RF and File Sizes

[consultant]

Doesn't anyone know what the total filesize should be approximately for 5 minutes of video ripped without transcoding from a DVD?

At what RF (rate factor) does the x264 filesize for the same 5 minutes of video equal the filesize of the original DVD video?

What I'm REALLY wonder is what RF gives you quality that does not have significant degradation in the image quality and how much smaller the file size would be.

I've been experimenting and RF of 20 has a bit more degradation than I want. But it is pointless if I go to an RF where I'm saving an insignificant amount of disk space (less than 20% savings.)

[nurbs]

Doesn't anyone know what the total filesize should be approximately for 5 minutes of video ripped without transcoding from a DVD?
Bitrate x Duration = filesize
DVDs don't come in standard sizes, but with 4 - 6 Mb/s it would be 150 MB to 225 MB.

At what RF (rate factor) does the x264 filesize for the same 5 minutes of video equal the filesize of the original DVD video?
Can't be answered. Depends on the properties of the source material and x264 settings used for encoding.

What I'm REALLY wonder is what RF gives you quality that does not have significant degradation in the image quality and how much smaller the file size would be.
I've been experimenting and RF of 20 has a bit more degradation than I want.
Different people have different opinions on what is good enough. For me CRF 21 is sufficient for DVDs, higher CRFs for HD content or animated content.
If 20 isn't good enough for you try a lower one. Slower or different settings and tunings may also help.

[consultant]

Thanks for the info. I'm getting a 100MB filesize for 5 minutes of DVD video using RF 18, which that is around a 50% filesize reduction from the source material. It looks good too. I think I found my 'sweet spot' although I'd like to have more than 50% reduction but considering DVD is already compressed MPEG-2 video, I suppose halving it is not bad.

[wyti]

then you can try to use slower settings with a RF of 18, you will get about the same quality but smaller file.
try "--preset veryslow" it gives a very good quality vs size ratio and still have a descent speed (on fast proc and SD content))

[nurbs]

then you can try to use slower settings with a RF of 18, you will get about the same quality but smaller file.
That's not true. He will get better quality/bitrate, but the file may come out bigger or smaller.

We've had this discussion:
http://forum.doom9.org/showthread.php?t=151439
http://doom10.org/index.php?topic=92.msg782#msg782

[consultant]

Well I got it down to 70MB. I'm using Handbrake. Unfortunately I'm encountering a strange problem with all my mv4 encodes in that I'm seeing jerkiness in the motion. What is strange is if I encode to an MKV file with same settings I don't see the jerkiness. Not sure why that is. I don't know enough about the settings I think to know what I need to tweak.

I installed MEGui and I didn't have a clue what an AVISynth script is. I just want something easy that does decent encoding.

[kypec]

I'm not very experienced in this matter but the jerkiness problem might have something to do with VFR (variable frame rate). Maybe it's not supported properly by your other containers than MKV?