[whatwg] Video : Slow motion, fast forward effects

Jonas Sicking jonas at sicking.cc
Thu Aug 7 12:11:11 PDT 2008

Dave Singer wrote:
> At 20:10  +1200 7/08/08, Chris Double wrote:
>> On Thu, Aug 7, 2008 at 6:20 PM, Ian Hickson <ian at hixie.ch> wrote:
>>>  On Thu, 7 Aug 2008, Biju Gm at il wrote:
>>>>  On Thu, Aug 7, 2008 at 1:49 AM, Ian Hickson <ian at hixie.ch> wrote:
>>>>  > playbackRate is the right way to do it, but maybe Firefox doesn't 
>>>> yet
>>>>  > support it.
>>>>  So can I assume HTML5 spec also allow playbackRate  to be negative 
>>>> value.
>>>>  ie to support go backward at various speed....
>>>  Yes.
>> Would you expect the audio to be played backwards too?
> I think that's extra credit and optional.  As you say, even with audio 
> coded in independent frames you have to flip the samples, which is a 
> pain.  For audio with forward dependencies, correct decoding means 
> decoding forwards and then flipping whole chunks of timeline (though AAC 
> doesn't suffer too badly if you don't do this, by the way).

Honestly, this seems useless enough that the spec should just say that 
when playback is less than 0 sound should be turned off. I'd hate to see 
engineers working on this just because "the spec says it should work 
that way".

/ Jonas

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