VC-1 over MPEG-4 AVC on Blu-Ray?

[Elias]

How come VC-1 is such a popular choice on Blu-Ray? It seems like most movies today are encoded in VC-1, whilst some are encoded in MPEG-4 AVC. A few, very rarely, are encoded in MPEG-2.

Now, MPEG-2 I understand the lack thereof: it's old, outdated and requires a much higher bitrate for the same amount of picture quality.

But MPEG-4 AVC certainly competes very well against VC-1 in terms of quality and bitrate ratio.

What's the deal here? Is Microsoft bribing the movie studios to encode their Blu-Ray movies in VC-1?

[toytown]

What's the deal here? Is Microsoft bribing the movie studios to encode their Blu-Ray movies in VC-1?

No, its the quality of the tools and there workflow that make VC1 such a good candidate for Bluray movies. Whilst AVC is better at lower bitrates (IMO), at the Bitrates Bluray achieves (20-40Mbit) its very hard to tell the difference between the codecs.

[Dark Shikari]

What, you think people choose the video format on Blu-ray for quality reasons?

The authoring houses involved in these decisions often wouldn't know good video quality if it hit them upside the head with a sledgehammer.

Plus, at the bitrates Blu-ray allows, if your encode has any visual difference from your source, you're doing it wrong, whether with VC-1 or H.264, or even MPEG-2.

[Guest]

I don't know how relevant it is as a factor, but trick mode implementation is much easier with VC-1.

[Elias]

So okay, we can rule out the quality factor for the sake of argument (I'm still convinced that MPEG-4 AVC requires much less size storage with the same quality, which is definitely a plus, but anyway). What other incentives do movie studios have to use VC-1 over MPEG-4 AVC? Is it encoding time? Somehow, I doubt that would be an issue.

[Dark Shikari]

(I'm still convinced that MPEG-4 AVC requires much less size storage with the same quality, which is definitely a plus, but anyway)Of course it does, by a wide margin--but do you think they care? They earn a great deal of money by spreading out your favorite TV series over 10 Blu-rays instead of 2. You can get near-perfect quality at ~10 mbps. Add in 1.5 megabit DTS 5.1 audio and you've got yourself 10 hours of video on one BD50.

They're not pressed for space.

[Elias]

Of course it does, by a wide margin--but do you think they care? They earn a great deal of money by spreading out your favorite TV series over 10 Blu-rays instead of 2. You can get near-perfect quality at ~10 mbps. Add in 1.5 megabit DTS 5.1 audio and you've got yourself 10 hours of video on one BD50.

They're not pressed for space.Oh yeah... that's a good point. For a second I forgot the greed of the movie studios. Those ...

[Doom9]

For some reason my post didn't make it.
Check out the blu-ray stats site. We currently have 50% AVC, 30% VC-1 and 20% MPEG-2 titles.
A bit of Blu-ray history also tells you how this is going to change: Sony, Fox, Paramount and Disney used to use MPEG-2 because their authoring facilities didn't offer AVC.
The studios that did HD DVD (Universal, Warner) probably went to VC-1 because they had less space, because it was readily available and because Microsoft helped with authoring and provided a more complete package.
All the MPEG-2 stuff is AVC today so that 20% is going to shrink in favor of AVC. Warner seems to be the only one consistently using VC-1 and that's probably because they went for authoring that did both initially and stuck with it (I haven't checked though.. I hardly ever watch a movie until the point where they show you the logo of the authoring company).
Looking at studios that used both in the past (almost every studio) also seems to indicate that the choice has something to do with authoring.

Anyway, I think all the VC-1 vs AVC flamefests at AVS need no continuation here - you shouldn't care about the codec but if the disc looks good, and speculating whether a chance of codec would've yielded a better result not only wild speculation at best (for starters you won't get the uncompressed source to try it yourself, and then you don't know what encoder is being used - is the Sony AVC encoder really up to x264? I don't know, do you?) but also purely a matter of personal preference (some like grittier looks which AVC is more biased towards (though this is very much dependent on the settings used... let's not forget that AVC also has an inloop filter).

[Guest]

What's the link for the bluray stats site, please?

VC-1 also has an in-loop filter, BTW.

[Doom9]

Here you go: http://www.blu-raystats.com/index.php
It's a great souce of info andt there's also one for HD DVD (http://hddvdstats.com/).
And as far as the inloop filter goes I actually was leading to the fact that there seem to be discs where it has been turned off for AVC - thus giving the whole thing a more grittier look - one that you hardly ever see with VC-1.

[CruNcher]

Here you go: http://www.blu-raystats.com/index.php
It's a great souce of info andt there's also one for HD DVD (http://hddvdstats.com/).
And as far as the inloop filter goes I actually was leading to the fact that there seem to be discs where it has been turned off for AVC - thus giving the whole thing a more grittier look - one that you hardly ever see with VC-1.

I would say a more Film like (celluloid) look ala good old ASP not this new Age Artificial super clean one (optimized for low bitrate SD) :).
But yeah that is really a subjective taste thing and @ really high bitrates vanishes slowly anyway with a Good tuned Encoder :).

[Sagittaire]

With BD50 there are no visual difference between codec.

With BD25 it's another story: BD25 are really more easy to produce than BD50 with very lower cost. H264 become really better than other codec at bitrate lower than 10 Mbps. here classical BD25 authoring:

- 2 or 3 GB for menu and bonus
- 10 Mbps for 1080p primary video stream
- 4.5 Mbps for primary audio PCM 5.1 stream
- 2.0 Mbps for DD 5.1 secondary audio stream (generaly 3 stream for US)

-> 16.5 Mbps min for mux stream imply that H264 become only interessing for 160 min movie. Large majority of movie are at 100-140 min. VC1 is really good codec in this bitrate interval.

[*.mp4 guy]

The problem with mpeg2 and vc-1 is that they have trouble dealing with complexity spikes gracefully, the maximum bitrate for blu-ray video is ~40mbps, which isn't always enough to give transparent quality during very dificult to encode scenes.

To date I've only seen one hd disc, and that was batman begins, and the quality was far below what I expected. Visible compression artifacts, temporal smeering, extreme blurriness. If this was because of vc-1, or just general incompetance, I'm not sure, but they could have done much better.

[edit] I just checked the blu-ray bitrate thread, and aparently batman begins was encoded at a much lower bitrate then I would have expected, maybe that explains it.

[Sagittaire]

The problem with mpeg2 and vc-1 is that they have trouble dealing with complexity spikes gracefully, the maximum bitrate for blu-ray video is ~40mbps, which isn't always enough to give transparent quality during very dificult to encode scenes.

To date I've only seen one hd disc, and that was batman begins, and the quality was far below what I expected. Visible compression artifacts, temporal smeering, extreme blurriness. If this was because of vc-1, or just general incompetance, I'm not sure, but they could have done much better.

[edit] I just checked the blu-ray bitrate thread, and aparently batman begins was encoded at a much lower bitrate then I would have expected, maybe that explains it.


Well local bitrate for BD is not really limited at 40 Mbps. It's max bitrate at 40 Mbps with really big buffer at 30 MB.

Batman Begin is really particular VC1 encoding from Universal at really low bitrate. In fact this encoding is simply demo VC1 technologie from MS.

[Blue_MiSfit]

I've seen excellent examples of both VC-1 and H.264 BluRay / HD-DVD releases.

Both standards are quite capable of producing high quality 1080p video at these data rates. As we all know, encoder implementations vary, but I've seen very few HD discs that I wasn't at least somewhat impressed by.

To be honest, in some cases the BluRay / HD-DVD version of a movie looks better to me than the massive 50-80mbps 4:2:2 MPEG-2 deliveries I get at work (and then promptly re-encode to H.264 for our VOD service). This is because of retarded encoding houses that can't do proper VBR, and thus can only do a nice looking encode at massively oversized CBR.

Awesome 1080p at 25mbps is good enough for me!!!

~MiSfit

[Dark Shikari]

Awesome 1080p at 25mbps is good enough for me!!!Says the one re-encoding to 3 megabit 1080p for VOd ;) ;)

[Blue_MiSfit]

LOL!!!! Cmon.. our quality service is ~8.5 :D