H.265 taking up more space than H.264??

Woxter

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Jul 10, 2015
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Hi guys, I was just testing the new HEVC due to the 50% saving space claim factor. I tested my blu-ray X-Men Days of the future past (Theatrical), made 2 copies with DVD Fab 9.3.0.7 GPU Acceleration (GTX 970) with the following presets:

-Encoding method: Variable bitrate 1 Pass: Average Bitrate: 20500 Kbps
The output source was MKV and with the DTS-HD MA track.

H.265 file was 23.5 GB....took 14 minutes
H.264 file was 20.9 GB....took 7 minutes

So...what the hell is going on here...I tried the same with CRF (16) and the result was H.265= 24 GB and H.264 = 26 GB
 

Woxter

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Jul 10, 2015
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Yes I thought about that..but my i7 4790K has trouble encoding HEVC..takes about 5 hours at best to encode a 30 GB file because Handbrake doesn't support GPU Accel such as CUDA or Open GL and my GTX 970 encodes a 30 GB file in 15 minutes...and I can use the PC while it does that..with Handbrake it's only CPU and getting 80 degrees for 5 hours on the CPU in Spain during July is not the best idea not only for the PC but because my own sake, here it's already 35-40 degrees hahah.
I'll try and cut about 500 MB and do a test sample and I'll post the results in case anyone is experiencing the same issues as me
 

robert600

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I just tried using dvdFab to do a H265 encode using CPU only - it was a disaster lol.

Here's a link to "How to Encode HEVC: Utilizing Nvidia GPU Hardware Acceleration" that might be good for you. I think the programs are all freeware. I'd be interested to hear how you make out as I'm tempted by those video cards if they actually work.

http://www.techspot.com/article/1131-hevc-h256-enconding-playback/page5.html
 

Woxter

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Thanks everyone, I just came back from erasmus a few days ago, I tried the software robert600 linked, it's really good! The only drawback is that in a 100" screen you can see the diference between that Staxrip (CQP) and DVDFab (CRF), no really a big issue since it's barely noticable, not even on my 65" HDR TV. I also tested CPU encoding...I could not tell the diference whatsoever from GPU to CPU, same file size, same quality on my friends 100" Proyector and my 65" TV.

I upgraded to a GTX 1070, now everything works fine, it seems it was also a bug from DVD Fab that is now fixed. For my surprise, Staxrip can enable 10 bit HEVC encoding using NVENC GPU Acceleration, so it works with my GTX 1070, I tried testing and I got around 240 fps encode time, the color depth was from an 8 bit source, it improves things, as it looks a bit sharper, but it's no big deal, I will continue with 8 bit HEVC.

I did more testing and finally got it working. I took Angels and Demons Mastered in 4K Disc and I made 2 copies at CRF 20 using CUDA on DVD Fab.

-H.264 File: 12,3 GB Encoding average speed: 515 fps took about 5.5-6 Minutes
-H.265 File: 9,85 GB Encoding average speed: 400 fps (That's a beast compared even to the i7-7700K which does it in 16 fps) took about 7-8 minutes.

As I mentioned before, I did a 10 bit H.265 at 240 fps, but it didn't look much better, just a little bit (size was also 9,85 GB). The 8 bit H.265 file obviously looked better than the H.264, here the difference was much more instant than 8 vs 10 bit HEVC. I also tried to compress even more the H.265 file to see when it would start to look similar to the H.264 and it was at CRF 23-24 somewhere around there the quality was the same as H.264 or at least very similar, but size came down to 5,44 GB, and with a DTS-HD MA 5.1 track included...that's seriously unbelievable.

Conclusion: Only encode in HEVC 10 bit when the source is 10 bit, as the quality is barely noticable from 8 bit and the encode speed is much slower (a bit less than half).

Here H.265 leaves you with 2 choices depending on your needs:

-1: Achieve the exact same quality of an AVC file by saving half the file size (50% savings)
-2: Whatever preset is used in AVC, will have much better Quality in HEVC and will also save you a bit of space (about 20%)

 

robert600

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wow - that is amazing! thanks for posting that info!
thinking of the angels and demons mastered in 4k - what size is it on the disk? - squeezing it down to 9.85 (@ 400 fps with DTS MA 5.1) in 8 mins sounds absolutely fantastic!
a GTX 1070 is now on the top of my 'wishlist' lol
 

Woxter

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Jul 10, 2015
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If you're talking about the movie itself uncompressed it's about 35 GB only english DTS-HD MA 5.1 in H.264 of course.
I would recommend the GTX 1070, really cheap for what it can offer and so far no problems with it, very happy.
 

Woxter

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Jul 10, 2015
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Yes and no, I mean, I don't know if my GTX 1070 supports 2-Pass Encoding, if so I would like to know how do I do it. I compared a sample with my X-Men Apocalypse Blu-ray. I wanted an "extreme" low bitrate so I set it to 500 Kbps at 1080p, the result was obvious H.265 looked better than H.264 with a 2-Pass, but the H.264 2-Pass looked just a little bit better than the H.265 with the GTX 1070 1Pass. So it does look better with a 2-Pass although I did it with Handbrake, it's also not worth it 500 Kbps because the sample was 152 MB and the 1 Mbps sample (I'll test that later) is 165 MB (Double Bitrate but takes up just 8% more space so 1 Mbps is better)

The thing I have to try is CRF and CQP vs 2-Pass I think that would be a fair test and since GPU support CRF and CQP then I could compare that vs 2-Pass CPU (takes ages with my i7 4790K at H.265)
 

Woxter

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Jul 10, 2015
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If you're talking about the "VBR2" it's not that, it's the closest thing, but that is what I used for comparing 1Pass vs 2Pass (I used that as 1Pass) the quality was still better in 2-Pass CPU and I just looked at a CQP and CRF encode with similar filesize and the quality was also much better than on 1-Pass (CRF and CQP was done with the same GPU than 1-Pass)