video but no audio in mp4 video

Hi Cromonna and welcome to the forums!

If you are having problems playing MPEG4 video in Quicktime 7.4 or 7.5 (and Apple are aware that some users have had such problems) you should carefully check in

/Library/Quicktime and
/Library/Internet Plug-ins and
Home/Library/Quicktime

to check whether you have any third party plug-ins that are not completely up to date.

Current versions of Flip4Mac and DiVX and Perian do NOT cause failure alone or in combination. However the one SPECIFIC extension that ALWAYS causes the failure alone or in groups is 3ivxMediaImp. All other 3ivx extensions DO work. Remove only that ONE SPECIFIC extension.

Please try this and see if it fixes your problem with QT Player, the QT Firefox Plugin, and iTunes not playing MPEG4 files (including mp4 files).

Older 3ivx and DivX components are often incompatible with new QuickTime versions and are, in many cases, obviated by component packs like Perian.

This is not the only explanation for issues with MPEG4 file playback in QuickTime 7.4 and later, however. The issue with videos from democracynow.org and others, including some of the videos on YouTube, for instance, is the result of that content not complying with MPEG4 standards (namely that they use bogus track dimensions). QuickTime had previously ignored invalid track dimensions but this was changed in order to support properly authored anamorphic content.

The recent update to QT 7.4.1 fixed a number of issues but some problems are unavoidable when working with non-standards compliant content. The standards are important for many reasons including keeping hackers from manipulating improperly coded web pages.

A further problem was the fact that the developers of iSquint conceded that in many cases, the files do not play because they have been created in a non-standard way (the tool used to create them was broken). They have therefore included a Debreaker as a part of the latest version of iSquint. If your files are of this type, then you can run them through this app without having to downgrade QuickTime. This could save you a lot of hassle!

http://www.isquint.org/getit.php

However, in other cases, there is a workaround (also the basis for why those files will still play in iTunes): there are a few ways to trick QuickTime into ignoring the invalid track data. For instance, rename the files .3GP and they'll show up just fine.

Post back if you want a list of the plug-ins you should have in order to play pretty much anything in Quicktime.

The recent (mostly security) update to Quicktime 7.5 has not changed the situation as described.

These are the downloads and the settings you need in order to view/hear pretty much everything that the net can throw at you: The setup described below has proved repeatedly successful on both PPC and Intel macs, but nothing in life carries a guarantee!

It is known to work in the great majority of cases with Safari 3.0.4, 3.1, 3.1.1, QT 7.3, 7.4.x and 7.5 and OS 10.4.11.

Assuming you already run Tiger versions OS 10.4.11 and have Quicktime 7.2 or above, and are using Safari 2 or 3, download and install ( or re-install even if you already had them) the latest versions, suitable for your flavor of Mac, of:

RealPlayer 11 (which is no longer in beta) for Mac from (you may need a different site for the US):

http://uk.real.com/player/mac/

Flip4Mac WMV Player from http://www.microsoft.com/windows/windowsmedia/player/wmcomponents.mspx (Windows Media Player for the Mac is no longer supported, even by Microsoft)

Perian from http://perian.org/

You should read this support page http://perian.org/#support in case you need to delete older codecs.

Adobe FlashPlayer should first be uninstalled using the appropriate uninstaller available here: http://kb.adobe.com/selfservice/viewContent.do?externalId=tn_14157&sliceId=2 and then the latest version obtained from here: http://www.adobe.com/shockwave/download/download.cgi?P1ProdVersion=ShockwaveFlash and installed.

(You can check here: http://www.adobe.com/products/flash/about/ to see which version you should install for your Mac and OS, but please see my footnote if you are running Leopard.)

In earlier versions than QT 7.1.3 in Quicktime Preferences, under advanced, UNcheck Enable Flash, and under Mime settings/Miscellananeous only check Quicktime HTML (QHTM).

You should also ensure, if you are running Tiger 10.4.11, that you have downloaded and installed all the correct version for your Mac of Security Updates up to and including 2008-003. (N.B. Security Updates require both a restart and a permission repair.)

In Macintosh HD/Library/Quicktime/ delete any files relating to DivX (Perian already has them). However it should be noted that Perian is not an internet plugin and will not play DivX files imbedded on a website. For that you will need the DivX Player browser plugin available from http://www.divx.com/divx/mac/

Now go to Safari Preferences/Security, and tick the boxes under Web Content (all 4 of them) to enable Java.

Lastly open Audio Midi Setup (which you will find in the Utilities Folder of your Applications Folder) and click on Audio Devices. Make sure that both Audio Input and Audio Output, under Format, are set to 44100 Hz, and that you have selected 'Built in Audio'.

Important: Now repair permissions and restart.

You should also consider having the free VLC Player from http://www.videolan.org/ in your armory, as this plays almost anything that DVD Player might not.

There is an additional 'fix' you could try if you are having problems with Flash and Quicktime, depending on which type of Mac you have:

On Intel Macs, make sure that you are not running Safari in Rosetta. You can check this, and change it, in the Get Info window.

On PPC Macs, go to the Hard Disk/Library/Internet Plug-Ins folder, and drag the file 'QuickTime Plugin.webplugin' to the desktop. Quit and restart Safari. If things have improved you can trash that file. If they haven't put it back, as the lack of this plug-in can cause QT content in some widgets to cease functioning.

And now there is an additional kid on the block: SilverLight. Microsoft has created their own version of what a replacement for Flash should be. You can read more about it here:

http://silverlight.net/

So, if you go to any sites that have been designed for this new Silverlight stuff, you can download the plug-in from here (but make certain that you are downloading SilverLight v.1.0 for OS X (10.4.8 upwards):

http://silverlight.net/GetStarted/

FOOTNOTE

If you are running Leopard:

Some users have mentioned that the latest Flash Player (v.9.0.115.0) conflicts with Leopard, and that they have needed to revert to v. 9.0.47. This can be downloaded from here:

http://kb.adobe.com/selfservice/viewContent.do?externalId=tn_14266&sliceId=1

Perian usually does!

Glad you got it working! 🙂