Windows Media Encoder 8 Tests!!

Well I guess everyone is wanting to know if Microsoft are telling porky pies about the Media Encoder 8! If you haven't heard about the new codec check it out here. Micro$oft claim:

According to my tests its a bunch of crap!! How can they claim near-DVD quality at 640 x 480 and at only 500kbps! AND near CD quality audio at 64kbps!! That means they claim to be able to fit a 2 hour 30 mins of near-DVD quality video with near-CD quality audio on a single 650MB CD-R!

To be fair I think the 64kbps audio is near CD quality and I also think that its almost beyond doubt that Mpeg-4 is the best format for Internet streaming there is! I don't want to hear any Quicktime or Real Media crap from anyone about that - Microsoft won the battle as usual, live with it! But I think for Microsoft to claim such wild things about their new codec is just plain crazy! Lets take a look at my initial tests on it anyway and you can decide:

Note: These following tests are based on the Beta version of Media Encoder 8 so it is of course possible that the full version will be much better quality etc.

THE TEST SETUP

Yes, yet again Digital Digest come up with the test examples before anyone else, so don't forget it baby! But I must be fair and give full credit to my pal PurpleMan who seems to have been the first to create a GUI for the newest Media Encoder. He was also the first to explain how to encode a DVD with it by frameserving. There are a couple more GUI's out now but I haven't had time to test them and no new GUI will change the following test results anyway.

First I downloaded Purplemans GUI and Windows Media Encoder Beta 8 from Microsoft Then I converted two DVD clips one at 432 x 288 and the other at 640 x 480. Both were converted to uncompressed AVI's with uncompressed PCM audio using Flask Mpeg. This means there is no loss of quality and the initial video is almost perfect and of course much better than you could get using any video capture card! Each clip was 60 seconds long and had both low motion scenes (when people are not moving) and high action scenes (where things explode etc). I think testing it this way is the most fair because I'm using a scene that has both action and calm scenes to test how it handles all aspects of video. As I'm sure you know the old Mpeg-1 VCD's always broke up into blocks on action scenes so we must give it both.

LOW MOTION SCENES

TV / VHS Resolutions (432 x 288)

Obviously I'm comparing the new Mpeg-4 codec's against the old DivX Mpeg-4 codec's (which beat both SVCD and VCD for quality see here for examples of that). All of the following tests are done using the highest quality Variable Bitrate settings of the WM8 codec.

Here is the original uncompressed AVI of a low motion scene:

Here is the same one encoded with the Windows Media 8 codec using its 2 Pass Variable Bitrate (VBR) at 800kbps:

That may look quite cool but first look at how the Divx Low Motion codec does this same scene at only 500kbps!:

How does the Windows Media 8 (WM8) codec deal with the same scene at 2000kbps? Take a look:

Here are the filesizes for the VHS video test:

Note: this clip has 64kbps audio too

Near DVD Resolutions (640 x 480)

At higher resolutions the newer WM8 codec seems to perform a little better on Low Motion scenes. I think this is due to the fact that at higher resolutions disruptions of smooth tone are less obvious - either way it does a fairly good job of it.

In my opinion the Divx Low motion codec still does a better job even at lower bitrates but it looks as if you can get away with it if you use a bitrate of about 1150kbps on the WM8 codec.

Here are the filesizes for the DVD video tests:

Note: this clip was done without audio

Conclusion

For low motion scenes the WM8 codec doesn't do quite as well as the old Divx Low Motion codec. This is especially true at VHS resolutions. At DVD resolutions this effect is less noticeable but the bitrate needs to be set to about 1000kbps or higher to get a smooth image! Generally speaking for non-action scenes the WM8 codec gives an overall sharper image with very slightly better colour matching, but there are still too many macroblock artifacts where there should be smooth tones!

FAST MOTION SCENES

TV / VHS Resolutions (432 x 288)

The clips I'm using are the same, just a different parts of the same movie clip. Here is how the original high action clip looked before compressing.

And this is the same scene rendered with the WM8 codec at 800kbps:

The final results of all my other pictures all looked so similar that I could see no point uploading them. In short, with any bitrate below about 800kbps I could see blocks on the WM8 codec, but anything above 800kbps they were not really noticeable But don't be disappointed the next near-DVD sized examples are much more enlightening.

Near DVD Resolutions (640 x 480)

This is the interesting part :). The new WM8 codec has improved significantly over the old Windows Media 7 codec when it comes to Fast Motion scenes. The scene below is a very fast motion scene even if it doesn't look like one. This is because the whole screen is moving with the water and the waves are very sharp requiring lots of shape details. First off we can see that at 2000kbps the WM8 codec is getting close to DVD quality. In fact there is little change as low as 1150kbps which is the average 2 CD VCD bitrate.

Even when the WM8 codec is set to 600kbps it can get a quality very close to the old Divx Fast Motion codec when it was set to 2000kbps! The same applies to the previous WM7 which is almost exactly the same as the Divx Fast Motion codec. Please don't let this confuse you, though. The final file size of the WM8 movie at 600kbps is still larger than the Divx Fast Motion at 2000kbps.

Conclusion

For Fast Action scenes the newest WM8 codec beats all others designed so far. But you need to be careful when using it because it is very unpredictable and will quickly eat up too much space if you let it!

IN A NUT SHELL

Does the new WM8 codec give Near-VHS quality at 250kbps as Microsoft claim?

Noooo! No chance in hell! At bitrates of about 600-700kbps you will get near VHS quality video depending on the amount of action in the movie. To do this you must use the Variable Bitrate (VBR) option. But this means that the final file size is still a bit unpredictable. In other words, even if you set a bitrate of 700kbps it is quite possible that you will end up with a final movie of 750MB or more!

Does the new WM8 codec give Near-DVD quality at 500kbps at resolutions of 640×480 as Microsoft claim?

Nope! Were you really expecting it to? Even at an average VCD bitrate of 1150kbps it barely reaches the standard needed. This is especially true when it comes to Low Motion scenes. Such non-action scene's are where the new WM8 codec fails most of all and where it has always needed some improvement.

Final Notes

The new WM8 codec is certainly much better than the old WM7 codec and also much better than the Divx Fast Motion codec. And so I think its quite a good replacement! I'd recommend using it at a bitrate of at least 600-700kbps for a single CD movie. Going higher probably isn't a good idea because it just get too large. Just imagine that the 600kbps WM8 is the same as the 2000kbps Divx Fast Motion codec and you won't be far wrong. For best quality on a double CD movie use a bitrate of between 900 to 1200kbps. Again higher bitrates will give slightly better quality but anything over 1500kbps will probably increase the filesize far too much. And finally, resizing the movie down a bit smaller than 640 x 480 will still give even better results.