Encoding 4K videos

I have been playing recently with both the Panasonic LX100 and the Sony RX100 IV

Both cameras shoot 8 bit 100 Mbps H264 video files. The panasonic codec appears more advanced but the video settings are pretty basic so most of the detail is lost.

Anyway I uploaded some sample files converted to prores and then coded them in H265, the resulting files are pretty small and have outstanding quality at 25 Mbps when I play them on Minix.

However when I tried to upload to youtube I got an error as H265/HEVC is not supported.

Has anyone found a (mac) application that can encode VP9? No product that I have supports it and encoding back to H264 means loosing lots of information from 100 -> 32 mbps?

It seems like the whole 4K situation is pretty undeveloped and the resulting files in 1080p look worse than my old HD encodes??

How about FFmpeg?

Yes I had not thought about command line tools. I will give it a go

The panasonic codec appears more advanced but the video settings are pretty basic so most of the detail is lost.

 

Isn't that statement a contradiction in itself?

 

Isn't that statement a contradiction in itself?

Video coding compresses what is available

So Panasonic has a worse starting point but compresses it very well so for example motion artefacts are less and preserves what is in the picture

Sony has a better starting point but compresses it less effectively so there will be possible artefacts depending on the scene

H264 is based on temporal compression and prediction this is what the codec does

libvpx-vp9 seems pretty amazing, with 20Mbps it can transcode my 4K Gopro Hero 4 footage very well.

I have been using hevc at 25 Mbps and the quality is excellent however YouTube doesn't support it. I need to figure out how my minix performs with vp9 and if hardware acceleration is supported

Premiere CC now support H.265:

http://www.eoshd.com/2015/12/tried-and-tested-premiere-cc-now-supports-h-265-natively/

No the video settings have to do with exposure color contrast etc

Video coding compresses what is available

So Panasonic has a worse starting point but compresses it very well so for example motion artefacts are less and preserves what is in the picture

Sony has a better starting point but compresses it less effectively so there will be possible artefacts depending on the scene

H264 is based on temporal compression and prediction this is what the codec does

ok, got it :-) Thanks

So I have tried encoding a webm file with Ffmpeg and it crashes all the time when I use two pass constrained quality. I am going to try with max bit rate only. Frank what encoding settings do you use? Also Ffmpeg vp9 is much slower than h265 on OS X

So I have tried encoding a webm file with Ffmpeg and it crashes all the time when I use two pass constrained quality. I am going to try with max bit rate only. Frank what encoding settings do you use? Also Ffmpeg vp9 is much slower than h265 on OS X

I followed this webpage and used constant bitrate of 20M

https://trac.ffmpeg.org/wiki/Encode/VP9

That's the only one that works but constant bitrate is outdated

That's the only one that works but constant bitrate is outdated

I have tried lossless, constant quality and variable bitrate and they all worked very well. May I know which one doesn't work for you? With -threads 12 I could encode 4K H.264 into VP9 webm at quite a high speed.

I am starting from Prores 422 with CRF=20 tile-columns 2 threads 4 multi-parallel 0

other settings are default (speed = 1) and it works at 0.2 fps

The encoder crashes entirely using two pass

I have a quad core i7 so best performance is with 4 threads (I have tested it on the encoder)

the multi thread works with

tile-colums 1 thread 2

tile-colums 2 thread 4

tile-colums 3 thread 8

...

tile-column 6 thread 64

in essence thread is max 2 to the power of tile-column

On a quad-core encoding speed drops when number of threads > number of cores

If I change the speed to 2 up to 4 it goes faster but quality drops

ffmpeg -y -i "input.mp4" -c:v libvpx-vp9 -pass 1 -crf 25 -b:v 0 -threads 4 -tile-columns 0 -frame-parallel 0 -auto-alt-ref 1 -lag-in-frames 25 -an -f webm /null

ffmpeg -i "input.mp4" -c:v libvpx-vp9 -pass 2 -crf 25 -b:v 0 -threads 4 -auto-alt-ref 1 -lag-in-frames 25 -c:a opus -b:a 64k -f webm "output.webm"

I tried the above codes successfully, but the output is just a bit smaller than the input H.264 4K file.

I think the strings you use are not correct. For two pass you would not use CRF and the tile-columns set to zero means single thread.

I have used the following for single pass and gives a compression of 4 times the H264 however I start from prores not from an already compressed file. I can post the correct commands for two pass however I get an exception all the time

ffmpeg -i Desktop/peter.mov -c:v libvpx-vp9 -b:v 0 -crf 24 -tile-columns 3 -threads 8 -frame-parallel 0 -b:a 384k Desktop/peter2.webm

The vp9 is terribly slow compared to HEVC and travels at 0.1 fps on my 3.4 Ghz quad core i7 that otherwise is very fast

After various tests I have decided that Vp9 is not worth the effort as youtune re-encodes anything you throw at it in H264 too