MPEG-4 skipping/messing up when played

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MPEG-4 skipping/messing up when played

Hey all,

I just made a short trailer for a film I'm making in iMovie 4 on my old G3 laptop (other work will be done on my intel iMac when it gets fixed).

The length of the trailer is 54 seconds, and when I export it using both the "export to Quicktime Movie" (which I believe is MPEG-4) AND the MPEG-4 setting directly, the movie plays all choppy and cut up...it lags pretty badly. Now I've exported a straight DV version and it plays fine, but the .mov and .mp4 versions are messed up. Can anyone tell me why, or recommend me a good video setting? It'll either go up on google video or rapidshare for download, so I'd like as high a quality as possible. I've exported MPEG-4 before, with best quality and 30fps and it played fine

Posted on Sep 14, 2006 12:31 PM

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Answer 1

Sep 14, 2006 1:32 PM in response to DGSpeed

Your playback issues are probably caused by the new H.264 video codec. It requires a very powerful computer and your (and mine) G3 just can't keep up.
Other (more modern) PC's and Mac's will have no trouble playing or viewing your file.
Don't use .dv for Web based files. Stick with .mov, .mp4 or .m4v extensions.
Uploads to Google Video should be sized for the iPod settings for best compatiblity and optimum file size.

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Answer 2

SDIllini

Level 6

16,675 points

Sep 14, 2006 1:48 PM in response to DGSpeed

Hi DGSpeed:

QuickTimeKirk knows what he's talking about-have a look here QT Pro Explained

Sue

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Answer 3

DGSpeed Author

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Sep 14, 2006 1:50 PM in response to DGSpeed

QuickTimeKirk,

Thanks for the reply. I have a .mov version, 58mb long that is excellent quality....the film has a few pictures first set to music that plays fine, but once it gets to moving video it messes up. I uploaded it to Google Video, and it still played choppy/laggy for me....are you saying it WON'T do that to others? Thank You

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Answer 4

Sep 14, 2006 1:59 PM in response to DGSpeed

58MB's for a 54 second file suggests that the data rate is very high. Too high for Web based files.
One minute of QuickTime video sized at 320X240 should be in the 500KB to 3MB file size.
Most of my Web based files average less than one MB per minute.
Could you open the .mov version you sent to Google and then open the "Movie Info" window of QuickTime Player? Report what it says for size, codecs, etc.

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Answer 5

DGSpeed Author

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Sep 14, 2006 2:19 PM in response to DGSpeed

I know thats quite high...I pretty much just kept as many standard settings I could and just made it best quality

Format: 16-bit Integer (Big Endian), Stereo (L R), 48.000 kHz
H.264 Decoder, 720 x 480, Millions

FPS: 18.96

Playing FPS: (Available while playing.) (it skipped from 0 to 1 to 1.14 to 7.07 while playing/lagging)

Data Size: 58.79 MB

Data Rate: 9.23 mbits/sec

Current Time: 00:00:00.00

Duration: 00:00:53.42

Normal Size: 720 x 480 pixels

Current Size: 720 x 480 pixels (Actual)

Those are all the specs....if you can recommend me ANY other setting I'll gladly use it, I keep having difficulty finding that one setting to use for my videos, a "magic" one if you will. Basically I'm most concerned about image quality, which I guess inherently comes with larger file size. Thanks for your help

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Answer 6

DGSpeed Author

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Sep 14, 2006 6:29 PM in response to DGSpeed

I guess it was the H264 setting that was messing it up, because I went back and encoded it as Quicktime Movie, .mov, in the H261 format with best quality and it came out great....24 megs with great quality. I guess I did find my "magic" setting. Thanks for the help

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Answer 7

Sep 15, 2006 6:11 AM in response to DGSpeed

Your audio track is "raw" (no compression). Use AAC to reduce it.
The video data (currently about 8MB/sec) rate should be reduced to about one MB per second. Maybe even lower. You'll have to judge the video quality yourself.
Dimensions should be reduced from the DVD size (720X480) to something more Web friendly (320X240).
This should shrink your file size by 50MB's.

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Answer 8

Sep 15, 2006 6:57 AM in response to DGSpeed

I made a few tests with different codecs, I'm no technician nor programmer, just a user, have a look here: Codexx

on another of my websites, I do use the free tool iSquint for my demo movies... have a look here HowDidYouDoTHAT, click on any demo movie.... e.g. the titles are crystal clear, sharp, no blurr...

as QuicktimeKirk recommends: smaller res, good audio compression, effective codec... I think, I have excellent quality, but just "burn" 1MB/min....

and avoiding h264, allows even users with older systems as mine to watch my site...

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Answer 9

DGSpeed Author

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Sep 17, 2006 10:00 AM in response to DGSpeed

Thanks for the replies, i'll try some of those tools you've recommended in the future. Are there any settings any of you would recommend for DVD? I think the final film will be huge in size because I care a lot about film quality, and would rather just burn it to DVD and show it rather than have the people i'm making it for download it.

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Answer 10

Sep 17, 2006 11:49 AM in response to DGSpeed

...Are there any settings any of you would recommend for DVD? ...

to reach the highest possible quality with the iApps, there's only one way:
use DV as import codec (as from miniDV), stay dv (avoid any useless inbetween-conversions), and let iDVD do the encoding straight from dv to mpeg2(=DVD)

just to mention:
iDVD cares for length, not size of a project...
a 2h HD project of >100GB fits onto a 4.7GB sl-dvd-r (iDVD will convert to standard, no HiDef with iDVD)

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