By Jan Ozer
The great migration from Flash to HTML5 is underway. For many producers, this means a switch from RTMP or HTTP Dynamic Streaming to a more HTML5-friendly format. Typically the choice comes down to either HLS or DASH. To help tease out the pros and cons of each, I wrote a blog post called “DASH or HLS? Which is the Best Format Today,” in which I set forth my thoughts on the subject, invited comments, and presented a one-question survey asking which format readers preferred.
From my perspective, DASH’s strength is that it’s a standard, and that while browser support is far from universal today, it is growing, and will improve over time. One big drawback is that the Encrypted Media Extensions needed to protect DASH content are a mess, but that only impacts content owners who require DRM. A more serious issue is that DASH is not supported on iOS devices, which means no playback without an app. Finally, while advertising support for HLS files is in place, support for DASH-encoded files is still in its infancy.
Some reader comments pointed out technical advantages for DASH, such as substantially lower end-to-end latency compared to HLS. Others pointed out that DASH might be subject to royalties, as MPEG LA is forming a patent group for DASH IP owners. Whether this will result in royalties is unknown, but obviously MPEG LA isn’t attempting to form the group just for fun.