Codec FAQ

How do I play nAvi, SMR or angelpotion files?
Is High motion better than Low motion?
The DivX codec does not show up after installing
What do the smoothness and crispness settings do?
What is the DivX4 codec?
What is the difference between DivX 3.11alpha, 3.20, 3.22 and DivX 4 Windows 4x / 50?
What is the difference between DivX and MS MPEG4 v3?
What is the difference between DivX, ASF, MPEG4, SMR, etc
What is the Krystal studio codec?
Where has the MP3 codec gone?
Where's the DivX & MP3 codec after I've installed WMP7?

Every format out there, including DivX, navi, angelpotion, smr, etc are based on MS Windows Media Video V3! Period! Whoever told you otherwise is a liar. The only changed are again the removal of the AVI encoding limit, the namechange and usually these codecs have a nicer settings window. If you have a nAvi/SMR movie you can download the SMR codecs from the download page. In case of an angelpotion file you should use the FourCC changer you can find on the Software page to change the FourCC code to DivX or another codec you have installed instead of installing the Angelpotion codec package which can seriously screw up your system.

Definitely not. In low bitrates the high motion codec will look a bit better in action scenes but in low action scenes it will look terribly. Besides.. if you look closely at it you'll see a lot of compression errors even in high motion scenes.. check the WM7 test for more info - it has sample video clips and a lot of pictures. Despite rumors DivX high motion will rarely go beyond 1000KBit/s. Even DivX low motion will only use the full bitrate you set when it encounters a really demanding scene.

Sometime the problem can be fixed by using the up and down keys on your keyboard in the codec selection window. Another reason can be that FlaskMpeg only picks the first video codec line in your system.ini file. So start sysedit (run - sysedit) and edit the system.ini file which is usually located at c:\windows\system.ini, then locate the [driver32] section. Move the DivX codecs on top of the list:

[drivers32]
vidc.DIV3=DivXc32.dll
vidc.DIV4=DivXc32f.dll
msacm.divxa32=DivXa32.acm

vidc.DIV3 is the DivX Low motion and vidc.DIV4 is the DivX high motion codec. Reverse the order if you want DivX high motion.

The smoothness refers to framerate, how smoothly the video plays back. In low bitrate movies the mpeg-4 codec gives you the option to preserve the smoothness of playback in favor of picture quality. This is the reason why frames are not dropped so much at low crispiness settings, because motion is considered more vital than picture detail. This is also the reason why MS streaming .asf files use default 75% smoothness, because motion compensates for detail loss in terms of viewability. Conversely, the crispiness is to do with sharpness and keeping detail. At 100% crispiness a movie will favor keeping higher quality sharp images and loose unnecessary frames making a less smooth playback. Because most DivX movies use a comparatively high bitrate there is no real difference between high crispiness or high smoothness because the bitrate can cope. With the Fast Motion codec the bitrate will often drop very low indeed. If you keep crispiness too high you could easily end up with dropped frames.

What is the DivX4 codec?

The new codec by the creators of the old DivX3 is downward compatible but is otherwise completely new. That means it can play DivX3 encoded content but its encoding is much more advanced than DivX3 and it supports 2 pass VBR encoding for better quality and size predictability (that is you can trust your bitrate calculator).

What is the difference between DivX 3.11alpha, 3.11 VKI, 3.20, 3.22 and DivX 4 Windows 4x / 50?

First there's a large difference between DivX 3.x and DivX 4 Windows. The former are based on the Microsoft MPEG-4 V3 codec whrereas the latter is an implementation of OpenDivX, the open source DivX codec which does NOT come from Microsoft but is individually developed. There's currently 3 versions of DivX 4 Windows: 0.47, 0.48 and 0.50, all are in alpha state and the higher the version number the newer it is. DivX 3.11alpha is the current state of DivX, 3.11 VKI changes a few bits in the codec so that it actually inserts keyframes at scene changes. Note that you don't need the VKI codec if you use Nandub, M4C, or mpeg2aviAR & mpeg2aviVBR. DivX 3.11 with the VKI patch is also often called DivX 3.2. DivX 3.22 finally is a repack of the 3.11 VKI codecs, but it only comes with one version of the codec: the DivX 3.11 VKI low motion codec which has been renamed to DivX (without the low motion). There's no reason to use anything but DivX 3.11alpha (install the VKI patch only if you're not going to use one of the 4 applications I mentioned) since the rest is just repacks. OpenDivX is still too slow to be a serious alternative and there's some quality issues to be resolved as well.

What's the difference between DivX and MS MPEG4 v3?

There's none, really. DivX is basically a step farther from the original hack of the MS MPEG4 v3 codec, which, after the beta phase did not allow to encode to AVI anymore so that limit was hacked out. Gej then changed the name and the fourcc code in order to allow both codecs to coexist.

All these codes are based on the Microsoft MPEG4 v3 codec. ASF is Microsoft's streaming format, but it uses the same codec. The official MS MPEG4 v3 codec only allows for ASF output, or also for WMV output using the Windows Media Encoder v7. There's hacked MPEG4 codecs which remove the ASF encoding only limit, and the only difference between them and DivX/SMR/etc is that these codecs have another name and another fourff code identifying them. The tell the media player which codec to use during playback. There's NO quality difference between the various codecs.

What is the Krystal studio codec ?

Krystal is nothing but yet another repack of the DivX 3.11alpha codec with the VKI patch. It comes with its own installer and it also supports only the DivX low motion codec, which once again has been renamed so it doesn't have low motion in the name. Furthermore the package also comes with the DivX 4 Windows 0.47 codec, which is OpenDivX, looks bad and is slow so there's no reason to use it. My suggestion is to stay away from repacks and use the regular 3.11alpha (with VKI patch if you don't plan to use Nandub, m4c, mpeg2aviAR or mpeg2aviVBR).

Where has the MP3 codec gone?

When flaking, don't try to make more than one file without closing FlaskMpeg.. it has the habit to leave the mp3 codec "open" so it can't be used anymore. In some cases you even have to reboot to fix the problem. If all doesn't help reinstall the DivX 3 codec.

Where's the DivX & MP3 codec after I've installed WMP7?

First of all... why WMP7 (Windows Media Player v7)? There's nothing really great about it so you'd better stick with the old release in this case. WMP and the latest Windows Media Encoder will overwrite the mp3 codec with its own version that hasn't been licensed for use in encoding software and therefore can only be used for mp3 playback, not encoding. Run the Register_DivX.exe file in the directory where you've installed the DivX codec. The same applies for disappearing DivX codecs. If you want to install the WMP7 then I strongly suggest that you install the DivX codec before it, then reinstall it after installing the WMP7. That way I was still able to use these codecs while having WMP7 on my system. The MP3 codec will be overwritten on purpose by the way since the MP3 codec that comes in the DivX package hasn't been properly licensed and FhG required that the WMP installer check for unlicensed codecs. A modified DivX installer that would properly install the MP3 codec would help to get around the problem.