Microsoft ReMixSEA07 (part 5)

Back to developer track – fell asleep (oops) so there’s nothing much about previous session. The main demo is about Orcas which is the next release of Visual Studio, together with query languages like LINQ and technology for extremely lazy people to dynamically generate tables / web pages (hey! lazy is good!!). And juggling of course.

Hop on to the design track to see see look look. Beau from Metaliq is presenting again. Here are some best practices he shared (unfortunately at his speed it was quite hard to take notes):

Preprocessing: It’s important to manage quality in every phase, optimize working habits to work with the codec and know your target output, etc. Most tools require you to work in a particular way for it to work for you. Frames need to be preprocessed properly because the dirty artifacts will be magnified after compression. This is because extraneous data gives the compression algorithm the wrong hints.

Interlaced video: Silverlight video is a Progressive Only protocol. This means you have to De-Interlace and convert it into Progressive. Then something about Inverse Telecine for TV. (*faint*)

Computer Pixel Edges: Computer graphics output has exact pixels (e.g. 1024 x 768), pixel edge to pixel edge, therefore one should crop out the unnecessary portions to fit the pixels. In most production camera shooting, there’s a Video Safe Area (specifically a Action Safe Area and a Title Safe Area) that’s smaller than the entire frame size where the cameraman will try to put all the action inside. For the web, it is worthwhile zooming in, unlike TV or big screen. Think about it: when we engage the computer, we lean forward, but when we “engage” the TV, we lean back.

Image Quality: There’s a broader range for computer playback. It’s important to make sure that black is really black (i.e. #000000). One can reduce noise by smoothing out overall image, every gradient and every grain. The point of this is to enhance the efficiency of the codec. A simple example thus is to adjust the black level for wide screen movies (i.e. those that got ripped from wide screen into standard ratio, resulting in two strip of black at the top and bottom) to be the same as the black in the show when view over the web.

Audio: Simply adjust the Max levels, e.g. -3db/90% and ensure that there’s no dynamic range changes (the levels stay put throughout the show). One simple way is to find the loudest part of the video and adjust to that. This will give the right expectation for the end consumer, so they don’t have to turn up or down their volume throughout the show.

So what is Progressive content? Basically any media that can be put up on a webserver. In other words, any webserver that can serve a JPG image can serve silverlight progressive content. It is the most efficient with Variable Bit Rate (VBR). However, random access is only possible to only what you have downloaded, i.e. you can’t skip ahead – say you only want to watch the 5th minute onwards. Thus it is ideal for short, high quality content.

Streaming Content, e.g. files from Windows Media Services (the capability is included in Win2K3). It has Constant Bit Rate (CBR), which allows random access to any point in the video. This reduces the need of local caching and therefore great for streaming movies.

Frame size: Silverlight works with square pixel videos, so you have to convert the aspect ratio if your source doesn’t have them. Some comparison with DV: 720×480, or 4:3 -> 640:480, 16:9 -> 832×480. What frame size to choose depends very much on your data rate, for example, today a 200-500 Kbps pipe would work well with 320×240 size. Frame rate should remain the same as the sourceif possible, but if there are limitations, one trick is to use the frame rate that’s an integer division of the source: 24 to 24, 12, 8, 6. But it’s still advisable to keep the higher frame rate for anything that requires > 200Kbps (they are going to “download” first anyway). (Someday I’ll understand all these when I start posting more home made videos.)

Expression Media Encoder is the new tool that’s currently available as free trail, also bundled with Expression Media Product. It’s a good starting point for beginners as well as for professional use. It’s no magical or secret sauce to video editing; it’s mostly WMV file manipulation only. There’s an option to choose various bit rates from the smallest VC-1 Motion Thumbnail to like some super duper bandwidth required rate. VC-1 Web Server 512k DSL is a good start. (Sounds like a new Digital Divide coming up – bit-rate?)

Admittedly, the tool is a far cry from an actual video encoding software (you know, stuff to edit StarWars). Here, you can trim, build mini previews and compare with the original side by side to see if the details that you want is too blur, choose from a bunch of job output template (like a custom player that surrounds it), put markers (like bookmarks that you can use to jump to certain parts of a longer clip). The rest of the animation (for the player) which looks more complicated is actually done in Expression Blend.

Finally, embedding the player is just a mini <div> block that kicks off the silverlight runtime.

I just got it downloaded and about to start editing when I realized that the video I took with my Nokia cell phone can only be saved as 3gp or mp4 file, both which can’t be imported into Expression Media Encoder. Grrr…..

Back to Top Banana. For the feature that got dragged into many frame, it’s actually many many mini video player (meaning that the framework can launch many many media player at the same time). The flexibility and capability is really impressive – have to prove this myself soon. I guess that concludes the day.
What I skipped but really should have went for was the web 2.0 panel. Peter should have a pod-cast somewhere.

Overall, REMIX was better than expected, in terms of the presenters and the content. The place is a bit small for the crowd, but ???? feeling is always fun. Tonight I’ll go home and clean up the posts and put some of the pictures and animations. Feedback form + signing out.