- From: Silvia Pfeiffer <silviapfeiffer1@gmail.com>
- Date: Sun, 23 Aug 2009 00:37:30 +1000
On Sat, Aug 22, 2009 at 10:49 PM, Robert O'Callahan<robert at ocallahan.org> wrote: > On Mon, Aug 17, 2009 at 8:04 PM, Max Romantschuk <max at romantschuk.fi> wrote: >> >> Silvia Pfeiffer wrote: >>> >>> Precision is influenced more strongly by the temporal >>> resolution of the decoding pipeline rather than the polling resolution >>> for currentTime. I doubt the previous implementations of "start" and >>> "end" gave you a 3 sample accurate resolution even for wav files. >> >> I'll chime in here, having done extensive work with audio and video >> codecs. With current codec implementations getting sample- or frame-accurate >> resolution is largely a pipe dream. (Outside of the realm of platforms >> dedicated to content production and playback.) Especially for video there >> can be several seconds between keyframes, frame-accurate jumps requiring >> complex buffering tricks. > > > Those tricks aren't that hard, at least for Theora; we do them in Firefox. Xiph has spent a long time on developing libraries that make seeking simple for Ogg Theora/Vorbis and Firefox has the advantage of using these libraries. I'm sure it's possible with other codecs / containers, too. But it's not trivial. Also, I still doubt that for lossy codecs a 3 sample accurate resolution on audio can be provided reliably every single time. I would be delighted to be proven wrong. Silvia.
Received on Saturday, 22 August 2009 07:37:30 UTC