Why 24fps is not enough for HDR movies

[Rasmus Larsen]

Apple TV+ has the highest streaming quality we’ve seen for 4K so far. It's higher than most iTunes movies. Over the weekend, I took the first batch of measurements. I'm planning to do more later. It's worth pointing out that Apple TV+ uses variable bitrate with a quite wide span from low to top, so the console must run for some time to calculate the average bitrate.

See has the highest bitrate so far. 29 Mb/s average video bitrate and 41 Mb/s video peak (I don’t know if it hits that occasionally or rarely, since the console only reports average and peak).



The Elephant Queen averages around 26 Mb/s for video bitrate.



Snoopy in Space: It's great to see Apple making 4K Dolby Vision the new default and Snoopy hits relatively high bitrates considering that it's a cartoon.



As you can see, there is no Atmos system connected to this TV so audio bitrate comes in at 386 Kb/s. It will most likely be higher with Atmos.

[Rasmus Larsen]

So that's approximately 1.5-2x the video bitrate of a typical HD Blu-ray disc (due to HEVC vs. AVC) and around half of a typical UHD Blu-ray disc (also using HEVC).

[Simons]

Nice work: https://www.macrumors.com/2019/11/04/ap ... g-quality/

[Rasmus Larsen]

Thanks

Here's Dickinson on Apple TV+.

[BeamrMark]

Some services like Netflix pushed the bounds on producing the highest quality, while doing so as bitrate efficiently as possible. While others made compromises, sometimes on the side of quality, in order to reduce bitrate even further, or compromised on bitrate, in order to deliver the highest quality possible.

One thing that probably isn't clear however in your article is that bitrate alone is not a sufficient marker for how good or bad the quality of a video stream will be. In the early days of digital video encoding, many services were forced to use CBR which is to say that the encoder would allocate the same data rate whether all the bits were needed or not in a frame.

Now that player and device capabilities have become much more advanced, VBR is a standard rate-control, and there is even a new rate control called CABR which stands for Content-Adaptive Bitrate. CABR is an innovation developed by my company Beamr. For those who are interested in how we are able to reduce the bitrate of a standard VBR encoded file by as much as 50%, all without any shift in the original quality, you will want to listen to this podcast https://thevideoinsiders.simplecast.com ... /episode22 discussing how the system works, and the 45 patents that back it up.

Bottom line, yes, good quality video will always need more bits than lesser quality. But with advances in codecs, such as HEVC, which Apple uses (and every other service delivering 4K today), and with innovations like Beamr Content-Adaptive Encoding technology, you will be surprised at how awesome the video can look at bitrates that are closer to 10Mbps, than 20Mbps, for 4k/UHD HDR.

[Rasmus Larsen]

Of course, bitrate is only part of the story but we have measurements for most leading streaming services. Taken the codec, resolution and other factors into account, the bitrate is a good indicator of video quality as it correlates quite closely to what we can visually observe, i.e. Apple’s 4K looks much better than Netflix’s.

[grantdagenius]

Hello thank you for your great work with the specific metadata! What program is that to be able to tell bitrates and codecs of a streaming video?

[Rasmus Larsen]

We will soon post a chart with measurements and bitrates for other streaming services plus a step-by-step method on how to check this stuff. That way we can all contribute to the chart.

[philg5150]

New to the site and it looks great! Would love to know how to check audio and video bitrate. Any update on this topic?

[thedude1980]

Does the Apple 4k TV device stream non Apple + content at a higher bitrate than other streamers like the new 2019 Fire Cube?

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[thedude1980]

Does the Apple 4k TV stream content any better/higher quality than others like the New 2019 Amazon Fire Cube?

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[Rasmus Larsen]

It depends on the streaming service. Some services reserve 4K, Dolby Vision and Atmos for select devices. But if you're getting 4K throughput the stream should be identical on an Apple TV 4K and Fire TV device.

[WillzyxTheZypod]

Hi Rasmus,

Any update on when we can expect the chart containing measurements and bitrates comparing the various streaming services? I am very interested in the results of your testing.

Thanks!

[Rasmus Larsen]

We'll get on it after CES. Hopefully in mid or late January.

[WillzyxTheZypod]

Awesome. I look forward to it!