Export result/settings seriously wrong!?

[Marcus_FPV]

Hi, when I export a videofile from Rush Windows 10-version this is the result below. Original file from camera is 3840x2160 90kbit/s 60fps 461Mb.

This is the exported results from Rush. Note that High and Medium result is the same:
Export setting High: 3840x2160 12kbit/s 60fps 58Mb (expected file size 394Mb)
Export setting Medium: 3840x2160 12kbit/s 60fps 58Mb (expected file size 394Mb)
Export setting Low: 3840x2160 45kbit/s 60fps 222Mb (expected file size 232Mb)
Export preset Youtube: 3840x2160 40kbit/s 60fps 197Mb (expected file size 204Mb)

Someone else experience this problem?

/Marcus

[Marcus_FPV]

I've done some more testing and the kbit/s and filesize are all over the place. The original file from camera is 3840x2160 90kbit/s 60fps 461Mb but strange things happen when converting to 30fps. Suddenly the medium setting increase in quality and file size compared to when exported in 60fps. The low settings on the other hand decreases in quality and file size. The high and Youtube preset almost stays the same. 

@Adobe you need to fix the export settings and also give us the possibility to choose kbit/s manually.

Export setting: Result

High: 3840x2160 12kbit/s 60fps 58Mb

High: 3840x2160 11kbit/s 30fps 55Mb
Medium: 3840x2160 12kbit/s 60fps 58Mb

Medium: 3840x2160 47kbit/s 30fps 237Mb
Low: 3840x2160 45kbit/s 60fps 222Mb

Low: 3840x2160 21kbit/s 30fps 110Mb
Youtube: 3840x2160 40kbit/s 60fps 197Mb

Youtube: 3840x2160 40kbit/s 30fps 200Mb

[Daneel]

I'm experiencing similar things, I also just posted about it. This is very confusing.

[Daneel]

I just found out something *very* interesting in this context. I just exported the same video file at the exactly same settings (4k@60fps at high bitrate) two times, once with hardware decoding/encoding acceleration activated in the settings and once without.

The results are:

With HW acceleration activated:
- Stream #0:0[0x1](eng): Video: h264 (High) (avc1 / 0x31637661), yuv420p(progressive), 3840x2160 [SAR 1:1 DAR 16:9], 49038 kb/s, 59.94 fps, 59.94 tbr, 60k tbn (default)

Without HW acceleration:
- Stream #0:1[0x1](eng): Video: h264 (High) (avc1 / 0x31637661), yuv420p(tv, bt709, progressive), 3840x2160, 113407 kb/s, 59.94 fps, 59.94 tbr, 60k tbn (default)

So as you can see, encoding *without* acceleration results in a more than 2x higher (!) bitrate than encoding *with* acceleration. Both exports use the same video codec (h.264). The version without HW acceleration also almost exactly corresponds to the calculated file size.

For me it seems that encoding with hardware acceleration seems to be buggy / resulting in a much less bitrate (and thus quality) than expected.

I think I will, for now, only encode with hardware acceleration deactivated, even if it takes longer, since I want to get the best quality before uploading to YT.

I do hope to hear back something from the Adobe team on this. This seems like a bug.

@Marcus_FPV - I'm pretty sure if you repeat your tests with HW acceleration off, you will get the real / correct file sizes. Maybe you want to give it a try.

[Marcus_FPV]

Thanks for your input! I'll give it a try and report back. 

[Daneel]

I just found out one more thing regarding this bug.

It only happens on my Surface Pro Laptop, not on my regular Desktop PC. On my regular Desktop PC the bitrate and corresponding file sizes are identical, no matter if HW acceleration is on or off. And they correspond to the estimation of the program. The difference here is that my Desktop PC has dedicated graphics (NVIDIA 1080), while my Surface Pro Laptop only has integrated graphics.

So this bug may be specific to computers with integrated graphics.

Maybe this helps the dev team when / if they try to reproduce this bug.

All the best, Michael

[Daneel]

... aaaand another update.

It seems Premiere Pro has the same issues with too low bitrate when using HW acceleration:
https://adobe-video.uservoice.com/forums/911233-premiere-pro/suggestions/44368392-issue-poor-hardwar...

In the case of the link above it is connected to Apple devices, but as we saw above it happens on Windows machines as well.

This unfortunately also means that Rush is unuseable for me on Tablets and Smartphones, since one cannot turn off HW acceleration there. So you will always get the low bitrate renders there, reducing the quality of your videos.

[Daneel]

My last one for today. Sorry for being so noisy about this today.

But I just researched this some more and it seems to be a well known problem, not only for Rush but for Premiere Pro as well, which has not been fixed since a long time.

Here is a video from 3 years ago about exactly this issues which we seem to have "rediscovered" now:
https://www.youtube.com/watch?v=DXWWJvuexqE&ab_channel=PugetSystems

For me that means no editing on mobiles / tablets and only using software encoding on PCs / Laptops in order to not reduce the quality of my videos.

[Marcus_FPV]

Ok, I've did a test using the high setting without hw acceleration and you're right. The bitrate and filesize are finally at the correct level compared to before. The downside is that a 40 sec clip took about 20min to render.