Hey Steve, This looks great; would be a really useful set of data for video players / publishers. Since none of the metrics have a time component, developers can sample the data over the window / at the frequency they prefer.
Would jitter be calculated over decodedFrames or decodedFrames+droppedFrames? In the first case, jitter is a more granular metric for measuring exact presentation performance. In the latter case, jitter can serve as a single metric for tracking processing power (simple!). In either case, it's fairly straightforward to calculate towards the other metric. Resetting the values when @src changes is a good idea. Changing @src is much used for advertising and playlist support (it works around iOS not supporting the play() call). Kind regards, Jeroen Wijering On May 3, 2011, at 12:15 AM, Steve Lacey wrote: > All, > > I've updated the wiki with a proposal... > > http://wiki.whatwg.org/wiki/Video_Metrics#Proposal > > Cheers! > Steve > > On Sat, Apr 9, 2011 at 7:08 AM, Silvia Pfeiffer <[email protected]> > wrote: > Ah, thanks for the link. I've included Silverlight stats, too, for > completeness. If somebody knows about QuickTime stats, that would be > another good one to add, I guess. > > Cheers, > Silvia. > > On Fri, Apr 8, 2011 at 5:21 PM, Jeroen Wijering > <[email protected]> wrote: > > > > On Apr 7, 2011, at 8:11 AM, Silvia Pfeiffer wrote: > > > >> I've also just added a section with the stats that the Adobe Flash > >> player exposes. > > > > Great. Perhaps Silverlight stats might be of use too - though they're > > fairly similar: > > > > http://learn.iis.net/page.aspx/582/advanced-logging-for-iis-70---client-logging/ > > > >> Apart from the statistics that are not currently available from the > >> HTML5 player, there are stats that are already available, such as > >> currentSrc, currentTime, and all the events which can be turned into > >> hooks for measurement. > > > > Yes, the network and ready states are very useful to determine if clients > > are stalling for buffering etc. > > > >> I think the page now has a lot of analysis of currently used stats - > >> probably a sufficient amount. All the video publishing sites likely > >> just use a subpart of the ones that Adobe Flash exposes in their > >> analytics. > > > > Especially all the separate A/V bytecounts are overkill IMO. > > > > One useful metric I didn't list for JW Player but is very nice is Flash's > > "isLive" property. > > > > Kind regards, > > > > Jeroen > > > > > > > > > >> On Thu, Apr 7, 2011 at 4:52 AM, Mark Watson <[email protected]> wrote: > >>> All, > >>> > >>> I added some material to the wiki page based on our experience here at > >>> Netflix and based on the metrics defined in MPEG DASH for adaptive > >>> streaming. I'd love to here what people think. > >>> > >>> Statistics about presentation/rendering seem to be covered, but what > >>> should also be considered are network performance statistics, which > >>> become increasingly difficult to collect from the server when sessions > >>> are making use of multiple servers, possibly across multiple CDNs. > >>> > >>> Another aspect important for performance management is error reporting. > >>> Some thoughts on that on the page. > >>> > >>> ...Mark > >>> > >>> On Mar 31, 2011, at 7:07 PM, Robert O'Callahan wrote: > >>> > >>>> On Fri, Apr 1, 2011 at 1:33 PM, Chris Pearce <[email protected]> wrote: > >>>> > >>>>> On 1/04/2011 12:22 p.m., Steve Lacey wrote: > >>>>> > >>>>>> Chris - in the mozilla stats, I agree on the need for a frame count of > >>>>>> frames that actually make it the the screen, but am interested in why > >>>>>> we > >>>>>> need both presented and painted? Wouldn't just a simple 'presented' > >>>>>> (i.e. > >>>>>> presented to the user) suffice? > >>>>>> > >>>>>> > >>>>> We distinguish between "painted" and "presented" so we have a measure of > >>>>> the latency in our rendering pipeline. It's more for our benefit as > >>>>> browser > >>>>> developers than for web developers. > >>>>> > >>>> > >>>> Yeah, just to be clear, we don't necessarily think that everything in our > >>>> stats API should be standardized. We should wait and see what authors > >>>> actually use. > >>>> > >>>> Rob > >>>> -- > >>>> "Now the Bereans were of more noble character than the Thessalonians, for > >>>> they received the message with great eagerness and examined the > >>>> Scriptures > >>>> every day to see if what Paul said was true." [Acts 17:11] > >>>> > >>> > >>> > > > > >
