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Nemo1985
3rd December 2020, 20:18
Hello, my nas is strugling with space, so I needed to convert some of my files on hevc. I know it's not the best thing to do but still...
I'm using handbrake (v1.3.3), Qc 18, medium, h265 10 bit.
Everything is usually fine the output file is usually smaller up to 50%, usually around 30%, but there is one episode of house m.d. which has scenes in both bw and color during all the episode, this file no matter what it comes out bigger than the x264 file.
I also tried to reduce the bitrate of about 20% compared to the h264 file, use the 2 pass encoding but still it's insanely big.

Any suggestion about which settings can I use?
Thanks

benwaggoner
3rd December 2020, 20:53
Is it particularly grainy? Grain is really random noise, and the hardest thing for codec improvements to improve.

To make a grainy file smaller, I'd start by trying --preset slower and --nr-inter 250.

Nemo1985
4th December 2020, 06:39
Is it particularly grainy? Grain is really random noise, and the hardest thing for codec improvements to improve.

To make a grainy file smaller, I'd start by trying --preset slower and --nr-inter 250.

Thank you for the quick answer.
Here is an example of b\w and color image of the episode: https://imgur.com/a/s0bjuTZ

I have a stupid question probably, how can I put those settings on handbrake? Do I put the voices on advanced options text box?

Thanks

benwaggoner
5th December 2020, 01:06
Thank you for the quick answer.
Here is an example of b\w and color image of the episode: https://imgur.com/a/s0bjuTZ
Doesn't seem particularly grainy, although it's kind of hard to tell from a single image. How the grain moves frame-to-frame can be a bigger factor.

I have a stupid question probably, how can I put those settings on handbrake? Do I put the voices on advanced options text box?

Sorry, I don't use handbrake. I just pipe whatever into x265.exe.

RanmaCanada
10th December 2020, 15:21
If you're using QC that means you're using your video card to compress your files, and not your CPU. If it was your CPU it would be CRF. Hardware encoding is no where near as efficient as software encoding.

LoRd_MuldeR
10th December 2020, 19:52
@Nemo1985:

First of all, you have to understand that you can get any file size with any video format. It all depends on the rate-control mode and the selected bitrate! (or target CRF value)

For example, even old-school MPEG-2 can be smaller than AVC (H.264), if you just set the target bitrate of the MPEG-2 encoder accordingly ;)


Now, HEVC (H.265) is supposed to compress more efficiently than AVC (H.264), which means that with HEVC you should be able to retain a similar level of quality at lower bitrate (i.e. smaller file) than with AVC.

But, again, in no way HEVC is guaranteed to produce a lower bitrate (i.e. smaller file) than AVC.

If you want the HEVC file to be smaller than the AVC file, you have to select a target bitrate (or target CRF value) for the HEVC encode that actually results in a lower bitrate than that of the AVC file you are comparing to! :sly:


Last but not least: HEVC (H.265) compresses more efficiently than AVC (H.264), only if both formats are encoded from a clean original source, and only if a "good" encoder is used for both formats!

As RanmaCanada already mentioned, hardware encoders almost universally produce significant worse results – at the same bitrate – than the best available software encoders.

Therefore, if the AVC file was encoded by a "good" software encoder, whereas the HEVC file is encoded by some hardware encoder, then you may very well need a higher bitrate for the HEVC file to retain similar quality! :eek: