August 16, 2011Sayeed Choudhury
Do you like jittery, staccato playback and long buffer times when you watch video on your phone or tablet? Neither do I. Neither does Qualcomm.
Let’s face it, though: the mobile video genie is out of the bottle, and it’s not going back in. Video streaming continues to dominate mobile bandwidth consumption, accounting for 39 percent of data usage in the first half of 2011, according to the H1 2011 Allot MobileTrends Report. Elsewhere, Frost & Sullivan notes that CTIA has called for an additional 800 MHz of bandwidth to cope with the onslaught of mobile video; the U.S. government is trying to provide 500 MHz of that request.
There’s no simple solution that will ensure a good mobile video experience. We’ve identified areas that are ripe for improvement and are working diligently to address them. DASH – Dynamic Adaptive Streaming over HTTP – is an important one. We see DASH as the industry’s best approach to streaming mobile video, while preserving the kind of video experience consumers expect.
What is DASH?
DASH is an open standard that addresses what we think are many of the biggest problems in delivering streaming video:
1. File size – In the old days, Web video was easy. You downloaded a 2- or 4- or 10 MB file to your device and then played it. That wasn’t really streaming, and it wasn’t scalable – imagine streaming high-definition movies that way. So DASH is a standard for chopping video streams into smaller segments.
2. Changing network conditions – To keep a stream of video flowing smoothly, servers need to send these smaller segments when the device can accommodate them. With DASH, the video lives on the server in several different bit-rates – for example, 250 kbit/s low quality, 500 kbit/s medium quality and 1000 kbit/s high quality. And here is the key; the device determines and then commands the server to send the best quality given the current network conditions (see diagram).
3. Proprietary formats – Most Web video is encoded in common codec formats like H.264 but stored in various streaming formats, depending on the media player on the device. Adobe, Apple, Microsoft, Netflix and many of the other names you associate with video delivery have their own streaming format and their own approach to streaming. DASH defines openly published profiles and the device’s native player can therefore easily support these various streaming profiles.
4. Digital rights management (DRM) – For premium video like movies and sporting events, content owners want their rights protected. DASH is focused only on the core streaming technology and hence works seamlessly with various DRM solutions.
If you want to know more of the technical details, Thomas Stockhammer, on our team has published a paper on the design principles and standards we’re putting into DASH.
What’s Qualcomm doing?
Qualcomm and Qualcomm Innovation Center, Inc. (QuIC) have participated as the work-item lead and helped promote DASH with 3GPP, and were the main authors of the DASH specification in MPEG. In collaboration with companies such as Ericsson, Apple, Netflix and Microsoft, Qualcomm has worked on the standard. Although MPEG-DASH content has yet to be published, we’re working with content owners to help bring this open standard to market.
As a result, we’re building a lot of expertise and we’ve chosen to make it widely available.As a matter of fact, to encourage adoption of the DASH standard, Qualcomm will not seek royalties or license fees for use of its DASH Essential Patents as defined in our DASH Licensing Commitment.
You’re going to see similar announcements from other technology companies who realize that it’s time for an open standard for adaptive, Internet streaming video – one which is also easy to implement and bring to market.
Keep an eye on DASH as the standard evolves, and let me know in the comments what your company is doing about the user experience in mobile video.
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August 16, 2011DASH – Toward a Better Mobile Video User Experience0DASH – Toward a Better Mobile Video User Experience