Compression Questions (what do I lose and how much)

twbannon

Hi, Newbie here. When compression has to occur (fitting a larger movie file to a 25GB disc), does the software remove all HD Audio from the whole movie, or just some where needed? based on how much is needed? In general, about how much GB of space is devoted to HD audio as compared to regulare Dolby Digital or DTS? If after deleting the HD audio, there is still not room, then does the software start lowering resolution? And, again, across the whole disc or where needed to make it fit? Thanks!

imhh1

ive seen original dts up to 4gb aprox. 5000 kbps
can be reduce how you want: normal dts 1gb aprox. 1500 kbps
i prefer downconvert to AC3 640 kbps (aprox. 500mb)

8855A

Compression BDs

@twbannon

When dvdfab opens the disc, it will show all the audio tracks on the right! just chose the one you want!

You can use the HD Audio if your blu-ray player isn't "Cinavia" infected, if it is you need to remove the HD Audio!

As you un-check the audio tracks it will show you how much GB's the movie is at the bottom!

Then if you need to compress and you set it to 25GB, it will give you a %, anything below 80% may effect the movie quality!

You should copy it to your HDD first at 50GB, then compress from your HDD, saves wear and tear on your burrner!

Hope this answers your question!:)

twbannon

Thank much. One more Q. If a blu ray is compessed to 75 percent (or less than 80%) would it still be better than a regular DVD? I am just thinking due to 23 GB instead of 6 or 7 - should be much better still? Everyone's insight is helpful. Thanks,

signals

In most cases you can compress a Blu-ray movie to fit on a single layer DVD size disc and it will still look better than a DVD. Blu-ray Copy does not lower the resolution it lowers the bitrate. It is still 1920x1080 unless you select one of the 720P type compression modes.

augerpro

[QUOTE=twbannon;118034]Thank much. One more Q. If a blu ray is compessed to 75 percent (or less than 80%) would it still be better than a regular DVD? I am just thinking due to 23 GB instead of 6 or 7 - should be much better still? Everyone's insight is helpful. Thanks,[/QUOTE]

I did some comparisons on compression I compress down to 8-10Gb, and so far what I see is slow moving shots look quite good, better than DVD. But movement really causes hickups and is worse than DVD, for the simple fact that the digital artifacting is much more noticeable than the overall softer appearence of DVD. Now I'm only using Quick Sync, if you use software mode (I think it is default?) then you can change the quality presets by modifying the preset file (it is pretty low quality to start with). You can read more about that in the post I linked. Attached is a preset file I made that should look quite good when using mkv.h264.audiocopy option. It goes in the C:\Program Files (x86)\DVDFab 8 Qt\profiles3\preset folder.

augerpro

Just noticed the OP is using Bluray Copy, not Bluray Ripper. In that case I'm not sure how you adjust quality settings, but I imagine it is similar to Ripper.