Blu-ray Disc vs. Streaming-Services Video Quality

[Alexandros Angelopoulos Apostolos]

I have some questions about how Blu-ray Disc video differs from VOD available on various streaming services.

1. What are the main differences between a Blu-ray video and a video from any of the streaming-services ones? What changes the most? Is it the amount of colours? Is contrast lower? How much less sharp are the streaming videos? Do the same differences apply whether it be 1080p HD content vs. Blu-ray or the 4K UHD Blu-rays and UHD streaming?
2. Are there any differences in quality between various streaming services? Is the same film on, for example, Amazon Video in the same format and of the same quality as it is on Netflix?
3. Are the codecs used by various streaming Web sites the same? For example, I see that Vimeo, YouTube, and iTunes Store use H.264.
4. If both a Blu-ray Disc and a streaming service use H.264, why is streaming video of lower quality? I presume it’s because of the compression scheme. Are the compression schemes all the same on various VOD Web sites?
5. So a single-layer Blu-ray Disc can contain up to 25 GB of data and the dual-layer one 50. If you were the download a 1080p streaming video, how much storage would it occupy?
6. Is the problem with the difference in quality a problem of internet speeds or does it lie somewhere else? A Blu-ray Disc can have a bitrate of up to 40 Mbps. What are the bitrate of streaming services?
7. What kind of speeds will you need for uninterrupted, smooth streaming of 4K UHD video? Or, more generally, how do you calculate the speed needed for a content with a particular resolotion, given that this will change a lot in the future? Will we eventually have even the true Blu-ray Disc audio experience in streaming, too?
8. Will streaming services eventually replace Blu-ray Discs and what are some of the things that need to happen for that to occur?

 

I forgot a lot of what I was going to ask, and one thread got lost when I accidentally shut down my browser, but I think I’ve managed to recover the gist of what I was going for.

[David Mullen ASC]

I've haven't watched much streaming but it seems similar to cable HDTV in that there is a lot of compression compared to a blu-ray 1080P image. My gut tells me that 1080P streaming will be a bit more compressed and softer than a 1080P blu-ray of the same master HD recording. But of course, you have to compare apples to apples, same master used, same resolution, etc. UHD has more resolution than HD so even a highly compressed UHD stream may look sharper than a less compressed HD blu-ray.

 

Unfortunately (to me) physical media will disappear and you won't be able to get any of these movies except through streaming services. But that's speaking as someone who still buys albums on CD...

[Tyler Purcell]

1) BluRay uses a 8 bit, 4:2:0 MPEG 4 Transport Stream codec, with around 35 - 45Mbps. Web based streaming services are almost all flash based, which allows for lower bandwidth playback, with the same quality content.

 

2) Web-based streaming is generally Flash based, but non-web based streaming is similar 8 bit 4:2:0 MPEG 2 or MPEG 4 program stream, but bandwidth is no more than 10Mbps.

Almost all web-based content providers ALSO transcode to a lower-resolution .h264 file for streaming on mobile devices (ipad/phone, etc). If you only have a mobile device, you may be seeing better quality video then your desktop computer, which is again, flash playback in most cases.

 

3) Refer to answer 2

 

4) Refer to answer 1 and 2

 

5) Well, you can do the math yourself. If you're streaming at 10Mbps... times 60 seconds in a minute, times 60 minutes in an hour...

 

6) Refer to answer 2

 

7) What holds people back from streaming UHD content is the cost to them. Remember, they have to pay for bandwidth. So if they send you a 50Mbps file, they are paying 5 times the amount to do that, then a 10Mbps file. If the 10Mbps file looks fine, why would they send you a 50Mbps file? Also, our infrastructure can't support it. There is no way we will see UHD streaming to the quality of UHD BluRay anytime in our future, it just won't happen. Even Gigabit internet, which is right around the corner, can't deliver anything near the bandwidth of UHD BluRay.

 

8) Disks are dead already. The video stores went out of business. The retailers have decreased their media sections to a few hundred titles and big name movies are being pushed out the door for $4.99 on BluRay, just to clear inventory. The disk market is a zombie walking around with no direction today. The vast majority of people want instant access to media, quality doesn't really matter to them. They want to sit down, press a button and watch content. The only way for streaming services to reach the bandwidth of BluRay is if they charge consumers for that bandwidth. This would mean $50/month netflix for everyone. I don't see that happening anytime soon.