[whatwg] Audio canvas?
Dr. Markus Walther
walther at svox.com
Wed Jul 16 03:51:50 PDT 2008
I have noted an asymmetry between <canvas> and <audio>:
<canvas> supports loading of ready-made images _and_ pixel manipulation
(get/putImageData).
<audio> supports loading of ready-made audio but _not_ sample manipulation.
With browser JavaScript getting faster all the time (Squirrelfish...),
audio manipulation in the browser is within reach, if supported by rich
enough built-in objects.
Minimally, sample-accurate methods would be needed to
- get/set a sample value v at sample point t on channel c from audio
- play a region from sample point t1 to sample point t2
(Currently, everything is specified using absolute time, so rounding
errors might prevent sample-accurate work).
More powerful methods might cut/add silence/amplify/fade portions of
audio in a sample-accurate way.
It would be OK if this support were somewhat restricted, e.g. only for
certain uncompressed audio formats such as PCM WAVE.
Question: What do people think about making <audio> more like <canvas>
as sketched above?
-- Markus
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