Thursday, August 09, 2012

Olympic video streaming improves further -- bottleneck is in the network

At the start of the Olympics, NBC's live video stream was unsatisfactory, but we noted improvement by day 9.

More good news -- the video seems even better now. On day 12, I was comfortable watching events streaming at 1080p at full screen on my Dell laptop with 4 GB of RAM an Intel Core 2 CPU with a 3.06 Ghz clock speed and an Nvidia Quadro FX 770M display chip.

This is not to say the video was perfect. It stuttered a bit, but was watchable. As you see below, there were thousands of dropped frames:

While the video is watchable for many sports, it is too choppy for something as quick as boxing. It is not like watching television.

When the video was running smoothly, the frame rate remaiined in the low 20s per second, but during stutters, it dropped to single digits. I played around with resolution a bit, and was surprised to see that the dropped frame rate did not change much when I switched from 240p to 1080p. I checked the Task Manager, and noted some, but not much, increase in processor load variablity when displaying 1,080p (shown between the arrows).

Based on this, it looks like my old laptop is not limiting video quality, and my next laptop will be faster and will not be running Flash. The link from my house to my ISP runs at around 15 Mbps, so that is not a problem. It seems like the frame-rate variability is in the network.

But, given the compression and network improvement NBC and their streaming partner YouTube have made during the last 12 days, I am confident that by the time of the next Olympics, Internet video will be TV quality.


  1. Farfle9:12 PM

    No, something is not right in terms of video decoding. On three different computers so far, I get the SAME exact symptoms you're describing, extreme stutter, low FPS drops, etc. It's basically unwatchable. I thought it was perhaps on NBC's end too, but then I tried it on another computer in the same household as the others, but this was a Core i3 with a decent descrete GPU, and the playback was buttery smooth, just like playback of normal Youtube HD content. This is quite odd...

    1. Were the three computers less powerful than the one that worked well? Had you stopped all other applications? How do your machines compare to my laptop? (I spelled out the configuration in the post).

      I heard from another person that they were getting fluid playback at 1080p on one of the first days, when I found it unwatchable on my laptop. Maybe we are hitting it at different times and different load conditions. I sent a message to NBC PR to see if they could tell me of any changes they or YouTube had made to the network, and they said they would get back to me, but did not.

      Regardless, I am confident that by 2016 we will achieve widespread "buttery smooth" video playback -- our client hardware will be way faster, the network will add capacity and YouTube will have learned a lot. This is the learning stage -- like crystal radio in the 1920s.