Why I think BluRay may be the future for CD-based music and HD video content... (1 Viewer)

[John Kotches]

James Morrow says:


Ok, so who's going to amend the ATSC standards to get WM9 approved, then update the entire HDTV infrastructure to get everything out there compatible?

Dish Network? DirecTV? Cable Companies? Huge infrastructures built around MPEG-2. Voom is looking into it, but they don't have anywhere near the installed/entrenched base as the others I've mentioned.

We're talking about 2 different situations -- a new product to market vs. an entrenched infrastructure.

Regards,

 

[John Kotches]

James Morrow says:


Ok, so who's going to amend the ATSC standards to get WM9 approved, then update the entire HDTV infrastructure to get everything out there compatible?

Dish Network? DirecTV? Cable Companies? Huge infrastructures built around MPEG-2. Voom is looking into it, but they don't have anywhere near the installed/entrenched base as the others I've mentioned.

We're talking about 2 different situations -- a new product to market vs. an entrenched infrastructure.

Regards,

 

[James Morrow]

... so it makes sense to support both MPeg2 and WMV on BD, then whichever way the market goes the player/recorder will be able to cope.

 

[James Morrow]

... so it makes sense to support both MPeg2 and WMV on BD, then whichever way the market goes the player/recorder will be able to cope.

 

[Michael St. Clair]

Blu-Ray already has to pay an MPEG2 license for backwards compatibility with DVD-Video. It's not like they'd be paying more for ATSC compatibility.

 

[Michael St. Clair]

Blu-Ray already has to pay an MPEG2 license for backwards compatibility with DVD-Video. It's not like they'd be paying more for ATSC compatibility.

 

[John Kotches]

James:

Those of us that are want the inclusion of more current codecs have never said that MPEG-2 should be excluded.

Simply put, more options are better.

Cheers,

 

[John Kotches]

James:

Those of us that are want the inclusion of more current codecs have never said that MPEG-2 should be excluded.

Simply put, more options are better.

Cheers,

 

[James Morrow]

Sounds good to me John.
{b] [/b]

 

[James Morrow]

Sounds good to me John.
{b] [/b]

 

[Lee Scoggins]

I'm for more flexibility as well. You never know what the future brings...

 

[Lee Scoggins]

I'm for more flexibility as well. You never know what the future brings...

 

[John Kotches]

Lee,

Why is it that your position parrots whatever Sony says?

A month or two ago, even earlier in this thread, you were saying that MPEG-2 was good enough. Now, with Sony saying they are considering other video codecs, you want them in.

Could you work on a little bit of consistency?

 

[John Kotches]

Lee,

Why is it that your position parrots whatever Sony says?

A month or two ago, even earlier in this thread, you were saying that MPEG-2 was good enough. Now, with Sony saying they are considering other video codecs, you want them in.

Could you work on a little bit of consistency?

 

[ElevSkyMovie]

Interesting.

 

[Lee Scoggins]

Kyle, the link doesn't work for me.

 

[Lee Scoggins]

John, I wish you would get your facts straight. Here's what I really said...

Here I am asking for evidence that MPEG4 is better or not:

 

[ElevSkyMovie]

Matsushita unveils DVD recorder adopting Blu-ray Disc format

OSAKA, Jun 30, 2004 (Kyodo via COMTEX) -- Matsushita Electric Industrial Co. on Wednesday unveiled what it calls the world's first DVD recorder that supports single-side, dual-layer Blu-ray Discs with a maximum capacity of 50 gigabytes.

The DMR-E700BD, the high-end model of Matsushita's DIGA DVD recorder series, will be put on the Japanese market on an open-price basis on July 31, said the major consumer electronics maker known for its Panasonic brand.

The new model can record up to four and a half hours of digital high-definition programming or up to 63 hours of analog programming, Matsushita said. The machine is equipped with built-in tuners for terrestrial digital broadcasting, broadcast satellites, 110-degree communications satellites and terrestrial analog broadcasting.

Matsushita is the second company after Sony Corp. to release a DVD recorder adopting the Blu-ray Disc, a next-generation large-capacity optical disc video recording format.

Using a blue-violet laser, the Blu-ray Disc achieves over two hours of digital high-definition video recording on a single-sided, single-layer CD/DVD-size disc with a diameter of 12 centimeters.

 

[James Morrow]

Interesting on the 50GB BD Recorder, Kyle, and fitting it into their DVD recorder line up. Sony are also due to release a 50GB machine this Summer.

On the subject of MPeg2, MPeg4 and WMV, it is often assumed that because MPeg4 and WMV are more modern than MPeg2 they are also capable of producing higher quality pictures than MPeg2. Certainly, at low bitrates their stability and quality compared to MPeg2 is impressive. However, this should not be surprising, because both have been specifically developed to produce the best possible picture quality at low bitrates. Being designed around minimum bitrates (quantity) rather than quality does not mean that, with minimum bitrates less of an issue, their quality will necessarily be better than a codec that is optimised to use more bits as effectively as possible – or one, such as MPeg2, which for whatever reason is not designed to work at such low bitrates. :p)

In order to achieve their very low bitrates, MPeg4 and WMV have to employ more aggressive compression techniques than MPeg2. One of the main techniques used is motion vector estimation. To understand and see the kinds of artifacts this produces (greatly exaggerated), it is useful to look at video at very low bitrates, such as videophones and many of the transmissions from the recent Gulf war. Instead of a stable, solid world, pieces shimmer and quiver, faces break up and drift back together, and so on. Of course, at higher bitrates these effects are less evident – but they’re there, nevertheless, because motion vector estimation is an intrinsic part of MPeg4 and WMV – supporting the very low bitrates they are designed to achieve. :frowning:

Tests in the eighties have shown that, under favourable conditions, a human being (and there are a lot of them about) can detect misalignments of around a hundredth of a pixel or less, so this is the kind of precision to which motion vector estimation has to work (under favourable conditions) in order to maintain the illusion of solid, fixed objects that don’t pulsate, shake or quiver, etc.. Favourable conditions include large displays operating at full 1920 by 1080 pixel resolution – i.e. using no interpolation functions. Less favourable conditions include smaller displays and, in particular, displays that use interpolation functions to display 1920 by 1080 pixel material via intrinsically lower resolution devices.

Unfortunately, the vast majority of current “high definition compatible” products are not capable of displaying properly registered 1920 by 1080 pixel resolution material. However, even when running the Microsoft 720p24 8Mbps demos on a 17” 1280 by 1024 pixels display strange pulsing and cogging and jerky movement effects are often visible on vegetation such as trees, scrubland, hedges etc., and there is a tendency for natural objects to look “manmade.” Whilst getting anything even vaguely reasonable at around 8Mbps is impressive, what does this mean at the kind of bitrates that the BD/HD-DVD is capable of – i.e. 24-28Mbps?

Coincidently, in 2003 the Blu-ray Disc Founders [BDF] carried out a detailed study of the performance of full resolution 1920 by 1080 p24 MPeg2 and MPeg4 AVC (part 10) encoded from fine grain film, coarser grain film and digital sources, with bitrates of 7, 12, 15, 20 and 24Mbps. However, they didn’t look into lower resolutions or interpolated images.

Participants included experts from the technical and production divisions of Hollywood studios and from the BDF companies – see the Blu-ray disc technical white paper, part 3 the logical and application specifications, for details, at

http://blu-raydisc-official.org/tecinfo/index.html

In summary, whilst MPeg4 worked at 7Mbps (MPeg2 wasn’t tested), less than a quarter of the viewers were happy with the quality as being sufficient for HD packaged material. At 12Mbps, once again, less than a quarter were happy with material from fine-grained film, although 45% were happy with MPeg2 on coarse-grained film and less than 40% were happy with either codec on largely computer-generated images. At 15Mbps, MPeg4 performed better than MPeg2 with fine-grained film, but still only achieved a less than 40% satisfaction rate, whilst MPeg2 performed better than MPeg4 on coarse-grained film, with a score of 60%, and both scored 60% on largely computer-generated film. Moving up to 20Mbps, MPeg2 was preferred over MPeg4 with all types of images, achieving scores of 60%, 90% and 100% where MPeg4 achieved 55%, 85% and 90%. Finally, at 24Mbps, MPeg2 achieved 100% acceptance, whilst on fine-grained film, MPeg4 only achieved 70%.

The BDF believes that the results show that data rates of 15-20Mbps are necessary to recreate the “feel” of the movie, that MPeg2 encoding technology for HD package media still has room for improvement and that there has been insufficient evaluation of the ability of MPeg4 with high definition images, but that MPeg4 can also improve. It was unclear, however, whether MPeg4 (which was developed for low image resolution and low bit rates) would be able to show a definitive advantage over MPeg2 without losing the high definition quality feel of the image. However, if there are reports of marked improvements in MPeg4 (or WMV) it will be necessary to re-test the technology through subjective evaluation tests, etc..

So just because WMV is impressive at 8Mbps does not mean that it will improve on MPeg2 at high bitrates – although it might. Blu-ray technology as capable of over four hours of high definition material at 24-28Mbps, so ideally we need a codoec optimised for encoding 1920 by 1080 p24 at these data rates. Whether this proves to be WMV or not, the option of longer play modes – particularly in a recording machine – using WMV technology exists. For example, 24Mbps could be a standard play mode [SP], with 16Mbps long play [LP] and 8Mbps extended play [XP]. On extended play, a 50GB Blu-ray disc could record over twelve hours of high definition video at the same quality as a two hour red-laser high definition disc.

 

[Lee Scoggins]

This is also interesting from a historic angle as well. Many people credit the fact that Sony did not have Matsushita in the Beta group for Beta's eventual failure.

I guess Sony has learned their lesson this time around.