Philips DVP-642 farce!

[disneyland]

Almost all of my DiVX encodes take advantage of GMC and QPEL. I was really enthusiastic about receiving my DVP-642 but completely missed it's major drawback...no support for the aforementioned. Ouch!

To validate my own theories I used three different encodes of a single 700mb CD version of Jesus Christ Superstar (2001) with an aspect ratio of 1.88, as an acid test. The first encode took advantage of both GMC and QPEL, the second, adhered to the DiVX Certified Home Theatre, and the third, a GMC and QPEL devoid custom encode at a lower resolution but still compatable with the hardware.

The latter two were vastly inferior to the encode with GMC and QPEL enabled. It subjectively looked more like DiVX 3.11 than 5.x.

The hardware is being returned to Outpost.com tomorrow. Very disappointing.

*end of diatribe*

Now for the question:
Doom9 states in the Gordion Knot Guide that as of December 2003, DiVX hardware will support QPEL and GMC. What hardware is now on the street that supports GMC and QPEL and what vendors carry it?

With thanks!

Disneyland Fantasmic!

aka: Gary Chambers

[monty0815]

The supported features all depend on the used chipset.
There are only a very limited number of different chipsets for playing mpeg4. The one you are looking for would be a player with a mediatek 1389 decoder chip, as these support GMC and QPel with DivX. You can find more information about limitations and players in the MTK 1389 information Thread.
There are other Chips like the ones from Zoran (which is the newest atm), ESS and Sigma.
ESS and Sigma don`t support GMC and Qpel, with their current models, don`t know about the Zoran.

cheers, monty

[SeeMoreDigital]

I generate just about all my Mpeg4 backups without GMC and Qpel. I also prefer not to crop and re-size them!

A 90 min movie, when burnt onto 1No CD~R can still look pretty good. 60min per 1No CD~R looks better. Three movies burnt onto 1No DVD~R also looks the business!

But I guess it all depends on what kind of quality you're expecting. Not to mention the screen you're watching your encodes on!

By-the-way. You are generating 2pass encodes, aren't you?


Cheers

[pelle412]

@SeeMoreDigital: If one generates 1-pass quantizer 2 encodes and don't care about size, would 2-pass encoding offer some added benefit?

I always "archive" my own movies using 1-pass q2 encodes (no crop, no resize, AR flags set to match DVD) but I use in addition to default XviD settings also QPEL, GMC, AQ, and VHQ4. My hope is that one day a player (standalone) will show up that can play these movies with proper aspect ratio and close to a DVD experience.

[SeeMoreDigital]

Originally posted by pelle412
@SeeMoreDigital: If one generates 1-pass quantizer 2 encodes and don't care about size, would 2-pass encoding offer some added benefit? This will depend on the bit-rate setting. But I've found even when using bit-rates of 2500-3500Kbps would benefit by using 2pass.

And anything below 2000Kbps would certainly benefit. You really can't beat a 2pass encode - if you have the time!

Originally posted by pelle412
...My hope is that one day a player (standalone) will show up that can play these movies with proper aspect ratio and close to a DVD experience. There are already some MediaTek chip-set based stand-alone players that can offer this functionality (in .AVI).


Cheers

[pelle412]

Originally posted by SeeMoreDigital
This will depend on the bit-rate setting. But I've found even when using bit-rates of 2500-3500Kbps would benefit by using 2pass.

I did my own test and the higher bitrate I choose the closer I get to 1-pass quantizer 2 encoding in terms of the quantizer distribution. So my conclusion is, encoding based on fixed quantizer in a single pass would save alot of time compared to 2-pass birate based encoding if file size isn't an issue (if it were you'd be encoding filesize based anyway).

Originally posted by SeeMoreDigital
There are already some MediaTek chip-set based stand-alone players that can offer this functionality (in .AVI).

Does it support 3 warppoint GMC?

[SeeMoreDigital]

Originally posted by pelle412
I did my own test and the higher bitrate I choose the closer I get to 1-pass quantizer 2 encoding in terms of the quantizer distribution. So my conclusion is, encoding based on fixed quantizer in a single pass would save alot of time compared to 2-pass birate based encoding if file size isn't an issue (if it were you'd be encoding filesize based anyway). If you're not bothered about using higher bit-rates or your finished file size, then I would stick with Mpeg2.

Originally posted by pelle412
Does it support 3 warppoint GMC? Why not look through the 19No pages of MediaTek information contained within this thread (http://forum.doom9.org/showthread.php?s=&threadid=67028)?


Cheers

[LordRPI]

For more information on what you can expect in a DivX Certified device, check here (http://www.divx.com/certified/player_faq.php)

[SeeMoreDigital]

Originally posted by LordRPI
For more information on what you can expect in a DivX Certified device, check here (http://www.divx.com/certified/player_faq.php) A word to the wise!

Not all MediaTek chip-set based players follow DivX certification to the letter...

...And thank God they don't!


Cheers

[LordRPI]

Yes, it is good that some go above and beyond ;)

[disneyland]

What hardware players (models) actually support GMC and QPEL? Pointers to a list would be great.

Also, I have received satisfactory results encoding using a variable bitrate with adaptive consecutive turned on as well as Psychovisual fast.

[SeeMoreDigital]

Originally posted by disneyland
What hardware players (models) actually support GMC and QPEL? Pointers to a list would be great. All current MediaTek chipset based players support Qpel and GMC.

The problem is, with GMC.....

DivX's codec is only able to generate Mpeg4 encodes with 1 warp-point GMC (which is very weak and is arguably not worth using). So any "DivX certified" player will most likely only decode Mpeg4 with 1 warp-point GMC.

XviD, FFdshow and Nero, on the other hand can generate Mpeg4 encodes with 3warp-point GMC, which is worth using!

Thinking about it. It might be time to create a new MediaTek thread, summarising the more up to date/current information... 19No pages with 362No entries (last count) is a bit long!


Cheers

[Codesmith]

Its not like it was a secret that the first couple hardware players were probably not going to support those feautures. Hardware device profies have been a part of the DivX configuration utility for some time.

There was adequate warning that certified devices were not going to be required to support those features.

IMHO at 1490 MB (1/3 DVD+RW) a 2 hour, Home Theater Profile compliant, DivX 5.2 with 6 Ch AC3 sound looks (and of course sounds) just as good as a DVD on my 27" Sony CRT TV & 5.1 Home Theater System.

(Maybe if I had a 60" DLP TV I might notice a difference)

Yes its far from a perfect product, but thats just the price you have to pay if you want to be an early adopter.

In a year or two I will probably be able to spend another $50 and upgrade to a player that handles more than 90% of my content.

But right now I am simply amazed at what I am getting for $70!