Question about BD recoding (ripbot)

[m3tallica]

Hi everyone,

I 've got some basic to intermediate level re-coding experience with ripbot264 and others in the past and I have a couple of questions I'm wondering if you can help with. Basically I have 4TB of external hard drive capacity upon which I use a media streamer to play movies on the TV. Now, I could simply use makeMKV to produce a raw loseless copy of my collection and I have space to do this, however I have a massive collection of BD and HD DVD and so I want to be as efficient as possible with room to spare, I currently use a calculator to tell ripbot to encode at CQ level 18 (I understand lower value is less loss) or 2-Pass x kbps. Therefore, some questions...

1. I've read the very useful guides for ripbot on here and thanks for that, but I'm wondering what others think the threshold is for a noticeable loss in video quality (not too fussed about audio and i'm certainly not a video pro)....I notice various torrents etc with 1080p figuresetc from an original BD source but with video bitrates around 8-12kbps, which is significantly less than the circa 29,000 - 35,000kbps i'm picking up on the original sources. Seems like a massive drop to me, is it as noticeable to others as I think it is, or am I being pedantic? I use a calculator to tell me whether to re-code at CBR or VBR so in the back of my mind is 'lowest resultant file size, best quality result' - what's the right balance? I find myself wondering whether I should say something along the lines of 'ok I wouldn't notice a 10% decrease in the source bitrate, or whether actually, the 8-12kbps files i'm seeing are actually showing very little loss to complain about?'

2. Therefore, would it be worth me recoding one of these files back to roughly the original source bitrate and show no loss or does the logic not quite work like that? I'm thinking the latter is true.

3. With ripbot in particular, I don't want to modify the original profiles, but the bitrate on the 4.0 profile seems a little low? Also i'm not quite 100% on what R-Frames and B-Frames refers to.

Any pointers would be much appreciated. Apologies if this is referenced elsewhere but I did a search and didn't really get all my answers.

[neomaine]

m3tallica,

Though you're somewhat concerned with size you're more concerned with quality. To me, this speaks directly to CQ 18 with x264. Stick with it. It will give you a constant (and very good) quality but with varying (and to me) totally acceptable file sizes.

You can worry about one of two things: quality or filesize. CQ (constant quality, not constant bitrate as you imply) will give you the same quality across the total video using whatever, and only, bitrate it needs. VBR will give you a more predictable filesize but will starve some areas of the video to assist others. 2 -pass helps this out but its not worth to me. Why spend all that time calculating and going through the video twice (or God-forbid three or more) when you can get the quality you want with one pass.

AT CQ of 18, most people will be fairly hard pressed to tell the difference. Personally, swapping out or adding drives for more space is a much more pleasant activity then the hoops you go through marginally better filesize. Especially when quality is more of a concern.

[m3tallica]

Thanks for your comments neomaine.

I did mean CQ rather than CBR - my mistake. I think that's the way forwards then, CQ18, luckily I've done quite a few like that already and yes, i'm more fussed about quality than filesize.

Cheers.

[m3tallica]

Sorry - follow up question please...

Profile 4.0 has a max bitrate of 25,000kbps, now I don't like messing with the presets - is it worth anything like using a custom profile to ramp that up to say 35,000kbps, or will it not work?

Cheers.

[creamyhorror]

I think 25,000 is a fair limit for mostly any sort of scene, since sometimes the bitrate spikes with x264 can be very high. But there shouldn't be any problem with going to 35,000.