- From: <bugzilla@jessica.w3.org>
- Date: Mon, 22 Jul 2013 17:35:15 +0000
- To: public-audio@w3.org
https://www.w3.org/Bugs/Public/show_bug.cgi?id=22723 --- Comment #17 from Srikumar Subramanian (Kumar) <srikumarks@gmail.com> --- (In reply to comment #16) > (In reply to comment #15) > > (In reply to comment #7) > > > If every node used this "wait for all inputs before running" logic, then > > > script nodes with buffer sizes greater than 128 need not impose a delay in > > > their signal paths. > > > > I just realized a subtlety in this. If a script processor node's > > onaudioprocess reads computed values from AudioParams, then the perceived > > k-rate for those AudioParams will be determined by the block size set for > > the script node and not the fixed 128-sample-block in the spec. Not only > > that, it will look like a filter-type script node (with input and output) is > > prescient and anticipates animated AudioParams, because the the > > onaudioprocess will only get to run once enough input chunks have > > accumulated, meaning the values of some of these k-rate AudioParams could > > already have advanced to a time corresponding to the end of the script > > node's buffer duration. > > No, according to the spec the implementation must do 128-frame block > processing all the time, which means that for example if we have 1024 frames > to fill up for a ScriptProcessorNode, we need to call the block processing > code 8 times, and each k-rate AudioParam will be sampled at the beginning of > each block. That holds only for the native nodes, doesn't it? With the real-time context, script processor nodes with buffer sizes > 128 (which is all the time) already have a lower k-rate than the native nodes if they read computed values of AudioParams within their onaudioprocess callbacks. Anyway, to ensure that the k-rate is uniform at least during offline processing, it looks like the only way is to raise onaudioprocess events for each 128-sample-frame block. The event dispatcher better put up some performance :) -- You are receiving this mail because: You are the QA Contact for the bug.
Received on Monday, 22 July 2013 17:35:17 UTC