- From: David Singer <singer@apple.com>
- Date: Tue, 25 Aug 2009 14:25:45 -0700
At 0:49 +1200 23/08/09, Robert O'Callahan wrote: >On Mon, Aug 17, 2009 at 8:04 PM, Max Romantschuk ><<mailto:max at romantschuk.fi>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. It's very easy in QuickTime or MP4. Timestamps of the frames can be sample accurate, so you decode the right frame, and trim the result. > >Rob >-- >"He was pierced for our transgressions, he was crushed for our >iniquities; the punishment that brought us peace was upon him, and >by his wounds we are healed. We all, like sheep, have gone astray, >each of us has turned to his own way; and the LORD has laid on him >the iniquity of us all." [Isaiah 53:5-6] -- David Singer Multimedia Standards, Apple Inc. -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.whatwg.org/pipermail/whatwg-whatwg.org/attachments/20090825/e49aa812/attachment.htm>
Received on Tuesday, 25 August 2009 14:25:45 UTC