Main Concept H.264 Issues with 23.976

[Larry Little]

I agree that this difference shouldn’t be noticeable, but there is something about the way that Sorenson is removing frames that adds a slight jitter to the video.

Ah — now THAT I can understand seeing! I totally misunderstood what you were saying. I thought you were saying that it’s simply playing the same number of frames at a slightly slower speed — i.e. that the entire movie takes just a tad longer to complete. You’re saying, however, that it’s actually DROPPING frames in order to “convert” the original framerate to 23.952fps.

Yes — that’s definitely something you could see since missing frames can be quite noticeable.

If Sorenson needs a better test to demonstrate what’s happening, just give them something with timecode burn-in, or perhaps some sort of leader with even movement in it, so they can actually see the number sequence skipping over frames.

Please keep us posted on what happens,

Larry

[Andrew Saliga]

Sorry, this has kind of been lingering. It came to my mind again today when I encountered this issue again.

Six different 30 second commercials, all 1080p, 29.97, ProResHQ. Without rhyme or reason, 3 of the 6 defaulted to various odd framerates. I had thought at time it was when using the MC H.264 encoder on content with audio and encoding with B-frames, but it seems that it’s not so predictable.

The latest I’ve from Sorenson is a major update coming out in June or July.

-Andrew Saliga

Steelehouse Productions
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