24P Compression for YouTube?

M

Milwalk

New member
I shot this video on a DVX100B in both 24P and 60i. I exported from FCE using H264 as a quicktime with an automatic data rate, Best Quality preset, current frame rate, 768x576 dimensions (native is listed as 557x417), and key frames every 24 frames. Here's the video:

http://www.youtube.com/watch?v=br3-Z-t9vHU

As you can see, there are horizontal lines on the video during quick motion in all scenes shot in 24p. This artifacting doesn't occur in the source footage or in the Quicktime export or after the video has been encoded as an FLV for Brightcove. It only occurs on YouTube, in both normal and high quality.

Has anyone else addressed this problem? I've troubleshooted for weeks, trying different combinations of MOV and MP4, changing the data rate, and key frames. Anyone have any suggestions? I'd appreciate any insight.

Cheers,
Rakesh
 
had the same problem a few days back.
got advice from C2V. let me past his quote, very good information!
C2V said:
When 24p goes to tape in a DVX, it is written at 29.97, and will have interlaced frames in the cadence: http://www.adamwilt.com/24p/index.html#24pRecording

These frames will not be as noticeable on the camera's LCD, and you may or may not notice it in FCE. They certainly won't be noticeable on a traditional, interlaced CRT monitor. But once you edit and export, and start playing on any progressive monitor, you'll see those interlaced frames jump out at you.

The only way to edit your 24p footage as 24p is to remove the pull-down upon capture and edit it in a 23.98 time line. Once you're done, you have to export it at 23.98.

The bad news is that, as you already know, FCE is not capable of any of this. It can only work with video at 29.97, which means that you're stuck with the interlaced frames in your 24p footage. Furthermore, there's really no good/easy/desirable way to remove the pull-down after the fact from an edited piece.

Wish I had better news for you.
Click to expand...
 
24P plays fine in Brightcove, Facebook but not YouTube

24P plays fine in Brightcove, Facebook but not YouTube

But why then don't the horizontal lines show when the video is compressed into an FLV and shown through Brightcove player or Facebook?

http://men.style.com/video/from-details/

The compressed MOV and MP4 play fine in Quicktime on my desktop. It's only after YouTube compression that the lines appear.

This leads me to believe there is something I can change in the export settings within FCE to make the final output file more amenable to YouTube compression, specifically, since the video plays without those horizontal lines in other Flash based players.
 
Also, isn't 24P actually 29.97 while 24PA is 23.98? Isn't that the fundamental difference between the two shooting options?

Thank you so much for the earlier response, by the way. Forgot to include that in the previous post. Any and all insight is greatly appreciated.
 
First, it looks as though the video at men.style.com is too small for you to see interlacing on it: since interlacing affects every other row of the 480 rows, if you don't display more than half the rows you won't see any interlacing.

As for 24P vs 24PA, both are 23.98 progressive frames per second encoded into a 29.97 interlaced data stream. The difference is in how they are encoded, with 24PA being encoded in a way that is slightly easier to decode, and that results in a slightly higher quality image. The 24P encoding should look slightly smoother before pulldown removal.

Since you cannot do pulldown removal with FCE, you might as well stick with 24P. (However, if you think you might some day upgrade to FCP and remove pulldown on the footage you are shooting, you might think about shooting 24PA.)
 
You just need to de-interlace it. I don't know about the artifacting.
Milwalk said:
I shot this video on a DVX100B in both 24P and 60i. I exported from FCE using H264 as a quicktime with an automatic data rate, Best Quality preset, current frame rate, 768x576 dimensions (native is listed as 557x417), and key frames every 24 frames. Here's the video:

http://www.youtube.com/watch?v=br3-Z-t9vHU

As you can see, there are horizontal lines on the video during quick motion in all scenes shot in 24p. This artifacting doesn't occur in the source footage or in the Quicktime export or after the video has been encoded as an FLV for Brightcove. It only occurs on YouTube, in both normal and high quality.

Has anyone else addressed this problem? I've troubleshooted for weeks, trying different combinations of MOV and MP4, changing the data rate, and key frames. Anyone have any suggestions? I'd appreciate any insight.

Cheers,
Rakesh
Click to expand...
 
I would agree with Andy that deinterlacing might solve the problem, though not necessarily. It's worth a shot though.

When you export from FCE, in the frame size settings does it give you the option to deinterlace?

Great video by the way. The lyrics were hilarious. I hope you get a good following on youtube and make some top dollar out of it.
 
Last edited:
Excellent vid. Saw it twice in a row and that doesn't happen much. Well written lyrics. It's gonna be big.
 
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