why iTunes can't play some MP4's video, but only audio?

Please help me troubleshoot MP4 playing problem in iTunes (want to play it eventually in iPod).

I downloaded 英语原人原唱歌曲视频1000部（一) MP4 files and added them to iTunes Library/Movies. I could play some of them such as "25Minutes.mp4", but when I play some others like "(EverythingIDo)IDoItForYou.mp4", it only has audio played, but no video played.

I installed klcodec413fbeta.exe but seems it still doesn't work.

贫农家的长工 and other experts, any ideas why? Thanks in advance for help.

所有跟帖： 

• 回复：why iTunes can't play some MP4's video, but only audio? -葳蕤- ♀ (191 bytes) () 08/07/2008 postreply 06:31:10

• 好像real play最新版本有直接下载mp4转换到ipod的功能 -葳蕤- ♀ (0 bytes) () 08/07/2008 postreply 06:38:50

• 感谢葳蕤, Thanks a ton, it works. But still can't understand... -msmong- ♀ (432 bytes) () 08/07/2008 postreply 17:53:20

• after converted MP4 to iPod version, a song size changed from 16 -msmong- ♀ (120 bytes) () 08/07/2008 postreply 17:59:52

• Another problem is the file size is very big now, 16mb convert t -msmong- ♀ (0 bytes) () 08/07/2008 postreply 17:56:37