Home field advantage can help propel a team to victory in just about any sport. In American football, a noisy crowd can make it difficult for opposing teams to effectively communicate, leading to false start penalties, and allowing defenders to get quicker jumps on the ball. In an effort to gain a greater home field advantage by increasing crowd noise, Penn State University will be rearranging the seating at Beaver Stadium, where the school’s football team plays. The university made the decision after graduate student Andrew Barnard performed a study in which he played recordings of simulated crowd noise at various points of an empty Beaver Stadium, and measured the resulting decibel levels on the field. He found that the southern end zone amplifies sound more effectively than any other part of the stadium. As a result, the student section, largely considered to be filled with the most raucous fans, will be located behind the southern end zone for the 2011 season.

This got me thinking- what is it about the architecture of certain stadiums that make them louder than others? For instance, Qwest Field, home of the Seattle Seahawks, is widely regarded to be one of the loudest venues in the NFL, despite the fact that it is an open air stadium. After reading the Wikipedia article, I discovered that Qwest Field can achieve this distinction by combining steep seating decks and an overhanging roof with metal bleachers to help reflect noise back onto the field in an effective manner.

While architects of sports stadiums may want to increase crowd noise, a loud, echo-filled environment can make conference calls truly unbearable. GIPS specializes in designing software to improve the user experience in all forms of voice and video communication. However, even the best software can be ineffective if environmental factors conspire to create a poor conference call. That is why anyone setting up a conference room should learn from places like Qwest Field, and heed the following tips to minimize echo and noise:

1. Acoustic echo is created when a microphone picks up the speech of the person on the other end of the phone call coming through the receiving side speaker. As obvious as it may sound, the best way to avoid echo is by making sure the speaker and microphone are a sufficient distance apart, and if possible, pointed away from each other.
2. Unlike in football stadiums, hard surfaces should be avoided in a conference setting. Carpeted floors and curtains over windows can actually go a long way toward reducing the amount of echo in a room, thus improving the user experience in a conference call.
3. Similarly, flat, parallel surfaces can cause sound to bounce back and forth, making echo more dramatic. If at all possible, avoid placing the speaker and microphone close to a wall or other large, flat object. This can be difficult since speaker phones are commonly placed on a large table in most conference rooms. However, echo can still be reduced by making sure the ceiling is not too low, and is not uniformly flat. A tall ceiling with overhanging lights or sound dampening panels can go a long way toward creating a good setup for conference calls.

It’s kind of scary seeing my mug on John’s post from the 27^th about GIPS mobile offerings.  However, as has been widely published in sources like Engadget, Gizmodo and the New York Times, there has been a crack in Apple’s normally impenetrable veil of secrecy around new product developments with the exposure of a prototype of Apple’s next generation iPhone.  The fact that the device has a front facing camera is the best response to the piece covered in John’s post.

A frequent criticism of Apple is that they don’t do anything that revolutionary.  It is that claim that makes Apple’s success all the more spectacular and game-changing.  Portable .mp3 players existed long before the iPod, but Apple’s entry changed not only the company, but the entire industry.  Similarly, the iPhone and the iPad were neither the first smart phone nor the first tablet PC on the market, but their introduction and resulting success have changed their markets significantly.  With the iPhone, hundreds of thousands of applications have proliferated, creating a whole new market for applications developers (historically a weakness for Apple).  Adding voice and video to some of these applications will enrich the experience for the end user.  To be sure, mobile video conferencing is again not a new category, as AT&T introduced video share about three years ago.  However, the service was not very usable and the device support was not where it needed to be.  However, with the introduction of frame-by-frame access to the camera which is included in iPhone OS 4 and the front facing camera which appears to be part of the 4G design, Apple will be poised once again to change the game with mobile video conferencing.

Now, no discussion of the leak would be complete without mention of the heavy handed response of Apple and the local authorities against Gizmodo and the individual who found the lost device.  However, coverage of that topic should be left to the professionals…or at least the fake professions at The Daily Show: 

We have written extensively that it takes much more than a codec to deliver high quality voice. Though we haven’t paid as much attention to it, the same principle also applies to video. I agree that a good codec is better than a bad codec, however a good codec is a necessary, but not a sufficient, condition to produce good video. In GIPS VideoEngine we work a lot with the codec settings, picture enhancements outside of the codec, jitter buffers, bitrate control and other parameters to achieve the best possible quality. Despite our best efforts, quality can also be affected by hardware, such as webcams and monitors. Even television and movies can suffer if they are not displayed on the right devices, or are transmitted using poor methods.   

I recently spent a week at our San Francisco office and took a late night flight back to Europe. I had planned to sleep most of the time, but during dinner I watched a movie with a recent Academy Award winner and the quality was terrible. The actors were good, I liked the movie, but the picture quality might have been the worst I’ve ever seen. In this case I think it was actually due to both bad encoding and bad equipment. The monitor wasn’t good, which is to be expected from airplane equipment, but the colors for dark images had really bad circular patterns. This phenomenon can be observed in a video call when not enough bits have been spent on the colors, especially at low bitrates, but I have never hear of this problem for watching a movie.          

Passengers Deserve Better Video

I bought a new plasma TV about a year ago and that really improved the video quality at home. After a while we bought new cables to use for our DVD player and the digital TV decoder, and the quality improved even more. I really like sports, especially the Swedish hockey playoffs and Tour de France, and our new TV has made watching them even more enjoyable, as long as the right channels broadcast the events. The introduction to one Swedish weekly sports show has the same annoying color pattern I saw on the flight. Spending some more bits on the colors would probably help, and if they made some changes to the bitrate control they might get rid of the really annoying blocky video that appears when they cut away to show the spectators. It’s amazing they have these problems, as I don’t think our customers would approve of this in a normal video conversation, even at low bitrates. Do the producers and network execs not have the right knowledge, or are they trying to cut costs? Maybe both?

The same blocky video quality can also be seen in some DVD movies for kids. I guess movie studios think children are not as discerning as adults. On the other hand, there are some children’s movies that have absolute top quality. My son loves the movie Cars, and even though I have probably seen Lightning McQueen roaring around the speedway for at least a thousand laps, the quality Pixar produces amazes me every time. Every scene is really great, no blocks, no bad colors, no bad nothing.  

Visiting the US isn’t just about work and long flights, it’s also about shopping. This time I ended up buying an iPod touch and I must admit the screen quality is great, a feature which saved my flight back home.

 Before ending the long post, I must give some credit to SVT, the Swedish TV provider owned by the government. SVT Play is their service for watching movies, shows and news on the internet, and mobile devices. Despite what my colleague Stefan has witnessed, I have always been impressed with their quality.

So yes, the codec is a big part of the video experience. But some products and services get it right, while others flounder, proving that hardware and transmission techniques are just as important.

The Net Neutrality debate continued this week with a ruling by the United States Court of Appeals for the District of Columbia Circuit that favors large network operators, and arguably could limit consumer’s access to the internet applications and services they crave. In the ruling, the Court decided the FCC does not have the authority to explicitly regulate the flow of internet traffic. Hence, the FCC’s landmark directive limiting Comcast’s ability to block BitTorrent traffic is unwarranted. The ruling could give network operators the precedent to selectively prioritize or block specific classes or types of internet traffic. Thereby, potentially having a profound effect on the further adoption of voice and video over IP services.

The communication space, particularly real-time video, continues to evolve and the options for consumers expand everyday:

-          Earlier this year at CES, several television manufacturers, such as Panasonic, introduced products to enable video conferencing from the comfort of one’s living room.

-          Mobile video is no longer a futuristic concept and networks and smartphone processors are reaching speeds capable of delivering and processing high-quality real-time video transmission.

-          Today, GIPS expanded our product portfolio by introducing VideoEngine-Mobile for the Android platform.

-          One can easily imagine a future generation iPad with a front-facing camera enabling high quality two-way video.

The promise of receiving voice and video from any device, at anytime, anywhere in the world, is becoming a reality.

As video becomes commonplace, the question at hand is—how will consumers receive the flood of packets laden with video frames and—will network operators have a say in determining which packet is most deserving of an unencumbered path through the internet. The debate surely will continue with more still to come from the Courts, FCC and Congress.

The interlaced video format was adopted in the late 20s when the television was first introduced. It was a very good trade-off between motion handling and spatial fidelity, while using half of the spectrum compared to a progressive scan for the same frame rate and resolution.  This format has since been deployed in all the analog TV sets in the whole world.  In order to match the display devices, all video cameras are also using interlaced format. The wide deployment and tight coupling of these devices made it almost impossible to change the interlaced video format for any purpose.

When video compression standards were first introduced in the late 80s and early 90s, naturally, interlaced video coding was a very important coding tool to deal with any video sources since the native video formats are all interlaced. This was especially true when full-screen, high resolution video is desired. There was almost no way to get commercially available high-resolution video without dealing with interlaced video. As a matter of fact, pretty much the only reason ITU-T introduced the first interlaced video coding tool in H.263++ in 2000 was due to the lack of high-resolution progressive-scan cameras.

Today, the digital video world has definitely changed. The personal computer, which was initially only intended for scientific applications, has now became an even more widely spread consumer device than television. PCs today are commonly used for streaming video, playing DVDs and video conferencing. Like television, PC monitors are all using progressive scan format for their display.  The second notable development is the advent of digital video broadcasting and the widespread use of widescreen LCD/LED monitors.  These LCD/LED display devices are also all using progressive format.  Thirdly, high resolution USB cameras have been widely adopted by the PC world for video conference and streaming applications. All USB cameras are using progressive scan format for their video.

In order to display interlaced video on a progressive screen, a technique called “de-interlacing” is necessary. Otherwise, we will observe jaggy edges for moving objects, due to the combination of two-fields to form a frame. Even with a fairly complicated de-interlacer, jaggy edges still can be observed for some video sequences. This is a very annoying artifact that everyone hates.

Given these deficiencies, someone might be wondering why we are still using interlaced format.  Are there any benefits besides the compatibility issues with legacy devices?  I think the following reasons demonstrate there are no other benefits, and that it’s time to abandon the interlaced video format:

(1)    A progressive video sequence will use fewer bits to compress compared to an interlaced sequence at the same resolution and frame rate. This is because the motion estimation and spatial correlation of the progressive sequence is much better than that of the interlaced sequence.  In other words, a progressive video sequence will offer a better video quality than that of the interlaced video sequence using MPEG or ITU-T video standard codecs such as MPEG-2 and H.264.

(2)    A progressive video sequence will display beautifully on the latest widescreen LCD/LED monitors, where an interlaced video sequence will display jaggy edges on these latest display devices.

(3)    For legacy interlaced display devices such as traditional TV sets based on CRT tubes, progressive video sequences can be easily converted to interlaced video sequences without noticeable artifacts. In fact, movie films are always shot in progressive format and have been converted to the interlaced video format for TV viewing for a long time. This conversion uses a technique called 2-to-3 pull-down to generate 60 fields per second from the 24 frames per second movie film material. If the progressive video sequence is already 30 frames per second or 60 frames per second, it will be even easier to convert it to an interlaced 60 fields per second TV signal with fewer artifacts.

(4)    The advancement in CMOS technology has made it possible to manufacture progressive CMOS cameras at a very low price point. Today, USB cameras are in widespread use world-wide. Virtually all USB cameras are using progressive format for PC video conferencing applications. This is one more reason why the video conference world has already almost abandoned interlaced video format. This is evidenced by the fact that H.264 baseline profile, which is mainly intended for video conference applications, excluded the interlaced video coding tools.

(5)    Studio high resolution video cameras today support multi-formats, including progressive video format.  The interlaced video format is only for backward compatibility with the interlaced display devices such as traditional analog TV sets. However, an interlaced video sequence can be easily converted from a progressive scan sequence without noticeable artifacts.

Sweden has exceptional public service television called SVT. During the winter Olympics, SVT broadcasted the most popular events, sometimes two or three at a time on different channels. As if that’s not enough, they also have a free web service called SVT Play, where they streamed almost all Olympic competition in good quality. Finally, for those really devoted to sports, SVT even has an iPhone app for watching the broadcasts on the go.

At first glance, the quality of the online stream appears to be really good. They’re encoding at a bit rate of 810 kbps and defaults to using Flash, probably with ON2 VP6 as the codec. For the Windows user, Windows Media is also available.

However, most people probably prefer to watch the stream in full screen mode. This is where I think SVT Play fails to deliver. If you look at the image below, which is a part of a full screen video sequence on SVT Play, you can see severe aliasing at the edges. This is the most apparent at the edge between the man’s neck and his shirt.

The aliasing appears due to bad – or nonexistent – interpolation when upsampling the images. Whether or not this has to do with problems with Flash or SVT Play I cannot tell for sure, but we can at least assume it can be solved since watching a YouTube video (which also uses Flash) in full screen looks good, as is demonstrated in the screen capture of a section of a full screen YouTube clip below.

There have recently been a lot of discussions about the video tag in HTML5, and what codecs to use with it. Some prefer license-free codecs, while some prefer the best possible performance. But one thing is for sure: regardless of how good your codec is, the experience is what is most important. Having bad post-processing will always have the last say, no matter how many bits and CPU cycles you spend on encoding your video source.

In a recent post, I wrote about how smartphones are red hot in Asia, and in China in particular, right now. Well there’s yet another smart ‘new’ category of devices targeting the mobile computing market that is emerging. This category may also take global markets by storm (or maybe not, who knows in this game?): ‘smartbooks’.

No doubt, smartbooks will arouse market interest worldwide. Market demand from Asia is (as with most everything these days) expected to be strong. Taiwan, is both a global design and ODM/OEM manufacturing hub for portable devices and as such has already shown keen interest in this new category. In fact, a number of Taiwan OEMs have already showcased smartbooks at Computex in Taipei June last year.

The devices and their lower price points (sub-US$200, possibly as low as US$100) have also attracted a lot of interest in mainland China. According to Young Liu, special assistant to the CEO at Foxconn, the world’s largest contract electronics manufacturer, the company has had requests from a number of telecommunications companies in China to develop smartbooks.

Qualcomm, which makes microprocessor chips based on ARM Holdings’ semiconductor intellectual property (IP) is at the forefront of popularizing the smartbook. In fact, it coined the name, taking it from the combination of the words that describe the two device categories that it claims this third new category sits between: the smartphone and the netbook. Both computing and cellphone companies are paying attention with Asus, Acer, Lenovo and Toshiba as well as Nokia, LG and HTC all developing smartbooks.
These new devices are based on technology traditionally found in smartphones, such as Qualcomm’s Snapdragon chip. Snapdragon is a beefed-up cell phone processor that runs at 1GHz and includes integrated support for 3G wireless connections as well as WiFi, Bluetooth, and GPS.
Nvidia, also seem excited at the prospects of smartbook devices powered by its ARM-based Tegra chip. The company has forecast that we may see computer makers’ launching laptops that include detachable screens that would be able to independently access the Internet and process data. So you’d be getting laptop with an e-reader type device thrown in.

The phenomenal uptake of web technology globally has fundamentally changed our everyday lives. Consumers’ expectations about what their PCs and mobile computing devices should deliver are growing rapidly. There’s never a dull moment in this industry is there?

After AT&T’s announcement last fall that they would allow VoIP applications to use the 3G network very little has happened. No applications offering such services have actually been approved by Apple to be sold in the Apps Store. Until now, that is. Today our customer Toktumi announced that their latest upgrade of the Line2 application for iPhone has been approved by Apple. This application is touted by Toktumi as “the first iPhone calling app that works over 3G, Wi-Fi, and cellular networks using the same number”. This is pretty big news. The end user can get better call quality (HD Voice), improved coverage (through WiFi), and save a lot on call charges. VoIP applications have previously only been available on Symbian, Windows Mobile, and most recently Android devices, while maybe the most popular smartphone has lacked such support.

The Line2 application offers much more than just a standard VoIP application (As opposed to e.g. iCall, which is another VoIP application fro the iPhone). In fact, I use it on my Blackberry even though there is no VoIP support on that platform. This is because RIM hasn’t opened up the development environment in such a way that it is possible to develop a true VoIP application for the Blackberry environment. That topic is worth its own post so I will refrain from commenting more on this very frustrating issue…

Browsing around the papers presented at the latest NOSSDAV workshop, I found “An Empirical Evaluation of VoIP Playout Buffer Dimensioning in Skype, Google Talk, and MSN Messenger”. Having worked extensively with GIPS’ jitter buffer algorithms, and having some knowledge of Google Talk, I was intrigued by the title. The paper had some interesting experiments, but also a few giant leaps to conclusions.

The paper’s authors have created a laboratory test bench for PC soft phones where they emulate different network conditions (delay, jitter and packet losses), and measure objective speech quality (PESQ) and the end-to-end delay. Then they apply a previously proposed hybrid between PESQ and the E-Model to arrive at a score which takes both measured speech quality and delay into account. The idea is that both audio quality and end-to-end delay contribute to the total conversation experience, which is an easily supportable proposition. Finally, they derive an optimal playout buffer delay for each network condition based on this hybrid measure. I will come back to this approach later.

The experimental part of the paper, setting up the lab and examining the three clients, seems all fine to me, even though I’m not sure that their delay estimation algorithm really can cope with the rapid delay changes that modern jitter buffers apply. They also make rather wild assumptions on coding, packetization, and soundcard delays. But those are minor issues. My problem is their use of the objective hybrid model as a guide to optimality. It is widely know that PESQ is rubbish when it comes to assessing agile jitter buffers, simply because it cannot follow the swift delay adaptation. Tagging on a delay impairment factor to obtain a total user experience number frankly doesn’t improve the situation.

The authors wrap up their work by comparing the measured delays of the three clients, with the delay that renders the highest score in their hybrid measure under the same network conditions. The three clients all exhibit different behavior – not very surprising since they have different jitter buffers – but none of them follow what the authors claim to be optimal. Hence, the user experience of all three VoIP clients could be vastly improved, if only the “optimal” delay would be applied, is their conclusion. Allow me to disagree.

Surely these VoIP clients can be improved, but to distrust the man-years of design and implementation, and endless hours of in-house and customer tuning and testing, I need something more than the broken compass that is PESQ.

Earlier this week I listened to a webinar from CommuniGate on HD voice. (In fair disclosure they are a customer.) It was interesting because you had three companies in the chain of HD voice – GIPS, CommuniGate and Deutsche Telekom.

The benefits of HD Voice were discussed and the subject also addressed why network operators should view it as an excellent value added service particularly for the SMB market. While the main focus of VoIP services to date has been cost reduction over quality, HD voice heralds a new generation of high-fidelity voice communication services, which allows business and consumer users to have a more natural and reliable voice communication experience than ever before.

Mobile operators are missing significant revenue opportunities in the SMB market where workers on the “move” need increasingly reliable high-fidelity voice quality to interact freely with other users and automated systems. It is estimated that the worldwide SMB market for VoIP services will reach $10.4 billion by 2014. Most of this revenue potential, however, will be directly dependent on how well integrated and easy to use various media will be, and to what extent it will deliver quality features not previously available to SMBs at accessible price points.

CommuniGate is beating the HD voice drum to get carriers to listen. Their MobileOffice, a Unified Communications hosting platform, enables network operators to deliver high-value, HD Voice enabled communication solutions to Small Businesses. To explain CommuniGate’s offering in more detail they have released a whitepaper that looks at FMC as the bridge of two “HD capable” networks; the mobile and the Broadband IP Network (Internet).

What I especially like about CommuniGate is they don’t just talk HD voice, they act on their beliefs. To make sure everyone “gets” the HD voice message – they’re offering a free trial. So rather than read about HD voice, why don’t you try it out for yourself.