Entries tagged with expression encoder - Channel 10

Silverlight 2 RC0 is out

benwaggoner — Wed, 01 Oct 2008 15:01:00 GMT

The first public release canditate (RCo) for Silverlight 2 is now available for download by developers. While anyone can install it, the main goal is for developers to make sure they aren't hit by any breaking changes for Silverlight 2 RTM so they can fix any issues. No one will be auto-updated to this release. Users will be auto-updated to Silverlight 2's final release when it's posted.

All Silverlight 1.0 projects should work fine, but there may be some Silverlight 2 Beta projects that require updates.

For the media folks, there's a couple of new things I want to mention.

There's a new scaling algorithm that's a lot faster and much higher quality - a nice compromise when you can get it!
Additional optimizations have been done for the VC-1 video decoder, so playback will be faster. The gains are biggest for content using B-frames.

Since the default Expression Encoder templates have "always on" scaling and its presets use B-frames by default, the above will provide a nice performance boost for existing content. The above are "always on" features - you don't need to update anything to take advantage of them. So expect smoother frame rates on lower-end machines.

Further information:

EDIT: Added ScottGu link

Expression Encoder Service Pack 1 preview

benwaggoner — Wed, 24 Sep 2008 03:19:00 GMT

James Clarke has a blog post up describing some of the new features in the forthcoming Expression Encoder 2 Service Pack 1.

It's got some great new stuff, and we're demoing it here at Streaming Media West this week.

Read the whole post - there's lots of good stuff in there. A couple of my favories are

A new Silverlight 2 base player using .NET. Among other things, this will enable players that display the video at 100% scale by default, improving quality and performance.
New A/B compare modes. Awesome stuff for high-touch encoding and codec tweaking
Some even more VC-1 advanced options for High Codec Nerditry.
The first public release of Microsoft H.264 compression technology.

Anyway, a lot of good stuff for a SP1. I'm looking forward to it.

Low Latency webcasting with Windows Media and Siverlight

benwaggoner — Sun, 22 Jun 2008 05:25:00 GMT

So, Streaming Media is doing a special "Europe edition" of Streaming Media, and I'm doing an article about webcasting for it. I've getting a bunch of questions about how to deliver low-latency live streaming to Silverlight, and so with their permission, I'm excerpting this section on that topic.

EDIT: A correction was made; turning off Fast Cache in Windows Media Services does not have any effect on webcasting latency.

While by default, Windows Media can offer 15-20 second end-to-end delay, it's possible to drive it down to 2-3 seconds with best practices on a good network, and we're looking at what we can do to push it to below even that. The critical thing is to tune the encoder, server, and player latency together.

There's an older but more detailed "Reducing Broadcast Delay" document on this topic over at the Windows Media portal that may be worth perusing.

Low Latency Webcasting

Latency is the measure of how much time goes between when video enters the encoder and leave the user display. Latency is something that doesn’t matter at all in some markets, and matters a lot in others.

The reason we have latency is buffering, and the reason we have buffering is for quality and reliability. By having the server wait several seconds after a video stream is received before sending it out, it’s able to support more peaks and valleys in the data rate, and makes it possible for a dropped packet to be detected and resent before its needed. In the same way, buffering in the player lets it average out data rates and recover dropped packets as well.

Large buffers were extremely important in the modem era, and are still useful in many kinds of networks today. The defaults are good for delivering high quality content over a variety of networks. But when minimizing the latency is important, and reliable networks are available, the end to end delay can be reduced substantially.

Since total end-to-end latency is the sum of the encoder latency, server latency, and player latency, plus how long it takes the packets to travel between each of those, improving latency requires tweaks to the encoder, server, and player in parallel.

Encoder

On the encoder side, reducing buffer size reduces startup latency. WME and Expression Encoder both enable you to go down to one second.. Using Lookahead or Lookahead Rate Control will increase latency beyond the buffer value (typically about another half a second for LRC).

For audio, Windows Media includes the “WMA Low Delay” audio codecs from 192-64 Kbps which provide lower latency than the normal WMA modes. If you’re targeting Silverlight 1.0 or WMP 10 or earlier, you’ll want to use that for low latency. If you can require WMP 11 or Silverlight 2, you can use the lower delay yet WMA 10 Pro codec at 32-96 Kbps.

Server

WMS features like Advanced Fast Start can dramatically reduce latency for on-demand content, but don’t apply to live webcasting as the server has to wait for content to arrive from the encoder it in real time, and so can only play out at real time.

Server buffering can be turned off entirely in WMS for Windows Server 2003 and 2008, yielding a significant drop in latency.

EDIT:

The previous version of this post suggested that turning off Fast Cache would help webcasting latency. On further research, this turns out not to be the case. Disabling Fast Cache will slow down on-demand startup time, but will have no effect one way or the other for live content.

Player

Normally the player isn’t under control of the streamer. By default WMP dynamically picks an optimum buffer size based on its measurements of network and stream performance. However, it’s possible to lower the buffer size in the player’s options. This can help reduce latency when watching streams with a good connection, but could produce pauses in the video when watching video from the general Internet.

Silverlight makes the player buffer size a controllable parameter, so an optimal setting can be applied for the content, and even adjusted on the fly. This is controlled by the BufferingTime parameter in a Silverlight MediaElement.

Announcing Expression Encoder Customer Panel

benwaggoner — Sat, 21 Jun 2008 06:29:00 GMT

The Silverlight and Expression teams are very customer focused, and we like to release products on a fast cadence. We've got a lot of methods of customer outreach, and I'm happy to share a new one, the Expression Encoder Customer Panel.

David Sayed has all the details over on his blog:

Expression Encoder Customer Panel

Now that Expression Encoder 2 has been released, the team is hard at work on the next version of the product.
We want to be as responsive to community feedback as possible, and would like to set up a panel of customers with whom we can have ongoing conversations.

What is the Customer Panel?

The Customer Panel is a way for us to build strong relationships with users of our product. We'll use it as a way to understand your needs, workflows as well as how you use the product. We'll also use it to float future feature ideas and get feedback on them

What is the time requirement?

The Customer Panel is an ongoing project. The overall impact should be minimal and if at any point you no longer want to participate, just tell us. Typically we'll aim to reach out the Panel every couple of months or so. There may some times when we reach out more frequently.

How is this different to a Technology Adoption Program (TAP)?

TAPs are for specific releases and focus on getting you pre-releases of the software to play with. We'll use the same framework for the Customer Panel, but it is longer lived and goes beyond a particular release. This is an opportunity to have lasting impact on product direction.

OK sign me up!

If you want to take part, please send me an email by clicking Here it is

Sample projects

It includes a number of sample projects (quoting from the help file). These are a good jumping off point for various scenarios.

Simple encode

The simple encode sample is a console application that demonstrates how to encode a file from a console application when showing progress. To use it, just run the built application (Simple.exe) at a command prompt.

Asynchronous encoding

The WPFEncode application demonstrates how to encode a file from a UI application when displaying the progress of the encoding process. To use the application, click the Browse button to point to a file that you want to encode and then click the Encode button to encode it. When the file is encoding, a bar displays the encoding progress.

When you press the Encode button, the application creates a thread to perform the encode to make sure that the UI thread is not blocked. The progress events are called from a non-UI thread. Consequently, we use the Windows Presentation Foundation Dispatcher to marshal the updates to the UI thread.

If you try to close the application when the encoding is still occurring, the application prompts you to confirm that you want to stop the process. If you confirm, the application stops the encoding thread but delays closing the application until the thread actually stops.

MediaInfo
The MediaInfo sample is a console application that demonstrates how you can use the MediaItem class to extract media and metadata information from a media file. To use it, just run the built application (MediaInfo.exe) at a command prompt with the full path of a media file as the parameter, as shown in the following example:
Publishing plug-in

Publishing plug-ins enables you to take video and Microsoft Silverlight template assets that you have created as part of an encoding job and then do something with encoded assets. For example, you can upload the media asset by using FTP, WEBDAV, or METAWEBLOG API, publishing the asset to an asset management system or web service, or creating a data CD.

The following code sample demonstrates how to use a publishing plug-in to add the output of an encode job to a Zip file by using the Open Packaging Convention components found in Microsoft .NET 3.0.

A publishing plug-in is required to derive from the PublishPlugin class, which in turn derives from the EncoderPlugin class:

Template plug-in

The template plug-in lets you customize template settings and interact with the job through the IPluginHost interface. The plug-in also lets you add or remove files from the template output when the template is published.

The following code sample demonstrates how to add the default template parameter control to Microsoft Expression Encoder with only several lines of XAML. It also implements a custom script command creation feature that shows how the template plug-in can interact with the current job by adding a script command at the current play head position of the selected MediaItem.

Within Expression Encoder, every template receives a template plug-in. If the template doesn’t specify one, a default one will be assigned. A template plug-in derives from the TemplatePlugin class, which in turn derives from the EncoderPlugin class.

What a difference a half-decade makes! Live VC-1 today and at launch

benwaggoner — Thu, 05 Jun 2008 02:11:00 GMT

A recent conversation over at the Streaming Media Advanced list sparked a rant from me about the importance of comparing implementations of codecs, not just codecs.

To that end, I thought I'd do a demo to show how much improvement there's been in Windows Media since the launch of Windows Media 9 Series back in 2003.

A recent conversation over at the Streaming Media Advanced list sparked a rant from me about the importance of comparing implementations of codecs, not just codecs.

To that end, I thought I'd do a demo to show how much improvement there's been in Windows Media since the launch of Windows Media 9 Series back in 2003.

Below, you'll find two streams, encoded with the same settings but with tools from different eras. The streams are both

Live encoding from a preprocessed file (so that preprocessing differences don't matter)
And yes, it's the "Lady Washington" footage again.
640x360
29.97 fps
600 Kbps video
64 Kbps 44.1 stereo WMA audio
5 second buffer
Keyframe every 5 seconds

The difference is that the first is encoded with the original Windows Media Video 9 codec (ala just Windows Media Player 9 installed, like a stock Windows XP SP2 machine), and the second with the VC-1 Encoder SDK implementation in Expression Encoder 2. Pretty dramatic differences, I hope!

	Live Windows Media 2003	Live Windows Media 2008
Silverlight embedded page	2003 in Silverlight	2008 in Silverlight
Direct link to WMV (right-click to download)	2003 direct WMV link	2008 direct WMV link

...reminding me that I really need to blog how to make a Silverlight dual media player that can play two versions of the same clip in sync.

So, what makes this big difference? There's been a huge amount of work and three major releases (Format SDK 9.5 and 11, and VC-1 Encoder SDK) since then, so I won't give a complete list, but a few of the highlights.

4-way threading instead of 2-way threading, doubling performance on modern machines.
Lots of SSE2 and SSE3 optimizations to improve performance.
"Adaptive Complexity" that dynamically adjusts the complexity of the encoder, to make sure it's always using all available CPU power, without ever dropping frames. This compares to the old default live complexity of 1 (out of a 0-4 range).
Using B-frames (supported in the old decoder, but not used in the original encoder) which improve compression efficiency and enable efficient encoding of flash frames.
Lookahead Rate Control, where the codec buffers a few frames into the future, so it knows when it needs to start saving some bits for an upcoming keyframe, or when it's save to use a lot of bits on a few challenging frames.

A lot of the above are about performance. With offline encoding, better performance just makes for faster encoding. But for live encoding, it helps quality, because it allows the codec to do more math per pixel to find the optimum way to encode that file.

So, how big a difference is this? Below is a graph showing the Quantization Parameter (QP) for the two encodes. QP is a measure of how encoded each frame is, with higher values more highly compressed. In VC-1, the range is 0-31. A good rule of thumb is that QP of much below 8 looks pretty good, and QP of 8 or above...won't. Now, a live SD encode at 600 Kbps is pretty darn aggressive, so there's plenty of spots where both encodes certainly show artifacts. And quality varies a lot throughout the file as the the complexity of the video goes up and down, as this is a Constant Bitrate (CBR) encode. Note the relatively low QPs near the end of the file, where the easy credits scroll comes in.

But still, the modern VC-1 implementation (in red) with all of the above is dramatically better. While the old encoder (in blue) spikes all the way up to the maximum QP of 31, the new one is typically several QP lower, and maxes out at a QP of 20 instead.

That said, man, my Excel-fu sure has declined over the years. Hard to believe I used to teach classes on making good-looking Excel charts back in the early 90's. Anyway, just remember that lower is better, and red is our current stuff.

Videos from the "Secret Compressionist's Ball"

benwaggoner — Thu, 29 May 2008 03:39:00 GMT

I've always called my annual compressionists party something like the "Ben Waggoner Compressionist's Party" but David Sayed from the Expression Encoder team suggests the much better name of the "Secret Compressionist's Ball"

Better yet, he's got a couple of video interviews from the party! You'll see me in the background in my mildly famous purple shirt in a few shots.

First, Tony Houghton from Promoscape, talking about Silverlight.

Second, Bruce Lidl from MainConcept talking about their VC-1 codec implementation they're now licensing out, including support on Mac and Linux.

The clips are embedded at smaller than they're encoded; double-click to see them in their full glory.

Expression Suite 2 and Expression Encoder 2 now shipping!

benwaggoner — Thu, 01 May 2008 22:43:00 GMT

May 1st is a happy day for me! I went over to www.microsoft.com/expression, and was delighted to find that the Expression Studio 2 is now shipping, including the final version of Expression Encoder 2. There's a 30-day trial available for download. Boxed copies of Studio are available today at CompUSA and Office Max, with other retailers coming. There will also be the Microsoft Expression Professional Subscription for $999/year (academic and volume pricing coming soon), which includes Expression Studio along with Visual Studio, Office, Visio, XP, Vista, Virtual PC, and Parallels Desktop (to run all of the above on Mac).

As I've said before, I feel that Expression Encoder 2 is the best compression tool at fulfilling the needs of its market since Terran Interactive's Media Cleaner Pro 3.1 (so long ago I can't even find anything on the web about it!). Here are some of my favorite things about it from my obsessive compression nerd's perspective.

First desktop priced VC-1 Encoder SDK based product ($199).
And the VC-1 implementation gives you great quality by default, and gives you an advanced mode that accesses the useful features, while handling the more esoteric ones behind the scenes. For example, the rule for WMV PowerToy was use Static Motion Vector Cost if using P-frame DQuant, otherwise use Dynamic. So Expression Encoder 2 just has a DQuant setting, and uses the right Motion Vector Cost based on that.
High quality scaling and deinterlacing modes
WMA Pro support, targeting Silverlight 2's support for that. So danceable music at 48 Kbps.
"Smart by default" - you can use the same preset and feed it a PAL 16:9 interlaced file and a NTSC 4:3 progressive file, and it'll do the right thing without having to do a single click: you'd get a 640x360 deinterlaced 25p file and a 640x480 29.97 file.
Which means you don't have a huge combination of settings to deal with all the video formats. Instead, the presets are scenario based; you just need one "1 Mbps streaming" option that'll handle all the video file variants.
Great multi-clip templates, so you can make a video gallery, with each clip having its own optional thumbnail-based chapter navigation (hmm, that deserves a nice demo).
Easy creation of thumbnail-based chapter navigation!
Captioning and metadata support, including ISAN.
Available soon, an integrated publishing module to go straight to Silverlight Streaming.
Support for a wide variety of source formats, including QuickTime, AVI, Windows Media, VOB (DVD), many other flavors of MPEG-2, MPEG-4, and AVISynth.
Automation available via both command-line and a .NET object model.
Simple editing features, like in/out points, preroll/postroll videos, and image and animated overlays.
GPU acceleration for previews
A great A/B compare feature, enabling short sections of the file to be encoded with a variety of compression settings, and then compared (playing in real time! zoomed in!, with an A/B split screen slider!) to both the source and each other.
An unbelievably cool live encoding module, which supports multiple cameras with live switching, streaming from files, including looping, live metadata insertion, and big quality improvements from lookahead rate control and dynamic complexity. I owe you a blog post describing that as well.

So, in summary, I guess I'd say I like it.

I've had a some blog posts highlighting different projects done with Expression Encoder 2 which you can follow along with.

Hands on with high-touch encoding: Streaming Media All-Stars Redo

Encoding screen recordings for Silverlight in VC-1 with Expression Encoder 2

"What Happens in Vegas" - 720p Movie trailer at 2 Mbps via Silverlight Streaming

I've got other information about Expression Encoder and how it fits into Silverlight at

My NAB Presentations

Silverlight Media technologies overview in Expression newsletter

And, of course I'll be covering Expression Encoder 2 as one of the products we cover in my

My June 23-27th class at Stanford

Hands on with high-touch encoding: Streaming Media All-Stars Redo

benwaggoner — Wed, 30 Apr 2008 06:47:00 GMT

Introduction

As Expression Encoder 2 approaches its immenent release, I've been using it for more and more real-world projects. This recent one was particularly chewy fun, and I thought it would make a good tutorial for a high-touch workflow.

As you may remember from a few weeks ago, I was one of the inaugural class of Streaming Media's Streaming Media All-Stars. There was a fun video montage of all of us on baseball cards being announce by ballpark-style narration. Good stuff, but the FLV compression wasn't quite up to my standards for this rare intersection of compression obsession and personal vanity. So I contacted Streaming Media and asked if I could take my own whack at it.

I'll have an expanded version of this post as an article in an upcoming issue of Streaming Media Magazine. If you don't get it, you can sign up for a free subscription.

The Source

One thing I noticed in the original is that the background graphics and a few of the animations were interlaced, as you can see in the last "before" image at the very bottom of the page.

While deinterlacing it may have been possible, the heavyweight motion-adaptive deinterlacers available for technologies like AVISynth can be finicky to configure, and extremely slow. And in the end, nothing beats getting the source fixed in the first place. Compression is the art of getting output that's as close to the original as possible with the bits you have available; often getting access to higher quality sources can provide a much bigger improvement to final quality than all the codec tweaking in the world.

So, I contacted the post house, and they fixed the background interlacing (it was just a matter of properly flagging the source as interlaced in After Effects) and re-rendered it for me as a lossless RGB PNG codec QuickTime .mov file. However, there were two shots that snuck through where one layer was still interlaced. I didn't want to wait for another disc, so I dived into After Effects (in the end, all difficult preprocessing jobs seem to wind up in After Effects). I used the "Reduce Interlace Filter" with a softness of 1 to blend the two fields together. Traditional deinterlace methods messed up the text on the cards too much. However, the softness increase from that filter wound up causing a slight visual discontinuity when it kicked in. So, I broke out the two shots with interlacing into layers, and then used a five-frame cross-dissolve transition from the original progressive frames to the start of the interlaced shot which hid the slight loss of focus (masked in part by the motion). Both interlaced shots ended on a hard cut, so I was able to switch back to the original video without a transition.

I then rendered the new version out from After Effects in 32-bit float (to reduce the risk of introducing banding via an 8-bit to 8-bit conversion) into the Lagarith codec in YV12 mode, which uses the native 8-bit 4:2:0 colorspace of VC-1 and other codecs. This means that Expression Encoder doesn't need to do any color space conversion, making compression slightly faster.

Markers

The other notable issue with the original clip was "keyframe popping"; when an obvious "jump" in the video happens at the keyframe rate of the video. Watch the original FLV, and you'll see it during any of the longer static shots. Since the whole section with the cards is one single long shot over 3 minutes long without any hard cuts, there wasn't a place for natural keyframes (automatically inserted at a hard cut) to go. Thus keyframe transitions would happen while the cards were otherwise static, making even a slight change visible.

I also wanted to show off the Expression Encoder templates a bit by doing thumbnail navigation. In EEv2, I'm able to graphically set markers on particular frames, and set them to be keyframes and/or thumbnails. A thumbnail becomes an image file which, with the supported templates, automatically gets included in the menus for navigation (think a chapter on a DVD). Normally you also want to make the chapter points keyframes, since keyframes support immediate random access, as no other frames need to be decoded before displaying a keyframe.

This was an opportunity to kill two birds with one stone; if I set the markers on the first static frame of every card, it'd be nice high quality image that all the later frames that reference that I-frame can be based on, propagating its quality forward. If I set my keyframe spacing long enough, there wouldn't be any other keyframes in that interval to cause keyframe popping, and so the static card would be very consistent.

So, I set a marker for each person, flagged to be both a thumbnail and a keyframe. The audio doesn't always sync up exactly so that the person's name begins after their card is down, so sometimes the first name is cut off. This would have been easy to fix by just delaying the audio a second.

You can also use non-thumbnail keyframe markers; these become keyframes without showing up in navigation. I stuck a few of those in as well in the intro/outro sections, on the first full frames after the logo gets built. Since the sponsor pays the bills (Ripcode in this case), I always want to make sure that logos remain nice and crisp.

Setting keyframes has been around in compression projects for ages now; I did a lot of this in Premiere 4.0 for Cinepak encodes in the pre-Media Cleaner days, since Cinepak was prone to keyframe popping issues. Modern codecs like VC-1 do a much better job of finding good natural keyframes, and also to reduce popping issues. The Silverlight version would have looked a lot better than the Flash even if I hadn't set them, but they did get a further boost in quality. But don't think this is something you should be doing in every case; this clip is unusual in having minutes without cuts with a mix of static and moving elements, at an extremely low bitrate.

Encoding Settings

Now, what encoding settings do we want to use?

Video

Frame Rate: Source. We want to capture all the motion in the source perfectly (29.97 frames per second in this case).
Keyframe Interval: 15 seconds. The longest gap between markers in the source is a hair left than 15 seconds, so this will prevent keyframe popping between cards.
Profile: VC-1 Advanced Profile. So we can use DQuant, as discussed below.
Mode: VBR Peak Constrained. This is a progressive download project, so VBR Peak Constrained gives us optimum quality.
Bitrate (average): 488 Kbps. Matching the original FLV's actual bitrate (400 Kbps was requested, but VP6 overshot by over 20%).
Peak bitrate: 896 Kbps. So video + audio + overhead (9 Kbps in this case) max bitrate is a consumer broadband friendly 1000 Kbps total.
Peak Buffer Size: 15 seconds. So the buffer duration can contain an entire Group of Pictures (a keyframe and frames that reference it).
Width and Height: 640x480. Same as source. The original project had both 320x240 and 640x480, but they used the same data rate, so I'm doing just the 640x480 and Silverlight embed can be set to the desired size.

Audio

Codec: WMA. We're targeting Silverlight 1.0 compatibility, so WMA Pro isn't an option
Mode: VBR. Always better quality for progressive download.
Bitrate: 48 Kbps. Matching the data rate of the FLV source. Also this is minimum bitrate for WMA VBR. I always try to use at least 48 Kbps for WMA progressive for that reason; it's a massive quality jump from 32 Kbps CBR for typical content.
Sample Rate: 44.1 KHz. Same as source. Also, 44.1 is the native audio rendering mode for Silverlight, and so offers the same quality and better performance versus 48 KHz.
Bits per Sample :16. The only option for WMA
Channels: Stereo. VBR audio requires stereo. I'd use mono if I needed to do 32 Kbps, since there isn't stereo separation important to the experience here.
Audio peak bitrate: 96 Kbps. Again, so total peak comes out as 1000 Kbps. The audio isn't that difficult or variable, so higher likely wouldn't sound any different.
Audio peak buffer size: 1.5 Kbps. The default is almost always fine.

Advanced Codec Settings

Video Complexity: Best (5). It's a short clip at a reasonable frame size. Complexity 3 probably would have been just as good, but the encode only takes about 12 minutes at 5, so I didn't bother doing anything less than the max (I love my new 8-core workstation!).

Perceptual Optimizations

Adaptive Dead Zone: Conservative. The normal default. It softens out edges that might ring or get too blocky, but not by too much. I tried both Off and Aggressive, and Conservative definitely looked the best, as usual.
DQuant: I-Frames Only. There aren't many I-frames (mainly the few dozen we set manually, and perhaps a few more natural ones), but they contain the important visual data of the faces on the cards, so we want them to be as high quality as possible. DQuant spends too many bits on smooth parts of the image to use on every frame, but upping the bitrates on a few dozen I-frames won't hurt quality much, and improves the quality of the static parts of the card we wind up staring at for those many seconds.

Filters

In-Loop: On. Always on unless using Simple Profile; it helps reduce artifacts and improve quality, particularly at these aggressive bitrates
Overlap: On. Further hides artifacts, which are a challenge with motion graphics at such a low bitrate
Denoise: Off. The source doesn't have a hint of noise. If there were a lot of textures, Denoise can help to soften them some for easier encoding, but there's not much texture either.
Noise Edge Removal: Off. This is really only useful for noisy edges of analog captures, and even then we're better off cropping. It obviously doesn't apply here.

Group of Pictures

B-Frame Number: 2. Normally we use 1 for film and video sources, but for this kind of motion graphics, 2 is more efficient. This gives us an IBBP pattern, so each B-frame is adjacent to a P-frame. 3 B-frame is less efficient in this case, probably since with the IBBBP pattern the middle B-frame is two frames away from a reference frame (only I and P frames can be reference frames), and the P-frames are too far apart and so require more bits to store the change over four frames instead of three since the previous I or P frame. Using 2 also gives us better random access than 1, since worse-case random access time is based on the maximum number of P-frames between I-frames. With 15 seconds between keyframes at 30 fps, that gives us 450 frames per GOP maximum. With 2 B-frames, that'll gives us 149 P-frames per GOP, the same (and thus the same random access) as if we had a 5 second GOP without P-frames (the old Windows Media Encoder default).
Scene Change Detection: On. This will give us natural keyframes where need them. The codec seems to do a good job of putting them in the right place. I've never changed this in EE.
Adaptive GOP: On. Always have this on.
Closed GOP: Off. This is required to be on for CBR encodes in EE, but slightly reduces quality with VBR encoding. In particular, it can increase keyframe popping, since an Open GOP pattern starts with B-frames before the first keyframe/I-frame, you get BBIBBPBBP..., with the B-frames able to reference the last P-frame of the previous GOP. This helps smooth over changes between GOPs, since you have the leading B-frame(s) to spread the change over.

Motion Estimation

Chroma Search: Full True Chroma. Motion Graphics is a canonical time we want chroma search. The encode is so fast, there's no reason to not go for the full meal deal and do Full True Chroma.
Match Method: SAD. For this kind of content with very simple, flat areas, the Sum of Absolute Differences Motion Match is actually both higher quality and faster than either Hadamard or my normal video/film default of Adaptive.
Search Range: Adaptive. The smallest range works for most of the frames, but there's some very fast motion when the cards zoom in which need the bigger range. Adaptive it is.

Output

The Output pane has some of my favorite usability features of Expression Encoder, letting us apply rich templates and automatic publishing.

First, the Template. I picked the "Clean" template, which has a nice subtle overlay control, and a popup navigation via the thumbnails we made above when you mouse over the top of window. It also supports going full screen with a double-click. One thing I like about Clean is that the video fills the frame exactly, without having to account for the control bar or other elements. So I can embed at exactly 640x480 for a 640x480 clip.

The publish mode (I've got the optional Silverlight Streaming publishing plugin installed) lets me automatically or manually upload the final project to our Silverlight Streaming service. This is a great way to test or deliver Silverlight projects. You can sign up for a free account with 10 GB of storage and 5 TB/month of bandwidth.

Before/After

So, how much did all this help? Here's a couple of the more pronounced before/after shots. All the below are inserted as 100% scale PNG, so there's no scaling or further compression to complicate the comparison. Note that the FLV came out darker for some reason. I'm not sure what the cause of that was; the VC-1 brightness matches the source. Perhaps something to do with the Mac/Windows gamma difference on the platform the FLV was encoded on? This actually makes VC-1's job relatively harder, since the motion graphics are easier to see.

And you can see the actual clips in action here:

Before: FLV VP6 in Flash

After: WMV VC-1 in Silverlight

Detail improvements

I grabbed a frame right after the transition that really shows the detail difference between VP6 and VC-1 here; it's especially striking in the texture of the shirt. The VP6 gets sharper after a keyframe pop, but this is how it starts. VC-1 quality in the card is maintained perfectly throughout.

FLV VP6:

WMV VC-1:

Deinterlacing improvements

In this frame (man, do I look like a stiff!), you can see the effect of my blend deinterlace to hide the fields. Notice the ringing artifacts in the original frame. Encoding fields as progressive is extremely challenging for codecs, since you have high motion 1-pixel high horizontal lines, combing high frequency and high detail. I normally don't like doing a blend, since those double-images are also hard to encode, but it was only for a very short duration in this clip, and the deinterlacing filters I had handy had a lot of trouble preserving the text perfectly.

FLV VP6:

WMV VC-1:

An exhaused me talks to James Clarke about Expression Encoder 2

benwaggoner — Wed, 09 Apr 2008 21:23:00 GMT

Oops, forgot to post this video clip of a VERY exhaused me at Mix talking to Expression Encoder's James Clarke about 2.0. The clip itself is actually quarter HD (960x540), so double-click on it to take it full screen.

Could be a good case study for the captioning features in Silverlight...