mp4 jerky video / out of sync audio Quicktime

[Jiggy1965]

I've downloaded an asf streaming video with vlc player at home and converted it to mp4. It plays fine at home (windows media player). It also plays fine at work on a Apple Tiger 10.4 with VLC Player. When I play it on Quicktime 7.6.4 however, the playback is jerky sometimes. Also the sound isn't always in sync with the images. Why is that?

I've also tried it with two dvd's I've ripped on this Mac with 4media dvd ripper and converted to mp4 in the process. They play fine in VLC player on the Mac, but there's this jerky playback and out of sync audio.

Other formats, like avi or mov play fine in Quicktime.

Can someone explain why my Quicktime has trouble playing mp4 files?

 

[simsaladimbamba]

Use VideoSpec (I prefer that, though it hasn't been updated since 11/2009), MediaInfo Mac (10/2010) or MediaInfo (10/2010, there is a Mac OS X version to download, VideoSpec and MediaInfo Mac are using the same library as MediaInfo) to analyse the .mp4 file and attach the report to your next post.

Btw, what specs does your Mac have?

 

[Jiggy1965]

I'm using an Intel Mac with 10.4. Quicktime 7.6. Two monitors. Perian and Flip4Mac installed. Here's the list. Plays fine on pc. Plays fine on mac with VLC player. Choppy in quicktime. Happens to all mp4 video's. A avi e.g. plays fine in quicktime.



*** MediaInfo Mac // Plain text file report
2011-01-25 15:58:22 +0100
Information for File: video.mp4

General / Container Stream # 1
Total Video Streams for this File -> 1
Total Audio Streams for this File -> 1
Video Codecs Used -> AVC
Audio Codecs Used -> AAC LC
File Format -> MPEG-4
Play Time -> 14mn 53s
Total File Size -> 66.5 MiB
Total Stream BitRate -> 625 Kbps
Video Stream # 1
Codec -> AVC
Codec (Human Name) -> Advanced Video Codec
Codec (Container Code) -> avc1
Codec Profile -> High@L1.3
Frame Width -> 352 pixels
Frame Height -> 264 pixels
Frame Rate -> 25.000 fps
Total Frames -> 22312
Display Aspect Ratio -> 4/3
Interlacement -> Progressive
Codec Settings (Summary) -> CABAC / 4 Ref Frames
QF (like Gordian Knot) -> 0.223
Codec Settings (CABAC) -> Yes
Video Stream Length -> 14mn 53s 40ms
Video Stream BitRate -> 518 Kbps
Video Stream BitRate Mode -> VBR
Video Stream Size -> 55.2 MiB
Date of Original Encoding -> UTC 2011-01-20 20:18:42
Audio Stream # 1
Codec -> A_AAC/MPEG4/LC
Codec (Human Name) -> AAC Low Complexity
Codec (Container Code) -> 40
Audio Stream Length -> 14mn 52s 922ms
Audio Stream BitRate -> 100 Kbps
Audio Stream BitRate Mode -> VBR
Number of Audio Channels -> 2
Audio Channel's Positions -> L R
Sampling Rate -> 44.1 KHz
Bit Depth -> 16 bits
Audio Stream Size -> 10.7 MiB
Date of Original Encoding -> UTC 2011-01-20 20:18:42

 

[Jiggy1965]

Does this list help identify the problem? I've streamed an asf file at home using a pc and converted it to mp4. I also converted some dvd vob files to mp4. Played all of them on Quicktime 7 on my mac at work and either the playback is choppy, or goes slowly, or the audio is out of sync which I can see when people are talking.

When I use VLC player there is no problem. I also installed/uninstalled Persian, no effect. Updated flip4mac, no effect.

Yesterday I streamed an asf at home and played it without converting to mp4. Results is that it plays but frequently pauzes on frames so the video seems to move very slowly.

Read somewhere that it might be because I use two monitors side by side? Could that be true.

Or does Quicktime just not play mp4 files as well as VLC does?