QuickTime Videos are herky-jerky on old Power Mac G4.

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QuickTime Videos are herky-jerky on old Power Mac G4.

I have an old Power Mac G4 AGP Graphics, (450 HHz with 1.12 GB SDRAM). I have a 128 mg video card. I am running Mac OSX (10.4.11). I purchased a new digital camera that records MPEG-4 videos at 640 x 480 pixels. It records at 30 frames per second. When playing these videos in the latest version of QuickTime on my computer, it plays the audio perfectly, but the video is herky-jerky. I notice on the QuickTime Inspector that the playback varies between 22 and 28 frames per second. Do I just need a faster processor or can I get these videos to play on this computer. Can I convert the videos to a lower resolution and make it work?

Power Mac G4 AGP Graphics, Mac OS X (10.4.11)

Posted on Dec 15, 2007 8:13 AM

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Answer 1

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QuickTimeKirk

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Dec 15, 2007 8:18 AM in response to HunkyPunky

Use the Movie Inspector window to note the video codec used.
H.264 requires a fast CPU (not graphics card).

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Answer 2

HunkyPunky Author

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Dec 18, 2007 7:20 AM in response to QuickTimeKirk

I realize that I probably need more processor speed, but I still do not understand something. How does streaming video play so beautifully on QuickTime. When I open up QuickTime and play one of the movie trailers that is advertised, (for example, National Treasure), it plays beautifully on the largest screen size they offer. What is the difference between the 2 videos? Is there anyway to convert my videos to the format of the streaming videos?

The video Codec while playing my digital videos from my digital camera says MPEG-4, Apple MPEG4 Decompressor, 640 x 480, Millions
μ-Law 2:1, Mono, 16.000 kHz.

I know this may sound extremely ignorant, but I have asked a lot of people locally that should be in the know and they had no definitive answer to this.

Thanks for any response.

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Answer 3

Dec 18, 2007 8:02 AM in response to HunkyPunky

MPEG-4 format should be easier to play on older machines than H.264 video codec.
Since you can view the Apple trailers (nearly all are H.264) your issues are related to the data rate used by your camera.
H.264 throws more emphasis on CPU speed where MPEG-4 throws it at the graphics card. A G4 should have lots of trouble playing HD content above 720 but no trouble with MPEG-4. What is your CPU speed? What kind of graphics card?
Use the Apple System Profiler (under the Apple menu) to learn more "About This Mac".

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Answer 4

HunkyPunky Author

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Dec 29, 2007 4:26 AM in response to QuickTimeKirk

The CPU speed on the computer in question is a Macintosh Power Mac G4 with a 450 MHZ processor. The graphics card is an ATI Radeon 9200 - 128 MB. The Bus Speed is 100 MHZ and the L2 Cache is 1 MB. I don't think that it is processor speed because I have 3 more Macs at work. One is a Power Mac G4 with a 1 GHZ processor and a 64 MG graphics card and it plays these videos just like my slower G4, (herky-jerky). I also have an eMac with a 1 GHZ processor and a 34 MG graphics card and it plays the videos in question perfectly. Go figure!

As I stated before, the computer in question plays streaming video perfectly, but the video from my new digital camera plays in a herky-jerky fashion. The video is recorded at 30 frames per second, but my computer will not play them any faster than about 25 and it varies. The video is MPEG4 and is 640 x 480.

Any advice is appreciated.

Thanks

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