MP4 problems - please help!
January 1, 2010 7:08 AM   Subscribe

My mp4 videos suddenly stopped showing video, only playing audio. What can I do to fix this?

Windows XP, been using Media Player Classic for at least a year without any problems. Today I discovered my mp4 video clips (which worked normally a month ago) only play audio, without showing the video. I tried installing VLC, and mp4 files work in it, but I'd much rather keep using MPC. Windows Media Player also doesn't play video, only audio.

The only possible change I can think of in the last month is installing Windows Live Sync. There may have been a .NET installation or upgrade because of Live Sync, but it's quite possible I've had it already installed - can't say for sure.

I had no problems with other formats (divx, mkv...)
posted by gakiko to Computers & Internet (8 answers total) 1 user marked this as a favorite
Could be a codec issue. Try installing a comprehensive yet not bloated codec pack, like CCCP or DefilerPak:

One or the other, not both. Whichever seems to strike your fancy.
posted by ehamiter at 8:14 AM on January 1, 2010

Generally, codec packs tend to cause more issues than they solve. For DirectShow playback of a file which is H.264 video and AAC audio in an MP4 container, you need an MP4 splitter, an H.264 video decoder, and an AAC audio decoder. I recommend Haali Media Splitter for splitting MP4 (and Matroska and OGM) containers and ffdshow tryouts as the audio and video decoder.

Defiler Pak is LONG out of date, especially with regard to the ffdshow build it installs, and CCCP is probably overkill here (not to mention the fact that it tries to configure many things for you, which can lead to headaches). One of the MPC/MPC-HC/ffdshow devs maintains the K-Lite Codec Pack and all its versions, but K-Lite really doesn't do anything that Haali+ffdshow+a front-end of your choice can't do equally well.
posted by Inspector.Gadget at 8:23 AM on January 1, 2010

DefilerPak may be old but is hardly obsolete. CCCP is also not that large.

K-Lite was the bloat I was referencing earlier.

K-Lite Full installs:
- three separate (and by default conflicting) MPEG4 ASP decoders
- two different and incompatible VP decoders
- no less than 5 different (and conflicting) MPEG1/MPEG2 decoders
- three MPEG4 ASP encoders, x264 VfW, three mutually incompatible VP encoders (3, 6, and 7)
- four Intel Indeo encoders - versions 2, 3, 4, and 5
- two MPEG4 SP encoders: Divx3 and MSMPEG4
- three different and incompatible AC3 decoders, two of which are actually the same (AC3filter, but two different versions, one being a leaked beta never intended for public use)
- various mp3 de- and encoders (the decoders being pointless since Windows comes with one)
- two different AAC decoders
- two conflicting Matroska splitters, two conflicting Ogg splitters and two conflicting MP4 splitters
- 4 different and incompatible MPEG splitters
- 2 different versions of VSFilter, 2.33 and 2.37
- at least two pointless and in many cases harmful directshow filters (Morgan Stream Switcher and Matrix Mixer)
- and ffdshow with all the plugins and the VfW interface.
posted by ehamiter at 8:46 AM on January 1, 2010

DefilerPak may be old but is hardly obsolete

It lacks ffmpeg-mt for decoding H.264, lacks customizable YUV->RGB conversion, lacks HD audio bitstreaming capability, etc. There is simply no reason to use software that is four years out of date and skip the thousands of updates and bug fixes done in the interim. And I agree K-Lite is bloated. I use only Haali, MPC-HC, ffdshow, and occasionally CoreAVC for some types of field-based H.264 content that ffmpeg-based software doesn't yet handle correctly.
posted by Inspector.Gadget at 9:07 AM on January 1, 2010

You can worry about which specific codec might be causing the trouble, but the simple fact is that the codecs which come prepacked with MPC - K-Lite and CCCP - should handle mp4s easily.

So the best first option is probably the same one you'd use in any case of a program which stopped working for some reason: completely uninstall Media Player Classic (via the "Add Or Remove Programs" menu on the Control Panel) and then download and re-install it. Better to try to let it set up the codecs correctly than to waste time trying to figure out what went wrong.
posted by koeselitz at 2:15 PM on January 1, 2010

... although, now that I've installed MPC to poke around with it a little, it seems like the problem is that MPC isn't using its internal codec; if Windows MP won't play mp4s either, then the best bet is that they're both relying on faulty system-wide codecs. You have to tell MPC to use its internal codec; that option may somehow have gotten changed, and that would probably cause this problem.

Go to View -> Options, click on Internal Filters, and make sure the boxes next to all the Source and Transform filters are checkmarked. In particular, make sure the box next to the MP4/MOV Source Filter is checked; if that one were deselected and your systemwide codec were faulty, that would probably cause the player to play only audio on MP4s.
posted by koeselitz at 2:31 PM on January 1, 2010

koeselitz, that solved the problem. Thanks!

I'll go into deeper investigation and look for the systemwide faulty codec some other holiday. :)
posted by gakiko at 4:10 AM on January 2, 2010

You're welcome. Happy to help!
posted by koeselitz at 9:36 PM on January 2, 2010

« Older Emergency cat situation?   |   Books about growing up without a mom Newer »
This thread is closed to new comments.