Smoother playback of full-motion video

Is kJams missing a feature you need? Post it here! Note: if iTunes has it but kJams doesn't, it's a good bet kJams will have it, but that I just haven't gotten around to it yet. But go ahead and request it anyway!
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El Ramos
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Smoother playback of full-motion video

Post by El Ramos »

First, great work on kJams, Dave! I'm grateful for a Mac-based karaoke solution.

I've encoded a few of my own full-motion, full resolution karaoke videos from laserdisc for use in kJams. Problem is, the video playback is pretty choppy, even when the rest of the interface is idle. Playback in QuickTime Player is 100% smooth though, so I'm pretty sure my computer has sufficient horsepower (I'm on a MacBook.)

The files are 640x480 MP4-encoded video with MP3-encoded audio. Total data rate is 4Mb/sec. (about 3/4ths the data rate of a DVD). Everything's wrapped in an AVI container.

Here's a screengrab:
Image

Any chance these could play back at the full 29.97 frames per second in kJams? I'd love to reproduce the original "video" look of a laserdisc!

dave
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Re: Smoother playback of full-motion video

Post by dave »

have you turned on "use coregraphics"? it won't get "smooth as glass" but it should improve playback performance.

i will be rewriting the whole quicktime engine using QTKit before 1.0 ships, with that you can expect "smooth as glass" performance even at high framerate on a very large monitor.

-dave

El Ramos
Posts: 23
Joined: Wed Aug 01, 2007 2:53 am
Location: Portland, OR
Contact:

Re: Smoother playback of full-motion video

Post by El Ramos »

dave wrote:have you turned on "use coregraphics"? it won't get "smooth as glass" but it should improve playback performance.
Turned it on now and do see a performance improvement, thanks. Scaling is smoother, too.
dave wrote:i will be rewriting the whole quicktime engine using QTKit before 1.0 ships, with that you can expect "smooth as glass" performance even at high framerate on a very large monitor.
To quote Dave: 8)

dave
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Re: Smoother playback of full-motion video

Post by dave »

8)

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