Q: I am trying to figure out how to “shrink” down a regular Blu-Ray movie, so that I can burn it to a single layer 25gb BD-R disc for playback as BD50 is too expensive. How can we shrink BD50 to BD25 keeping all features, 3D, menus and languages?
A: Before answer the question, let’s check more detail requests of compressing BD50 to BD25 as below:
- Shrink BD50 to BD 25 with menus, subtitles and audios
- Shrink 3D BD50 to BD25
- Shrink BD50 to BD25 with the best Blu-ray Copy
Is it possible to shrink BD50 to BD 25 with all menus, subtitles and audios?
As the sound files in Bluray movies (Dolby True HD, Dolby digital, DTS HD, DTS, etc.) couldn’t be compressed because of their authorized structure. It is unbelievable that some softwares said they fit with same as original(same resolution, same format, same scale) after compressing. In fact, those tools made it work by re-encoding and demuxing the Blu-ray HD audio into AC3, etc. for shrink BD50 to BD25.
I got some experiences that when ripping from a BD50 to a BD25, a typical movie will fit onto a BD25 without actually re-encoding the video at all. I’d say the max video size I typically see is 20GB. If you’re limiting yourself to one audio track (I stick with AC3 640kbps, and on a rare occasion will use DTS 1.5mbps), you should almost always have enough space on a BD25 to completely avoid having to spend hours re-encoding.
For lots of people, the lossless audio isn’t worth the space. AC3 at 640kbps sounds pretty damn good. Some people argue that DTS at 1.5 mbps is better. I can’t tell much difference besides volume levels and the sound is more “sharp” with DTS. So, even if it’s better, it’s not 2.3 times better! On that same note, DTS-MA and Dolby TrueHD DEFINITELY aren’t worth the space waste on my BD-25s. If you stick with DTS or AC3, you’re not going to have many issues with movie only without re-encoding video to a BD-25.
If you want to compress BD50 to BD25, it is highly recommended to keep only movie with 1 language and 1 subtitle and get the best quality for that.
There maybe a lot of ways available in the market, i just want to introduce the best one of them. Here i will introduce a paid way – compress BD50 to BD25 with the best Blu-ray Copy.
How to shrink 3D BD50 to BD25 with original 3D effect?
I’ve done some research and test on 3D blu-ray copy and found some software are really NOT creating true 3DBDs, they’re creating 2D BDs that have a picture layout that is conducive to working with 3DTVs. The right way should follow below steps while shrinking 3D BD50 to 3D BD25:
- Firstly, decrypt & Rip 3D BD50 to hard disc, and the output files may be more than 50GB. Then add the SSIF file into components: Main (L) M2TS, Derived M2TS.
- Second, decode Main M2TS to left view with AVC codec (uncompressed) and put in 1st buffer, then decode Derived M2TS to derived view with MVC codec and put in the 2nd buffer. Compare the 2 buffers and apply changes from 2nd buffer to 1st buffer to create Right view, put into 3rd buffer. Compress 1st buffer using AVC codecs and 3rd buffer using MVC codecs with lower quality levels.
- Third, reauthor/remux the output files into M2TS files, re-interleave it into SSIF file(s) and rest the BD structure before burn it to a new BD25 disc.
I tested and found only one blu-ray copy software in the market is doing in this way, it’s made true 3D BD25 discs after compression. Here is the one: best Blu-ray Copy.
How to Shrink BD50 to BD25 easily?
There is no complicated operations for shrink Blu-ray 50GB to Blu-ray 25GB. The software is easy-to-use. Just load the Blu-ray disc you want to deal with and choose the “Full Disc” or main movie option, set output as BD25, then start to copy.
First, run the software and load your blu-ray disc.
Second, choose Full Disc Copy mode to compress BD50 to BD25 if you want to keep all stuff and select BD25 as output format. Or choose Main Movie mode if you only need the main movie, select one subtitle and audio for output.
Note: Only in the main movie mode, you are allowed to choose the audio track and subtitle track for output.
Third, Click “Copy” button on the left-corner of the popup side bar to start shrink BD50 to BD25.