Quote:
Originally Posted by DigitAl56K
Well, to begin I'd say that our compression in the ASP encoder was not very limited. If you compare it to an unrestricted encoder such as XVID on best settings you'll probably struggle to get more than 5-10% better efficiency for the same quality while the DivX profile-compliant version will have much better compatibility with devices. At the end of the day it's a balancing act. Personally, while I always strive for the highest quality I can get I really won't loose any sleep over 50MB of hard drive space, but recoding a video later just so that a friend can watch it on their DVD player is going to be a real pain.
Levels are one way to go, but then ASP also had levels. Levels work only if all manufacturers fully support everything in the same level equally well, and that doesn't always happen. There are ASP devices even today that still can't pass DivX Home Theater certification. What we actually did with ASP was to talk to many manufacturers to understand what all of their devices were capable of in terms of feature support, rate support and so forth, and then define a profile that we believed would bring interoperability across many of these devices without sacrificing efficiency too much. We're doing the same now for H.264 and we have had a lot of feedback that is very varied. The challenge is to bring this all together into a good solution not only for the manufacturers but for the community. Beyond the spec for the video bitstream we also need to ensure that every element of the format is specified and that conforming media will play reliably everywhere. It's neither a small nor easy task.
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Well IMHO I think that saying that 50MB of space is plenty of space to waste for the same quality of video. I suppose if I look at it from your compatibility point with your profiles the quality is fine for that.
I however don't really buy into the argument that the levels can't be used. they are well defined on what one should expect out of each profile. A hardware manufacturer can't say the support x level if they really don't. So in reality it would be best to push fully compliant support across hardware manufacturers.
While this is definitely detrimental to DivX on the branding level as DivX compliant would simply be another word for AVC Levels Compliant I think it would be better off for AVC as a whole and accomplishes the same point of what Divx certification does.
that's the main difficulty with ASP is that there are so many different vendor specific profiles going around (Nero, Divx, Xvid (various)) that I personally see myself looking at a huge chart going.....so what plays what? Will my Nero files play on divx will my divx files play on nero. If everyone sticks to the standard I don't have to ask myself that question if I buy such a hardware device. We need to avoid it in AVC if at all possible.
At least that's how I feel about it. Not sure how many would agree with me but I think that fewer profiles is better.