MPEG 4 RESEARCH FINDINGS

I: OVERVIEW

I have been researching MPEG-4 for use in our video streaming workflow and for our future video archival system. The dream of the MPEG-4 platform is to be able to stream high quality digital video to the client without concern for what media player they may be using. MPEG-4 was designed to do this. Does it succeed? The short answer is, yes, but the platform is still in it’s infancy and consequently has some problems that need to be addressed. While MPEG-4 is the only solution right now that will allow us to send out one video stream that will play on the 3 major media players, encoding and serving tools are still in their infancy and Microsoft is making it difficult to easily implement MPEG-4.

II: STREAMING VIDEO

MPEG-4 will play back in Quicktime, Real, and Windows Media Player with the Envivio plug-in. It is no simple task to accomplish this. Attention must be paid to the MPEG-4 profile type the video is encoded in and that the client has the proper version of the media players and the proper plugin (chiefly, the Envivio plugin is necessary for Real and WMV. This is available as a single, free download). Other MPEG-4 only players by Dicas and Envivio work well but are unlikely to be on many clients’ computers at this time. There are also MPEG-4 players available for the Linux platform and mobile wireless devices such as PDAs and cell phones. I do not have access to a Linux box or these wireless devices so I cannot vouch for their abilities to playback MPEG-4 video. Still, the fact that MPEG-4 was designed with these devices and cross platform playback in mind means that the video should play back on these platforms eventually. The major drawback to MPEG-4 playback I have found so far is with Windows Media Player version 9. Even with the Envivio plug-in WMP 9 will not play back streaming MPEG-4 files and sometimes only plays the audio or only the video of MPEG-4 files on the local hard drive. Hopefully Microsoft and Envivio will fix this with the full release of WMP 9 or a newer Envivio plug-in.

III: MPEG-4 CREATION TOOLS

The other drawback to jumping into MPEG-4 is the current lack of tools. There are at present 3 end-to-end professional level tools for encoding, serving and authoring MPEG-4. They come from Envivio, iVast and Dicas. The bulk of tools out there at the moment are experimental tools created at universities. Though it is easy and cheap to encode MPEG-4 files using the Dicas encoder, there is only the suite of tools from Envivio cover an end-to-end solution from encoding to authoring to serving the video. I am still waiting on pricing and site licensing information from Envivio, but it it likely to be very expensive.

IV: INTERACTIVITY

One of the most exciting aspects of MPEG-4 is the level of interactivity possible under one platform. The file format allows for multiple levels of video, text, VR, 3D VRML worlds, custom UIs and skins. A ZDNet article highlights a possible application "For example, video functions almost like a Web page, allowing people to interact with the picture on the screen or to manipulate individual elements in real time. Like that dress that Julia Roberts is wearing? Simply click on her face to buy it." For more in depth examination of the BIFS (BInary Fornat for Scene) that makes the MPEG-4 2D/3D/weblink compositing work, click here.

The tools to take advantage of this power are in their infancy, and that's being euphamistic. At the time of this writing, the only professional level tool for adding any kind of interactivity to the MPEG-4 format is Envivio Broadcast Studio. Also, other than custom player UIs popular on music sites using Quicktime player, there is not much call for a high level of interactivity with streaming video. When a user clicks on a video link they want to sit there and watch the video, not have to occupy themselfs moving 3D sprites around.

V: QUALITY

This is obviously a very subjective topic, so you can decide for yourself by clicking on the links on the right-hand sidebar at Codec Shootout to see for yourself. Now, every company is going to tout their codec as the highest quality at the lowest compression settings. My personal opinion is that all the current codecs are of high quality. Some do show a slight edge over others yet the difference is negligable. Also, we are very concerned with the quality of the audio since so much of our video is Powerpoint and audio. The audio quality of MPEG-4 is very good. Another factor is that all the demos of the various codecs out there were produced using programs like Premier and Cleaner in post production for the highest quality and probably taking several hours to render a 3 minute clip. We do not have that luxury. That said, under our popular streaming video settings, 56K and 220K, the MPEG-4 files were much larger and of generally lower quality than similar Real Video, Sorenson or WMV clips, especially at the lower data rates. You can judge for yourself by clicking the links below. These clips were all done using a demo version of Dicas's Mpegable encoding software.

Some of these files do not play back in certain media players. This is due to the use of various ISMA Profiles. Note that the quality of these videos might be effected in part by my unfamiliarity with the Mpegable software settings and not the video codecs themselfs.

VI: INDUSTRY SUPPORT AND THE FUTURE OF MPEG-4

One of the best things about MPEG-4 is that it has enough industry support and the idea behind it is so desired that in the very near future MPEG-4 will be as easy to create and as ubiquitous as MPEG-1.

The only holdout is Microsoft, which is a bad enemy to have. Microsoft sees MPEG-4 as an obstacle to it's plan to get WMV onto all DVD players and wireless devices. Their views can be summed up in this White Paper. This is very reminiscent of their stance towards Java. Let's hope there is not the same amount of litigation involved. Then again, Microsoft threw everything they had against Java and as buggy as Java has always been it is still a major player on the web.Personally, I don't believe that the ISMA (Internet Streaming Media Alliance) and the government will let Microsoft kill MPEG-4 outright. MPEG-1 and MPEG-2 were such great successes that it seems highly unlikely that the industry will not adopt this standard as well.

VII: COST ANALYSIS

It is possible to encode and stream MPEG-4 at very low cost. Many companies are advertising MPEG-4 hardware compression, but I have found that a software only solution is possible and much cheaper. At this point I recommend using the Mpeagable S4 encoder from Dicas. This product is full featured and costs around $300 US. One drawback is that it is a German company and though I have gotten email responses from them in good English I don't know if the language barrier will cause problems in the future. All the examples above are being served from an Apple Darwin Streaming Server running on a Windows 2000 box. This software is a free download and is open source (just don't ask me to write any C++ plugins for it!). It should run on Windows 2000/XP and Linux boxes. I found the installation and setup to be very painless and hassel free. So far the performance has been solid and responsive, especially considering that the computer it is running on is a workstation and not a server.

When MPEG-4 first appeared, the process of decompressing the video on the client's computer required a faster machine than was currently the standard. The MPEG-4 videos I test streamed performed well on several client machines. Clients with older machines (800MHZ and below) may experience choppy playback.

MPEG-4 itself is not free. The original licensing plan angered many in the industry and threatened the adoption of MPEG-4 in the mainstream. The new licence provides free use for up to 50,000 implementations. More than enough for our uses- for now. You can read more details about the licensing here and here.

VIII: CLOSING COMMENTS

I will go out on a limb and recommend MPEG-4 be used as the standard for the upcoming video archival system. In the end the battle seems to be coming down to Windows Media versus MPEG-4. Everyone outside of Microsoft seems to be putting their eggs into the MPEG-4 basket. I believe that MPEG-4 and Windows Media will reside side-by-side on most PCs and MPEG-4 will be the standard for PDAs, cell phones, and Macintosh computers (under a Quicktime wrapper, of course). Windows Media performs better and the tools for encoding and serving will give us much less worry. The only question is do we want to be all things to all people (MPEG-4) or go with what's easiest yet not as universally accepted (Windows Media)?