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.

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.