linux

> BTW, I noticed that, by default, ffmpeg on Ubuntu 20.04 is installed with
> Snap. I hate Snap. I had nothing but problems with MakeMKV installed with
> Snap, and had to compile MakeMKV from scratch.
What is snap?
> I tried doing that with
> ffmpeg, but I couldn't get it to install absolutely everything I needed. I
> ended up with no Nvidia hardware support, for example.
Try using that anyway, if it works then your solution is probably getting a newer version of FFmpeg, then you can work on configuring with hw acceleration support, or finding a static build that includes it. 

Regards,
Ted Park