Deinterlacing for YouTube

[AnthonyGA]

I have been using X4 to prepare videos in HD for YouTube, and it seems to be working just fine. The input files are from a Sony Handycam and are 1080/50i. I haven't figured out how to control the output format in order to ensure the best quality (the documentation is spotty), but I've determined through trial and error that selecting "same format as first video clip" gives excellent results.

There's only one problem: since the output file is also 1080/50i, when it is uploaded to YouTube, it gets forced to 1080/30p. My guess is that YouTube imposes an upper limit of 30 fps, and it sees the 50i and decides that it will convert to 30, which is the maximum it allows. YouTube doesn't seem to realize that the video will be 25p after deinterlacing. So it creates a 30p video that stutters with fast-moving objects because every fifth frame is duped.

So my question is: is there a way to create output files in exactly the same format as input clip files, only deinterlaced, so that I have a 25p file to upload instead of a 50i file? That way YouTube might not try to convert to 30 fps and just leave it at 25, which would eliminate the stuttering.

Also, how can I ensure that my output files retain the greatest quality from the original input files? I've tried all sorts of things, and it seems that just about every output option results in a substantial loss of quality except for "keep format the same as the first video clip," which works well.

[Trevor Andrew]

Hi

You could try Make Movie Templates Manager.
Using the ADD function would create a template to your video files properties.
Then edit the template to use 25 Frame Based.

It is possible that this option is not available using your frame size, but worth a look.
I assume its 1920 x 1080

Then try creating a template to Mpeg4 H264 again using HD sizes
Maybe 1280 x 720 x 25

[AnthonyGA]

Thanks for the suggestion. I tried it, but it looks like I can't get 1920x1080 and frame-based at the same time.

Maybe I'll just let it slide. It's really a problem with YouTube to some extent, since it should not be forcing 30 fps when it deinterlaces. If it just left the video at 25 fps after deinterlacing, everything would be fine.

I admit that I'm totally bewildered as to how to control output formats in Video Studio, and the documentation isn't very detailed. It still seems that if I select "use same format as first video clip," that produces the best output results (apart from the 50i, which in itself wouldn't necessarily be a problem if YouTube didn't process it inappropriately).

[Black Lab]

According to YouTube they recommend you upload your video as close to the original properties as possible. That they are then converting it is out of your hands.

[Trevor Andrew]

Hi Anthony

Being in Pal country we do tend to have problems when it comes to frame rates, YouTube may default to Ntsc standards and 30 fps.
Where problems exist with uploading the original HD files You Tube recommend converting to Mpeg 4, unfortunately the standard VS MP4 template uses 30 fps so a manual approach has to be adopted.

If only we were in NTSC country we wouldn’t have a problem.

You can however convert your video to Mov using MPEG 4 compressor and use 25 fps frame based. As below

QuickTime Movie Files
24 bits, 1920 x 1080, 25 fps
Frame-based
MPEG 4 Visual
50% Quality, 24 Key Frame Rate
None, 8.000 KHz, 16 bits, Stereo

You could try AVI Mpeg4

Microsoft AVI files
24 bits, 1920 x 1080, 25 fps
Frame-based
Microsoft MPEG-4 Video Codec V1
PCM, 48.000 kHz, 16 Bit, Stereo

Both templates created by using the Make Movie Templates Manager
Use “User Defined” option to set the frame size.
I tend to use 1280 x 720 as the frame size

My template would use:-

QuickTime Movie Files
24 bits, 1280 x 720, 25 fps
Frame-based
MPEG 4 Visual
50% Quality, 24 Key Frame Rate
None, 8.000 KHz, 16 bits, Stereo

[AnthonyGA]

Hmm, well, I tried the template you suggest for QuickTime, and the quality is terrible.

I tried the AVI with Video 1, but Video Studio crashes at the end of the rendering.

Some of the other codecs look promising, but they take a really long time to render, and I haven't verified that YouTube will accept them.

I guess I'll still hold off for now. The image quality is more important than conversion to 25p. I'll have to continue experimenting to see if I can get conversion to 25p with no loss in quality (and without waiting all day for it to render).

[Ron P.]

Maybe YouTube should be confronted with this problem, since it appears that YouTube is forcing the 30fps in it's conversion, or as you say using the NTSC specs. However if that's the case, does YouTube do the same for SD PAL video, or does it convert it and retain the 25fps? If it does not retain the 25fps, it would be YouTube's issue not Corel, or any other NLE's for that matter.

[Trevor Andrew]

Hi Ron

I do not know what you tube does to the uploaded files, but assume they re-code, i thought to Flash????????
I just don’t know how to select the properties once they are uploaded

Video Studio tends to use 30 fps for its default MP4 template. (Create Video File-Mpeg4-HD) Even though we install the program for Pal.

So I revert to Make Movie Templates Manager.

However I have just looked at the Upload to Web-YouTube MP4 and it does use 25 fps.
I suggested some convert settings but Anthony seems to be having problems with them, which surprised me. Is there an inherent problem with the video given that upload to YouTube also had quality issues?

Anthony
maybe you can try the Create Video File- Upload to Web-YouTube MP4
and
The AVI option I suggested used MPEG4 compression not Video 1

[AnthonyGA]

It's fundamentally a YouTube problem; I'm just trying to find a workaround. YouTube is very mysterious (even more so than Corel, it seems) and almost never responds to suggestions, feedback, or bug reports directly. I have tried to bring it to their attention.

Ideally YouTube should just deinterlace but leave the frame rate the same. It appears that 50i is seen by YouTube as surpassing the 30 fps limit that it imposes on videos, so it forces the video to 30 fps after deinterlacing. The problem (if I've understood what it's doing correctly) is that it should deinterlace first, then check to see if it's over 30 fps. That way 50i would be deinterlaced to 25p and would stay 25p on YouTube's servers. But that's not happening, so I'm trying to find a way around it, since I know that YouTube stores some videos at 25p.

I haven't tried the Web thing; maybe I'll try that next.

[erdna]

Suppose YT would convert to 25p, what do you think your PC monitor would do...still play it back at 60 fps. Computers have been "invented" in the USA and do not know 50 fps. So Pal people, including myself have to live with the 1 out of 5 dupe...

[AnthonyGA]

You would think so, but when I play 50i on my monitor (which is set to 60 Hz), I don't see any judder at all, and yet the judder is obvious when I play back YouTube video. If I download a video from YouTube and examine it frame by frame, every fifth frame is repeated. For whatever reasons, the YouTube video shows obvious judder even though the original 1080/50i does not.

[erdna]

I think I reported this before, but YT "HD" does more than just repeat frames to create 60p...it also deinterlaces by taking only one field (540 lines) out of two, and line doubles it to become a 1080 progessive mode. So the content refrech equals a 25p shot. If with this potentially juddery movie (filmlook!) they also repeat an already motion resolution crippled frame, and you get what you see.
Edit: as can be understood, also the vertical resolution is halved in the YT "HD" concept