iMac Pro iMac Pro HEVC / H265

[h9826790]

Just found this on the Apple website (it wasn't there, isn't it?)

Really sounds like the T2 chip is handling the HEVC decode now.

 

[Intell]

Image signal processor (or ISP) is industry language for the chip or process that handles camera interaction. It does not do de/encoding of media files that are on the disk.

 

[Bradleyone]

Also, just intuitively, the idea of handing off video encoding to the T2, which I understand is basically a customised iPhone 7's A10, would be like setting up a rack of smartphones to do Bitcoin mining.

Yes, it could be done, but no, probably not the best tool for the job!

 

[h9826790]

Just know about Activity monitor is the easiest way to know if AMD hardware decoder is in use. From the Hackintosh community, it's confirmed that AMD GPU hardware decode is available. So, iMac Pro should be using it.

Software decode.

And hardware decode

 

[d5aqoëp]

VLC is going the way of WinAmp. Outdated and thoroughly beaten by

Project IINA on macOS
PotPlayer on Windows
Infuse on Apple TV and iOS
MXPlayer + Neon codecs on Android

The Win 98 era UI of VLC is the no.1 thing that turns me off. I hate to install some unfinished custom skin. The last time I tried, it did not display subtitles in the bottom black bars. It had to display them on the actual picture.

 

[anticipate]

I know e are talking about HEVC decoding here, and this is a very interesting discussion. on my iMac Pro HEVC decoding seems to barely tax anything at all. I have suspicions that it is hardware decoded; I'll have to look at activity monitor.

As for ENCODING, I don't think it is. H.264 seems to be though! The iMac Pro's export H.264 faster than all current quicksync macs, despite not having quicksync. I am able to export 4K "best quality" H.264 in 2X real time. (Maybe that is the CPU? I don't know). A 15 min 4K file took 7 minutes in compressor, for example.

HEVC however took 5.5 hours (!!). So something's wrong.

[I used Compressor in both cases, latest version, from a prores file. I used the Apple Device presents]

 

[h9826790]

I know e are talking about HEVC decoding here, and this is a very interesting discussion. on my iMac Pro HEVC decoding seems to barely tax anything at all. I have suspicions that it is hardware decoded; I'll have to look at activity monitor.

As for ENCODING, I don't think it is. H.264 seems to be though! The iMac Pro's export H.264 faster than all current quicksync macs, despite not having quicksync. I am able to export 4K "best quality" H.264 in 2X real time. (Maybe that is the CPU? I don't know). A 15 min 4K file took 7 minutes in compressor, for example.

HEVC however took 5.5 hours (!!). So something's wrong.

[I used Compressor in both cases, latest version, from a prores file. I used the Apple Device presents]

Thanks in advance, looking forward for your Activity monitor check.

In my experience, that speed is hard encoding speed. A simple test can be down by selecting 2-pass. If that's CPU encoding, the encoding time should be roughly 2x single pass.

If that's hardware encoding, 2-pass will disable it, and make the encoding time much longer.

5.5 hours for HEVC definitely means no hardware encoding available. May be few more OS update can "fix" it (assume Apple has this plan, or iMac Pro users' noise is strong enough).

 

[BeatCrazy]

I know e are talking about HEVC decoding here, and this is a very interesting discussion. on my iMac Pro HEVC decoding seems to barely tax anything at all. I have suspicions that it is hardware decoded; I'll have to look at activity monitor.

As for ENCODING, I don't think it is. H.264 seems to be though! The iMac Pro's export H.264 faster than all current quicksync macs, despite not having quicksync. I am able to export 4K "best quality" H.264 in 2X real time. (Maybe that is the CPU? I don't know). A 15 min 4K file took 7 minutes in compressor, for example.

HEVC however took 5.5 hours (!!). So something's wrong.

[I used Compressor in both cases, latest version, from a prores file. I used the Apple Device presents]

This is fascinating. Can you try another test of HEVC encoding? Seems like if they enabled HEVC decoding, the encoding piece would go along with it.

My HEVC decode of 10-bit 4K used <10% of my (base) iMac Pro CPU.

 

[Trebuin]

This is fascinating. Can you try another test of HEVC encoding? Seems like if they enabled HEVC decoding, the encoding piece would go along with it.

My HEVC decode of 10-bit 4K used <10% of my (base) iMac Pro CPU.

The software has to be written to accept it. To date, I only know of QS implemented to encode, but that's an Intel thing that hasn't been implemented in Xeon processors.

Edit: unless Apple has built in their own code to support something in AMD in one of their own software packages. If that's the case, you have to use that specific software to benefit.

 

[BeatCrazy]

Interesting blog post here: https://larryjordan.com/articles/first-look-hevc-vs-h-264-in-apple-compressor-4-4/

I might try some HEVC encoding via Compressor tonight.

 

[anticipate]

Edit: unless Apple has built in their own code to support something in AMD in one of their own software packages. If that's the case, you have to use that specific software to benefit.

That is the theory, since clearly it's using hardware support for H.264 encoding (it is much much slower on Xeons otherwise and there is some GPU use during exports)

HEVC also seems to be hardware decoded on the iMP. But not the encoding... not in compressor anyway,
[doublepost=1516224110][/doublepost]

Interesting blog post here: https://larryjordan.com/articles/first-look-hevc-vs-h-264-in-apple-compressor-4-4/

I might try some HEVC encoding via Compressor tonight.

Those were my findings, on the iMac Pro. Yet look at this:

http://barefeats.com/imacpro_vs_pt4.html

He is showing fast speed using compressor to export Bruce to HEVC. I wonder what I am missing...

 

[anticipate]

Well, I tried to export to HEVC via compressor (and also via QT) and it is slow as molasses on the iMac Pro. I am trying to transcode a ProRes 422 4K file that is 14 min long, and it is telling me it'll take 3-4 hours in QT. Looks similar on Compressor... and other transcodes I attempted this week show about 5+ hours for a 20 min clip. The CPU use is about 700%.

I have attached the activity monitor for compressor, which shows the hardware encoder. But it seems ridiculously slower, and the GPU has no real use (a blip to a few percent here and there).

...

Transcoding to H.264 is totally different. CPU use is about 400% and there is 13-14% constant use of the GPU.

/Applications/Compressor.app/Contents/PlugIns/Compressor/CompressorKit.bundle/Contents/Frameworks/H264Encoder.framework/Versions/A/Frameworks/mch264enc.framework/Versions/8.0/mch264enc

THAT (single pass) encode is running 2X faster than real time; it finished in 7 min (which is even faster than QuickSync). Far faster than the old trashcan MacPro, and faster than my MacBook Pro. I will use H.264 then for 4K client deliverables. Forger HEVC.

I used the Apple devices 4K preset there. But when I tried changing it to a much higher bitrate and multipass H.264 (which QuickSync on other Macs doesn't accelerate), I saw about the same thing. The time was reduced from 7 to about 15 minutes, just about real (1:1) time.

I will attempt HEVC on my Kaby-Lake MacBook soon to see if it engages QuickSync there and how long it takes.

 

[Anonymous Freak]

VLC is horrible regardless. Just use IINA.

Yeah, stable builds of VLC just don't have *ANY* CPU/GPU specific optimizations. Go for the daily builds, or another player. The only thing I use VLC for anymore is playing extremely esoteric formats like ancient RealPlayer videos or the like.

 

[h9826790]

Those were my findings, on the iMac Pro. Yet look at this:

http://barefeats.com/imacpro_vs_pt4.html

He is showing fast speed using compressor to export Bruce to HEVC. I wonder what I am missing...

That's not fast as all, BruceX is just a 1.23 seconds long 23.98FPS video, and it cost the iMac Pro to use 71 seconds to encode. That means the encoding speed is 71/1.23/23.98 = 2.4FPS. Hardware encoding should be ~10x faster.

It's just because the power Xeon, make the encoding speed faster than other Mac.

 

[anticipate]

That's not fast as all, BruceX is just a 1.23 seconds long 23.98FPS video, and it cost the iMac Pro to use 71 seconds to encode. That means the encoding speed is 71/1.23/23.98 = 2.4FPS. Hardware encoding should be ~10x faster.

It's just because the power Xeon, make the encoding speed faster than other Mac.

I was very tired when I wrote this and I thought about it. You're right - that is very slow. But I am seeing slowdowns encoding HEVC way more than 10x. More like 20-30x slower than real time.

Of note - everything seems slow on his tests. It's just what degree of slowness we are talking about. Does Apple not HW accelerate HEVC encodes at all? The playback is, clearly (on iMP). H.264 encodes are (on iMP, MB, iMac)

 

[Trebuin]

I was very tired when I wrote this and I thought about it. You're right - that is very slow. But I am seeing slowdowns encoding HEVC way more than 10x. More like 20-30x slower than real time.

Of note - everything seems slow on his tests. It's just what degree of slowness we are talking about. Does Apple not HW accelerate HEVC encodes at all? The playback is, clearly (on iMP). H.264 encodes are (on iMP, MB, iMac)

If I recall from watching that test, no. Handbrake will not hardware encode x265 yet, but will x264 if it is set up correctly. There's two hardware encode options I've seen with handbrake, the one through the advanced settings tab to use openCL and the other using QS. QS is not a good hardware encode and only works with the the intel graphics chips...the xeons don't have this integration. I also played with 10bit and 12bit x265 last night and nothing with that other than slower encodes.

 

[h9826790]

If I recall from watching that test, no. Handbrake will not hardware encode x265 yet, but will x264 if it is set up correctly. There's two hardware encode options I've seen with handbrake, the one through the advanced settings tab to use openCL and the other using QS. QS is not a good hardware encode and only works with the the intel graphics chips...the xeons don't have this integration. I also played with 10bit and 12bit x265 last night and nothing with that other than slower encodes.

AFAIK, that OpenCL option is not really hardware "encoding". It just use OpenCL to look ahead (analysing), or resize the video (rendering) etc. In most case, it won't speed up anything, but may actually slow down the whole process a bit, or even crash.

QuickSync is actually using the hardware to encode. Very different in nature. And only QuickSync can really speed up the process (also relief the CPU).

 

[BeatCrazy]

I was very tired when I wrote this and I thought about it. You're right - that is very slow. But I am seeing slowdowns encoding HEVC way more than 10x. More like 20-30x slower than real time.

Of note - everything seems slow on his tests. It's just what degree of slowness we are talking about. Does Apple not HW accelerate HEVC encodes at all? The playback is, clearly (on iMP). H.264 encodes are (on iMP, MB, iMac)

Are you using Compressor 4.4 for the HEVC encode?

Did you get a chance to try with your 2017 MacBook yet? Mine is stuck somewhere between China and Dallas

Maybe there are no Macs that support hardware encode for 10-bit HEVC?

 

[CWallace]

IFixit thinks the T2 die size is too small to be a modified A10/A11.

The T2 chip would be handling significantly less functions than the A-Series in an iOS device so it stands to reason it's physical footprint would be smaller.

Also, just intuitively, the idea of handing off video encoding to the T2, which I understand is basically a customised iPhone 7's A10, would be like setting up a rack of smartphones to do Bitcoin mining. Yes, it could be done, but no, probably not the best tool for the job!

Assuming the T2 is doing encoding, it would be optimized for performing that task so it would be significantly better at it then a general-purpose device.

 

[EugW]

Are you using Compressor 4.4 for the HEVC encode?

Did you get a chance to try with your 2017 MacBook yet? Mine is stuck somewhere between China and Dallas

Maybe there are no Macs that support hardware encode for 10-bit HEVC?

There are no Macs that support hardware encode for 10-bit HEVC in QuickTime.

However, the Kaby Lake Macs with iGPUs do have the hardware to support it.

 

[BeatCrazy]

The T2 chip would be handling significantly less functions than the A-Series in an iOS device so it stands to reason it's physical footprint would be smaller.

Assuming the T2 is doing encoding, it would be optimized for performing that task so it would be significantly better at it then a general-purpose device.

As mentioned above the "image signal processor" capability of the T2 is related to the iSight camera functionality, which is why it's unlikely to be for encoding/decoding media files.

There are no Macs that support hardware encode for 10-bit HEVC in QuickTime.

However, the Kaby Lake Macs with iGPUs do have the hardware to support it.

Compressor 4.4 lets you pick between HEVC 8-bit and 10-bit 4K output. I tried on my Skylake MacBook Pro, and the 8-bit output encoded in near-real time, so obviously hardware accelerated. The 10-bit option looked like it was going to take 5+ hours for the same 60 second video, so I cancelled.

Later tonight, I'll try 10-bit HEVC encode on the iMac Pro. And when my 2017 MacBook shows up, I'll try 10-bit encode on there, as well.

 

[anticipate]

Are you using Compressor 4.4 for the HEVC encode?

Did you get a chance to try with your 2017 MacBook yet? Mine is stuck somewhere between China and Dallas

Maybe there are no Macs that support hardware encode for 10-bit HEVC?

I haven't tried the MB yet. I am using 4.4 Compressor...

I should add it doesn't allow 8 bit HEVC at all. Compressor says "unsupported"

 

[EugW]

Compressor 4.4 lets you pick between HEVC 8-bit and 10-bit 4K output. I tried on my Skylake MacBook Pro, and the 8-bit output encoded in near-real time, so obviously hardware accelerated. The 10-bit option looked like it was going to take 5+ hours for the same 60 second video, so I cancelled.

Skylake has no hardware 10-bit HEVC encode at all.
Kaby Lake has it (in the iGPU), but it's not supported on macOS (yet).

P.S. It's too bad we don't get hardware decode for VP9 on macOS.

Later tonight, I'll try 10-bit HEVC encode on the iMac Pro. And when my 2017 MacBook shows up, I'll try 10-bit encode on there, as well.

Let us know what happens, but I suspect it will still be painfully slow on the iMac Pro, but not quite as painfully slow as the Skylake MacBook Pro.

 

[Trebuin]

As mentioned above the "image signal processor" capability of the T2 is related to the iSight camera functionality, which is why it's unlikely to be for encoding/decoding media files.



Compressor 4.4 lets you pick between HEVC 8-bit and 10-bit 4K output. I tried on my Skylake MacBook Pro, and the 8-bit output encoded in near-real time, so obviously hardware accelerated. The 10-bit option looked like it was going to take 5+ hours for the same 60 second video, so I cancelled.

Later tonight, I'll try 10-bit HEVC encode on the iMac Pro. And when my 2017 MacBook shows up, I'll try 10-bit encode on there, as well.

Software and settings perform differently. Compressor is one of those that I hated because the settings were horrible. I can currently encode a 60 sec 4k video in about 60 seconds in 8 bit HEVC, and about 70-80 seconds in 10 Bit HEVC. Adjusting difference qualities can also make a significant difference: a can get that 4k 60 sec video transcoding at about 5fps vs the 30 average for my personal settings. The only way you really can tell if it's hardware encoding is from the GPU use through some sort of monitor. Also, for some reason, 10 bit goes through a two pass encode while 8 and 12 bit do not when using quality parameters.

 

[anticipate]

Software and settings perform differently. Compressor is one of those that I hated because the settings were horrible. I can currently encode a 60 sec 4k video in about 60 seconds in 8 bit HEVC, and about 70-80 seconds in 10 Bit HEVC.

Using what program/hardware?