Export Times: HEVC vs Web presets
I just about fell out of my chair. I have a 1 hour-long video to export and always use the WEB-HIGH preset. I thought I would try this new fangled HEVC and WOW! 12 HOURS (NOT A TYPO) was the time for the export! I let it run for about 10min to let it settle down because it started out at 20 hours then seemed to get nestled in at 12 hrs. I switched it to Web-High and changed to use the Hardware Accelerations Apple 264 option and dropped it to 11 MINUTES!!! Has anywho who has done a complete HEVC export noticed the time being that dramatically ling compared to the h264? If it takes that much longer.. is.it.worth.it?!?
Only some very recent Macs are designed to support HEVC in hardware. On my 8 core iMac Pro with Vega 64 GPU I did a full Retina screen capture for 1 minute and used HEVC scaling to 1920x1080 and it exported in 13 seconds. Without a Mac that supports HEVC encoding in hardware, software HEVC encoding is extremely slow.Reply
See this article as one example.
Newer Macs, including the late 2015 27-inch 5K iMac, the 2017 21-inch iMac, and MacBooks and MacBook Pros from 2016 and 2017, will support hardware acceleration for coding and decoding HEVC video. The Kaby Lake chips in the 2017 laptops also support HEVC decoding. Hardware acceleration means faster encoding times in pro apps like Final Cut and Motion, and longer battery life when you're playing back HEVC video.Reply
I have a new i7 Mac mini on the way that supports HEVC... yay!
But, what happens to the compatibility of the resulting export?
I’m guessing it would need to be converted again for most uses? Is this just mainly (for now) a better *compressed* version for storage (if you don’t want to save the original)? What do you do with it?Reply
Steve Wilkinson said:
I’m guessing it would need to be converted again for most uses?
It depends. Recent computers do better decoding HEVC than older computers. I'm not sure if that's "most uses."
Steve Wilkinson said:
Is this just mainly (for now) a better *compressed* version for storage (if you don’t want to save the original)? What do you do with it?
It's used like H.264. In the early days of H.264 some computers handled it better than others. Just a new more efficient codec which can be either smaller files or better quality depending on how it's used.Reply
CraigS Cool, thanks. I did a bit more research... I was mainly wondering how widely it is supported. It looks like YouTube, for example, supports it. So, if I'm understanding correctly, we could export as HEVC and upload that to YouTube to save some time? I think YouTube ends up re-encoding it anyway to different resolutions (and their own codec/format).
It was mainly a 'how useful is this HEVC / H.265 stuff right now' kind of question. :)Reply
Steve Wilkinson HEVC generally saves file size or improves quality. I don't see it as something that saves times except a smaller file will upload faster. If you have a computer that can handle the encode through hardware as some of the newest Macs can then it may be worth using.
It's really useful when smaller file size or higher quality at a given bit rate is important.Reply
CraigS Just to follow up... pretty incredible gains from the bit of testing I've done so far. The other nice thing is that since it is using the T2 (not CPUs) as much, it also doesn't run the machine as hard.
Stuff that used to take like 45 minutes or an hour+ on my MacBook Air to prep for YouTube 1080p (admittedly, a slower machine) now just takes like 10-15 minutes on my i7 mini.
I need to do more projects in ScreenFlow to get a better feel on the numbers. This was also working with 'Retina' footage my son accidentally recorded on his MacBook Pro without switching screen rez, so like 2080 x 1800 source rez.
I had to just export an H.265 file and then manually upload it to YouTube, but that worked well and wasn't much harder. It worked fine with YouTube, so I think that is my new workflow (until ScreenFlow adds H.265 into the YouTube upload?).
But, I also rip BluRays and convert them with Handbrake, and when I got the setting right there, my jaw dropped. I can convert a MKV from a BluRay to a 1080p H.265 M4V with as good or better quality (and much smaller file size) as I used to with H.264, at less than 10 minutes per hour of movie. (With Turbo Boost turned off, and very little to no fan noise.)
More testing would probably be necessary against more apples to apples machines (ie: similar pre-HEVC CPU vs HEVC CPU), but my impression at this point would be that if you do a lot of this kind of work, it might be worth getting a new model just for H.265 export time savings.Reply
CraigS OK, so I put some numbers to this, for anyone interested. I haven't done a huge project yet, but I would expect the results to be similar in proportion. Also, this is a ~15 minute project being exported at 1080p. I'm not sure what impact working at other resolutions would have, but from what I've read, the difference in processing time to encode with h.264 vs h.265 gets even wider the higher the resolution.
Anyway, first I tested with Turbo Boost off on my 2018 Mac mini i7 (6-core). I use a utility called Turbo Boost Switcher to turn it on/off. (cf. https://www.rugarciap.com ) The reason, as you'll see, is that Turbo Boost doesn't make a massive difference, but it sure does make the mini noisy! So, I mostly run with it off as I prefer quiet.
No Turbo Boost
h.264 'Normal' settings = 9 min 15 sec (file size 662 MB)
h.265 default 3kbps, 256 AAC = 2 min 55 sec (file size 339 MB)
h.265 6kbps, 128 AAC (to match h.264 settings) = 2 min 59 sec (file size 659 MB)
h.264 'normal' settings = 8 min 32 sec
h.265 default (as above) = 2 min 55 sec
I'm having a hard time telling the quality difference between them. There may be some. The source footage is some of my son's Minecraft play from the PS4, so not the best thing to check for detail or color, etc. I'm not that great at distinguishing video quality either. But, as you can see, with HEVC, even if you crank the quality up, it doesn't impact the time that much.
But, that's some serious time savings, plus the fans hardly run. And, at least so far, I'm happy with the quality so it save space/upload-time. Pretty hard not to like unless I discover some quality issue I don't like with higher quality source footage (but I don't anticipate that).Reply