Best Blu-ray PQ Codecs?

[mugupo]

VC-1, AVC, or MPEG2?

[Rik1138]

Each one has it's advantages and disadvantages based on the content being encoded and the bitrate you have to play with. Depending on the situation (and the encoding software being used), you can make any of the codecs look better than the other two with the same source.

What people are most likely to do to answer this poll is to think of a movie they think looks good, and assume it's because of the codec...

Rik

[Clark Kent]

From my observations it appears the most transparent codec used is AVC at high bitrates (typically 30 MBPS and above).

[Monkey]

Hard to say because I had a HD DVD player and they mostly had VC-1 encodes. HD DVD's recieved poor scores in regards to PQ and AQ on average compared to Blu-Ray during the format war. Of course HD DVD's had significantly less bandwidth and space to work with as well.

[Canada]

Both VC 1 and AVC are advanced video codecs and there for take up less space than MPEG 2 would to achive the same result.

As long as the VC-1 and AVC transfers are handled correctly they should be able to produce the same quality picture.

[Monkey]

Originally Posted by Canada

Both VC 1 and AVC are advanced video codecs and there for take up less space than MPEG 2 would to achive the same result.

As long as the VC-1 and AVC transfers are handled correctly they should be able to produce the same quality picture.

But MPEG2 can look just as fanstastic from my experience. Kingdom of Heaven (Mpeg2) for example looks better than most if not all of my HD DVD's

[davcole]

I would side on the Advanced codecs. While MPEG2 isn't bad, it does have a different, less detailed look to it over the discs i've seen along with having those mpeg2 anomolies.

I too saw KINGDOM OF HEAVEN and I wasn't that impressed with it especially in comparison to other AVC or even VC1 films i've seen.

Comparing the two codecs, i'd have to say that AVC seems to capture grain structure a bit better. I've also not noticed the amount of banding on AVC that I see at times on VC1.

[Clark Kent]

The problem with VC-1 now is that development of it has completely stopped by Microsoft. The encoders are not getting any better while many companies are still researching and spending money to improve AVC encoders. AVC encodings in a few years will slaughter VC-1 encodings.

[SkantDragon]

I'm a software engineer, and I actually work with these codecs professionally. Here's a bit of info about these codecs.

AVC is another name for MPEG4 part 10. The MPEG4 standard was developed by the same standards body that created the MPEG2 standard. MPEG4 is a essentially a superset of MPEG2. The same compression techniques MPEG2 used are still there and available to the encoder in addition to the newer techniques added in MPEG4.

In short, everything MPEG2 can do, AVC can do better. Literally.

VC-1 has an interesting history. It's basically Microsoft's ripoff copy of AVC.

At one point, Microsoft developed MPEG4 part 2 support for Windows. And then, as Microsoft often does, they 'embraced and extended' it to create a similar but slightly different variant which became Windows Media 8 (WMV)... and then proceeded to downplay MPEG4 in their OS. I don't believe Microsoft admits this origin, but it's pretty obvious. This is also around when DivX stole the code from Microsoft to use as the basis for their codec.. and then later Xvid split off from DivX.

Microsoft then developed Windows Media 9, which is derived from MPEG4 part 10 pretty much the same way Windows Media 8 was derived from MPEG4 part 2. From there... Microsoft has been very interested in becoming _the_ standard in the video industry. But Windows Media was proprietary technology. So they standardized Windows Media 9 as VC-1.

This is part of how Microsoft got into the whole format war. And why HD DVD predominantly used VC-1 while Blu-ray predominantly used AVC.

But basically, the origin of the whole lot of it is the MPEG group. The rest is pretty much stolen. The world of video codecs is a very tangled web.

Anyway... all that aside... it basically means that AVC and VC-1 are _very_ similar codecs. VC-1 is juuuust different enough to avoid losing law suits. In actual use, VC-1 is actually better than AVC for some scenes because Microsoft specifically optimized for those scenes. But overall, with a broad range of material, AVC usually edges out VC-1 slightly.

Now all that said... all three codecs... AVC, VC-1, and MPEG2 are capable of producing perfectly transparent video quality given high enough bitrates. What varies between them is how much bitrate is required to reach that quality for any particular scene. And how their artifacting looks when the bitrate is not sufficient to achieve transparency (MPEG2 gets blocky, while AVC and VC-1 blur.. making it look like the camera just wasn't in sharp focus even though it was).

In the end, it works like this. MPEG2 is _significantly_ less capable than the other two. In general, it requires roughly twice the bitrate for the same quality. So when you see MPEG2 on a release, that's a bad sign. The video quality might be good anyway. But, in general, MPEG2 can not achieve transparency in complex or action scenes even at high Blu-ray bitrates.

Between AVC and VC-1, they're both really good, and they're nearly identical. Differences you're seeing in transfers between them really have to do with the compressionists involved and the policies of the studios, not really the codecs themselves.

In particular, Microsoft has had their digital download agenda going for a good while. And they're pushing VC-1 as their means of doing that. Which means there's kindof a 'how low can you go' attitude that comes with the whole VC-1 thing.

So where you tend to see differences between AVC and VC-1 releases in general, it's more about attitudes of the people involved rather than technical differences between the two codecs themselves.

Anyway... probably more about codecs than anyone wanted to know here.

[Clark Kent]

Good post and very informative.

[masc360]

thanks skant that is some great information. while i never knew for sure i always though that vc-1 and avc were pretty equal, as long as whoever was doing the transfer was taking their time to do a good job.

[starkent08]

isnt it mpeg4 not 2 duh

[hardcorefrokid]

Nice piece of info there, SkantDragon. Answered a bunch of my questions.

[davcole]

Loved the insight on the codecs but I do have a few questions?

My understanding is that after AVC was developed that they added the HP part after finalization. I believe that was for adaptable blocking similar to VC1 whereas AVC-HP was originally one standard blocking?

I don't know how it is in the real world but i've heard people speculate that bandwidth starved VC1 causes banding artifacts that aren't always in AVC. Is this a byproduct?

Would you say they look the same if at the same bandwidth?

[Anthony P]

Each one has it's advantages and disadvantages based on the content being encoded and the bitrate you have to play with. Depending on the situation (and the encoding software being used), you can make any of the codecs look better than the other two with the same source.

exactly.

[Anthony P]

In short, everything MPEG2 can do, AVC can do better. Literally.

that is not exactly true. In general, you are right, but like you said "MPEG4 is a essentially a superset of MPEG2", that means it has extra overhead. Now in the vast majority of cases that extra overhead is more then compensated for by AVC's advanced techniques. But there are situations where it is not the case.

[Anthony P]

My understanding is that after AVC was developed that they added the HP part after finalization. I believe that was for adaptable blocking similar to VC1 whereas AVC-HP was originally one standard blocking?

the original MPEG-4 was tweaked and created for very low BW, low movement, like videoconferencing. That is why more "parts" where added with time as features where added/changed to handle more situations.

[Ray O. Blu]

I voted for VC-1 based solely on the fact that Band of Brothers and Baraka use it.

[blu_world]

anyone know why black hawk down is encoded with mpeg 2 and is a 5 star transfer.....oh..50GB Blu-ray's

[kris26]

isn't avc is nothing but mpeg-4 as well as x.264?