Today we are interviewing Gabe Frost who is a lead program manager for the Media Platform team in the Operating System Group that Microsoft calls OSG for short. The team is about 40 engineers, comprised of Program Managers, Developers and Quality Engineers. We plan, design and build all the video and audio playback and streaming capabilities in the Windows operating system. This includes PCs, tablets, phones and Xbox.
Question: Gabe, What are some of the most interesting technologies Microsoft has introduced since adding XBOX One, Windows Phone, and the Surface tablet into the market in terms of video/audio?
Q: We have been reading about new emerging video technologies such as 4K. Tell us a little bit about this and when consumers can expect this high definition video shift to occur?
A: The 4K screen resolution is equivalent to four 1080p videos in a 2×2 grid. If existing H.264 encoding tech were used for 4K video, the bitrate would be about 45Mbps. For comparison, a high-quality 1080p video is between 8-10Mbps. Obviously, streaming 4K over the web wouldn’t work very well at 45Mbps given most people don’t have fast enough broadband, so a new codec is needed for widespread use. This is called High Efficiency Video Coding, or HEVC, and was recently adopted as the H.265 standard. HEVC is significantly more efficient than the previous generation H.264 video codec, also known as Advanced Video Coding, or AVC. HEVC offers the same quality at greatly reduced (30-50%) bandwidth and storage, or much higher quality at similar bandwidths. Said more simply, when using HEVC, you can stream 1080p video at half the bandwidth previously needed, and 4K video at the current bandwidth you use for 1080p. That’s game changing. There’s other benefits to HEVC like richer colors. If you’re thinking of buying a 4K TV today, make sure it has two both HDMI version 2.0 and HDCP 2.2. Trust me. TVs are just starting to become available that meet the 4K requirements, and Netflix is already streaming 4K content using HEVC. So the shift is occurring right now, but we’re in the very early days.
Q: What are some of the best file formats to use in terms of music and video on our devices and what are some things to think about when making a choice?
A: Media codecs and formats are pretty confusing. Most of the time, it’s not something that your typical consumer would care about. Most people don’t understand the difference between formats and codecs because the terms are often used interchangeably. Different file formats support specific types of audio and video. Let’s take an MP4 file that has a .m4v or .mp4 file extension. This file uses the MP4 file format and is also called a media “container.” This container holds compressed video and audio streams. The video is encoded with H.264 and the audio is encoded with AAC, or Advanced Video Coding. The MP4 format was just recently updated to support H.265/HEVC video, but companies like Microsoft and Apple will need to update their MP4 implementations to support H.265/HEVC as defined by the standard. For music, consider an MP3 file that has a .mp3 file extension. This is an example of why the difference between a file format and codec are hard to distinguish. MP3 is both a file format and an audio codec.
There are different levels of fidelity for both the video and the audio. For video, most people are familiar with the resolution such as 480p, 720p or 1080p, but there is also a frame rate which is the number of video frames that are shown every second. This is most commonly 30 frames-per-second (fps) or 60fps. Motion pictures are almost always 24fps. It would take much longer to explain why there are different frame rates – perhaps during another interview. A good measure that people would be most familiar with is a Blue-Ray movie. These movies are almost always use the MP4 container with H.264 video with 1080p resolution and 24fps.
For audio, most people are familiar with the bitrate such as 128Kbps, 192Kbps or higher. iTunes for example encodes their MP3 files at 192Kbps, but that’s not the whole story. The more interesting question to ask is at what rate (how many times per-second, which is also called Hertz or Hz) did the audio get sampled, and for each audio sample, how many bits of information get stored? A good measure that people would be most familiar with is a CD. The audio on a CD is uncompressed and sampled at 44.1Khz (that’s 44,100 times per-second) with each sample using 16bits of data, resulting in a bitrate of about 1Mbps. Because the standard for CD audio is 44.1KHz/16bit, nearly all ubiquitous digital files use this, but compress the audio so the files are much smaller. iTunes MP3 files are 44.1KHz/16bit, but the bitrate is so much lower (192Kbps) because the audio is compressed with MP3, and MP3 gets that compression at the expense of fidelity. As I’m sure most of your readers would attest, CD audio sounds better than an MP3 downloaded from iTunes. Dolby Digital HD audio is sampled at 96KHz/24bit, which is much higher fidelity than CD. If you could find digital audio files with higher fidelity like 96KHz/24bit, you wouldn’t be able to hear that difference on an iPod – you would need a higher end system that has the right digital components.
Q: What are some interesting ways to use the “Play To” feature in Windows?
A: My favorite use is to watch videos from the web on my Xbox. From my laptop or tablet with Windows 8.1, whenever I’m watching a web video, I swipe out the Charms bar from the right edge of the screen (or use Windows key + C), tap Devices, then Play. Here you’ll see your Xbox 360 or Xbox One. When you choose your Xbox, the video plays on the big screen. You can then use your laptop or tablet like a remote control.
[Editorial note – there is a video of this in action here: http://windows.microsoft.com/en-us/windows-8/charms-tutorial scroll down to the Devices charm.]
We want to thank Gabe for taking time out of his busy scheduled to meet with us and share his insight into his role at Microsoft. We hope this interview provided insight into Microsoft’s Media & Devices. Thanks again for being a loyal reader of our Predictably Better newsletter. We’ll be back next month!