Has anyone used X264 to produce a replicated BD title?

[benwaggoner]

Ok, i have several questions:

1. What is max allowed vbv-buffersize and vbv-maxrate for Level 4.0 from blu-ray specification (i.e for 4.1 are 30000/40000 buffer/maxrate), not H264.
Not sure beyond "25 Mbps max." I don't have the Blu-ray spec handy.

2. So definitly L 4.0 dosen't require slices? can be then L 4.0 video primary video?
Yep. You could even use AVCHD spec for primary video.

3. What is max allowed vbv-buffersize and vbv-maxrate for Level 3.2 from blu-ray specification for SD content, and what resoultion and fps allowed for SD, and is L 3.2 maximum for SD?
Sorry, no idea.

4. Is there anything about BD5/9 and special restrictions such as VBV or other?
It's been recommended to use lower peaks for red-laser media for better accuracy. 3x has been bandied about (like the HD DVD "3x" mode), for which 25 Mbps video would be a fine constraint.

That said, BD-on-red-laser isn't something that a lot has been done with, and I expect we'll find significant theory/practice divergence, particularly on early hardware BD players.

[benwaggoner]

Chengbin: on past DVD projects, I've normally just filled the disc up - I just don't see any reason not to when you're guaranteed a certain amount of space. A little headroom is good since the sizes can be a little unpredictable, but re-encoding a bonus feature to be 3% smaller to get the whole thing to fit is really no big deal with the speed of today's SD MPEG-2 encoding.
That's find for replicated discs (well, I like to have a max 9.6 Mbps for a little headroom since very early DVD players sometimes didn't did the full 10 well).

But for DVD-R discs, early players can work better with a lower peak. So if I'm making DVD-R optimized for general consumers (so grandma with a 10 year old hand-me-down player) I'll use

Peak video + audio of 6.5 Mbps
Closed GOP


Won't matter for < 5 year old players or PC playback, of course, but raises compatibility for the old stuff.

6.5 Mbps peak isn't bad for 24p, but can be low for 30i. Carbon Mastering Mode FTW...

[benwaggoner]

LoRd_MuldeR, I see you didn't finish reading my post, I said "from a master". :)

Anyway, I'm very excited to see what Lyris can do with his project using x264. BTW, p_l_e_a_s_e use the full 50GB of the disk. I've seen so many Blu-rays with low 20mbps bitrate and the disk still has 10-15GB free. But then truthfully this 40mbps cap is kind of a bottleneck. If you use high average bitrates (like Jumper's 33mbps), if you use bitrate viewer on it, it will probably look like CBR.
Using up 50 GB for a movie is really specsmanship.

Having 40 Mbps peaks can make things a little easier on the compressionist, but they are NOT required for a high quality encode for VC-1 or H.264. I doubt those "low 20 Mbps" titles would have looked any better at 10 Mbps higher ABR. Bear in mind lots of BD encodes have in-loop deblocking off to avoid any potential detail loss, but I don't think that should be needed with a well-tuned adaptive quantization encoder.

It'd be interesting to mess around with BD-compliant streams to see how low CRF would have to go in order to generate ABR at 25+ Mbps.

x264's one weakness there would be Open GOP support, I suppose. However, with Level 4.0, you're allowed a 2 second GOP as opposed to the 1 second with 4.1, which can offer another efficiency boost. 25 Mbps Level 4.0 with 2 sec max GOP and single slice likely would outperform 26 Mbps Level 4.1 with a 1 sec max GOP and 4-way slicing.

Most HD film source really doesn't have THAT much detail. I did a 2.39:1 HD DVD spec 1080p MPEG-2 at 8.5 Mbps ABR disc about four years ago, and it looked really quite good most of the time. The only really bad shot was a bunch of soldiers running through a forest at dawn. Panning shots through moving foliage and lots of shadow detail was not pretty. But it was definitely HD quality for 98% of the content.

[benwaggoner]

He mans that if you were encoding from an original lossless source ("Master"), then you would need significant more bitrate to retain all detail, because there is so much detail/grain in that source.

However we usually don't have access to such sources. What we have are BluRay's, which have already been filtered and compressed in a lossy way. Many detail is already gone for good when we get the data!
Honestly, I've looked at plenty of real 10-bit 4:2:2 HD masters, and the kind of detail you're looking for is rarely there as well.

For CGI or VFX-heavy Digital Intermediates, sure, but I'd say the average recent BD disc is very close to what's in the master. In the cases where I've been able to compare a title someone had a complaint about with the source, most of the time the defect was present in the source (at least the 8-bit 4:2:0 compression source).

There's probably only a few dozen features that really have that intense HD "pop" that many seem to crave. But we're still mainly talking 35mm film with a 1/48th of a second shutter speed. There's a reason they have an on-set photographer instead of don't just blowing up frames for marketing materials :).

[moviefan]

Concerning the Blu-ray compatibility discussion with Level 4.0, is the following list a summary of key options/limitations? (media I would like to use is DVD9)


VBV-maxrate: 25000 (with L4.1 I used 30000)
VBV-bufsize: VBV-maxrate - audio-bitrate - some headroom for subtitles (???)
no b-pyramid
no multiple slices required
ref: 4 (formula gives 4 for 1920x1080 for L4.1, how about L4.0)?
bframes: 3
min-keyint: 1 (or 2?)
keyint 48 (2x fps)
nal-hrd + aud option


Could someone please confirm that these settings are maxed out within the limits of the Blu-ray specs and (probably only concerns VBV) should not be less compliant for BD9s? As many others already said, I also hope to achieve max. BD compliance with x264 and L4.0 with BD restrictions seems to be covered entirely by x264 by now.

[kolak]

There's the possibility of both (or a combination). I'm a freelance author right now so there's nothing set in stone.

Regarding how a $3000 encoder is going to compare to x264: one of the most respected names in the video world said that none of the main studio's encoders matched the quality of x264. Certainly, on most BD titles, I can see small compression artefacts that I don't see on (quite grainy) test encodes I've done. I imagine this is the "speed over quality" argument again.

Oh, if anyone wants to buy me a copy of Cinema Craft HD, I will gladly try that out ;)

Don't worry - it's not so so great. It's quite fast and has nice features, but quality with grainy sources is not perfect as you would expect.

Andrew

[kolak]

25 Mbps is really a very high bitrate for 1080p24 H.264! using single-slice x264 with good settings. I'd expect Level 4.0 x264 with 25 Mbps peaks to be transparent for almost all real-world film content. 1080i30 without MBAFF, could be an issue, but 24p should be just fine. HD DVD titles looked great with older encoders, shorter GOPs, and similar or even lower peaks (one highly rated title was VC-1 with 13 Mbps ABR and 19 Mbps PBR).

Remember Blu-ray's peak bitrate was defined for MPEG-2 applications. It's rather overkill for modern codecs.

Ben, have you seen this (check mouseover):

http://www.avsforum.com/avs-vb/showthread.php?t=1169645


It's quite ineteresting how VC-1 puts relatively more bits into B frames than AVC encode (even if AVC encode has much highier average bitrate many B frames form VC-1 are bigger).


Andrew

[kolak]

Ok, i have several questions:

1. What is max allowed vbv-buffersize and vbv-maxrate for Level 4.0 from blu-ray specification (i.e for 4.1 are 30000/40000 buffer/maxrate), not H264.
2. So definitly L 4.0 dosen't require slices? can be then L 4.0 video primary video?
3. What is max allowed vbv-buffersize and vbv-maxrate for Level 3.2 from blu-ray specification for SD content, and what resoultion and fps allowed for SD, and is L 3.2 maximum for SD?
4. Is there anything about BD5/9 and special restrictions such as VBV or other?


That is for now.

Thanks.


1. 30Mbit buffer and 24Mbit for maxrate.
2. Double yes.
3. 24Mbit buffer, 24Mbit maxrate, quite many resolutions, up to 60p, no- you can use level 4.1 if you need to.
4. There are special restricion in case of BD5/9. Disc read rate is limited to about 30Mbit, so there are bigger restrictions.


Andrew

[kolak]

Sadly, if compliance isn't at least "likely", then I really doubt I'll use x264 (unless some sort of solution appears). Even if it involves going with a slightly less high quality but compliant encoder, the quality gains wouldn't be worth the amount of sleep I'd lose (or the consequences of putting a dodgy disc out there).

The best-looking disc in the world done with x264 would be pointless - not to mention a liability! - if it creates playback problems.

Chengbin: on past DVD projects, I've normally just filled the disc up - I just don't see any reason not to when you're guaranteed a certain amount of space. A little headroom is good since the sizes can be a little unpredictable, but re-encoding a bonus feature to be 3% smaller to get the whole thing to fit is really no big deal with the speed of today's SD MPEG-2 encoding.

I don't have problems to fill up BD50 up to 99% :)
Usually they're about 90-95% full. Hollywood studios seem to have problems with this, even if calculator is a part of Windows :)

Andrew

[kolak]

If compliance could be guaranteed and access to a stream verifier was possible, this is an option I would certainly consider running past the money people (assuming that the off-the-shelf encoders were producing visibly poorer results). Real-world issues could get in the way though.

I know there are a lot of people who would love to see a free, high quality BD compliant AVC encoder. And also people who would probably be quite disturbed by the appearance of one...

I think, it shouldn't be free. There should be some charge and part of it could go to charity :)


Andrew

[kolak]

x264's one weakness there would be Open GOP support, I suppose. However, with Level 4.0, you're allowed a 2 second GOP as opposed to the 1 second with 4.1, which can offer another efficiency boost. 25 Mbps Level 4.0 with 2 sec max GOP and single slice likely would outperform 26 Mbps Level 4.1 with a 1 sec max GOP and 4-way slicing.



You can have 2 seconds GOPs only if bitarte (max bitrate) is lower than 15Mbit and this does work with 4.1 level also.


Andrew

[benwaggoner]

You can have 2 seconds GOPs only if bitarte (max bitrate) is smaller than 15Mbit and this does work with 4.1 level also.
Right, sorry. Conflating two different parameters there.

However, 15 Mbps peak + 2 sec GOP could be a compelling option for trying to get long-form content on DVD-5/6 media where the ABR is low enough that PBR isn't going to make it that high anyway, and you're more worried about overall efficiency.

[benwaggoner]

I don't have problems to fill up BD50 up to 99% :)
Usually they're about 90-95% full. Hollywood studios seem to have problems with this, even if calculator is a part of Windows :)

There's always last-minute changes in extras that can use up extra capacity. So the compressionist might target only 90% disc capacity in the disc budget to allow for some extra movie trailers or that Icelandic audio track without having to reencode everything.

[benwaggoner]

Ben, have you seen this (check mouseover):

http://www.avsforum.com/avs-vb/showthread.php?t=1169645


It's quite ineteresting how VC-1 puts relatively more bits into B frames than AVC encode (even if AVC encode has much highier average bitrate many B frames form VC-1 are bigger).
The default behavior from EEv3 and other tools is to have B-frames use a QP 0-2 higher than its reference frames, based on the amount of motion in the video. But CineVision PSE allows this to be overridden per-segment.

[shon3i]

1. 30Mbit buffer and 24Mbit for maxrate.
2. Double yes.
3. 24Mbit buffer, 24Mbit maxrate, quite many resolutions, up to 60p, no- you can use level 4.1 if you need to.
4. There are special restricion in case of BD5/9. Disc read rate is limited to about 30Mbit, so there are bigger restrictions.


Andrew
Thanks

So here is 100% Blu-Ray compatible x264 settings

* Level 4.0
* VBV-maxrate: 24000
* VBV-bufsize: 30000
* no b-pyramid
* no multiple slices required
* ref: 4
* bframes: 3
* min-keyint: 1 or 2 (2 is recommend by authoring apps)
* keyint 24 or 18
* nal-hrd + aud option

And this is for all media BD 5/9/25/50 no exceptions.

[moviefan]

@shon3i: And you are sure about min-keyint 2? I thought it's only valid for max bitrate of 15 Mbps...?

[shon3i]

@shon3i: And you are sure about min-keyint 2? I thought it's only valid for max bitrate of 15 Mbps...?
Absolutley, aslo H264 encoders such as Sonic Cinevision, Elecard use min keyint 2 as default for bluray profiles. Aslo MeGUI BD profles aslo use 2 as min.

[nm]

@shon3i: And you are sure about min-keyint 2? I thought it's only valid for max bitrate of 15 Mbps...?
You are confusing min-keyint with keyint (which is restricted to 1 or 2 in seconds).

[Lyris]

The default behavior from EEv3 and other tools is to have B-frames use a QP 0-2 higher than its reference frames, based on the amount of motion in the video. But CineVision PSE allows this to be overridden per-segment.
Ben, you're the guy to ask for this: do you have any idea if the output of Expression Encoder has been used successfully in BD authoring?

Apologies if it's a silly question, but I know very little about this tool. I seem to remember trying it many years ago without luck.

[kolak]

There's always last-minute changes in extras that can use up extra capacity. So the compressionist might target only 90% disc capacity in the disc budget to allow for some extra movie trailers or that Icelandic audio track without having to reencode everything.

I can understand it, but also not :)
90% is fine, but we have some disc from Warner with <20Mbit average bitrate and 40% empty BD50 :)

Andrew

[Lyris]

Guys (and gals): does anyone have any high quality video sources that you want me to test with these encoders.
By high quality I mean studio-grade, not recompressed from an existing compressed source.

So far, I'm encoding some clips from a RED ONE, as well as some scenes from "Big Buck Bunny" with a grain layer added on top (I will do clips of the original noise-free version too).

[kieranrk]

@Lyris

You could try

http://www.vuze.com/details/IK3JKDZY3JMHS7U7IMADZ36TE4K2HXCT/Army+Nurse.html

It's a DVCPROHD US military recruitment video (who knows why they decided to upload it raw?) - You'll need torrent access though but it is a legal video.
There are a few more raw versions like that on vuze too.

Also there's this raw - http://www.archive.org/details/Sita_Sings_the_Blues - 192GB in total (and it seems like you can't just download a part of it)

[rack04]

Thanks

So here is 100% Blu-Ray compatible x264 settings

* Level 4.0
* VBV-maxrate: 24000
* VBV-bufsize: 30000
* no b-pyramid
* no multiple slices required
* ref: 4
* bframes: 3
* min-keyint: 1 or 2 (2 is recommend by authoring apps)
* keyint 24 or 18
* nal-hrd + aud option

And this is for all media BD 5/9/25/50 no exceptions.

Correct me if I'm wrong but doesn't Level 4.0 and Level 4.1 allow 5 ref frames for 1920x1080 and 9 ref frames for 1280x720?

One thing that I've noticed on my standalone Panasonic BD-35 while playing Blu-ray discs encoded with x264 is that it freezes with ref frames greater than 7 for 1280x720.

[benwaggoner]

Ben, you're the guy to ask for this: do you have any idea if the output of Expression Encoder has been used successfully in BD authoring?
I doubt very much. The VC-1 library used in EEv3 is certainly capable of BD compliant output, but EEv3 doesn't support elementary stream output, and doesn't attempt to offer BD-related control.

Carbon Coder uses the same SDK, and does correctly support BD-compliant .vc1 files.

Apologies if it's a silly question, but I know very little about this tool. I seem to remember trying it many years ago without luck.
Maybe you were using something else? Expression Encoder is only a couple of years old now.

[benwaggoner]

Guys (and gals): does anyone have any high quality video sources that you want me to test with these encoders.
By high quality I mean studio-grade, not recompressed from an existing compressed source.
How long do you need.

I have the trailers for "The Island" and "Match Point" from Dreamworks with permission to redistribute for compression testing. I've got Lagarith 1920x1080p23.769 with 5.1 audio AVI files I could probably post somewhere.

...and that 45 minutes of 35mm "Lady Washington" source I keep thinking I'll finally be able to finish up an edit of in a couple of weeks...

[shon3i]

Correct me if I'm wrong but doesn't Level 4.0 and Level 4.1 allow 5 ref frames for 1920x1080 and 9 ref frames for 1280x720?

One thing that I've noticed on my standalone Panasonic BD-35 while playing Blu-ray discs encoded with x264 is that it freezes with ref frames greater than 7 for 1280x720.
From H264 specification by formula Int(MaxDPB * 1024 / 1.5 / (w * h)) where w=width, h=height and MaxDPB from table A-1 (H264 specs), give max 4 reference frames for 1080p with level 4.1 or 4.0, and 9 for 720p. But according Blu-Ray specs for 720p is alowed max 6 reference frames for level 4.1 or 4.0 and 4 ref frames for 1080p. Encoders such Sonic Cinevision and Elecard in their BD profiles always lock for more than 4 refs. So 4 ref, are safe value for all resolutions including SD material

[Lyris]

How long do you need.

I have the trailers for "The Island" and "Match Point" from Dreamworks with permission to redistribute for compression testing. I've got Lagarith 1920x1080p23.769 with 5.1 audio AVI files I could probably post somewhere.

...and that 45 minutes of 35mm "Lady Washington" source I keep thinking I'll finally be able to finish up an edit of in a couple of weeks...
That's a really great offer - if I set up an FTP account somewhere, would you be able to upload "The Island" trailer? I actually own the UK Warner HD DVD so there's a potential for comparison.

[kolak]

From H264 specification by formula Int(MaxDPB * 1024 / 1.5 / (w * h)) where w=width, h=height and MaxDPB from table A-1 (H264 specs), give max 4 reference frames for 1080p with level 4.1 or 4.0, and 9 for 720p. But according Blu-Ray specs for 720p is alowed max 6 reference frames for level 4.1 or 4.0 and 4 ref frames for 1080p. Encoders such Sonic Cinevision and Elecard in their BD profiles always lock for more than 4 refs. So 4 ref, are safe value for all resolutions including SD material

H264 specification is one thing and Blu-ray one is another. It's almost obvious that BD one is going to have more restrictions.
Another thing is that quite often pro encoders have even bigger limitation than BD spec.

Andrew

[Lyris]

OK, a small update.

I've tried out the Dostudio Encoder - not happy with the output, especially after having been used to x264. Visible compression artefacts in just about all cases when using 35-37mbps with the test videos I used (Red One clips, and a grained version of Big Buck Bunny). I imagine it'll serve it's purpose and make an affordable pathway into BD for many smaller producers, but as an anal-retentive videophile, it gets a no from me. X264's Level 4 ~20mbps encodes are blatantly better, a great reminder (if one was needed) that bitrate isn't everything.

There does seem to be light at the end of the tunnel, though: I've been trying Mainconcept Reference and while not quite at the level of X264's quality, what it's producing is at least slightly better than the encodes I see on retail BDs. Most importantly of all, it appears to be compliant (control is given over all necessary parameters, and the BD preset seems to set them all correctly). The next step will be working with a replicator to make sure that the output is actually compliant.

[nm]

There does seem to be light at the end of the tunnel, though: I've been trying Mainconcept Reference and while not quite at the level of X264's quality, what it's producing is at least slightly better than the encodes I see on retail BDs.
Do you get better results with Mainconcept at L4.1 than with x264 at L4.0?

[shon3i]

H264 specification is one thing and Blu-ray one is another. It's almost obvious that BD one is going to have more restrictions.
Agree, but one thing is for sure, that for 1080p is max 4 ref (according both H264 or Blu-Ray specs) and for 720p is 6 refs (according Blu-Ray specs).

Another thing is that quite often pro encoders have even bigger limitation than BD spec.

Andrew Better leave some room for errors :)



I've been trying Mainconcept Reference and while not quite at the level of X264's quality, I don't know why but Mainconcept Reference use very restricted version of their SDK, which have much more tweakable options. Only Sonic Cinevison use most advanced options from Mainconcept and can be compared with the x264, and may be approximate, even in some situations better. Mainconcept CLI use all features but :)

what it's producing is at least slightly better than the encodes I see on retail BDsMaybe hardware encoders?

[Lyris]

Do you get better results with Mainconcept at L4.1 than with x264 at L4.0?
No. x264 still looks better despite having around half the bit rate.

[Chengbin]

No. x264 still looks better despite having around half the bit rate.

I'm amazed.

This begs the question, how hard can adding slice support be? x264 used to support slices, but was removed because of a better multithreading technique. Is the old slice algorithm is bad?

[shon3i]

Old method can hurt more quality, but i aslo think that no one use more than 4 slices, without some special reason. Anyway if some one use more slices, quality shouldn't drop so drastically.

New metod is indeed better for decoding on modern (multi core) procesors and better for encoding because drop in quality are very, very small. But is also have only effect when is decoded with decoder which support that metod (ffdshow-mt, coreavc). The only thing which i can't understand is why we need this because we have DXVA, CUDA, which can decode Blu-Ray video normaly, and slices which are almost suported by every decoder (HW/SW), and we have enough powerfull processors to decode in single core 1080p video.

[Chengbin]

Old method can hurt more quality, but i aslo think that no one use more than 4 slices, without some special reason. Anyway if some one use more slices, quality shouldn't drop so drastically.

We all know slices hurt quality. But even with slices, x264 is still a lot better than commercial encoders since it doesn't hurt too badly. Unless there is compatibility issues with current features, why not just put the old code back and call it a day for Blu-ray compatibility? You can always improve it later.

[shon3i]

why not just put the old code back and call it a day for Blu-ray compatibility? You can always improve it later.
Exactly, I tried a few times to convince the same, in the past, but no one was interested.

[Dark Shikari]

Exactly, I tried a few times to convince the same, in the past, but no one was interested.You can't "put the old code back"; that would be far more difficult than just writing support anew.

[plonk420]

will this be on x264's Summer of Code 2010 if it's not added by then? :)

[Dark Shikari]

Well, at least the work is done already. You just have to "trace" it, which I believe it is much easier than writing something new."Trace" the complete overhaul of most of the frame handling code, which will be further rewritten by threaded slicetype? Are you insane?

[shon3i]

You can't "put the old code back"; that would be far more difficult than just writing support anew.
True, but for now I am satisfied with the fact that the 4.0 level does not require slices, because i backup my blu-rays to BD-5/9 media for now.

[Lyris]

OK, so now I've tested a bunch of encoders. The bitrates used for all of the tests were 35mbps average, 38mbps peak, except for X264 Level 4, which was tested at 20mbps due to the AVC Level 4 constraints. In brief:

1. X264: best quality, even at Level 4, but I can't get it to play (perhaps I have the wrong settings).

2. Mainconcept Reference: very, very, very good quality at these bitrates. It doesn't retain the high frequency grain as well as X264, but it still produces what is, in my opinion, an excellent result at the bitrates I'll be using it at. Certainly, it looks better compression-wise than just about every BD title that I've bought. I have burned discs using the trial version of Netblender DoStudio and they play back in all of the BD players I have here (Sony PS3, Panasonic BD35, Oppo BDP83, and a ridiculously expensive Denon A1). Slowest encoder of the bunch (with everything set to highest quality on 2pass): 0.7fps on a 2.8ghz Quad core.

Looking at MCR's output and judging it on its own merits, it looks fantastic. Only when you compare it to the source (and indeed to x264) do I start seeing minor flaws.

3. Netblender Dostudio Encoder: quality is not acceptable by videophile standards, but plays back fine. EDIT: turns out I'm experiencing a bug with the encoder, the poor quality is NOT the intended operation. Netblender are investigating. Fastest of the software-only encoders. Only accepts QuickTime input (d'oh... I'm very much a Windows guy. I can't live without AviSynth).

4. CodecSys CE-10. This is the one that uses a LAN-connected Playstation3 to accelerate encoding. I was getting around 6-8fps with the "Fine" mode. However, the quality is not good enough. Some frames in each GOP (presumably I frames) look excellent, sometimes even slightly better than x264, but things fall apart afterwards into compression artefacts (this is using the company's recommended BD-compliant settings). Most troublesome of all, the 4 slices in the frame are actually often VISIBLE in my test encodings! That is, you can actually see 4 clearly marked sections of the picture. No dice.

In short, I have a very good feeling about the Mainconcept Reference Encoder and hope to see its output pass verification. It's not quite up to X264's standards - but what is? - and it hopefully makes up for that in terms of compatibility with the BD spec.

[Dark Shikari]

OK, so now I've tested a bunch of encoders. The bitrates used for all of the tests were 35mbps average, 38mbps peak, except for X264 Level 4, which was tested at 20mbps due to the AVC Level 4 constraints. In brief:

1. X264: best quality, even at Level 4, but I can't get it to play (perhaps I have the wrong settings).Are you using the NAL-HRD patch? That's necessary for compliance.

[Lyris]

I am not. I'll take a look at the patches thread and try to figure that out.

Some comparisons. Images are PNGs (OK, overkill I know), and are about 5mb each.

http://lyris-lite.net/avc/squirrel.png

http://lyris-lite.net/avc/trap.png

http://lyris-lite.net/avc/overhead.png

http://lyris-lite.net/avc/fur1.png (I frame? The Codecsys encoder looks great here)...

http://lyris-lite.net/avc/fur2.png ...(but turns to mush in the next frames).

http://lyris-lite.net/avc/slice.jpg - JPEG image showing visible slices seen on the CodecSys output.

[kolak]

In short, I have a very good feeling about the Mainconcept Reference Encoder and hope to see its output pass verification. It's not quite up to X264's standards - but what is? - and it hopefully makes up for that in terms of compatibility with the BD spec.

Cinevision can at least match x264 or even produce better results for grainy sources, but I like quality from the latest version of x264.
Some features of Mainconcept's SDK can be found only in Cinevision and they work quite well.

Andrew

[shon3i]

In short, I have a very good feeling about the Mainconcept Reference EncoderToo bad you don't have access to sonic cinevision, which have advamced features of Mainconcept such as Grain optimization, several levels of AQ (including Dark AQ).

which was tested at 20mbps due to the AVC Level 4 constraints. In brief:You know, you can go up to 24mbps, and highest peak up to 30mbps. I think x264 at level 4.0 can beat everything else with 4.1 :)

Cinevision can at least match x264 or even produce better result for grainy sourcesAgree, but only with nominal blu-ray bitrates, with lover bitrates x264 still produce better looking video.

[kolak]

Agree, but only with nominal blu-ray bitrates, with lover bitrates x264 still produce better looking video.

Yes- I've forgotten to add this.
I'm more BD bitrates guy, so I'm not realy interested in 5Mbit HD encodes (some time ago I was).

I've done some test recently and Cinevision was slightly better, but I know it quite well, so I can tweak it. x264 has more settings and I don't have experence with it. Difference was very small- but on 2x zoom Cinevision looked more clean. This was fairly noisy 30p source, so Cinevision shined with its grain optimization.

AQ stuff in Cinevison is very powerful, but also makes problems with some sources.


Andrew

[Lyris]

You know, you can go up to 24mbps, and highest peak up to 30mbps. I think x264 at level 4.0 can beat everything else with 4.1
I actually tried this, but x264 gave me warnings. The mistake is probably on my end - I've been experimenting with Mainconcept more lately. I will try a patched x264.

[nixo]

These warnings?

x264 [warning]: VBV bitrate (24000) > level limit (20000)
x264 [warning]: VBV buffer (30000) > level limit (25000)

Main profile is used during fast first pass. I think they can be safely ignored.

--
Nikolaj

[Revgen]

A) Here's my understanding of blu-ray compatibility. Please correct me if I'm wrong.

1) Levels can either be 4.0 or 4.1 for HD.
2) Level 4.1 requires at least 4 slices for Blu-Ray.
3) Level 4.0 doesn't require slices.
4) Limited to 3 b-frames or less.
5) Limited to 4 ref for 1080p. Limited to 9 ref for 720p.
6) Limited to 30000kb VBV Buffer size.
7) 4.0 is limited to a max-bitrate of 24000kbps for Blu-Ray.
8) Blu-Ray doesn't handle b-pyramid well.
9) "--nal-hrd" and "--aud" options must be enabled for compatibility.
10) Max Key Intervals must be set to 24. Minimum Key Intervals must be set to either 1 or 2.


B) Here's my list of questions about blu-ray compatibility.

1) Are there limits to subme? Megui's blu-ray profile has "--subme 2" toggled.
2) Are there limits to me? Megui's blu-ray profile has "--me dia" toggled.
3) Can trellis be used? It's disabled in MeGUI's blu-ray profile. If so, then how high can the setting be?
4) Are mixed-refs allowed? Megui's blu-ray profile has them disabled.
5) Is "--mvrange 511" necessary? It's included in the MeGUI blu-ray profile.
6) Megui's blu-ray profile has "--ipratio 1.1" "--pbratio 1.1". Can these be different? If so, is there a limit?
7) MeGUI's blu-ray profile has qcomp set to "--qcomp 0.5". Is this necessary? Or can it be x264's default qcomp setting?
8) Can I disable the inloop filter?

I don't expect anybody to answer all my questions, but if some of them can be answered, then I'd appreciate it.

[Chengbin]

B) Here's my list of questions about blu-ray compatibility.

1) Are there limits to subme? Megui's blu-ray profile has "--subme 2" toggled.
2) Are there limits to me? Megui's blu-ray profile has "--me dia" toggled.
3) Can trellis be used? It's disabled in MeGUI's blu-ray profile. If so, then how high can the setting be?
4) Are mixed-refs allowed? Megui's blu-ray profile has them disabled.
5) Is "--mvrange 511" necessary? It's included in the MeGUI blu-ray profile.
6) Megui's blu-ray profile has "--ipratio 1.1" "--pbratio 1.1". Can these be different? If so, is there a limit?
7) MeGUI's blu-ray profile has qcomp set to "--qcomp 0.5". Is this necessary? Or can it be x264's default qcomp setting?
8) Can I disable the inloop filter?

I don't expect anybody to answer all my questions, but if some of them can be answered, then I'd appreciate it.

Subme, merange, trellis has nothing to do with decoding. Use whatever you want. MeGUI has subme 2 and me dia toggles for first pass, where you can get away with crap settings.

I read that don't touch mvrange, leave it at 511.

Mixed-refs should be allowed, but I'm not 100% sure.

ipratio and pbratio has nothing to do with decoding. Those parameters just tell x264 the bitrate allocation for each type of frame. Use whatever you like.

I believe qcomp is lowered to 0.5 because Blu-ray has a maximum bitrate of 40mbps. At Blu-ray bitrates, qcomp of 0.5 can also save some bitrate because your bitrate is already so high. You can use any qcomp you like, just the higher the qcomp, the more chances of going over the maximum bitrate, and wasting bitrate on high motion scene when they have enough bitrates.

Of course you can disable inloop deblocker. Many Blu-rays disable that because they blur too much.

Hope this helps.