[Sunspark]

Why don't apps like this leverage gpu hardware acceleration?

On my old tablet, Netflix runs a-ok, the media player has hardware acceleration and runs a-ok, but Amazon Prime stutters.

I haven't checked it in years, so maybe it is better now, but I am skeptical this is the case, because if the original creators of the Android app didn't think hardware accelerated video might be a nice idea, why would it be different now? This is a structural issue.

[lathiat]

There is a cross sectional problem between what codecs that specific hardware supports (and generally is supported by all the popular devices), how much bandwidth you have on your connection and how many different codecs the various streaming services can support and cache locally.

There are trade offs to be made.

[Sunspark]

Fair, but in this case I think the tablet should be usable. Sure it's old and only a dual-core cpu, but checking the list of hardware accelerated qualcomm decoder codecs it supports, it lists: vc1, divx, divx311, divx4, avc, mpeg2, mpeg4, h263.

Surely AVC which is h.264 should still be supported..

Maybe it gets tripped up trying to use the software google decoder codecs instead?

That said, I am not able to test it anymore. The tablet is on kitkat and I'm not able today to find a site hosting a minsdk older than lollipop. It's not a big deal, but it's disappointing to see apks for services that used to work just disappear. They always gobble on about "security". Why is it a problem for everyone else except Netflix? Netflix loves supporting devices.

[plorkyeran]

"Supports AVC" doesn't mean a great deal on its own. H264 has a number of different profiles (over 20, although only 3 are commonly used), and 20 different levels. Most of the potential combinations aren't relevant, but supporting the full range of hardware decoders while also sending something reasonably close to the best quality that the device supports can mean encoding ten different versions.

If it's a particularly low-end/old device, Amazon may have simply decided it's no longer worth encoding a version supported by your device's hardware encoder, while Netflix still does.

[nopenopenopeno]

Can you recommend any resources for learning about video codecs?

[the_only_law]

Not sure if this is what you’re looking for, but this popped up a while back: https://blog.tempus-ex.com/hello-video-codec/

[astrange]

This is vaguely okay but makes the common mistake of overemphasizing that codecs use an IDCT. That's just a component of intra-prediction, it isn't necessarily important or used, and in H.264+ it isn't even a real IDCT when it is used. It's a simpler transform that isn't mathematically accurate but is bit-exact, which is more important.

[nopenopenopeno]

This is perfect! Thank you!

[Sunspark]

doom9 has a lot of good discussion.

[dylan604]

I remember back in the day when doom9 was blocked at the corp firewall level because it had posts on how to circumvent things. Nevermind it was the unofficial support for things like AVISynth, x264, etc. Even the nascent days of ffmpeg were there. It took a lot of cajoling and back and forth with legal depts, but eventually, was allowed to be granted access on an individual basis

I owe a lot of what was accomplished to folks like DG and the other troopers from the bad ol' days of VFW based apps. It was like monkeys throwing rocks at the space ships compared to whats now. Remember when 2 cores was fast?

For the person up thread talking about learning things, I wish I was in that position today with them rather than 20 odd years ago where everyone was in the dark, and thank the heavens for sites like doom9 that shone lights in dark places!

[nopenopenopeno]

>For the person up thread talking about learning things, I wish I was in that position today with them rather than 20 odd years ago where everyone was in the dark

Where would you start today?

And what was being circumvented? Copyright protection?

[nopenopenopeno]

Now we’re talkin! Thank you!

[shmerl]

Didn't everyone agree to align on AV1? So that should become a non issue as its adoption progresses.

[Sunspark]

What about all the older CPUs and GPUs out there that don't have hardware support for AV1?

[snuxoll]

Or even new ones, like the AMD Radeon RX 6500 XT that had the AV1 decoder chopped off the Navi die for some inexplicable reason.

[dannyw]

The reason is because it's harvested from a laptop chip; and in laptops, the Ryzen 5000 media engine features AV1 decode, so it's wasted die space.

Still, the 6500 XT is an awful GPU.

[ChuckNorris89]

>the Ryzen 5000 media engine features AV1 decode

No it doesn't.[1] Ryzen 5000's iGPU is based on the older Vega architecture and has no AV1 support, so everyone like me who just bought a brand speaking new laptop with Ryzen 5000 will be screwed soon enough.

[1] https://cpufinder.com/amd-ryzen-7-5800u

[shmerl]

That's why I said as it's being adopted. Right now it's just the very beginning of this phase (for instance AMD just started providing hardware decode in RDNA2).

So I expect this to become a non issue at some point.

[Sunspark]

As long as they don't take it as an excuse to reduce bitrates further. It's getting pretty bad these days with macro-blocking everywhere. This practice really took off when covid started. I actually cancelled Netflix because of it. Amazon is not as bad for macroblocks, but I have run into a few shows that show macroblocks, such as Mr. Robot.

[ksec]

>As long as they don't take it as an excuse to reduce bitrates further.

I actually think it is easier ( comparatively speaking ) to push for improved Networking so someday bitrate becomes less of a concern. Just like what happened with Audio. Even with the state of the art VVC Encoder, you only get about 65% ( or 2.8x ) reduction in bitrate in most common cases compared to x264. 65% reduction in 20 years isn't exactly a lot. We have easily got 20x bandwidth reduction in cost in the past 20 years.

Netflix are testing with 800Gbps per box now. May be when PCI-E 5.0 is available along with higher memory bandwidth they could try 1.6Tbps per box within the this decade.

[tormeh]

AV1 fixes the "square blocks in dark scenes" artifacts. It just doesn't have them. So that's good news.

[ksec]

>Didn't everyone agree to align on AV1?

Not that I am aware of. I have more faith in that with AV2.

[shmerl]

Judging by the list of backers, it looks like everyone who matters anyway.