YT slow playback speed

[erdna]

Since quite some time I have been succesfully uploading FullHD (AVCHD 1920x1080 50i) movies on YT. Some weeks ago I got a strange playback problem with my last uploads: video's are played in (very smooth!) slow motion mode at some resolution settings. The same Divx video's on the contrary always playback OK
In order to illustrate the YT playback speed problems I uploaded two times the same 10sec video. The first video has been rendered as a fullHD AVCHD video in VSX4 (never got problems in the past with similar video’s), the second is a fullHD DviX version of that same video (from another converter). The lower resolution settings in the AVCHD video slow down while the 720 and 1080 settings run OK
http://www.youtube.com/watch?v=XhXaC_lTIdQthe
http://www.youtube.com/watch?v=2UI_RMlrIao
Somebody else got a simular problem?

[lata]

Hi

It may be an interlacing issue,

YouTube prefer you to use/upload frame based / NON – Interlaced video.

Div X is not interlaced so should play ok

Your video file is Interlaced, --50i --I have no idea why you are having problems now if the same types worked before.

You Tube as far as I know convert your uploads before playing them, it will be this conversion that is causing the problem. If they convert 50i to 50p they may have effectively doubled the number of frames increasing the time to 20 seconds.

http://support.google.com/youtube/bin/s ... e=guide.cs

I would suggest you only upload Non-Interlaced video

[erdna]

Thanks Trevor for your reply. Yes, ik know YT prefers progressive, bit it all worked before with my interlaced AVCHD files.
I think I now found the culprit: Some weeks ago I installed a free ‘up to date’ K-lite codec pack, which I suppose took over the codecs which came along with VS.
The reason I strongly suspect this codec pack, is because after uninstalling it on my desktop and re rendering the same scene (as AVCHD interlaced) there were no speed problems anymore. Also on my laptop I re installed VSX4 (still with K-lite on board) and the problem was gone also. I suppose VS forced again its own codec.
And indeed YT de-interlaces, and for the 50Hz video world also converts to 60Hz. I did quite some test on that de-interlacing on 50Hz fullHD…During a certain period they de interlaced by line doubling (verticalresolution loss). Somewhat later they did not de-interlace for some weeks. Since several months they de-interlace again (by line doubling)
Plse find hereunder some test results
1, a 50p fullhd testpattern as a reference (see line-on line off for vert resolution and de interlacing )
http://www.youtube.com/watch?v=zOAu89aWL2Y
2.what YT did in the beginning (line doubling)
http://www.youtube.com/watch?v=DVDo5IHZoSE
3. what YT did later on (full vertical res)
http://www.youtube.com/watch?v=j3UWhNOsADU
4. what YT does today (line doubling)
http://www.youtube.com/watch?v=P7MhkXg6ED8
5. FYI: interlaced AVCHD playback speed test render without K-lite
http://www.youtube.com/watch?v=i_TMj7oLsfs