Gizmodo's Take on Vudu's HD Quality

[gazzie4]

Re: Gizmodo's Take on Vudu's HD Quality

I must say, I am very happy with vudu, but the HD is not where it should be. I still prefer HD DVD and Blu Ray. The way I see it though is, for movies that I don't want to buy, vudu is a great alternative. If it came down to a higher bit rate download instead with an external hard drive for better quality, I may go to buying movies only on vudu, but at this moment it is just not there yet. This is not to say that vudu is bad or lacking anything, it is just not exactly what I am looking for right now on the purchase front. Rental works great, not big on purchase yet.

[redwein]

Re: Gizmodo's Take on Vudu's HD Quality

1080p/24 = 1920 x 1080 pixels x 24 frames per second.

If each pixel is a bit, we have 2,073,600 pixels per 1080p frame. So this is 2.0736 Mb per frame.

I would suspect that each pixel is more than a bit. After all a bit will just specify on or off but a pixel has color, intensity, etc.

[HeadHodge]

Re: Gizmodo's Take on Vudu's HD Quality

FYI: I saw lots of compression artifacts while watching the SuperBowl in HD on Fox last night...

Thanks for the reply.

We had a mini Super Bowl party at our home. It was a really great game, but I think I was too plastered to notice the artifacts. Hic

[Rusdude]

Re: Gizmodo's Take on Vudu's HD Quality

Because HD is defined by resolution (ie: NUMBER OF PIXELS) and not by bitrates...

But we all know that bitrate makes a lot difference. Good 720p is better than low-bitrate 1080p. Even with DVDs, I believe Superbit line was made specifically to focus on higher bitrate.

[HeadHodge]

Re: Gizmodo's Take on Vudu's HD Quality

I don't really need to know all the nitty-gritty details, just enough to respond to those people who ask how can Vudu deliver good 1080p HD quality at 4 megs/second bit rate. People know/hear that Blu-Ray/HD-DVD offer 25-50 megs/second and with much the same codecs, so many tend to assume that Vudu is much inferior.

It's hard to argue with these know-it-alls without good ammunition, so it'd be helpful if someone from Vudu (VolkerS ?) stepped-in and gave us a brief overview of why/how Vudu maintaining good quality.

I agree, probably a good benchmark system would be way better and more productive than knowing the actual nuts and bolts of how it's done.

BTW, Believe me I'm really happy with Vudu, but there's always room for improvement as time and technology allows. I'm no basher, just looking for a spirited discussion.

[NA9D]

Re: Gizmodo's Take on Vudu's HD Quality

P.S. To NA9D, I know about H.264 but people know that it's one of the high-def media codecs. So then people begin to question how Vudu can do 1080p with bitrates 5-10 less than BR/HD-DVD. I don't want to refer them to Wikipedia, I would like to have a good summary specifically for Vudu that we could refer people to.

P.P.S. This is one example of what I've come across and would like to know how to refute:

Because HD is defined by resolution (ie: NUMBER OF PIXELS) and not by bitrates...

[NA9D]

Re: Gizmodo's Take on Vudu's HD Quality

Well, look at it this way:

1080p/24 = 1920 x 1080 pixels x 24 frames per second.

If each pixel is a bit, we have 2,073,600 pixels per 1080p frame. So this is 2.0736 Mb per frame.

This equates then to a raw bit rate of 49.7664 Mb/sec raw bit rate for the image.

I think you can figure the compression ratio from there pretty easily!

Now, look at iTunes. It's a 720p/60 format:

720p/60 = 1280 x 720 x 60

This equates to 55.296 Mb/sec raw data rate.

So Vudu compresses less than iTunes. That we know...

[Rusdude]

Re: Gizmodo's Take on Vudu's HD Quality

Does DirectTV or Comcast disclose there bitrates or quality? They are trade secrets just as VUDU's/

I don't really need to know all the nitty-gritty details, just enough to respond to those people who ask how can Vudu deliver good 1080p HD quality at 4 megs/second bit rate. People know/hear that Blu-Ray/HD-DVD offer 25-50 megs/second and with much the same codecs, so many tend to assume that Vudu is much inferior.

It's hard to argue with these know-it-alls without good ammunition, so it'd be helpful if someone from Vudu (VolkerS ?) stepped-in and gave us a brief overview of why/how Vudu maintain good quality. It'd then go into FAQ/be stickied.

P.S. To NA9D, I know about H.264 but people know that it's one of the high-def media codecs. So then people begin to question how Vudu can do 1080p with bitrates 5-10 less than BR/HD-DVD. I don't want to refer them to Wikipedia, I would like to have a good summary specifically for Vudu that we could refer people to.

P.P.S. This is one example of what I've come across and would like to know how to refute:

I download TV shows in HD from Xbox Live all the time. They are far better in HD than they are in SD.
Could it possibly be that Vudu's encoding techniques and bitrates stink, since they're trying to do HD streaming over 4Mb/s?
Xbox Live HD video content is around 6-10Mb/s, IIRC.

[NA9D]

Re: Gizmodo's Take on Vudu's HD Quality

The problem is that I don't understand it well enough to know what I really want. I only have my audio codec ripping experience to fall back on.

Thanks for replying though. I really do apprecate it.

Regards

Well, you should be able to find out information on H.264 here: http://en.wikipedia.org/wiki/H.264

That should be titled "Everything you ever wanted to know about H.264 but were afraid to ask."

And knowing the file size and the download rate, you can calculate all sorts of things!


FYI: I saw lots of compression artifacts while watching the SuperBowl in HD on Fox last night...

[HeadHodge]

Re: Gizmodo's Take on Vudu's HD Quality

Does DirectTV or Comcast disclose there bitrates or quality? They are trade secrets just as VUDU's/

If you go to Biztalk.com you can find technoids that know (or claim to know) bitrates and resolutions transmitted by Directv on a channel by channel basis, which satelitte is transmitting it, and which encoding method is used. How they know this is beyond me.

Don't have Comcast, so don't anything about them.

[NA9D]

Re: Gizmodo's Take on Vudu's HD Quality

You know the thing about this all is that no one (not even the "Moderators with an Agenda") have stated that Vudu is as good as or better than HD-DVD or BluRay. I would expect Vudu's HD quality to not be as good. And some day, I'll buy a BluRay player but I'm waiting for the format war to end.

But what does Vudu bring me? The ability to instantly watch any of the movies in the library w/o having to run to the doggone video store or pay a monthly fee to Netflix. The HD quality is certainly as good as what Comcast gives me on their VOD system but with far more selection.

If there's a movie that I really want in HD, then I will probably buy it on an HD format. So say they release Lord of the Rings in BluRay and in HD on Vudu. I'd buy the BluRay version in a heartbeat as its something I'd want to have on my library shelves and when I want to watch that movie, I want the full experience. But Vudu gives me a great experience for movies that aren't my "favorites" or aren't until I watch them the first time...

[HeadHodge]

Re: Gizmodo's Take on Vudu's HD Quality

I don't know what else you want. We know the file size is about 3 to 5 Gigabytes depending on the movie. The bit rate of the encoding is variable. The codec used is H.264 which is a public standard.

The exact details of Vudu's encoding is proprietary (ie: trade secret).

The problem is that I don't understand it well enough to know what I really want. I only have my audio codec ripping experience to fall back on.

Thanks for replying though. I really do apprecate it.

Regards

[RonV]

Re: Gizmodo's Take on Vudu's HD Quality

On the other hand, it would be nice (and interesting) if Vudu could be a little more transparent about there encoding quality. It doesn't seem to really cut it by just saying they use Mpeg4 (or H.324, or whatever they use)

Does DirectTV or Comcast disclose there bitrates or quality? They are trade secrets just as VUDU's/

[HeadHodge]

Re: Gizmodo's Take on Vudu's HD Quality

it'd be nice if someone in the position of authority could do a comprehensive comparison of image quality of various formats (e.g. SD DVD, Vudu SD, Apple SD, Xbox SD, Vudu HD, Apple HD, Xbox HD, cable/FIOS HD VOD, Blu-Ray/HD-DVD) across multiple titles so we could have good basis for saying ___ is best VOD and ____ close to high-def media. Until that happens we might be stuck with with [mini-]reviews like this.

I agree, it would be nice to have some definitive benchmarks. It would also make great sales and marketing material too (assuming the product in fact compares well with the competition).

[NA9D]

Re: Gizmodo's Take on Vudu's HD Quality

On the other hand, it would be nice (and interesting) if Vudu could be a little more transparent about there encoding quality. It doesn't seem to really cut it by just saying they use Mpeg4 (or H.324, or whatever they use)

I don't know what else you want. We know the file size is about 3 to 5 Gigabytes depending on the movie. The bit rate of the encoding is variable. The codec used is H.264 which is a public standard.

The exact details of Vudu's encoding is proprietary (ie: trade secret).