Blu-ray ripping newbie needs advice on 720p/1080i...

[dh2005]

Hello everyone,

I'm hoping this makes sense - the last time I tried to explain it on another forum, people got the wrong end of the stick.

I'm about to start ripping my Blu-ray discs, for playback on a Popcorn Hour A-110 media streamer. I have a TV that can display up to a maximum of 1080i, so there's no sense in leaving them at 1080p after I've ripped them. It's my intention to re-encode them down to a lower bitrate, but I need some advice on which bitrate to choose and which program to do the encoding with.

Basically, I want the video to look as good as possible - so, I want a bitrate that will produce a result that looks like true 720p/1080i (so that the difference is imperceptible on my TV). And I want to leave the audio completely untouched.

Does that make sense?! I don't think it's very complicated, but I managed to completely spanner a couple of people on that other forum...

Thanks in advance,



DH.

[Guest]

Try re-encoding with x264 at several different bitrates and choose the lowest one that you think is good enough.

[dh2005]

Thanks for the reply.

So, is there no definitive bitrate that corresponds with my requirements? As in, if 1080p is circa 40Mbps, then 720p would be 20Mbps...? Or does it not work like that?

[Guest]

I understand now why you had trouble on the other forum. :)

Your requirements are so vague and cover so many different possibilities that there is no way to give you a general formula.

[dh2005]

Yeah...? Well, maybe you can set me straight.

Is it not true that 1080p video streams taken from Blu-ray peak around the 50Mbps mark? Is it also not true that 720p has approximately 50% of the video data of 1080p? I have been told these things by people who supposedly know what they're talking about...

If those two things are true, would setting the bitrate at around 25Mbps not guarantee that I get something that looks truly 720p?

Personally, I don't think that's too difficult to understand - it's simple arithmetic. Or maybe I've lived 29 years without realising that I'm a Maths genius... though I doubt it.


EDIT: I see you've amended your previous post. Does the above clarify things at all?

[dh2005]

The reason I'm seeking a "general formula" is that the alternative you've suggested, with all due respect and gratitude for the advice, is just plain annoying. I am not going to rip every Blu-ray disc at several different bitrates then sit through each film several times deciding which looks best. I want to know, in very simple terms, whether setting the bitrate at 20/25/30/whatever-Mbps will yield a result that always looks good on a 720p television.

Ideally, I'd like to be able to leave them at 1080p - but sadly, that's not a practical option because my media streamer starts to struggle with bitrates in the high-40s, and I don't want my playback to stutter. Other than that, any suggested bitrate is fine. I have hard drive space to burn.

[Dark Shikari]

If you don't know what bitrate to use, use CRF.

[dh2005]

Okay. Thanks... what's that?

[dat720]

Constant Rate Factor

Rather than encoding to a desired bitrate you encode to a desired quality level.... I use it for all encoding, I don't aim for file sizes.
You can get blurays "rips" into the 10-15mbps range retaining perfectly acceptable quality using a CRF value or 19-20

Don't worry about your TV being 1080i, encode them at 1080p, your TV will still play them back unless your playback device tries to force itself to 1080p, you can usually set a max resolution tho, for instance PS3 you can set the max resolution your display supports so it won't force itself to a resolution that your display does not support.

[dh2005]

Thank you.

All I'm keen to do is get the max bitrate down a little. Once the Popcorn Hour machines get beyond 45Mbps, they start to get upset.

So, is the program I need called x264...?

[setarip_old]

@dh2005

Hi!

You might want to set aside any requisite math skills and try "BD-Rebuilder" and/or "AVCHDCoder" (Both are presently freeware)

[Guest]

Personally, I don't think that's too difficult to understand - it's simple arithmetic. You're asking me to confirm your understanding of simple arithmetic? :)

You can't get the ratio just from the frame size, e.g., 720P vs 1080P. You have to state the frame rates as well. Then you can calculate a valid ratio. 720P is often 59.94 fps, so you have to decide what your target frame rate is going to be, and you have to know the frame rate of the source.

[10L23r]

also, if you didn't know, the numbers don't scale linearly.. that is 720p30 at about 30mbps will be about the same quality (without upsizing on your tv or computer) as 1080p30 at 50 mbps even though 1080p has more 2.25x more pixels that 720p.

[Adub]

Even though (as I am sure Dark Shikari will agree), bitrates of 50Mbps for 1080(i || p) are simply ridiculous. The video becomes so super saturated with bits, there is little point in adding any more (at least with a decent encoder, such as x264). Other encoder have a tendency to distribute bits in a not-quite-so-efficient way.

So, in short, my recommendation is that you run a series of small tests. Take a Bluray/HD DVD of your choosing. Encode a small sample of it (either a mix of high motion/still motion scenes, or through the use of Avisynth's excellent SelectRangeEvery() function), and encode at a variety of different bitrates and/or CRF values. Then view each one individually upon your desired display and see which one (of the smallest file size) you can stand. It's a completely relative decision. Some of us seasoned veterans may be able to tell the difference, and scream at the smallest artifact, but that's because we have been doing this for so long.

The fact is, over 95% of the population can barely tell the difference between SD and HD. And a majority of those who can, don't really care. So, you have to decide for yourself what you like.

[dh2005]

Thanks everyone.

Regarding the Maths - yeah, as I said in my second post, I wanted to know whether my simplistic understanding of the scaling was right. I'm happy to be corrected on that.


Adub;

You say 95% of the population struggle to tell the difference between SD and HD...?! That would be 95% of the partially-sighted population, right?! Because you'd have to be blind...!!! Seriously, is that statistic grounded, or did you pluck it out of the air?

Actually, I had an argument with a friend, Luke, over exactly that issue. A mutual friend of ours bought a PS3 and got Batman Begins on Blu-ray with it. I already owned it on DVD, and we ran them side-by-side on a Panasonic Viera 40" plasma, with the DVD in an upscaling player and the Blu-ray in the PS3. Luke said he couldn't really tell the difference, and that of the two he preferred the DVD. I almost ripped his head off... idiot.

Also, can I clarify something...? You said that x264 adds bits? I thought it took them away - as in, it reduced the bitrate. Or, again, is that not how it works?!


EDIT: ... and also also, regarding your comment about me deciding for myself what I prefer - I want it to be the best that it can be. I'm really fussy when it comes to video (at least, insofar as I can be as a student, without the income to drop several grand on TV...). That's kinda the whole point of this thread - I want the limiting factor in the video quality to be my 720p TV, and not the files. I'm looking to reduce the bitrate only to the point at which the difference is imperceptible on my current setup. If that's not possible, I might as well just stick to watching the discs in my Blu-ray player.

So, if anyone has any recommended settings to use (number of passes, bitrate, CRF, or whatever options x264 has...) that will yield excellent results for all kinds of video, that would be great. If only as a starting point for me, so that I can then go on to run those tests you've suggested.

Anybody...?

[Sharc]

....A mutual friend of ours bought a PS3 and got Batman Begins on Blu-ray with it. I already owned it on DVD, and we ran them side-by-side on a Panasonic Viera 40" plasma, with the DVD in an upscaling player and the Blu-ray in the PS3. Luke said he couldn't really tell the difference, and that of the two he preferred the DVD. I almost ripped his head off... idiot.
As has been said many many times in this forum,
video quality is very subjective. If Luke prefers the DVD he says so because it looks better to HIM, so he is right ... and not an idiot.

I'm looking to reduce the bitrate only to the point at which the difference is imperceptible on my current setup. If that's not possible, I might as well just stick to watching the discs in my Blu-ray player.
That's definitely an option.
Again, what is "best" and what "difference is imperceptible" depends largely on the playback equipment and on the eyes and perception of the viewer.

So, if anyone has any recommended settings to use (number of passes, bitrate, CRF, or whatever options x264 has...) that will yield excellent results for all kinds of video, that would be great. If only as a starting point for me, so that I can then go on to run those tests you've suggested.
You may want to try BD Rebuilder or RipBot264 if you prefer a highly automated backup process with very good results.
If you want to experiment with x264 settings you can select one of the many free GUIs in this forum, and start with following x264 settings:
--crf 18 --ref 3 --mixed-refs --bframes 3 --weightb --b-adapt 1 --direct spatial --subme 7 --trellis 1 --psy-rd 0.7:0.2 --partitions all --8x8dct --me umh --threads auto --thread-input --progress --no-psnr --no-ssim
I doubt that you will be disappointed by the result.

[dh2005]

Well, he's a good mate and we've known each other a long time, so I have no qualms in calling him an idiot. We've called each other worse, over the years...!

I just think it's really peculiar that a person not be able to tell the difference between two pictures, one of which is objectively sharper than the other, then decide that the softer picture with muddier colours is in any way better. And the guy doesn't have an eye disease, so his vision's physiologically probably very similar to mine. I know some people prefer the sound of vinyl over CD etc. because they believe that the sound has more "character", and I can see their point, even though I don't agree with them - but I don't consider "character" to be a consideration when it comes to DVD vs. Blu-ray. As far as I'm concerned, one's worse and one's better. If only because you can see more of what the camera captured on Blu-ray, and you're therefore watching a more faithful representation of what was recorded.

I do recognise, however, that sometimes the appearance of a film is deliberately downgraded by a filmmaker because of a certain feel that he or she wants to get, and therefore there are times when a rougher image is artistically the superior choice... but I'm talking about technicality here, rather than artistry. And given that Batman Begins was filmed in HD, it's the director's opinion that that's how the film looks best, and I have to agree. Luke, of course, has a different view! To which he is, of course, absolutely entitled... and I, in return, am entitled to absolutely disagree with him!

Thanks for your thoughts on this. I'll look into the programs you've recommended.

[slipknot!]

dh2005, why don't you just decrypt your Blu-Ray's to hdd, and then mux into a container that your Popcorn Hour A-110 supports. Doesn't it support all the Blu-Ray codecs?
Doing it in this way provides you the exact quality as it was on the disc. And there is no need to mess with codecs, bitrates, framerates, etc. Or do you need the size to be much smaller?

[dh2005]

No, no. Size is not the issue. But when the bitrate hits the high-40s, the A-110 struggles to keep up.

The way I figure it, particularly given that I don't have a 1080p TV anyway, I can encode them down to a lower bitrate so that the A-110 never has a problem with the playback, and not notice the difference anyway because of the limitations of my television.

If it were possible to be sure of smooth playback straight off the disc, I wouldn't be bothering everyone with this thread...!


EDIT: yeah, you're quite right. It'd be much, much simpler. But because the A-110 can't necessarily handle peak 1080p Blu-ray bitrates, playback can sometimes stutter and grind. And that's not an acceptable outcome for me.

[dh2005]

Actually, I have another request:

Does anyone know of how to get subtitles into a Blu-ray rip? The A-110 doesn't support native subs from Blu-ray, which knocks-out Pan's Labyrinth and The Orphanage... unless I learn Spanish which, much as I like those films, would be slightly excessive!

[slipknot!]

Is there any Blu-Ray that has bitrates higher than 40 mbps? All (99.99%) the new ones have 15-30 mbps video. I think you really don't need to reencode it to 720p if you are not limited with the final filesize. Keep it original and untouched just as the sound. So you will not need to reencode them again if you buy a new TV soon.

[dh2005]

Hah! Dude, I wish that I'd be buying a better television anytime soon, but given that I'm gonna be at university for another two years, and that I'll have around £60,000 of debt to address thereafter, luxuries like 1080p televisions are a distant ambition! Particularly when I have one of the best non-1080p televisions on the market.

I've monitored the bitrates of a couple of discs that I own (Transformers and No Country For Old Men, I think...), and their bitrates have definitely peaked well into the 40s. Unless my PS3's been lying to me...

... so, are modern discs better encoded so that the bitrates don't get above 30?! I wasn't aware of this.

[slipknot!]

Casino Royale: 24.1 Mbps
X-Men 1: 27993 kbps
X-Men 2: 24203 kbps
X-Men 3: 30145 kbps
Die Hard 1: 25 mbps
Die Hard 2: 27 mbps
Die Hard 3: 27 mbps
Die Hard 4: 26843 kbps
Harry Potter 1: 17601 kbps
Harry Potter 2: 15400 kbps
Harry Potter 3: 18.9 mbps
Harry Potter 4: 12.6 mbps
Harry Potter 5: 13.5 mbps
Resident Evil 1: 25849 kbps
Resident Evil 2: 16 mbps
Resident Evil 3: 28 mbps
Spider-Man 1: 25 mbps
Spider-Man 2.1: 25 mbps
Spider-Man 3: 25 mbps
Pirates of the Caribbean 1 (Remastered): 19 mbps
The Bourne Identity: 30 mbps
The Bourne Supremacy: 28030 kbps
The Bourne Ultimatum: 26319 kbps

[slipknot!]

As you see there is about 10-15 mbps for audio tracks, and it's more than enough :D
I've monitored the bitrates of a couple of discs that I own (Transformers and No Country For Old Men, I think...), and their bitrates have definitely peaked well into the 40s. Unless my PS3's been lying to me...
Is it bitrate of video or bitrate of all the disc (video + 10-12 audio tracks)?

[dh2005]

Are they average, or peak bitrates? I'm aware that Blu-ray playback isn't sustained at 50Mbps, but it can get that high, can it not?

Thank you for your help, by the way.


EDIT: And yes, I think those bitrates were video and audio.

[slipknot!]

Are they average
average
And yes, I think those bitrates were video and audio.
I think you will not need more than 1 audio track (3 mpbs) for watching

[dh2005]

Ah. Okay... so, does the bitrate incorporate not only the audio track that I'm listening to, but also the ones that I'm not?! That would be odd.

[slipknot!]

I've monitored the bitrates of a couple of discs that I own (Transformers and No Country For Old Men, I think...), and their bitrates have definitely peaked well into the 40s. Unless my PS3's been lying to me...
Transformers (Central Eastern Europe) has 38 mbps video. And Dolby TrueHD 5.1 Surround (48kHz/24-bit) is 6,9 mbps :(
But my No Country For Old Men has 20 mbps video.

[slipknot!]

Ah. Okay... so, does the bitrate incorporate not only the audio track that I'm listening to, but also the ones that I'm not?!
I think yes, it shows the bitrate of all the tracks, but I'm not sure

[dh2005]

Ah! Now, that would be a promising development. Thank you!


I must say, the standard of knowledge over here at Doom9 is much, much better than anywhere else that I've looked.

[Sharc]

you might find this tool useful:
http://www.winhoros.de/docs/bitrate-viewer/index.html