MPEG2 included in BluRay standard, why?

[me7]

I was wondering why MPEG2 was included in the BluRay specification in the first place since I can't think of any reason to use MPEG2 for 1920x1080 video on a device that guarantees AVC support (since it's part of the standard too).

[idbirch2]

Maybe some disc authors are more familiar with MPEG2 encoding techniques and maybe licensing plays a part too. I don't know for sure but I would have thought that producing an MPEG2 BD would cost you less than a VC-1 or AVC disc. Also, I have noticed most little studio intros are MPEG2 and so are most extras, maybe there is a reason for that.

[kabanero]

I was wondering why MPEG2 was included in the BluRay specification in the first place since I can't think of any reason to use MPEG2 for 1920x1080 video on a device that guarantees AVC support (since it's part of the standard too).

What's wrong with MPEG-2?

[JohnnyMalaria]

Backwards compatibility, too. Imagine not being able to play CDs on a DVD player. It also gives movie makers greater flexibility when choosing their distribution format. Smaller studios can keep their existing MPEG2 systems and not have to invest in new hardware and software.

[nwg]

Nothing wrong with mpeg2. Some of my best looking discs are mpeg2 and some of my worse is avc/264.

[mmace]

I always encode in MPEG2 when I have enough space, saves days on encoding time!

[smok3]

yeah, the machine should be able to playback good/old DVDs i guess, so why not include the ability to do HD with mpeg2 as well.

[me7]

yeah, the machine should be able to playback good/old DVDs i guess, so why not include the ability to do HD with mpeg2 as well.

Because some studios might end up using it and produce BluRays of lesser quality. If I wanted to defeat the almighty DVD with a new format that is supposed to look a lot better, I'd make sure that the studios use an efficient codec. Remember how some HDDVDs looked better than their BluRay counterparts even though the have less space, just because they used a better codec?

Nothing wrong with mpeg2. Some of my best looking discs are mpeg2 and some of my worse is avc/264.

really?

[rik1138]

Mpeg2 is a better codec than any of the Mpeg4 codecs if you have enough bitrate. For Blu-Ray, bitrates over 20 or so on VC-1/AVC won't make much noticeable improvement. But if you can do Mpeg2 at 35-38 MB, it will look FAR better than VC-1/AVC even at those same bitrates. Mpeg4 was designed to look pretty damn good at low bitrates (not great, but more than acceptable for almost anyone). Mpeg2 looks horrible at low bitrates.

If you notice the Mpeg2 Blu-Rays that look really good (like Simpsons for example) were encoded at nearly 35mb average. If you want to cram 4 hours of video on the disc, you have to use a lower bitrate and that would kill the quality of Mpeg2. Thus, the Mpeg4 codecs were created for that purpose...

Rik

[Dark Shikari]

Mpeg2 is a better codec than any of the Mpeg4 codecs if you have enough bitrate. For Blu-Ray, bitrates over 20 or so on VC-1/AVC won't make much noticeable improvement. But if you can do Mpeg2 at 35-38 MB, it will look FAR better than VC-1/AVC even at those same bitrates.There is so much stupid crammed into this post that I'm not entirely sure where to start.

[LoRd_MuldeR]

Mpeg2 is a better codec than any of the Mpeg4 codecs if you have enough bitrate. For Blu-Ray, bitrates over 20 or so on VC-1/AVC won't make much noticeable improvement. But if you can do Mpeg2 at 35-38 MB, it will look FAR better than VC-1/AVC even at those same bitrates. Mpeg4 was designed to look pretty damn good at low bitrates (not great, but more than acceptable for almost anyone). Mpeg2 looks horrible at low bitrates.

It's very simple: H.264 allows a much more efficient compression than MPEG-2. So at a given bitrate H.264 will always look better than MPEG-2. But if you raise the bitrate enough, the differences will become smaller and smaller until both look 100% transparent. If ever MPEG-2 looks better than H.264 at a given bitrate, then get rid of your lousy H.264 encoder and get a good one! Also: If you compare different discs, where some are MPEG-2 and some are H.264, this is completely useless for a H.264 -vs- MPEG-2 comparison! As these discs were made from different sources. And we know exactly nothing about the quality of the original sources and how they were pre-processed. For a useful compassion you must make two encodes (one MPEG-2 and one H.264) from the very same source (with identical processing) and at the same bitrate. And you must use a reasonable bitrate, where you can still spot the differences. Not an ultra-high one where both encodes look transparent anyway.

Also: I think a Blu-Ray disc has far enough space. So you can use a bitrate that is high enough for MPEG-2 to look transparent. Using H.264 instead of MPEG-2 in that case would be no better, as the video can't look better than transparent. It would only make sense to use H.264 instead of MPEG-2 in order to get the same quality at a lower bitrate and to safe some space on the disc. This of course is no benefit, as long as you keep that space unused. But it might make sense if you want to put a bunch of "extras" in that space...

[me7]

Also: I think a Blu-Ray disc has far enough space. So you can use a bitrate that is high enough for MPEG-2 to look transparent. Using H.264 instead of MPEG-2 in that case would be no better, as the video can't look better than transparent. It would only make sense to use H.264 instead of MPEG-2 in order to get the same quality at a lower bitrate and to safe some space on the disc. This of course is no benefit, as long as you keep that space unused. But it might make sense if you want to put a bunch of "extras" in that space...

Still no valid reason to prefer MPEG2 over AVC. MPEG2 can look transparent at extremely high bitrates, but there can always be a complex high motion scene in the middle of the movie that puts MPEG2 close to it's limits, while AVC could compress it with ease.
So at the end, AVC >= MPEG2 in any possible scenario. MPEG2 can't lead to better results, right?

[Doom9]

If you notice the Mpeg2 Blu-Rays that look really good (like Simpsons for example)Actually, The Simpsons Movie is AVC ;)
Blu-ray was originally aimed at MPEG-2 - hence the 50GB space. Adding more efficient codecs was more of an afterthought and fueled by the fact that HD DVD used them (and used them from the getgo.. if you check the HD DVD stats you'll see that very few titles ever used MPEG-2... for Blu-ray the intial slate was all MPEG-2 as Sony didn't have their AVC encoder ready). It stands to reason that without competition Blu-ray might have turned out to be MPEG-2 only.
Now if you look at the Blu-ray stats, you can see the MPEG-2 percentage steadily decreasing. Due to the initial MPEG-2 slate, it will be a long time until those titles are just a blip on the radar, but today MPEG-2 is not a popular choice for Blu-ray anymore.

[LoRd_MuldeR]

MPEG2 can't lead to better results, right?

Yes. At least not at the same bitrate. But, as explained by Doom9, the total size of a Blu-Ray disc was designed for MPEG-2. So there definitely is enough space to give MPEG-2 the required bitrate. And at that bitrate both, MPEG-2 and H.264, will look transparent. Using the more efficient Format in that case (H.264 instead of MPEG-2) is no benefit, because it simply can't look better than transparent! That's the same reason why a Format comparison (e.g. MPEG-2 -vs- H.264) is pointless at ultra-high bitrates, where both formats look transparent. But what they can do is: Use H.264 instead of MPEG-2 and lower the bitrate. If they don't lower the bitrate too much, the lower bitrate H.264 version will still give the same level of quality that the higher bitrate MPEG-2 version had. So H.264 can save some space on the Blu-Ray disc. Space they can use for extras and stuff. But I don't think H.264 inherently gives better quality than MPEG-2 on a 50 GB disc for a standard-length movie...

[me7]

Blu-ray was originally aimed at MPEG-2 - hence the 50GB space. Adding more efficient codecs was more of an afterthought and fueled by the fact that HD DVD used them

This was the answere I was looking for, now it makes sense.
Thanks.

@LoRd_MuldeR: Still no reason to choose MPEG2 over AVC. If you would master a BluRay and you had the full BD50 for the main feature without extras, would you use MPEG2 because it will most likely be transparent or just use AVC? I'd simply stick with AVC.

[LoRd_MuldeR]

Still no reason to choose MPEG2 over AVC. If you would master a BluRay and you had the full BD50 for the main feature without extras, would you use MPEG2 because it will most likely be transparent or just use AVC?

I think I had to use whatever my company can do. Many companies have really expensive MPEG-2 hardware encoders, so they will prefer to keep on using them ;)

But for my private encodes - if I ever get a BR burner - I would use H.264, just because x264 is such a great encoder and it's free :D

[mmace]

But for my private encodes - if I ever get a BR burner - I would use H.264, just because x264 is such a great encoder and it's free :Dthat's what I thought, I've had my burner nearly 2 years now, but it just takes so loooooong to encode that I just use MPEG2 wherever possible now, I can't handle 2+ days for a 1.5 hour film to encode, especially with the amount I do

[smok3]

so the question is:

what is the cli for x264 that will encode the same video at the same amount of time (with at least half the bitrate) as XY mpeg2 encoder and still look better than mpeg2 version.

is that so?

[rik1138]

Now if you look at the Blu-ray stats, you can see the MPEG-2 percentage steadily decreasing. Due to the initial MPEG-2 slate, it will be a long time until those titles are just a blip on the radar, but today MPEG-2 is not a popular choice for Blu-ray anymore.

This has nothing to do with quality though, it's about cramming as much stuff on the discs as possible. I _HAVE_ seen the same source material encoded in Mpeg2, AVC and VC-1 using the encoding hardware that the studios use for digital theatrical projection, and for Blu-Ray encoding. At 30mb+ bitrates, Mpeg2 ALWAYS looks better. Sure, it's probably not noticeable to most people, but if you know what to look for, you will see the difference. And if you want to get really technical, there's software that can analyze the encoded frames and compare them to the source, and Mpeg2 always retains the most accurate image. The artifacting that is inherent in Mpeg4 encoding never goes away. It's always present, even at the highest bitrates. This is why the studios use Mpeg2 for their master storage format. The studios are going away from tape all together (at least on the consumer production side of the business- making discs and streaming video), their movies are now stored in high-bitrate Mpeg2 streams that are then transcoded to Blu-Ray, DVD and any streaming formats they want to use. The main artifacting with Mpeg2 is blocking, and this can be eliminated with a high enough bitrate. Mpeg4 has motion artifacts, coloring artifacts, etc that are always present, even at high bitrates. Mpeg4 was NOT designed to take advantage of a ridiculously high bitrate, that's not what it is for. If Mpeg4 could look as good as Mpeg2, why would they insist on using Mpeg2 for storage? Why is Mpeg4 never used for digital theatrical use?

If you have access to professional encoding hardware, try it yourself.

If you want the best possible picture quality on Blu-Ray, encode a 34+ MB Mpeg2 stream. If you have to put 4+ hours of video on a Blu-Ray disc, then you will have to use a different codec...

[Guest]

Mpeg4 has motion artifacts, coloring artifacts, etc that are always present, even at high bitrates. Please cite your sources for these claims.

[rik1138]

Please cite your sources for these claims.

Uh, my eyeballs? Just do the tests yourself. If you can't see the difference, then the entire argument doesn't affect you... It's like people that can't tell the difference between CDs and MP3s. If you can't tell an MP3 just by listening to it, then there's no argument for you to prefer one over the other...

If you look at exactly how the different profiles of Mpeg4 encoding work (how they reference previous and upcoming frames, how they detect motion between frames, and what they do to an image to compress it), you will know what to look for. Image softening and motion artifacts are usually the easiest to see, but at high bitrates it can be hard to see anything unless you have the source material to A/B it with.

All of these codecs (as used by the studios on Blu-Ray) are more than adequate for they purpose. Have you seen any Blu-Ray disc that just looked horrible solely because of the compression? For the most part, they all look pretty damn good (again, ignoring the quality of the source material), so it is kind of a pointless argument. But the original poster wanted to know why Mpeg2 was included in Blu-Ray. Most people believe Mpeg2 is inferior to the Mpeg4 codecs. This isn't true, it's simply different. Each codec shines in a certain application, so they included them all.

[Guest]

You're totally full of it. You're just making stuff up.

[rik1138]

If you would master a BluRay and you had the full BD50 for the main feature without extras, would you use MPEG2 because it will most likely be transparent or just use AVC? I'd simply stick with AVC.

This is another reason Mpeg2 has been declining in use on Blu-Ray. In most cases, you have to use Mpeg4 to accommodate extras, lossless audio, etc, etc. So if your workflow is all geared toward using AVC for example, you will just use AVC all the time unless a client requests something different. And, outside of the studios themselves, there really aren't that many decent Mpeg2 encoders for Blu-Ray... Sonic makes one, but they focus on VC-1 encoding for the most part, so the Mpeg2 encoder doesn't really get a lot of development... I've only used it a couple of times, and wasn't overwhelmed by the quality... I'm not even sure who else makes a pro Mpeg2 encoder (we pretty much have a VC-1 workflow, so that's our focus...)

[rik1138]

You're totally full of it. You're just making stuff up.

*shrug* Suit yourself... Considering that you have provided absolutely no useful information to this thread, I don't know what else to say to you... I've been making DVDs for the studios for nearly 8 years now, and have been working with HD DVD and Blu-Ray since before it came out to the public... I have no reason to make anything up...

[JohnnyMalaria]

Most people believe Mpeg2 is inferior to the Mpeg4 codecs. This isn't true, it's simply different. Each codec shines in a certain application, so they included them all.

Exactly!!!!!

All compression schemes have their strong points and their weak points. Certain kinds of video will be reveal one scheme's weaknesses while making another shine.

And most/all compression schemes *used for distribution* are trade-offs.

And (2) MPEG2 covers a wide range of options. An MPEG2 stream encoded as I-frame only will out-shine any interframe compression - at the cost of storage space.

Jeez - this is like a Mac/Windows battle!

[Guest]

I've been making DVDs for the studios for nearly 8 years now, and have been working with HD DVD and Blu-Ray since before it came out to the public... I have no reason to make anything up... If you're so savvy, you should be able to explain the technical causes of these unavoidable artifacts you are talking about.

And BTW, I've been working with MPEG2, AVC, and VC-1 decoders for a major semiconductor maker for 9 years, so drop the appeal to authority. It might impress your drinking buddies but it means nothing here. Back up your claims! If you're unable to give technical reasons, then give us some samples and test results that we can verify. In the absence of that, it's just FUD.

Here's a challenge. You provide a source clip. You encode it in MPEG2 at a high bitrate and I'll do it in AVC at the same bitrate. If your claimed artifacts are apparent, I'll concede. Up for that?

[Dark Shikari]

An MPEG2 stream encoded as I-frame only will out-shine any interframe compression - at the cost of storage space.I know you're trolling intentionally, but you're doing it very well. I'm laughing uncontrollably here.

[Shinigami-Sama]

you guys do know that this board does have people that know what they're talking about right?
keep the trolling on 4chan kthnx


also why keep mpeg2?
transition period, not everyone wants to replace all their encoding ecosystems for a format they don't know will succeed

[vamsiklak]

anyway
provide clip
encode in mpeg-2 with certain bitrate
encode with avc, vc-1 with same bitrate as mpeg-2 and then see
which looks better and howmuch space it will consume

[LoRd_MuldeR]

anyway
provide clip
encode in mpeg-2 with certain bitrate
encode with avc, vc-1 with same bitrate as mpeg-2 and then see
which looks better and howmuch space it will consume

Not hard to predict:

1. If you use the same bitrate for all three encode, then all three encodes will consume exactly the same space, of course

2. If you don't use any borked encoders and if you choose a "medium" high bitrate, then the quality will be H.264 > VC-1 > MPEG-2

3. If you only choose the bitrate high enough, then the quality will be H.264 = VC-1 = MPEG-2

[vamsiklak]

oh ok
that leads me another question

which codec will take longer time encode?
i did tried mpeg to avc of 7.5gb man let me tell u it took 2days almost with quadcore 6600
i wonder how long it will take mpegdvd to mpeg bluray of 7.5gb
just curious

[LoRd_MuldeR]

This question cannot be answered generally, because encoding time greatly depends on how well the individual encoder is optimized.

Also encoding speed can vary between "pretty fast" and "pretty slow" for the same format and for the same encoder, depending on what settings were chosen.

However I'd guess that MPEG-2 encoding usually should run significant faster than H.264 or VC-1, because of MPEG-2's reduced complexity.

But the more interesting question would be: If you tune your MPEG-2 and your H.264/VC-1 encoders to run at the same speed, which one would give better results?

[vamsiklak]

got ya

i don't have vc-1 encoder software
but i do have h.264 and mpeg2
which i already did with h.264(avc)7.5gb 2days end up with 13.4gb

i will do mpeg-2 and i will post it later this week


thankyou all for the input
keep up the good work

[Shinigami-Sama]

oh ok
that leads me another question

which codec will take longer time encode?
i did tried mpeg to avc of 7.5gb man let me tell u it took 2days almost with quadcore 6600
i wonder how long it will take mpegdvd to mpeg bluray of 7.5gb
just curious

who cares how much time it takes?
x264 can run realtime on a single core of a peryn

and honestly stop trolling