Export settings GoPro 4K HEVC videos

Help/How To
1

Hello,

I recently started using Shotcut (12.22.21) to edit my videos from my GoPro Hero7.
The original videos have the following properties 4K 50fps.

Video
Format : HEVC
Format/Info : High Efficiency Video Coding
Format-Profil : Main@L6@Main
Codec-ID : hvc1
Codec-ID/Info : High Efficiency Video Coding
Bitrate : 78,0 Mb/s
Breite : 3 840 Pixel
Höhe : 2 160 Pixel
Bildseitenverhältnis : 16:9
Modus der Bildwiederholungsrate : konstant
Bildwiederholungsrate : 50,000 FPS
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Bits/(Pixel*Frame) : 0.188
Titel : GoPro H.265
Color range : Full
Color primaries : BT.709
Transfer characteristics : BT.709
Matrix coefficients : BT.709
Codec configuration box : hvcC

Audio
Format : AAC LC
Format/Info : Advanced Audio Codec Low Complexity
Codec-ID : mp4a-40-2
Bitraten-Modus : konstant
Bitrate : 192 kb/s
nominale Bitrate : 48,0 kb/s
Kanäle : 2 Kanäle
Channel layout : L R
Samplingrate : 48,0 kHz
Bildwiederholungsrate : 46,875 FPS (1024 SPF)
Compression mode : Lossy
Titel : GoPro AAC

I would like to use the codec H.265 / HEVC “hevc_nvenc” with VBR.
But what quality, GOP, B-frames and code threads should I set?

I value good quality with small file size.
The quality for H.264 was once mentioned here as 55%.
The default setting is currently 45%.

Thank you!

Greetings Lutz

2

Cut a sample 30s clip of a random video and try different export settings, only you know what is the cutoff for quality vs filesize that would satisfy you.

Don’t touch GOP, b-frames and other advanced settings until you know you have a reason to.

But in general for x265 the quality factors is:

  • 65% (crf18) for very high quality,
  • 60% (crf20) for high quality,
  • 55% (crf23) for good quality but way smaller filesize
  • 50% (crf26) for less important stuff but still ok, basically phone-quality at this point
  • and I sometimes also use 45% (crf28) for archiving longer stuff that I don’t particularly want to keep but also don’t want to delete

Anything above 65% I personally don’t really think should be used unless you deal with studio quality or just want to upload and delete after. It’s simply better to just keep the originals.

3

Thank you very much for your quick and detailed answer.

Do you use “libx265” as codec?

I use “hevc_nvenc” as codec.
Thanks to the Nvidia graphics card the rendering is up to 10x faster.
But the quality parameter is different!

My original GoPro video has about 78MBit/s,

with codec “libx265” and 65% quality about 87MBit/s,
with codec “libx265” and 60% quality about 67MBit/s,
with codec “libx265” and 55% quality approx. 43MBit/s,

with codec “hevc_nvenc” and 55% quality approx. 81MBit/s,
with codec “hevc_nvenc” and 50% quality approx. 55MBit/s,
with codec “hevc_nvenc” and 45% quality approx. 42MBit/s.

My target will be about 65MBit/s and so I am at a quality of 51%!

4

I do always use libx265 as I target efficiency (and I just let the encode run in background on my pc) and only use GPU encoding for quick project testing or sometimes separately exporting a larger resolution for youtube.

For recent video cards you might find some sweet spot but in general libx265 will be better at compressing than nvenc (CPU is more efficient but slower, GPU is way faster but larger files).

5

I was not aware of this.
I had thought that the quality and compression of libx265 and nvenc are the same and only the graphics card makes it faster.
Since I am very concerned about the file size in addition to the video quality I will probably have to use libx265.
Too bad! :frowning:

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