At 0:49 +1200 23/08/09, Robert O'Callahan wrote:
On Mon, Aug 17, 2009 at 8:04 PM, Max Romantschuk
<<mailto:m...@romantschuk.fi>m...@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.
