Identify a problem with youtube quality

tom-kristoffersen wrote on 10/29/2017, 6:53 AM

On you tube i have created a video. It was recorded with different cams and different fps.
Main cam was set to 1080 with 50 fps. Gopro 6 cam was filmed with 1080 and 100fps.
Converted to avchd with 50 fps. I am using magix movie edit pro 2017.

Here is the movie:

At around 5 minute you can see the image suddenly gets alot worser.

However, some clips taken which has the same format, is looking good.If you
compare with the clips at around 13.25(its not perfekt but ok).

Any idea why this is happening? I compared it with the original movie before
uploading to you tube.The original is either not perfect at 5 minutes, you can see there is
some different, but not as bad as it is on youtube.

I took the clip at around 5 minute and increased the bitrate, converted it and
uploaded it to youtube to see if that was the problem but didnt help. The result was the same.

Comments

johnebaker wrote on 10/29/2017, 12:12 PM

The video is suffering from compression artefacts which are worse when there is movement and fine detail in the video eg the trees to the side of the track.

I downloaded the FUll HD mp4 and ran it through MediaInfo and compared the results to a Full HD video used on a website and on YouTube.

The significant differences are in the video bitrates:-

Your video from YT - video bitrate 4.60 Mb/s for 50 fps

My video from YT - video bitrate 3.13 Mb/s for 25 fps

My video on website - video bitrate 41.6 Mb/s for 25 fps

As you can see the bitrate of my video on YT is significantly lower than the same video on another website. Your video also shows the same reduction in bitrate

YT is applying a lot of compression on the videos, also YT will down scale the video to lower resolutions and bit rates depending on the viewers Internet connection speed - and there is little you can do to control either of these problems.

HTH

John EB

tom-kristoffersen wrote on 10/29/2017, 12:45 PM

Thanks for your answer. I had a suspect that this was a YT problem.

Here is what i am thinking: Will it help to increase the resolution on the movie? I am considering using
2.7k with 50 fps on my gopro6 instead of 1080. Then convert it to 1080p.Will that be helping?

johnebaker wrote on 10/29/2017, 1:45 PM

Without testing, my instinct tells me that YT will reduce the 2.7k video to 1080p and still create the issue with compression.

HTH

John EB

tom-kristoffersen wrote on 10/29/2017, 2:06 PM

ah ok, maybe vimeo next then for me:)

Scenestealer wrote on 10/29/2017, 4:49 PM

I am considering using
2.7k with 50 fps on my gopro6 instead of 1080. Then convert it to 1080p.Will that be helping?

I don't quite understand - isn't the reason you shot 100fps because you wanted a slomo effect on playback? Anyway it will still only be 50fps on your exported file and it might be worth exporting the movie at 25fps for upload to YT because with fewer frames the individual frames should be compressed less for the same bitrate.

Also might be worth exporting to 720p instead of 1080 in the hopes that with less data YT may compress it less.