WebRTC Expert Feature

October 29, 2013

VP8 vs H.264 in Real Deployments

Over the last six months I have been enjoying excellent WebRTC-based video conferencing, provided by a variety of the current available sites (Tawk, FACEmeeting, Bistri, etc.). What I have generally experienced has been excellent, both in overall video quality and general experience. I have noticed that occasionally echo is an issue if an end point has a separate microphone and speakers, but with a headset or a dedicated speakerphone device, the audio quality is also excellent.

However, I have heard from some of the current video vendors a characterization of WebRTC and VPS as a video solution that is OK for "lower quality". In other words, the message they are sending to their customers is that, while they support WebRTC, they do not see it as being useful for "serious" video. I will leave names out of this, but maybe you can guess who they are. However, in a recent call with Scott Wharton of Vidtel, an interesting point was raised. Wharton said that, purely through anecdotal reports from its customers, it is seeing more issues with quality impact of packet loss in VP8 versus H.264.

It would appear that most of the comparisons of H.264 and VP8 have been done in more static environments where the comparison focuses on the codec and video quality, but not on what happens when packets are lost. I suggested to Wharton that packet loss was less of an issue today, but he assured me that his customer base is often operating over lower speed links and the often see packet loss of up to 5 percent. In this case, Wharton believes that the H.264 codec is masking the loss more effectively than the VP8 codec in its implementation. Obviously there are a number of factors here, but I am using WebRTC andVP8 in a relatively "pristine" environment. I have a 50 Mbps Comcast cable modem and relatively limited other use when I am doing video. 

I think this discussion raises two points to the industry: first, “Is there a difference in VP8 and H.264 in a packet loss situation?” and second, “As we move to VP9 and H.265, is this an issue that needs to be examined?” I repeatedly hear people say that WebRTC is better than Skype video, but we have no comparisons. Generally, the people using WebRTC today are the leading edge of technology that tend to have better networks and services. However, the promise of WebRTC is to bring a new communications paradigm that includes video to the entire market, so issues of quality in lower bandwidth and packet loss situations will be common. If the user experience is significantly impacted by the performance of the codec in these less than ideal situations, adoption will be impacted.

I would be very interested in hearing others thoughts on this topic. This will be a great topic for discussion during the Video Sessions at WebRTC Conference & Expo in Santa Clara Nov. 19-21. It would be great to hear others experience in this area.

Want to learn more about the latest in WebRTC? Be sure to attend WebRTC Conference & Expo, Nov. 19-21 in Santa Clara, Calif. Stay in touch with everything happening at WebRTC Conference & Expo. Follow us on Twitter.

Edited by Rachel Ramsey


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