[whatwg] Synchronized play/seek of multiple <audio> elements?
Emil Tin
emil at koblo.com
Mon Mar 23 07:39:27 PDT 2009
i understand that SVG is meant for advanced timing etc.
but it would be very useful to have a simple mechanism in html/
javascript for playing sounds together. conceptually, sounds would be
placed on a timeline at a certain time. the sounds on the timeline can
then be played back together and will start at the right times.
forgive me if my understanding of html tags is lacking. but an idea
would be to add two optional attributes to the audio tag:
timeline: the name of a group of audio tags that are syncronized
time: time this sound starts playing (in milliseconds). defaults to
zero if omitted
example:
<audio src="pads.mp3" timeline="ambient" time="0" id="my_song" >
<audio src="cello.mp3" timeline="ambient" time="0">
<audio src="voice.mp3" timeline="ambient" time="2000">
<audio src="bells.mp3" timeline="ambient" time="5000">
playing each sound works as usual, you can start, stop rewind, seek
etc on each sound like normal.
but you can also play the group together. this would cause pads and
cello would start together. 2 seconds later, the voice would play, and
at 5 sec, the bells would start. the group would be started from
javascript using somthing like my_song.playgroup()?
the idea could be used for syncing to video too, in which case audio
and video plays in sync when they're on the same timeline:
<video src="nature.mov" timeline="ambient" time="0" >
<audio src="pads.mp3" timeline="ambient" time="0" id="my_song" >
<audio src="cello.mp3" timeline="ambient" time="0">
<audio src="voice.mp3" timeline="ambient" time="2000">
another idea would be to group the audio tags inside a timeline tag,
but that might be a more complicated change?
<timeline id="ambient">
<video .... time="0">
<audio .... time="400">
<audio .... time=" 1200">
</timeline
and then from javascript use: timeline.play();
kind regards,
emil tin
On 18/02/2009, at 11.20, Ian Hickson wrote:
> On Wed, 18 Feb 2009, Emil Tin wrote:
>>
>> However, I've been unable to find any information on how to trigger
>> several audio files in a synchronized manner.
>>
>> Does the html 5 specification provide any way to to this?
>
> Not currently.
>
> --
> Ian Hickson U+1047E )
> \._.,--....,'``. fL
> http://ln.hixie.ch/ U+263A /, _.. \ _
> \ ;`._ ,.
> Things that are impossible just take longer. `._.-(,_..'--
> (,_..'`-.;.'
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